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ABSTRACTS FROM AOCS JOURNALS

AssesIlment of l'otential Prooddllnt and Antioxidant Actions.. Dkezie I.Aruoma. OleA International. American Drywall Building. Vide Bontielle.Saint Luciu, West Indies. and The Pharmacology Group. University of Lon-don King's College, London SW3 6LX. United Kingdom.

Suggestions thaI oxidali~'C stress plays IIrole in human diseases have led10 the pnlpC)§8I thai health might be impm'ed by increased dietary intake ofantioxidants. P1nnt-derh'w antioxidants. such as ttavcncids or rosemaryUlnJCtS. are increasingly proposed as import.:Ult dietary antioxidant factors.and foods rich in antioxidants are also receiving anemion. Before wicescaleusage of n:nur.lll1nd synthetic antioxidants can be suggested. it is necessary10 establish the properties of such molecules. Assays for characterizing !hepeeential prooxidanllamioxid:uu actions of food additives, antioxidant sup-plements. antioxidant drug molecules. and nutrienl oomponenlS have beende1.~1oped for this JIIIll105C.[JAOCS71.1617-1625(I996)]

The Fn'undlic:h Isotherm in Stud)']ng AdsorplKm in Oil Precessing, A.Proctorll and J.E Toro-Vuque~. lIDepartmem of Food Science. Universityof Arkansas. Fayeuevllle. Arkansas 72704. and bCenU'O de lnvestigacion yde Estudios de Posgndo de la Focultad de Ciencias Quimicas.. Un;'-ersidadAut6noma de San Luis Potosi. Zona Universitaria. 78240 San Luis Potosi.Mbico.

The obja:th"1: of mis review is 10 di<;CIIS!ithe ruSlOJ)' of the use of theFreundlich isotherm in i/n·estigating adsorption processing of \'egetable oilsand to evaluate ilS current value in adsorption studies. Tbe Freundlichisotherm was originally developed to explain the adsorption of a singlesolute from sotuttcn. However. II similar adsorption pattern has beenobserved when studying a more complex system of adsorption of vegetableoil pigmenUi onto bleaching clay during colTIITICTCialbleaching of vegetableoils. The Freundlich isotherm has been useful fOt" uecaoes in finding thecommerctal value of adsorbcnUi as long as a narrow experimental interval ofadsorbate is used. More recent studies have >.hown that a complex series ofinten!Clions controls the adsorption process. While the isotherm summarizesthese interactlons. investigating them is vital to understand the physico-chemical Iecrors involved during adsorption. Statistical modeling and spec-uoscopy are useful in understanding the vegetable oil bleaching/refiningprocess as a multiple-component adsorption system.IJAOCS 73. 1627-1633 (1996)]

The Procl'S!iing of New Oilseed Crops-An Economic E"alualion. F.Petrus Cuperus. Gernrd Boswinkel. and Johannes T.P. Derksen. Agmtechno-logical Research Institute (ATO-DLO). NL-6700 AA Wageningen. TheNetherlands.

The economics of pilot- 10 large-scale processing of the new oilseedcrops Crombt! lIiJ),ssirlica. Euphorbia /agasClle. and DilllOf{lhOliJeca p/uI'i-{Jlis imo oil. fatty eclds, or esters were estimated. II was found mat the pro-cessing COSUifor Crnmbt! seed to oil is in the $aITIe range as mat for rope-seed (-0.5 U.S. Slkg). Production of fatty acid esters from vemohc anddimorphccolic acids requires some special downstream processing opera-tions mat result in processing COStSof aoo..U I U.S. $/kg ester. Good-qualityDimorpiJOIhec/l oil is much more difficult 10 obtain end requires supercriti-cal carbon dioxide extraction. Processing costs can be as high as 4 u.S. $/kgoil.IJAOCS 73. 163S-1640 (1996)]

Comparalh'~ l'erformance of Sieltm and Nilrogtn as Stripping Gas inJ>h}-sical Kennlnj& of EdilHe Oils. M. V. Rui:z-M"ndel.. G. Mlirquez-Ruil..and M.C.1Jobarpnes. Instituto de la G11IS.a.41012-Sevillc. Spain.

011\"1:.sunflower. and soybean oils were physically refined in a disoon-unuous laboratory system with either nitrogen or steam as stripping gas dur-ing the deodori1.ation step. Comp-1rative assays were also carried out onolive oil in a 100MT disoontinllOUS illdusuial plant. Vaporization efficiencyof free fony acids was cak:ulated. and quality of refined oils and composi-tion of deodorizer distillates were analyzed. Results indicated lhat. in allil.SS3)'$. the efflCie of free fany acid diSlillalion "'"as highq: ""hen ni

......--.....as u~. n-c amount of OJ was muc lY\Io'crthan at ofsteam for refined oils of similar high quality. The results also suggwed thatthe amount of stripping gas had a clear influence on the composition ofdeodorizer distillates because lower quantities of Iriglycerides and

unsaponifiable malta" were found when nitrogen was employed.[JAOCS 73. 1641-1645 (1996)1

ChemlCIIllilld Thermal Chllracteristics of l\1ilk_Jo'lItJo'ractions lsolalt'dby a l\'Ic1t CrystaJlil.lltlon. P.S. Dimick. S. vena Reddy. and G.R. Ziegler.Department of Food Science. 1lle Pennsylvania Stale University, UniversityPart. Pennsylvania 16802.

Anhydrous milk fat (AMF) was fractionated by a two-stage dry frac-tionation process to produce three fractions: high melting (HMF). middlemelting (MMF). and low mehing (lMF). The HMF (m.p. 42"C) exhibited abrood melting range similar to 11 plastic fat. The MMF (m.p. BOC) resem-bled the original AMF (m.p. 31"<:). but with slightly higher solid fat con-tent. The: LMF (m.p. 16°C) was liquid at ambient temperature. Differencesin the thermal propcnies of the$e fructions wen: atuibutcd 10 the uiacylglyc-erots (TAG) and their Iany acid composition. SatlltDled TAG with carbonnumbers of 36-54 .....ere concentrated in the HMF; whereas unsaturatedTAG of carboro number 36-54 predominated in the l.ME Likewise. theIong..chain 53tlltDled fany acids .....en: significantly higher IIJ1d the Iong-cbainunsaturated fatty acids wen: signifICantly IOlller in the HMF fruction. Binaryblclltls of milk-fat fructions ....ith a runge of melting profiles wen: producedby mixing HMF with AMF. MMF. or LMF. Laboratory-prepared fractions.....ere similar to commercially available fractions.IJAOCS 73. 1647-1652 (1996)1

Comparison of Isopropanol and Hexane for gstracnon of Vitamin Eand Oryunols from SlablUud Rice Bran. Weicheng Hua• John HenryWel1so• Tal-Sun Shinb• and J. Samuel Goc.fberh, Departments of aBioIogicaIand Agricultural Engineering and bFood Science. Louisiana Agriculturalfuperimcnt SlJItion.Louisiana Stare University Agricultural Center, Baton Rouge. Louisiana70803.

The effecUi of solvers-to-bean ratio (2:1 and 3: I. w/w). eXlrlICtion tem-perature (40 and 6O"C). and lime (5. 10. IS. 20. and 30 min) .....ere studiedfor hexane and isopropanol exlTllClion. Increasing the solvem-io-ban ratiosand cxtraction temperature increased the D/IlOUnlSof erucic oil. vitamin Eand oryzanol recovered for both sotcens. An eXlTlICIionlime of 15 min wassufficient for optimum crude oil, vitamin E. and cryzancl extraction. Pre-beated isopropanol (3:1 solvell!/br.m ratio and 6O"C) extracted less crude oil(P < .05) but more vitamin E (I' < .05) and similar amounts of oryeenol (P> .05) relative to prellcated IlclCllIIC. The data suggest that isopropanol is apromising IIltemati\'e soh"1:m to hexane foc eX1rDCtionof oil fmm stabilizedrice hnln.IJAOCS73.165l-16S6(I996)1

Hexane Sorption in Oilseed !\leals. D.A. Cardarelli and G.H. Crapiste.PLAPtQUI (UNS-CONICET). 8000 Bahfa Blanca, Argentina.

Sorptionul equilibrium of helCunein oilseed meers was studied as a func-tion of tempenHure. solvent activity. and oil content. A dynamic techniquewas implemented based on gravimetric measurements with a Cahn etec-trobnlance. Sorption and desorption isotherms of hexane in sunflower andsoybean meals were determined at atmospheric pressure in the range 50 to95°C. The equilibrium was reached faster during the adsorption process andat high hexane IICtivities. The: final equilibriurn was not influenced by parti-cle size and sample geometry. Hexane sorption is strongly dependent ontemperwure. meal composition al1d oil content. and the effect of hysteresisis negligible. Hexane is mainly retained by adsorption on the cell structure,absorption in the residual oil. and capillary condensation in the meal pores.Experimental equiltbrium datu were fitted to the GAB equation. and theparameters wen: detennined by nonlinear regression analysis. This modelTCPf"CSCnts53tisfllClOtily the sorption behavior in 11wide range of conditions.IJAOCS 73. 1657-1661 (1996)1

tnnuence of pH and Salt COlICenlrntion on Prcreln Solubility, Emull;ify-ing lind Jo-OlImlng]'roper1it'5 ofSesume Protein Concentrate. U.E. inyangand A.O. Iduh, Department of Food Science and T.-.chnology. University ofAgricuilun:. Nigeria. West Africa.

1lle effects of pH and NaCi concentration on protein solubility. emulsi-fICation. and foamability of sesame protein concenlrnte from dehulled seedswere investigated. The p!"O(Cincontent of the concenl1Ule was 70.7%. Pr0-tein solubility. emulsion. and foaming capacities varied with pH and ionic5tR:ngm. Protein solubility. which was least at pH 4. (2.1 '1» ranged from6.6% at p~1 2 to 13.1<J, at pH 10. The: solubility increased with increase in

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Compositional Pllll.lysis of the sterol fraction of olive oil can be used toassess the degree of purity of the oil and the absence of admixture withceer plant oils. This determination also permits characterization oflhc typeof olive oil in queslioo: virgin. refined, or solvent-extracted. In thoe peeseerwort. 130 samples of olive oil were analyzed, the sterol frar;tions were sep-arated from the unsaponifiable fraction by silica gel plate chromatognlphy.and later they were analy.ted as the trime\hylsilyl ether derivatives by cepit-lary column gas chromatography. From the results obtained. it was conclud-ed mat this methodology is able 10 differentiate among virgin. refined. andso]vent-extracted olive oils. Stigmasterol, creosteot, ~-avenasterol. 67-stigmasterol. and .1.7-avalllSla'Ol pennit the differentiation of the three typesof oil from one another. Campeslerol, dS.23-stigmasladil:noI. ji-siIOSlerol.and M,24-stigmastadienol pennil the differentiation of only two oils fromeach olhcr but confirm the conclusions obtained for other 5lm:lls. Correla-tions between the different sterols of virgin, relined. and solvem-exrrecredolive oil also have been obtained,[JAOCS73.1685-1689(1996))

ABSTRACTS FROM AOCS JOURNALS

ionic strength. mllging from 9.8% III 0.0 M \0 16.1'lb at 1.0 M concentra-tion. The emulsion capacity runget! from 6.2 mL oillg sample at pH 2 to19.4 mL oillg sample at pH 10. 1lle emulsion capacity increased from 11.5mL oillg &ample at 0.0 M \020.9 mL oil/8 sample at 1.0 M salt concentra-tion. Slabili!), of the emulsion increased with increase in NaCl concentra-tion. ranging from 42<:1.at 0.0 M concenmuioo w 70% at 1.0 M coeceeua-uon. but 0.5 M NaCI ptQduced the most stable foam after 120 min of whip-ping while the least stable was lit 1.0 M.[JAOCS 71, 1663-1667 (1996)]

Emulsifying Capacity of Coconut Proteins IL'i II .'unction of Salt, Pbos·phalli', lind Temperature. K.S. Kwon and K.C. Rbee, Food Profein R&DCemer, Texas A&M University. College Stalion. Texas n843-2476.

Nitrogen SoI)lubililies of proIeins in derailed coconut flour (CF) andcoconut proIein ooncemralc (CPC). prepared by ultrafiltrntion. were oerer-mined in Willer and 2% NuCl. 'The effect of ternperasure. disodium phos-phate, and ~I on emulsifying capacities (EC) of these products also wereinveWgatcd by a model system. Between pH 4.0 and 5.0, nitrogen solubili·ties of CF and CPC in ....'ater were lower than those in salt solutions. In saltsolutions. the nitrogen solubility was kIoweM at pH 1. and i~ steadilyas pH increased from 3.0 to 6.0. CF had higher EC values than CPC at allsalt and phosphate 1c\'Cls.Additionally, increased pho5pbalc I~Igencnllyincreased the EC at both salt levels. but these increases wen: 001 signifkamat 0.9% pbosphete level as compared to the 0.7% phosphate level (P <0.05). Although the emulsifying temperature of 4O"C showed higher ECvalues than both 60 and 8O"C III aU salt and pho5phate levels, the ovmllltempenture effect was IJOII signiflCallt (P > 0,05). However, EC decreasedsigniflCalltly with the addition of salt at all phosphate b'Cls.[JAOCS 7J, 1669-1673 (1996)1

Supen:rtllcal Clirbon Diol'lde ":I''''llclion of Dimorphothua pfUlwlis OilSeeds. F. Petrus CUpeNS. Gerard Bcswmkel. Ban G. Muuse. and JohannesT.P. Derksen. Agrotcchnological Research Institute (ATO-DLO). P.O. Box17. NL-67oo AA Wageningen, The Netherlands.

The possibility of uU"llCtion of Dimorphothua oil with supcrcriticalcarbon dioxide is demonstrated in this anicle. Before utraction. the seedshave to be pretreated to improve UtnlCtion yield. Experiments showed thatthe be5t pretreatment procedure for Dimorpholh«a was heating the seedsunder reduced pressure to lOO"C for 60 min, followed by flaking or milling.To give an impression about the efficiency of the supercrirical extraction. amathematical model has been developed to estimate the overall mass uans-fer coefficlent (AplC). Also, an empirical relation between Ar and theinterstitial velocity has been fourld. The physical propcnics of !fie supercrir-leal DimorphotMca oil an: in good agreelTll'nt with those of COIlventionallye.ttmeted oil, except for 8 lower phospholipid content. It is expected thaIfurther relining of supercrhical Dimorplwlheco oil will be marginal.[JAOCS73.1675-16!9(1996)[

y-Linolenic lind Stearldonic Acids In Mongolian Boraginaceae. NanzadTsevegsuren and Kun Ait7.etmllller. Institute for Chemistry and Physics ofLipids. 8AGKF. 0-48147 Milnster. Germany.

Seeds of ninc: Central Asian species of Boraginaceae wen: investigatedfor the lirst time for their oil content nnd for the fatty acid composition oftheir seed oils by cupiUary gas chromatography. Levels of y-linolenic acidmnged from 6.6 to 13.0%. and levels of stearidonic add ranged from 2.4 to21.4% of tatal seed fatty acids. The seed oil of Hocte/i(J defleH1 exhibitedthe hig~t stearidonic acid content (21.4%) that has been found so far innatun:. Other high COIltenl5of this fally acid wen: in three UJppu/o species(17.2 to 18.1%). Seed oils of c,'nog/ossum divaricatum arid Ambl)"lwlUSrupu.lris contllin considerable amounl5 of cis-Il-eicosenoic (5.3 10 5.8%)and ds·13·docoscnoic acid (7.0 to 9.7%) besides j-unolen!c (10.2 to13.0%) arid stearidonic acid (2.4 to 6.5%). which distinguish these oils fromthose of GIller Boraginaceae genera.[JAOCS73,1681-1684(I996)]

Determination or Sterols by Capillary Column Gas Chromatography.Differentiation Among Dlfferent'lYpes of Oli"e Oil: Virgin, Refined,and Soh·ent,":xtracted. Orondo Jirotne.oo:de Blasa and Amando dd ValleGonz.f.letb. aDepastment of Analytical Cbemistry, Nullition and Food set-ence. Faculty of Chemical Sciences. Ijntvershy of Salamanca. 37008 Sala·manca. Spain. and bCenlral Laboratory of the Spanish Customs House.Madrid. Spain.

Supercritical Fluid Chromatographic ARIII)".w.of New Crop Seed Oilsand 1lttir RtllCtions. Douglas G. Hayes and Roben Kleiman. New CropsResearch. NCAUR, ARS, USDA. Peoria, Illinois 61604.

Supercritical ffuid chromatography (SFC) with an open tubular columnof nonpolar stationary phase separated triglyccridcs from crembe, meadow-foam. Euphorbio laguscoe, and vernonia oils based on their molecularweight. The triglyceride compositions wen: consistent with the literature.SFC prova! ase to be II valuable tool in analyzing lipase-catalyzed transcs-teriflCation n:actions where lesquen:lla oil and escuoes wen: among thesubslrales employed. Analytc molor:ular ....'Cighl5 could be estimated from aretention time- (or elution density·) molecular weight calibration curve. Anincrease in isothermal column tempentun: during SA: ~un: or densityprogramming improved the resolution of high-ll1(llecular-weight (>600 Da)anatytes but yielded poorer resolution for enatytes of motecutar weight <200. A simultaneous pressure and temperatun: ramping program provedsuperior in enhancing resolution in several instances.I/AOCS 73. L69I-1697 (l996))

Detennination of Total trons Fatty Acids in Foods: Comparison or Cap-lllary-Column GllS Chromatography and Single-Bounce Horizontal At-tenuated Total Rcncctlon Infra~d Spectresccpy, Laila H. Alio. GeraldAngyal". Carol M. Weavefl. Jeanne I. Roder"!, and Magdi M. Mossobab.Offices of °Food Labeling and bScientific Analysis and Support. Center forFood Safety and Applied Nutrition. Food and Drug Administration. Wash-ington. DC 20204.

The total IrtlfIS fauy acid content of 18 food products was determined.after ocid hydrolysis. enrecuon and methylation of fatly acids, by gas chro-mntography with a polar lOO'l>cyanopropylsiloxane capillary column andby single-bounce horizontal attenuated total reflection spectroscopy(SB·HATR). The: trans fmty acid methyl esters (FAME) of 9-hexadccenoate(9/·16:1), s-ccreeecencae (9/·18:1), and 9,12-octadccodienoate (9/.121'18:2) wen: identified by comparison of their retention times witll those ofknown standards arid quantitated. The isomers C.I· and l.c·18:2 wen: iderni-lied from their published n:tention limes and included in the quamitation oftram FAME. Neat 5G-jJL portions of tlle FAME that were used for gas-chromatogmphic analysis also wen: unalY7.ed by SB-HATR. This techniquerequires neither weighing nor quantitative dilution of test poruoos prior tospectroscopic quantitation of isolated double bonds of Irons configuration.A symmetric 966<m-1 absorption band on 8 horizontal background wasobtained from unhydrogcnated soybean oil FAME as the n:faence material.For 9 of II producu with tfUm fat content >5% of total fat, n:su115obtainedby S8·HATR were higher than those obtained by gas chromatography,Results obtained by the gas-chromatographic procedun: wen: slightly 10 sig-nificantly higher than those obtained by SB·HATR for the si.t foods inwhich Irons fat content was <5% of lata I fat.[JAOCS 7), 1699-1705 (1996)]

RlIpid and Complete Extraction of Free Fatty Acids from 011sHds forAcid \'aJue DetennlnaUon. O.YO. ~zin. YLI.1\u"'yan.1. Kuselman. andA. Shcnhar. Thc: National Pbysical Laboratory of tsraet.Jerusalem 91904.Israel.

The rapidity and uncertainty of the acid value determination in cilseedsan: defined by the nile and completeness of the free fauy acid Clltraction.The strategy of reagent development for utraction has been discussed. and

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a set of reagents thai provide rapid and complete extraction has beenobtained. The set consists of two reagents. Reagent A contains tri-ethanolamine in a mixture of water. isopropanol. and heptane. Reagent Bcontains a strong acid and inorganic salt in water. Reagent A allows the car-rying OUI of rapid (1-2 min) solid--liquid cJttroction of the free fatty acidsand some other acids from onseecs. Reagent B provides the separation ofthe free fatty acids only into the heptane phase (-5 min). which can be useddirectly for the free Iatty acid determination. Two techniques for this deter-mination have been applied: pH-metric and ritrimetric. The advantages ofthe proposed set of reagents are described.IJAOCS 73. 1707-1711 (1996)1

Physicochemical Characteristics of Liposomes Formed with InlernalWool Lipids. L. Coderch. A. de la Maul, A. Pinazo. and J.L Parrn. Centrode Investigaci6n y Desarrollo. C.S.I.c., 08034 Barcelona. Spain.

The bilayer-forming capability of internal wool lipids and their physico-chemical properties were studied in an attempt to enhance our understand-ing of the lipid structure present in wool and other keratinized tissues. Inter-nal wool lipids were extracted and analyzed. and the mixture obtained[sterol esters (10'1». free fatty acids (24%). sterols (11%). ceramides (46%),and cholesteryl sulfate (9%)[ was shown 10 form stable liposomes. A phase-transition u.mperature of 6O"C was obtained from nuclear magnetic reso-nance spectra for this lipid mixture. The spontaneous perrreabiliry of thesevesicles was lower than that of pbosphatldylchollne liposomes but slightlyhigher than that of the vesicles fanned with lipids extracted from other kera-tinized tissues with higher amounts of cholesterol. The transmission elec-tron micrographs showed large vesicular aggregates of approximately 300nm, which seem to be made up of smaller structures of approximately 20nm in sire. This parucular structure could IICCOUntfor the large diametersand small internal volumes found by dynamic light-scattering and spec-trofluorometric measurements./JAOCS73.1113-1118(1996)1

Improving the Lew-Temperature Properties or Alternative Diesel Fuels:Vegetable Oil.~rlved Methyl Esters. R.O. Dunn M.W. Shockley, andM.a. Bagby. Oil Chemical Research, USDA. ARS. NCAUR. Peoria. Illinois61604.

This work ellplOfes near-term approaches for improving the low-tem-perature properties of triglyceride oil-derived fuels for direct-injection com-pression--ignition (diesel) engines. Methyl esters from transesterifled soy-bean oil were evaluated as a neat fuel and in blends with petroleum middledistillates. Winterization showed that the cloud point (CP) of methyl soyatemay be reduced to _16bC. Twelve cold-flow additives marketed for distil-tares were tested by standard petroleum methodologies. including CPo pourpoint (PP). kinematic viscosity. cold filter plugging point (CFPP). and low-temperature flow test (LTFT). Results showed that additive treatment signif-icantly impTO\1:Sthe PP of distillate/methyl ester blends; however. additivesdo oot greatly affect CP or viscosiry. Both CFPP and LTFT were neatly lin-ear functions of CPo a result that compares well with earlier studies withuntreated distillate/methyl ester blends. In particular. additives proved capa-ble of reducing L1FT of neat methyl esters by 5-60c. This work supportsearlier research on the low-temperature properties; that is. approaches forimproving the cold now of methyl ester-based diesel fuels should continueto focus on reducing CPo/JADeS 73, 1119-1128 (1996))

Separsucn and Identification or Ximenynic Acid Isomers in the SeedOil or Santa/um spicatum R.Br. as Their 4,4-DlmethJlo:mzoline Deriva·ttves. Yandi D. LiuCl. Robert B. Longmores. and John E.D. roxb, ClSchoolof Pharmacy and bSchool of Environmental Biology, Curtin University ofTechnology. Perth 6001. WA. Australia.

The seed oil of SU/JIuilmr spiCUlum contains a significant amount ofximenynic acid. Irons-II-octadecen-9-ynoic acid, a long-chain acetylenicfatly acid. as a major component (34%). 'The identity of lrons-ximenynicacid was confirmed after isolation by' ultraviolet. infrared.. and nuclear mag-netic resonance (NMR) (IH_ and l3C_) spectroscopy and by gas chro-matography/mass spectrometry (GClMS). The cis isomer of ximenynic acidwas also found «1%) in some samples. The cis and froM isomers werecharacterized by GCfMS comparison of their methyl esters and 4,4-dlmethyloxazoline derivatives.IJAOeS73.1129-1131 (19%»)

The Seed Oil of Bemardio. pulchella (Euphorbiaceae) -A Rich Sourceof Vemolic Acid. V. Spitzer". K. Aitretmilller", and K. Vosmannb, "Fatul-dade de Farmlkia, Curso de P6s-Gradua.;;lo. UFRGS. 90.610.000 Porto Ale-grelRS. Brazil and blnstituu. for Chemistry and Physics of Lipids. BAGKE48006 MUnster. Germany.

The fatty acids from the seed oil of Bemardia pulchella (Euphor-biaceae) have been analyzed by gas chromatography (GC) and GC-massspectrometry (MS) analysis of their methyl esters. Vernolic acid is the maincompound (91%). along with other usual fatty acids. In addition to thequantitation by GC analysis. IH-nuclear magnetic resonance (NMR) signalsfrom the seed oil have been used to estimate the total epoxy fatty acid con-ten\. 'The structure of vernolic acid has been proven by spectroscopic meth-ods (infrared. IH. and 13C_NMR) and by GC-MS analysis of the corre-sponding silylated hydroxy-methoxy derivative. The 4.4-d.imethylo~azolinederivatives of the fany acid mixture have also been examined by GC-MS.and it was shown that this derivarizadon reaction is not suitable for thestructure analysis of vernolic acid.[JAoeS 73. 1133-1135 (1996)1

Epoxy AUyUc Carboeancns as Conceptual Intermediates in the lIiogen.esrs of Diverse Marine Oxynpfns. Willihm H. Gerwlck, College of Phar-macy, Oregon State University, Corvallis. Oregon 91331.

Marine organisms. especially marine algae. are extremely rich in adiversity of novel oxylipin structures. Many of these oxyljpins contain fune-ticnalities and rings of a type and location unlmown in mammalian systems.In this perspective reviewing marine oxylipins. a proposal is formulated forthe central intermediacy of an epoxy allylic caebocation in the biogenesis ofthese diverse structures. This proposal is strengthened by the relatively largenumber of examples which are consistent with this type of mechanistictransformation.[liplddJ. 1215-1231 (1996)]

Purification and Chaeacterizatlen or a 28 kDa Cytosolic Inhibitor ofCholesteryl Ester Hydrotases in Rat Testis. Denise S. Hines, SiowfongWee. and W. Mclean Grogan. Department of Biochemistry and MolecularBiophysics, Virginia Commonwealth University. Richmond. Virginia 23298-0614.

A 28 kDa inhibitory protein was purified from rat testis cytosol bysequential 40-65% ammonium sulfate precipitation. calion exchange chro-matography, anion exchange cbrorneeography, and preparative SDS--jxlly-ocrylamide gel electrophoresis. The heat-stable. trypsin-labile protein exhib-ited nonenzymatic. concentration-dependent inhibition of testicular andpancreatic cholesteryl ester hydrolases at all stages of purification. Copuri-fying at each stage was a 26.5 kDa protein which comprised 2.5% of themass of the two proteins. Polyclonal antibodies raised to either or both 28kDa and 26.5 kDa proteins by direct injection of excised electrophoreticbands cross-reacted with both proteins on western blots, immunopreclphnt-ed both proteins. and neutralized inhibitory activity. Amino acid composi-tions of the individual proteins electreeluted from SDS--jxllyacrylamide gelswen: different from those of oeer surface-active proteins of similar molecu-lar weights. Both proteins e~ibited identical pI of 4.8 on chromatofocusingcolumns and two-dimensional gel electrophoresis. Although the subcellulardistribution of the 28 kDa protein is unknown. its testicular cvrosouc con-centration. calculated from the purified protein mass. was 8 x 10-9 molsfL,which probably underestimates the actual concentration by an order of mag-nitude. This is greater than the minimum concentrntion required for in vuroinhibition (10-'>' molsIL), consistent with a physiological role for this pro-tein.[lipids J/. 1233-1243 (1996)1

Protection by Different Agents Against Inactivation of Llpoxygenase byHydrogen Peroxide, Manuela Perez-Gllabert. Genit A. Veldink. and Jo-hannes F.G. Vliegemhart. Bijvoet Center for Biomolecular Research. UtrechtUniversity. NL-3584 CH, Utrecht. The Netherlands.

H202 is a potent inactivator of lipoxygenase. In this paper, the ability ofdifferent agents [mannitol. oleic. stearic and linoleic acid, n-buuUJol. and

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ABSTRACTS FROM AOCS JOURNALS

hydroperoxy octadecadienoic acid (HPOO)] to prevent the inactivation oftomato lipoxygenase by hydrogen peroxide has been studied. Tbe involve-ment orQH' in the inactivation process is suggested by the ability of manni-tol \0 prevent the loss of uctivity. This mdical would be produced by reec-tion of H202 with lhe Fe(l!) lipoxygenase. The most effective protectionwas displayed by HPOD. the product of the reaction of lipoxygenase withlinoleic acid. This result could be uplained by the conversion of the nativeenzyme into the Fe{lIJ) lipoxygenase in the presence of HPOD: the Fe{IlI)enzyme is not able to react with H20Z. and no OH' will be produced. Theprotective effect obtained wilh oleic and stearic acid could be explained byan occupation of the active center by these inhibitors. The enzyme wouldnot transform them. but their presence would hamper the conversion ofH.,o, in OH' and limit the damage in the active center.[Upi(bJ/.1245-1250(I996)[

Lipid Pero<ro:idation in Low Density Lipoproteins from Human Plasmaand Egg Yolk Promotes Acc:umulation or I-Acyl Analogues or Platelet-Activating Factor-Like J..ipids. Akin! Tbkumura. Masaoki 'toojrma. YasukoYoshioka. and Kenji Fukuzawa, Faculty of Pharmaceutical Sciences. TheUniversity of Tokushima. Tokushima 770. Japan.

Oxidative modification of low density lipoprotein (LDL) is known to bea key event for induction of atherosclerosis. However. there has been lillieprogress in structural elucidation of oxidized lipids. especially oxidativelyfragmented pbospbolipids relaining a glycerol backbone. In this stlllly. wefound that LDL derived from egg yolk has no platelet-activating factor(pAF) acetylhldrolase activity. and that prolonged incubation of egg yol~LDL with Cu + resulted in the fonnation of various PAF-like lipids: l-acyltype phosphatidy1cholines with an sn-2-shon-chain dicarboxylme or mono-carboxylate group. Only a very snmll amount of the PAF·like lipid havingan sn-2-shon-chain rnonocarboxylaje group was detected by gas chro-matography-mass spectrometry in Cu2+ -oxidized LDL from human plasmawith high PAF-acetylhydrolase activity. which has been reponed tohydrolyze PAF·like lipids to lysophosphatidylchollnes. Preincubation ofplasma LDL with diisopropyl l1uorophosphate dose-dependently inhibitedPAF·acetylhydrolase activity. resulting in accumulation of the PAF-likelipids when the LDL was oxidized with Cu2+. As well as PAF andl:;sophOSPhatidy1chOlines. several PAF-1ike lipids were found to inhibit[ H[thymidine incorporation into cultured vascular smooth muscle cellsderived from rat aorta. llIc possible fonnation of PAF-like lipids by lipidperoxidanon in LDL is discussed as well as its possible significance forinduction of atherosclerosis.[Upids3/.1251-1258(1996)[

Oxidation Products of Cyanidin J-O-II-D-glucoslde with a Free RadicalInitiator. Takanori Tsuda". Katsuml Ohshimab. Shunro Kawakishi.c andToshihiko Os.awac. "Tokaigakuen women's College. Nagoya 468. Japan.h-fond Research Institute. Aichi Prefectural Government. and'lJepartmentof Applied Biological Sciences. Nagoya University. Nagoya 464 -01. Japan.

Recenrty, we have reported that anthocyanins show strong antioxidativeactivity. hut no attention has been paid to anthocyanins from the viewpointof the reaction mechanism of atkylpcroxyt radicals: therefore. we investigat-ed the reaction prcdccts of amioxidative anthocyanins (cyanidin 3-0-11-1>-glucoside). Cyanidin 3-0·lI-o-glucoside was reacted with 2.2'-.12ooi5(2.4-dimet hylvalercnitrile) to generate the alkylpercayl radicals. and the reac-tion products were isolated by high-performance liquid chromatography.The products were identified as 4.6-dihydroxy-2-0-J3-o-glucosyl-3-oxo-2.3-dihydrobcnzofur~n and protocatechuic acid. Based on reaction products. theantinxidative mechanism of cyanidin 3-0-J3-o-glucoside may be differentfrom that of a-tocopherol: ~yanidin 3-0-J3-o-g1ucoside would produceanother radical scavenger. as il would break down the structure and scav-enge the radicals.[Upidd/. 1259-1263 (1996)[

Increased Formation of !'hosphatidy1inosilol-4-I'hosphale in HumanPlatelets Sthnulatl'd with Lysophosphatidi( Acid. Indu Mani. Douglas C.Gaudette. and Bruce J. Holub. Depanmem of Human Biology and Nutri·tional Sciences. University of Guelph. Guelph. Ontario. N IG 2Wl. Cllnada.

Lysophosphatidic acid (LPA. I-acyl-sn-glyccrol 3-phosphate). at a con-cemrenon of 1-40 ).11'.1. was fO\lnd to induce !he formation of [3H[illOSitol-labelled pbosphatldylincsitol-a-phosphare (PIP) witbout significantly alter-ing the levels of either phcsphatidylinositol (PI) or phospbctidylinositol bis-phosphate (pIPV in washed human platelets. Preincubation of platelets with

the cyclooxygenaserlipoxvgenase inhibitor. BW755C at 100 ]!NI. did not

alter the LPA-induced formation of I'll'. Activation of platelets with thephorbol ester. phorbol 12-myristate t j-aceraie (PMA). elicited 11similarresponse (induction of PIP formation). The specific protein kinase C (PKC)inhibitor. GFI09203X (10 ]!NI). completely blocked the effect of PMA butnot the LPA-induced generation of PIP. The present results indicate thatLPA can induce PIP formation ,.;1I PI-4-kinase activation. through processeswhich are independent of the eicosanoidffxA2 pathway and are not PKC-depeAden\.[Upids 3J. 1265-1268 (1996)]

Differential Inhibitory Effects of Garflc-Derlved Organosulfur Com-pounds on Cholesterol Biasynthesis in I'rimary Rat Hepatocyte Cul-tures. RolfGeblurdt and H:llgund Beck. Physiologisch-Chemisches lnstinn.University ofTiibingen. 0-72076 Tilbingen. Germany,

Using primary rat hepatocyte cultures. the potency of several garlic-derived organosulfur compounds 10 inhibit cholesterol biosynthesis in totoas well as at early and late steps of this metabolic pathway was compared.Concerning early steps. allicin significantly inhibited incorporation of[14C[aeetate inlO nonsaponifiable neutral lipids already al concentrations aslow as 101-11.1.while diallyl disulfide and allyl mercaptan were effectiveabove 100 I-IMonly. Likewise. inhibition in response to the two vinyl-dithi-ins started at 500 11M. If [14C[acetate was replaced by ,14C]mevalonate.inhibition due to allicin. diallyl disulfide. and allyl mercaptan disappearedsuggesting that HMGCoA-reductase was the target of inhibition. tn con-trast. for the vinyl·dithiins a stimulation of mevalonate incorporation wasfound. Concerning the late step. the potency to exert accumulation of lanos-terol presumably by inhibiting lanosterol len-demethylase decreased in theorder allicin> diallyl disulfide> allyl mercaptan '" 1.3-vinyl-dithiin» 1.2-vinyl-dhhtin. the effect of the latter compound being close to zero. Withrespect to the total inhibition of [14C[acetate labeling of cbclesterol. thehalf-maximal effective concentrotion-value of allicin was detennined to be17 ~ 2 IlM compared \0 64 ~ 7 IlM for diallyl disulfide and \0 450 ~20 IlMfor allyl mercaptan. Cytotoxicity as determined by the lactate dehydroge-nase leakage assay was slightly higher for the two vinyl-dnhiins than fordtanyt disulfide and allyl mercaptan. but was apparent only at concentro·nons higher than 10 mM and. consequently. was irrelevant for the effectsdescribed. These results demonstrate that different garlic-derived Drganosul-fur compounds interfere differently with cholesterol biosynthesis and. thus.may provoke multiple inhibition of this metabolic pathway in response togarlic consumption. The fact that allicin wa~ the most effective inhibitorargues against the possibility that its degradation products. namely diallyldisulfide or allyl mercapatan. might mediate its effects. a possibility thatmight be true. however. in the case of the vinyl-dithiins.[UpidsJJ.1269-1276(1996)[

Biosynthesis or Eicosapentaenolc Acid in the Mlcroalga Porphyrid;IImcruentum, I: The Use of Externally Supplied Fatty Adds. DeveraShirdnll. lnnu KhOlinll. Yair M. Heimerl'. and Zvi Cohen", "The Laboratoryfor Mieroalgal Biotechnology and bAlben Katz Center for Desert Agrobiol-ogy. Jacob Blaustein Institute for Desert Research. Ben-Gurion Universityof the Negev. Sde-Boker Campus 849'Xl. Israel.

The biosynthetic pathways of eicosapemaenoic acid (20:5n-3) inmicroalgae. in general. and in Porph)"ridi"''' cruemuJII. in particular. are IlOIknown. Some of the putative imermediates along the suggested pathwayscould not be detected probably due to their low endogenocs level. In orderto increase the endogenous levels of the intermediates. we provided variousfatty acids in the growth medium. Exogenously supplied fatty acids wereindeed incorporated into algal lipids and were further metabolized along then-6 and n-3 pathways. In the n-6 pathway. 18:2 was desamrated to 18:3n-6.elongated to 20:3n-6. and subsequently cesmurated to 20:4n-6 and then to20:5n-3. In the n-3 pathway. 18:2 was first desaturated to 18:3n-3 whichwas then sequentially converted. apparently by the same enzymaticsequence of the n-6 pathway to 18:4n-3. 20:4n-3. and 20:5n-3.[Upids3/.1277-1282(1996)1

The Fally Add Composition or Human GHomltS Differs from ThaIFound in Nonmalignant Brain TIssue. Douglas D. Manin". Michael E.c.Robbiru;a. Anhur A. Spector'>. B.-Chen Wenll. and David H. Hussey". Divi-sion of Radiation Oncology. Departments ofaRadiology and bBiochemistry.The University of Iowa Hospitals and Clinics. Iowa City. Iowa 52242.

To compare the fatty acid composition of tumor tissue from glioma

INFORM. Vol. 8. no. I {January 1997}

143

patients with !hal of normal brain tissue. tissue samples were obtained from13llliorna p;llicnlS!II1d from 3 nonmalignant p;uicnlS. Following lipid extrac-tion. tolaI fall), acid composition was mea.o;;ured using gas--liquid chromalog-I1Iphy.Samples were funha separated into phospholipids and neutralfipids.Represenl1lti\'c samples were then separated inlO phospholipid classes bythin-layer dU'OlT1l11ogruphy and the Iauy acid composition assayed. Levels ofthe polyunsatumted fatty acid (PUFA) eocosabexeenoic acid (DHA). weresigniflCal11ly reduced (p. 0.Q29) in the glioma samples COIllparM with !lOr-

mal brain samples: mean values were 4.8:1: 29% and 9.2 ± 1.0%, respective-ly. This miuclion in glioma DHA comem was also observed in terms ofphospholipids (4.6:1: 21 % VI. 9.6:1: 0.8'1., P:= 0.002), The phosphatidylser·ioe and phosphalidylethanolamine phospholipid classes wen: n:duced in theglioma samples. Differences were also noted in the 0-6 PUFA contentbetween glioma and oormaI brain samples. TIle glioma content of the 0-6PUFA linoleic acid was significantly greater (P < 0.05) than thai oeeerved inthe comrol samples in terms of total lipids. Thus. the fany acid compositionof human gliomas differs from that fOlind in nonmalignant brain tissue.[lipidf 31. 1283-1288 (1996)1

Increasing Didary Llnokk Acid in YOl.lI1g Rats Increases and 'lben IX-creases Doc:ouhulM'nok Acid in Retina But Not in Brain. Hui-Min SuoLisa A. Keswick. and J. lbomas Brenna. Division of Nutritional Sciences.Cornell University, Ithaca, New Yorio::I~l

TIle accumulation of fany acids in retina. brain. liver. and plasma of 30-day-old I1Itpups consuming vDriOllSlevels of linoleic acid (LA. 18:2n-6)and constant u-linolenic acid (ALA, 18:3n-3) is reponed. Dams were fedgraded levels of LA during gestation and lacwion. and the pups were main-tained on the diet of their dams until the end of the brain gJU"1h spurt at 30d of life. Milk. and pup brain. It'Iina. Ijl'el', and plasma were analyzed quan-titatil'ely fOf fauy acid profile. lbe percentage of OOcosahexaenoic acid(DHA. 22:6n-3) in retina increased from an LA-deficient dietary level.peaked at the 9: I (LAIALA) level. then fell fOf the 41: I and 69: I levels, Incontrast. the bruin DHA percentage was unaffected by dietary LA levels.Retinal unserurarcd fany acid levels p311111eledliver and plasma levels. Themilk faUy acid composition mirrored the diets. These data sllow that theretinal fatly ecid composition responds sensitively to dietary Iany acid com-position. similar to liver and plasma. while the brain unsaturate composmonis Ilearly independent of dietary composition.llipidf 31. 1289-1298 (1996)]

Ultrasound-As..~l~led O.ddatin Cleavage of Acetylenk and EthylenjcBonds in Unsuturuted Fatty gsrers with PollISI;ium Permanganate. Mar-cel S.F. Lie Ken Jie and Pmbhavathl Kalluri. Department of Chemistry. TheUniversity of HOllg Kong, Pckfulum Road. Hong Kong.

The effect of uurasound on the oxidation of unserurated fany esters WIIS

investigated. Unserunned Iauy esters containing acetylenic or olefinic hoodsor both were oxidatively cleaved with KMn04 in aqueous acetic acid(AcOHlH20. I: I. vol/vol for olefinic fany esters and AcOHlH20. 9: I.vol/vol for acerylenic fany esters) to yield the corrc:sponding carbo~ylie acidmoieties in quantitative yields, when the reections were conducted underultrasound (20 kH7.. 53 Wlcm2. 8-15 min). The methyl ester derivatives ofthe carboxylic acid moieties formed were identified by gas-liquid chro-matographic analysis. The procedure constitutes a facile method for thedetermination of the position of the unsaturated center (olefinic oracetylcnic) in an unsaturnted fatty ester substrate. especially where theunsaturated system consists of an acetylenic bond.[lipids 31. 1299-1301 (1996)1

Preparation or Flilly Add Methyl Esters from Lipoprotein andMacropha~ Lipid Subclas!iCs on Thin-Layer Mates. Wolfgang SanlerU.Helga Reicher'. Pilar Ramosb• Ute Panzenboeck", Marianne Haynb, Her-mann Esterbauerb. Ernst Mallel'. and Gerhard M. KostnerU. Departments ofClMedical Biochemistry and bBiochemistry, University Graz, A-BOlO Graz,Austda.

A simple. accurate. and fast procedure fOf quantitative analysis of fanyacids (fA) in simple lipid subclasses from different biologicul ~mens ispresented. Lipid exll'llCU of isolated plasma lipoproteins (''Cf)' low. low. andhigh density lipoproteins: VLDI... LDI... and HDL. respectj"ely) and perma-nent n74 mouse macropllages were fractionated into lipid subclasses bythin-layer chromotogr.iphy (TLC) on silica gel 60 plates. Bands comigratingwith authentic lipid standards were scraped off under argon and subjected todirect. in Silll transesreriflcanon wilh BF~1eOH in the presence of the

TLC adsoriJent. Fauy acid methyl esters were subsequently quantitated bycapillary gus chromatogr.aphy. A comparison of the FA content present intotal lipid utmcts and in lipid subclasses separated by TLC revealed recov-eries ranging from 93 (J774 cell extracts) to 99.7% (LOL). 111e methoddescribed is applicable fOf the measurement of FA in individual lipid sub-classes and was successfully applied to quantaatively analyze the FA COI11-

position of the phospholipid. triao:.:ylglycerol, and cllolesteryl ester fractionderived from VLDL. LDL. and HDI... In J774 lipid extracts. the FA compo-sition of the phospholipid·. IllOIlOaC)'lglycerol-. diacylglycerol-. fmc fanyacid-. triacylglycerol-. and cbolesteryl ester fraction was quantitated. Inaddition we have analyzed the time-dependent loss of !be major HDLpoIyunsarurated fauy acids (18:2. 20(4) in the phospholipid and choIestaylester fraction during eopper-dependent pemxidaJ.ion of HDL We MI'C notencountered analytical problems concerning low FA recoveries from CE-rich lipid extracts lIS indicated by almost quanlitative recoveries of FA inLDL. HOI... and J774 utracts.[Lipids31,1303-1310(l996)]

Analysis orTria('ylgIJcuol~ by Sih'cr-Ion lIigh-Pu10nnaDfe LiquidChromatognphy-Atmospheric Pressure Chemical 10Dizalion MIIS5Spectrometry. PIlivi L.aakso and PIliv i ~tilainen. Depanment of Biochem-istry and rood Chemistry. University ofTur1ru. AN-20014 Turtu. Finland.

Triacylglycerols of the seed oils rich in a- andIOf .,.lioolenic acid moi-eties were separated by sill'el'-ion high-perfoonance liquid chromatogntphy(HPLC) followed by on-line almO!iphcric pressure chemical ioniution-massspectrometric (APCI-MS) detection. Mass spectra of most triacylglycerolsexhibited abundant [M + H]+ and 1M - RC02J+ ions. which defined themolecular weight and the molecular association of fatty acyl residues of a tri-acylglycerol. respectiI'Cly. Sill-er ions formed ..,,-eakercomp1exes with triacyl-glycerols containing .,.linolenic acid than with ucse containing a-linolmicacid. i.e .• the elution order of molecules was XYT.l,> XYT a' XT-1:r> XT -1a> XTaT a' and TyT.,T." > T.,T.,Ta> T.,TaTa TaT aTa. wliere Ta'"a-linolenic acid. Ty• r-]inoienic acid. an(l X. Y", fatty acids different fromlinolenic acid. Fcrfhermoee. silver-ion HPLC resulted in partial separntionwithin equally unsaturated triacylglycerols according 10 differences in thecombined number of acyl carbons. Regioisomeric forms of triucylglycerolswere not determined from the seed oil samples. although differences weremeasured with reference compounds in the relative abundances of [M -RC02J+ ions formed by a loss of a flllty acyl residue from the ,171-2 positionand the 511-113 positions. Silver-ion HPLClAPCI-MS provided valuableinformation for StnlCtun: elucidation of seed oil triacylglycerols: 43 molecu-lar species were identified from croedterry seed oil. 39 from evening prim-rose oil. 79 from borage oil. 44 from alpine curraor. DI1d56 from black cur-I1Int seed oils. TIle qunntitation requires 10 be studied further. especially inthose cases where severat molecular weight species of triacylglycerols elutedin a single chromatographic peak.[lipids 31. 1311-1322 (1996)]

A'-ailability or Antehidonie Acid in Major »IHl'ipholipids orMurosll andtltt' Stomach Wall or Rltls, Sigurdut 01i Olafsson and Sigmundur Gudbjar-nason. Science Institute. University of Iceland, IS-107 Reykjavik:, Iceland,

The purpose of this study WIIS to examine the availability of arachidonicacid in phosphatdidylchcllne (PC) and phosphatidylethanolamine (PE) ofmucosa aod the stomoch wall of adult male Wistar I1ItSfed a standard diet.There were significant differences in the fatty acid composition of PC andPE between various parts of the stomach. 11Ie mucosa had the lowest levelof arachidonic acid (20:4n-6) in PC. follo ....ed by the com::sponding sromachwall Of glandular part. whereas the forestOll'lllCh or the upper pan had thehighest level of 2O:4n-6. TIle level of 20:4n-6 in PE was identical in gastricmucosa and the stomach wall of both the lower and upper parts. The levelsof 18:ln-9 and 18:2n·6 were significantly higher in both PC and PE ofmucosa man in the stomach wall. The levels of 16:0 and 18:0 in PC werelower in mucosa than in either forestomach Of the glandular pan. In mucos-al PE. the levels of 18:0 and 22:6n-3 were lo",er than in forestomach andglandular part. 11Ie glandular part had significantly higher level of 16:0 andlower level of 2O:4n-6 in PC compared 10 the fCRStomach. Cooclusions:The ar.IChidonie acid level of PC was signirlCantly different in l'lIriOUSpartsof the rat ~omach, with the !oIo·est level in mocou. whereas the level of2O:4n-6 in PE was identical in mucosa and stomach wall. 'rtese ~lipids had higber levels of saturated fauy acids in the stomach wall than ingastric mucosa.[Lipids J/. 1323-1325 (1996)1

INFORM, 'wbI. 8, no. 1 (January 1997)