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Sporidesmin, a mycotoxin from Pithomyces chartarum is a hydrophobic molecule. It can therefore be easily incorporated in the cell membrane, where it is likely to cause changes in the bilayer organization and the properties of membrane proteins. In order to understand the redox behaviour of sporidesmin in a hydrophobic environment, we have investigated the effects of oxidized and reduced sporidesmin on the phase transition properties of bilayers and on the susceptibility of bilayers to pancreatic phospholipase A2 (PLA2). The changes induced by sporidesmin in the thermotropic phase transition profiles of dimyristoyl-sn-3-phosphatidyl choline (DMPC) bilayers were similar to those caused by solutes known to localize in the glycerol-backbone region of the lipid bilayer, suggesting a similar localization for oxidized and reduced sporidesmin. Neither form of toxin disrupt the bilayer or membrane organization even at relatively high mole fractions. At concentrations

Results of an X-band (≈ 9.3 GHz) EPR study of Cu2+ doped barium formate single crystal at RT and at LNT show that Cu2+ enters the host lattice at substitutional Ba2+ sites as well as at an interstitial site. Both the copper (II) complexes show a low symmetry and low site symmetry effects are evident in EPR at RT. The g and A tensors are non-coaxial at RT for both the copper complexes, however, they become coaxial at LNT. From experimental EPR data the ground state orbitals are obtained and discussed. The ground states are found to be mainly d with some admixture of d. From the observed g-value the energy splitting of the d-orbitals of the metal ion are also obtained. The angular behaviour of EPR spectra is in conformity with the symmetry class of the host crystal as determined by X-rays. Die Ergebnisse einer X-Band (≈9,3 GHz) EPR-Untersuchungvon Cu2+-dotierten Bariumformateinkristallen bei Zimmertemperatur und der Temperatur des flussigen Stickstoffs zeigen, das Cu2+ in das Wirtsgitter sowohl substitutionell auf Ba2+-Platze als auch interstitiell eingebaut wird. Beide Kupfer(II)-Komplexe zeigen niedrige Symmetrie und die niedrigen Gitterplatzsymmetrieeffekte sind in der EPR bei Zimmertemperatur nachzuweisen. Die g- und A-Tensoren sind bei Zimmertemperatur fur beide Kupferkomplexe nicht-koaxial, werden jedoch koaxial bei der Temperatur des flussigen Stickstoff. Aus den experimentellen EPR-Daten werden die Orbitale des Grundzustandes erhalten und diskutiert. Es wird gefunden, das sie hauptsachlich d-Orbitale mit einer Zumischung von d sind. Aus den beobachteten g-Werten werden die Energieaufspaltungen der d-Orbitale der Metallionen ebenfalls erhalten. Das Winkelverhalten der EPR-Spektren befindet sich mit der mit Rontgenstrahlen bestimmten Symmetrieklasse der Wirtskristalle in Ubereinstimmung.

Results of temperature dependence of EPR spectra of Mn2+ and Cu2+ ions doped calcium cadmium acetate hexahydrate (CaCd(CH3COO)4•6H2O) have been reported. The investigation has been carried out in the temperature range between room temperature ( 300 K) and liquid nitrogen temperature. A I-order phase transition at 146 ± 0.5 K has been confirmed. In addition a new II-order phase transition at 128 ± 1 K has been detected for the first time. There is evidence of large amplitude hindered rotations of CH3 groups which become frozen at 128 K. The incorporation of Cu2+ and Mn2+ probes at Ca2+ and Cd2+ sites respectively provide evidence that the phase transitions are caused by the molecular rearrangements of the common coordinating acetate groups between Ca2+ and Cd2+ sites. In contradiction to the previous reports of a change of symmetry from tetragonal to orthorhombic below 140 K, the symmetry of the host is concluded to remain tetragonal in all the three observed phases between room temperature and liquid nitrogen temperature.

A detailed EPR study of Mn2+ is carried out from melting temperature to 77K. In Co(ClO4)2.6H2O, two new structural phase transitions are detected at T1 approximately 354K and T2 approximately 243K in addition to the previously known transition at T3 approximately 155K. In Ni(ClO4)2.6H2O the recently reported new phase transitions at T1 approximately 361K and T2 approximately 311K are confirmed and a new phase transition at T3 approximately 245K is observed. The phase transition occurring at T3 in both the crystals seems to be purely a structural one, while all the other phase transitions in both crystals involve changes in both structure and configurational disorder of the perchlorate ions. The space group symmetry C2v7 (Pmn21) of the crystal remains unchanged from melting temperature to T3 in Co(ClO4)2.6H2O and from melting temperature to 100K in Ni(ClO4)2.6H2O. The transitions at T1 and T2 in both crystals involve changes in the water-perchlorate sublattice symmetry. The two crystals are isostructural in the phases between the melting temperature and T1, and between T1 and T2.

An EPR study has been carried out on Mn2+-doped single crystals of hexaquonitrates of Mg and Ni, Mg(OH2)6.(NO3)2 and Ni(OH2)6.(NO3)2, at room temperature ( approximately 300K) and at X-band. Mn2+ substituting for Mg2+ in Mg(OH2)6.(NO3)2 exhibits two identical, but differently oriented, magnetic complexes, whose z axes make an angle of approximately 15+or-1 degrees with each other in the zx plane. However, Mn2+-doped Ni(OH2)6.(NO3)2 crystals exhibit only one single thirty-line spectrum indicating the equivalency of two Ni(OH2)62+ complexes per unit cell. The EPR spectra are analysed using a spin-Hamiltonian of orthorhombic symmetry to get the best fit parameters. These studies reveal that the two crystals are not isomorphous and that the site symmetry at the cation sites is very low.

EPR of Mn2+ doped in ammonium iodide single crystal has been studied at X-band in the temperature range 573–577 K. The observed temperature dependence of line widths and spin Hamiltonian parameter b20 below room temperature is related to the structural transformations in the crystal. The coexistence of high temperature phase (NaCl) and low temperature phase (CsCl) is attributed to the large thermal hysteresis in line widths and b20. The dissociation of ion vacancy pairs occurs near 500 K and is reflected in the reversible change of an anisotropic EPR spectrum in an isotropic sextet near this temperature. The ion vacancy pair models for NaCl and CsCl phases are discussed along with the effects of thermal processing of the samples. Heating the crystals above 500 K leads to expulsion of Mn2+ impurity from the crystal.

The electron paramagnetic resonance of Mn2+ doped in single crystals of Zn(ClO4)2·6H2O has been studied at X-band in the temperature range 300–380 K. A phase transition, observed at ∼ 346 K, is reported for the first time.

EPR of Mn2+ doped in single crystals of strontium acetate hemihydrate [Sr(CH3COO)2⋅1/2H2O] has been studied in detail at ∼300 K and the spin Hamiltonian analysis is presented. The angular variation of the EPR spectrum of Cu2+ in strontium acetate hemihydrate crystals in relation to the principal axes of the D‐tensor of Mn2+ has also been studied. From this study the unit cell symmetry of strontium acetate hemihydrate crystal is determined to be triclinic, contrary to the previously reported monoclinic symmetry from a preliminary x‐ray structure analysis. It is further concluded that Cu2+ and Mn2+ get incorporated at different sites in strontium acetate hemihydrate crystals.

The results of the EPR study of VO2+ doped in NH4I and NH4Br single crystals in the temperature range 430–77 K are reported. The observed spectra suggest a liquid‐like behavior of these crystals for VO2+. A single eight line isotropic spectrum was observed in the temperature ranges ∼373 to ∼245 K in NH4I and ∼430 to ∼233 K in NH4Br. No spectrum was observed in the temperature ranges ∼245 to ∼173 K and ∼ 233 to ∼223 K in NH4I and NH4Br crystals, respectively. A spectrum with two sets of eight isotropic lines was observed from ∼173 K for NH4I and ∼223 K for NH4Br to 77 K. The observed mI dependence and temperature variation of linewidths are discussed. The anomalies in temperature dependence of linewidth confirmed the structural phase transitions in the host lattices.

A temperature dependent EPR study of Mn2+ impurity-doped crystals of Mg(ClO4)2·6H2O has led to the detection of two critical temperatures T1 ~ 335K and T2 ~ 324K where the EPR characteristics undergo distinct changes. The monoclinic distortion of the water octahedron around the metal ion shows little temperature dependence between T1 and T2 and T2 and T3 ~ 272K, while it is found to be comparatively strongly temperature dependent above T1 and below T3, decreasing as T approaches T1 from the high temperature side and as T approaches T3 from the low temperature side. At room temperature the water-perchlorate symmetry seems to deviate slightly from the perfect P63mc symmetry proposed from previous X-ray measurements by West. Although the space symmetry group of the unit cell appears to remain unchanged at T1 and T2, the temperatures T1 and T2 are suspected to be related to structural phase transitions in this crystal.

The optical absorption and EPR spectra of Cr3+ in binary sodium borate glasses have been studied as functions of chromium concentration and Na2O/B2O3 ratio in the glass; the ligand field and EPR parameters have been calculated and were found to be independent of Cr3+ concentration in any particular glass. In low-alkali borate glasses (Na2O = ∼ 11 or ∼ 14 mol %) a single symmetrical EPR line was observed with g ¦=g⊥ =1.984±0.001 corresponding to perfect octahedral symmetry of the Cr3+ ion in these glasses. With increasing Na2O content of the glass, the EPR line becomes more asymmetric (characteristic two-peaked pattern); this has been explained as being due to axial elongation of the six co-ordinated Cr3+-complex in these glasses.

Electron paramagnetic resonance (EPR) of Mn2+ doped in CoSO4⋅7H2O single crystals has been studied from 300 to 77 K and at ∼9.3 GHz. Two different types of crystals of CoSO4⋅7H2O have been obtained, which grow in two different temperature ranges about 298 K. The two forms exhibit different types of spectra: one form [to be referred to as CoSH(I)] shows two 30 line Mn2+ spectra with D=459×10−4 cm−1, ‖E‖=134×10−4 cm−1 and the other form [to be referred to as CoSH(II)] shows only a single 30 line spectrum with D=234×10−4 cm−1, ‖E‖=19 ×10−4 cm−1. The observation of resolved Mn2+ spectra at 300 K and its broadening on lowering the temperature in CoSO4⋅7H2O:Mn2+ crystals has been discussed in terms of ’’host spin–lattice relaxation narrowing.’’ The observed shift in the Mn2+ gz value from that in diamagnetic hosts is probably due to the Co2+ ions, which produce a local static magnetic field at the site of Mn2+ ions. From the observed linewidth in the EPR spectrum of Mn2+ in single crystals of CoSO4⋅7H2O the T1 ...

From a detailed temperature variation study of the EPR spectra of Mn2plus doped in single crystals of Cd(CIO4)2 ·6H2O and Cd(CIO4)2· 6D2O a new phase transition is detected in addition to those reported previously by Dayal et al. The various phase transitions in Cd(CIO4)2O crystals can be summarized as The transitions occurring at T1, T2 and T4 are of first order while that one occurring at T3 is of higher order. The space groups in phases II, III, and IV seem to be the same viz. C. The phase transitions occurring at T1,T2, and T3 do not seem to be of the order -disorker type as far as the orientational order-disorder of water octahedra is concerned. The crystal Cd(CIO4)2 ·6D2O is concluded to be isostructural with Cd(CIO4)2 · 6H2O. Aus einer ausfuhrlichen untersuchung der Temperaturabhangigkeit der EPR-Spektren von Mn-dotierten Cd(CIO4)2 · 6H2O-und CdCIO4)2 · 6D2O-Einkristallen wird ein neuer Phasenubergang zusatzlich zu den bereits von Dayal et al. berchterten bestimmt. Die verschiedenen Phasenubergange im Cd(CIO4)2 · 6H2O Lassen sich folgendermasen aufreihen: Die ubergange, die bei T1, T2 undT4 auftreten, sind von erster Ordnung, wahrend der bei T3 von hoherer Ordnung ist. Die Raumgruppen der Phasen II, III und IV scheinen gleich zu sein, na;mlich C. Die bei T1, T2 und T3 auftretenden Phasenubergange cheinen nicht vom Ordnungs-Fehlordnungs-Typ zu sein, so weit es die Orinetierungs-Ordnung-Unordnung der Wasseroktaceder be trifft. Es wird angenommen, das der Cd(CIO4)2 · 6D2O-Kristall isostrukturell mit Cd(CIO4)2 · 6H2O ist.

Room-temperature (≈ 300 K) EPR studies of Cu 2+ -doped in NH 4 I single crystals are reported. The Cu 2+ ion is found to substitute for NH 4 + and get associated with a second or fourth neighbour cation vacancy. The spectra for the two distinct types of centres have been analysed and the parameters presented.

ERP of Mn2+ doped in ammonium iodide single crystals has been studied at room temperature (∼300 K) and at X band (∼9.3 GHz). An axial complex with the following spin‐Hamiltonian parameters has been observed: g∥=2.0014±0.0005, g∥=2.0028±0.0005, b02=−1611±2 G, b04=6±1 G, ‖A‖=‖B‖=90±1 G. Some unusual features observed in the spectra at X band due to the large value of b02 have been discussed.

The EPR of Mn 2+ in NH 4 Br single crystals has been studied at X-band in the temperature range from 573 K to 77 K. At room temperature, an isotropic spectrum (spectrum-I) comprising a sextet superimposed on a broad line is observed. On heating the crystal up to 400 K the sextet disappears due to explulsion of Mn 2+ impurity from the crystal. On lowering the temperature, the isotropic spectrum-I disappears about at 230 K and a new spectrum (spectrum-II) appears below this temperature. The spectrum-II is highly anistropic and unusual and is believed to be due to very large zero field splitting of Mn 2+ . Spectrum-I is attributed to Mn 2+ ions substituting for NH 4 + with charge compensating NH 4 + vacancies far away from Mn 2+ . The transformation of spectrum-I into spectrum-II is attributed to the structural transformation of NH 4 Br.

The aggregation of Mn2+-Na+ vacancy dipoles and precipitation of Mn2+ has been studied in Mn2+-doped single crystals of orthorhombic NaNO2 using EPR. The aggregation process seems to take place in two stages, being extremely slow in the second stage compared with the first stage. In crystals grown in aqueous solution a new intermediate phase seems to be precipitated during growth itself.

Of the various EPR spectra observed in the ferroelectric phase of NaNO2, a spectrum designated as spectrum II is observed to have some peculiar properties like dependence of its intensity on growth conditions of the crystal, its disappearance below ≈60°C after heat treatment of the crystal, its reappearance by heating above ≈60°C and also by application of an external dc electric field at ≈30°C. These observations suggest the possible existence, around Mn2+-vacancy complex in the ferroelectric phase of NaNO2, of a metastable structure intermediate to the paraelectric and ferroelectric phase structures.

Results of an EPR study of vanadyl ion (VO2+) doped in single crystals of α-calcium formate are reported. Impurity sites in the unit cell and the molecular structure of the vanadyl complexes in the crystal are discussed. The spin-Hamiltonian parameters are determined from single-crystal EPR data at room temperature and from powder EPR data at room temperature and at liquid nitrogen temperature. The g and A tensors are found to be axially symmetric. From the optical and EPR data, the MO bonding coefficients and crystal field parameters are calculated and discussed. Two distinct vanadyl complexes at substitutional sites (Ca2+) and one interstitial vanadyl complex have been identified.

An EPR study is performed on Mn2+ doped single crystals of lithium ammonium tartrate monohydrate (LAT), both in the paraelectric and ferroelectric phases. The Mn2+ EPR spectra in the paraelectric phase are attributed to Mn2+ substituting for NH+4 (1) and associated with a neighboring Li+ vacancy. The phase transition at Curie temperature (∼98 K) is found to be of the second order. From the fourfold increase in the number of magnetically distinguishable complexes on going from the paraelectric to the ferroelectric phase and subsequent data for the monodomain crystal, the existence of four kinds of domains is confirmed. The present EPR results on Mn2+ are combined with the previously reported EPR results on Cr3+, and the symmetry of the ferroelectric phase which was believed to be monoclinic (P21) until now is concluded to be triclinic. The triclinic symmetry explains the previously reported but unexplained anomalies in the dielectric constant eaa and elastic compliance SE44 at Tc. The triclinic ferroelectr...

Bovine spermatozoa were fractionated on Percoll density gradients into two major subpopulations of motile spermatozoa and a minor fraction containing mostly nonmotile spermatozoa with abnormal morphology. Fractionation required the addition of bovine serum albumin and a continuous Percoll gradient buffered with sodium bicarbonate. It is postulated that, under suitable ionic conditions, the binding of bovine serum albumin to spermatozoa amplifies subtle differences between subpopulations. These studies were directed toward separating Y- and X-bearing spermatozoa. However, when the subpopulations were evaluated by flow cytometry, their Y:X ratios were similar to that of an unfractionated control.

Leafroll-infected tubers of four potato varieties and three hybrids were treated with hot water at temperatures ranging from SO C to 55 C for 10 to 25 minutes. Considerable inactivation of the virus was obtained when the whole tubers were treated at 55 C for 17 minutes. Cut tubers, treated at 52 C for 25 minutes showed a good number of plants free from virus. Varieties showed differential response to heat treatment. Kufri Red gave a high percentage of germination in spite of heat treatment. All the varieties withstood the treatment well up to 53 C. Poor germination was associated with high temperature and long duration. Cut tubers were more susceptible to heat than whole tubers.

The electron paramagnetic resonance of Mn2+ ion doped in single crystals of sodium nitrite (NaNO2) has been studied at 9.5 kmc from room temperature (∼27°C) to 180°C. Only one magnetic complex of Mn2+ has been found. The complex gives different spectra in the ferro- and para-electric phases of the host crystal. The resonance lines of the allowed transitions at room temperature have been fitted to a spin-Hamiltonian of orthorhombic symmetry. The resonance lines show a strong angular dependence in their widths. The differences in line width and the presence of forbidden transitions along the principal axes are attributed to the spread in the crystal field due to the torsional oscillations of the NO-2 groups.

Electron paramagnetic resonance of Mn2+ has been studied in single crystals of magnesium sulfate heptahydrate (MgSO4 · 7 H2O) at 300°K. Mn2+ was found to substitute for Mg2+ and exhibit four inequivalent magnetic complexes corresponding to the tetramolecular unit cell of MgSO4 · 7 H2O. The results are compared with those for Mn2+ in isostructural NiSO4 · 7 H2O. The observed differences in the EPR of Mn2+ in crystals of the two salts are attributed to the magnetic interaction of Ni2+ and Mn2+.

Electron paramagnetic resonance of Mn2+ has been studied in nickel acetate tetrahydrate [Ni(CH3COO)2·4H2O] and nickel sulfate heptahydrate (NiSO4·7H2O) at 300°K. The Mn2+ was found to substitute for Ni2+ in both the systems and exhibit inequivalent magnetic complexes, two for the bimolecular Ni(CH3COO)2·4H2O and four for the tetramolecular NiSO4·7H2O. Besides, the Mn2+ resonance lines exhibited a direct dependence of linewidth on the intensity of Zeeman field and a shift in g value towards the lower side from the free‐spin g value. These features have been explained in terms of the interaction of the Mn2+ ion with Ni2+ host ions.

Nearly 100 isolates of Lactobacillus were obtained from human and animal sources. Screening tests with the isolates revealed seven possible bacteriocinogenic strains and 26 strains sensitive to one or more of these inhibitory strains. Three homofermentative strains were selected for additional study after it was shown that their inhibitory substances differed in activity spectrum and in susceptibility to inactivation by proteolytic enzymes. One of these, L. helveticus strain LP27, was shown to produce a potent bacteriocin called lactocin 27. The lactocin was isolated from the culture supernatant fluid as a protein-lipopolysaccharide complex. In the presence of sodium dodecyl sulfate the complex was dissociated, and the activity was found to reside in a small glycoprotein (molecular weight 12,400). The amino acid composition of purified lactocin 27 is similar to that of the L. fermenti bacteriocin; neither requires disulfide bonds for activity.

The paramagnetic resonance spectra of Gd3+‐doped NdCl3·6 H2O and PrCl3·7 H2O single crystals are studied at room temperature. A six‐line spectrum for H ‖ Z and a seven‐line spectrum for H ‖ X corresponding to ΔM=±1 transitions, are observed in the case of Gd3+‐doped NdCl3·6 H2O, whereas Gd3+‐doped PrCl3·7 H2O shows a seven‐line spectrum for H ‖ Z as well as for H ‖ X. The absence of the seventh line in the case of Gd3+‐doped NdCl3·6 H2O for H ‖ Z spectrum is explained as due to large zero‐field splitting between ±52 and ±72 levels. The angular variation of the observed spectra in ZX plane from θ=0° to θ=90° is studied and the spin‐Hamiltonian analysis is presented. A number of lines have been observed in the low‐field region in the case of Gd3+‐doped PrCl3·7 H2O and they have been analyzed as due to transitions with ΔM>1.

The contribution of the ferroelectric soft-mode to the zero-field splitting is calculated and separated from the thermal contribution arising from the splitting due to the electron-phonon interaction. The predicted effect is compared with the measured values in Mn 2+ -doped NaNO 2 .

X‐band EPR of Mn2+,Cu2+, and Co2+ ions doped in ammonium iodide single crystals have been studied at low temperatures. The Mn2+ and Cu2+ spectra show the presence of only one type of complex for each with features similar to those observed at room temperature with no unusual changes. The results on Co2+ ion, reported here for the first time, reveal the presence of three equivalent Co2+ complexes having tetragonal symmetry with their tetragonal axes orthogonal to each other. The charge‐compensation mechanism and possible vacancy complexes are discussed, and the spin‐Hamiltonian parameters reported.

The paramagnetic resonance of Gd3+ in Sm(NO3)3.6H2O single crystals, grown from solution, is studied at room temperature. A seven line spectrum for H//Z as well as for H//X corresponding to ΔM=±1 transitions are observed. The spin Hamiltonian analysis is presented.

Enriched subcellular fractions of nuclei, mitochondria, endoplasmic reticulum (ER), plasma membrane, and cytosol were prepared from liver and hepatoma 7288CTC taken from male inbred BUF rats. Purity was established by marker enzyme activities and distribution of DNA, RNA, sialic acids, total phospholipids, and cholesterol. The subcellular fractions of hepatoma differed from those of liver: 5'-Nucleotidase activity was elevated in ER and mitochondria, cytosol RNA was increased, and cholesterol was elevated in all hepatoma subcellular fractions. Neutral lipid classes of hepatoma subcellular fractions differed quantitatively from those of liver: Hepatoma nuclei and mitochondria contained elevated levels of free fatty acids (FFA) and triglycerides (TG). Generally, the fatty acid profiles of FFA, TG, and sterol esters from hepatoma subcellular fractions were more uniform and showed less organelle specificity than did liver. Hepatoma FFA and TG contained lower percentages of palmitate and higher percentages of stearate in all subcellular fractions than did liver. The sterol esters from most hepatoma subcellular fractions compared to those from liver were characterized by much higher levels of long-chain fatty acids of 20 carbon atoms or longer. The oleate-to-vaccenate ratio in FFA of liver subcellular fractions exhibited some specificity, but not that of hepatoma subcellular fractions. The oleate-to-vaccenate ratio in the acyl chains of liver and hepatoma TG did not reveal organelle specificity.

The results of the EPR study of VO2+ doped in NH4I and NH4Br single crystals in the temperature range 430–77 K are reported. The observed spectra suggest a liquid‐like behavior of these crystals for VO2+. A single eight line isotropic spectrum was observed in the temperature ranges ∼373 to ∼245 K in NH4I and ∼430 to ∼233 K in NH4Br. No spectrum was observed in the temperature ranges ∼245 to ∼173 K and ∼ 233 to ∼223 K in NH4I and NH4Br crystals, respectively. A spectrum with two sets of eight isotropic lines was observed from ∼173 K for NH4I and ∼223 K for NH4Br to 77 K. The observed mI dependence and temperature variation of linewidths are discussed. The anomalies in temperature dependence of linewidth confirmed the structural phase transitions in the host lattices.

Phospholipids from homogenate, nuclei, mitochondria, endoplasmic reticulum (ER), plasma membrane (PM), and cytosol of liver and hepatoma 7288CTC (from inbred male BUF rats) were analyzed for their concentrations, fatty acid compositions of individual lipid classes, and levels of octadecenoate positional isomers. The phospholipid concentrations of hepatoma mitochondria and ER were less than 60% of liver values. Sphingomyelin concentrations were elevated dramatically in hepatoma nuclei, mitochondria, and PM. Hepatoma nuclei and mitochondria contained only 25% or less the concentrations of phosphatidylethanolamine (PE) as those of liver, whereas ER, PM, and cytosol fractions of hepatoma contained equal or greater concentration of PE than did the corresponding liver fractions. The fatty acid profiles of the individual lipid classes were somewhat characteristic of liver organelles but not of hepatoma. Lipid classes thought to be located preferentially on the outer bilayer of liver PM contained lower percentages of polyunsaturated fatty acids than did hepatoma PM. For hepatoma generally the lipid classes tended to exhibit a more uniform fatty acid profile among organelles, the polyunsaturated fatty acid percentages were decreased, and the octadecenoate percentages were increased. Octadecenoates isolated from individual lipid classes of organelles contained high levels of cis-vaccenate, in addition to oleate, and some class and organelle specificity was observed in liver. In contrast, hepatoma octadecenoates exhibited little class or organelle specificity, and much higher oleate concentrations were found in PM phosphatidylcholine, PM PE, and ER PE in hepatomas than in liver.