Deuterium (2H) nuclear magnetic resonance (NMR) quadrupole splittings and relaxation times have been measured for a variety of specifically deuterated lipids intercalated in lamellar-multibilayer dispersions and single-bilayer vesicles of egg lecithin and lecithin-cholesterol mixtures. The deduced order parameters and relaxation times vary with position of deuteration, acyl chain length, unsaturation, and temperature. The order parameters and spinlattice relaxation times T1 indicate rapid intramolecular motions of restricted amplitude in both the choline head group and hydrocarbon chains. The ordering profile for the acyl chains is similar to that predicted by statistical-mechanical theory. The order parameters yield estimates of the bilayer thickness and linear coefficient of expansion in close agreement with the x-ray determinations. A comparison of the deuterium and electron spin resonance spinprobe order parameters demonstrates the perturbation of the bilayer by the bulky nitroxide probe. The transverse relaxation time T2 for single-bilayer vesicles is quantitatively accounted for by a simple modification of classical relaxation theory which takes into account the modulation of the static quadrupole interaction by rapid local molecular motions and the modulation of the residual quadrupole interaction by the slower overall tumbling of the vesicle. It is unambiguously demonstrated that molecular motion and order in single-bilayer vesicles are very similar to those in lamellar multibilayers. Significant differences occur only for a few segments near the terminal methyl groups of the acyl chains, where the order parameters for vesicles are 10-30% smaller than those found for lamellae. The incorporation of cholesterol in lecithin bilayers is shown to increase the degree of orientational order in vesicles and lamellae, and to increase the hydrodynamic radius of vesicles. Thus, single-bilayer vesicles and multilamellar dispersions of phospholipids are equally useful models for biological membranes. They yield equivalent information about the internal organization and mobility of lipid bilayers, when the spectral manifestations of overall vesicle motion are correctly taken into account.

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The oil forlned during fernlentation by a strain of Torldopsis nrag~roliae consisted 1nai111y of partly acetylated 2-0-0-D-glucopyranosyl-D-glucopyrano units attached 0-glycosidically to 17-L-hydroxyoctadec;unoic ancl 17-L-hydroxy-9-octadecenoic acids.A strain of osmophilic yeast, Torulopsis magnoliae, isolated fro111 SOW thistle petals, was found to produce (1) an extracellular, heavier than water oil. The main components of the oil are now shown to be glycolipids (I and 11) consisting of 2-0-/3-D-glucopyranosyl-D-glucopyranose units linked /3-glycosidically to 17-L-hydroxyoctadecanoic and 17-Lhydroxy-9-octadecenoic acids, the sugar moieties being partly acetylated.The oil was labile both to acid and alkali. I-Iot methanolic sodium methoxide removed the acetyl groups, which constituted about 1.5 substituent groups per mole (the positions of these substituents were not determined). The deacetylated product, after fractionation, yielded a solid (I and II),which contained allnost equal quantities of lactonic and acidic glycolipids, and it was on this mixture that the characterization studies of the sugar portion were carried out.Acid methanolysis of the deacetylated oil yielded 2 moles of methyl-a-D-glucopyranoside and 1 mole of a mixture of fatty acid methyl esters. Gas -liquid phase chromatography of the esters on a silicone column showed one principal peak a t the C20 saturated position with a shoulder suggesting partial resolution of saturated and unsaturated esters (2). However, on a butanediol succinate colulnn (3) no peaks appeared after 2 hours (normal emergence time for a C20 ester was 30 minutes). The properties suggested that the major con~pounds present were C18 esters containing a polar substituent, such as a llydroxyl group (4) and the presence of the latter group was confirmed by infrared spectroscopy. From the quantity of permanganate-periodate reagent (5) consumed, the mixture was shown to contain 65% of nlonoolefinic ester. Fractional crystallization of the methyl esters also yielded 65% unsaturated and 35% saturated ester. However, later fermentations contained only about 10yo of the saturated material. Catalytic hydrogenation showed that the unsaturated c 1 8 ester (IV) contained one double bond and the product obtained was identical with the saturated Cl8 con~ponent (111). The position of the hydroxyl group in these compounds was shown to be a t C17, by the formation of 17-0x0-stearic acid (V) when the saturated acid was oxidized with chromium trioxide. An authentic specimen of V was synthesized by the method of Bergstrom et al. (6) from 15-bromopentadecanoic acid. The latter was prepared from 15-hydroxypentadecanoic acid which was in turn obtained from the 15,lB-dihydroxypalinitic acid described by Leinieux (7).The unsaturated component (IV) was shown to be 17-hydroxy-9-octadecenoic acid methyl ester since the acid on oxidation with permanganate-periodate (5) yielded azelaic 1Manz4script received Decevlber SO, 1960.

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This review deals, with waxes of members of two quite different groups of insects, the bees and the scale insects, which secrete large amounts of wax. The former use was as a structural material and the latter as a protective material. The compositions of waxes from some of these insects are described and particular attention is paid to the compositions of the unhydrolyzed waxes and to the presence of hydroxy acids. New analyses of beeswax and of wax of a species of bumble bee are reported. The structures of the diesters, hydroxyesters and diols of beeswax are elucidated. The bumble bee wax contains major proportions of saturated and unsaturated hydrocarbons, and of long chain saturated, mono‐ and diunsaturated esters. The relationship between structure and function of the waxes is discussed.