Sterol Ester Fraction Research Articles

Biosynthesis of lipids by bovine meibomian glands.

Isolated bovine meibomian glands incorporated exogenous [1-14C]acetate into lipids. Thin layer chromatographic analysis of the lipids showed that wax esters and sterol esters contained 61% of the total label. Radio gas liquid chromatographic analysis of the acid and alcohol moieties of both ester fractions showed the label was distributed equally between the two portions of the ester in both cases. Cholesterol and 5-alpha-cholest-7-en-3 beta-ol were the major labeled sterols, and anteiso-C25, anteiso-C27 and anteiso-C23 were the most highly labeled alcohols. The major labeled fatty acids in the wax esters were anteiso-C15, n-C16, anteiso-C17 and n-C18:1, whereas anteiso-C25 and anteiso-C27 were the major labeled acids in the sterol esters. The diester region with 6% of the total label contained labeled fatty acids and fatty alcohols each with anteiso-C25 as the major component and omega-hydroxy acids in which n-C32:1 was the major labeled component. The triglyceride fraction which contained 8% of the total lipids was composed of labeled fatty acids similar to those found in both sterol and wax ester fractions. Chromatographic analyses of the labeled lipids derived from exogenous labeled isoleucine showed that anteiso-branched products were preferentially labeled. The labeled triglyceride fraction derived from [U-14C] isoleucine also contained esterified C15, C13, C11, C9, C7 and possibly shorter anteiso-branched acids.

A method for the separation of seed oil steryl esters and free sterols: Application to peanut and corn oils

AbstractA method for separating and quantitating seed oil steryl esters and free sterols was developed using a combination of preparative column, thin layer (TLC), and gas liquid chromatography (GLC). Cholesteryl heneicosanoate and cholesterol served as internal standards. The method was applied to corn‐oil samples (Mazola, Kroger) obtained from the local market and peanut‐oil samples prepared in the laboratory from commercial varieties of peanuts (Florunner, Starr). Concentration (mg/100 g oil; mean ± SD) of steryl esters and free sterols in the 4 oils were: Mazola, 1420±40 and 370±8; Kroger, 950±40 and 320±4; Florunner, 74±0.5 and 150±3; and Starr, 51±0.5 and 130±2. Sitosterol was the major sterol in both the free sterol and steryl ester fractions of all oils and together with campesterol, stigmasterol and Δ5‐avenasterol made up 90–95% of all sterols. Steryl esters of peanut oil contained higher proportions of linoleic acid and long‐chain acids (C20–C24) than did whole oil. Corn‐oil steryl esters also contained a higher proportion of linoleic acid than did whole oil. Squalene was the major hydrocarbon of all oils with the remaining hydrocarbon fraction consisting of a mixture of compounds.

Lipid composition and metabolism in oospores and oospheres of Achlya americana

Oospores and oospheres of Achlya americana Humphrey were isolated by sonication and filtration through nylon-mesh cloth of progressively diminishing porosity, and their lipid composition was investigated. The average dry weight of an oospore was 3.2 ng. Approximately 37% of the dry weight was composed of lipid. Triacylglycerols represented 88.7% of the total lipid, unesterified fatty acids made up 9.7%, and sterols, sterol esters, phospholipids, and mono- and diacylglycerols each constituted less than 1% of the total. Palmitic, oleic, and linoleic acids were the predominant fatty acids, along with smaller amounts of myristic, palmitoleic, stearic, arachidonic, and eicosapentaenoic acids. The fatty acid composition of the triacylglycerol fraction was similar to that of the total lipid, while that of the phospholipid fraction was higher in oleic acid. The unesterified fatty acid fraction was higher in saturated components than the total lipid, while the sterol ester fraction was higher in unsaturated fatty acids. In both the total lipid and the various lipid classes, unsaturated fatty acids increased during spore development. The sterol fraction consisted of 72% fucosterol, 22% cholesterol, and 7% 24-methylenecholesterol. In both oospheres and oospores, 1-[ 14C] acetate was assimilated most readily into phospholipids, triacylglycerols, and unesterified fatty acids, and was incorporated preferentially into palmitic, palmitoleic, and oleic acids. 1-[ 14C]-Arachidonic acid was incorporated by isolated oospheres into eicosapentaenoic acid, indicating that arachidonic acid is the immediate precursor of eicosapentaenoic acid.

The effect of AY-9944 on yeast sterol and sterol ester metabolism.

The effects of the hypocholesterolemic drug AY-9944 (trans-1,4-bis(2-chlorobenzylaminoethyl)cyclohexane dihydrochloride) at two concentrations (10(-4) M and 5 X 10(-4) M) on the synthesis of sterols and sterol esters by Saccharomyces cerevisiae were investigated. Although growth was not markedly affected by the drug, there was a decrease in the free sterol to sterol ester ratio with increased drug concentration. A concomitant increase in the saturated fatty acids esterified to sterol relative to the unsaturated fatty acids was also noted in response to increased drug concentration. Ergosterol accounted for 94.7% of the free sterol in the control culture and for 87.8% of the 5 X 10(-4) M drug-treated culture, respectively. However, in the sterol ester fraction, the ergosterol content decreased from a value of 45.1% in the control culture to 2.4% in the 5 X 10(-4) M AY-9944 treated culture. The sterol ester fraction simultaneously showed increased levels of the delta 8 sterol, fecosterol, in response to increased drug concentration from a 7.4% control value to 57.4% in the 5 X 10(-4) M drug-treated culture. The accumulation of the delta 8 sterol suggests that the site of action of the drug is probably at the delta 8 to delta 7 isomerase step in the biosynthesis of ergosterol. The fact that ergosterol is retained as the major free sterol suggests a biological advantage to the retention of this particular sterol. In addition, the near normal growth in the presence of the drug, in spite of the occurrence of an altered sterol ester profile, indicates that the composition of the sterol ester fraction is not as critical as the free sterol fraction.

The meibomian lipids of the rabbit. II. Detailed composition of the principal esters

The major sterol of rabbit meibomian secretion was shown to be 24, 25-dihydro- Δ 8-lanosterol both by gas-liquid chromatography on three different stationary phases and by mass spectrometry. Major ester components of the secretion were identified as wax esters or sterol esters by thin-layer chromatography on urea-silica gel, and separated by preparative gas-liquid chromatography. The principal wax esters contained anteiso-branched C 25–C 31 fatty alcohols and anteiso-branched C 15–C 19 fatty acids in combinations making esters in the range C 40–C 46. Only esters of dihydrolanosterol, containing anteiso-C 15–C 19 fatty acids, were detected in the sterol ester fraction.

A Comparison of Comedonal and Skin Surface Lipids from Hairless Dogs Showing Clinical Signs of Acne

Certain animals in a colony of hairless dogs (Mexican Hairless x Beagle) display the clinical features of acne vulgaris, including both open and "closed" comedones, milia, pustules, and abscesses. In order to compare the canine disease with human acne, lipids from the various types of noninflamed lesions and from the skin surface were analyzed by thin-layer (TLC) and gas-liquid (GLC) chromatography. TLC of total nonhydrolyzed lipid from comedones and milia gave similar patterns, with free sterol, ceramides, and free fatty acids comprising the bulk of the material and sterol esters and wax diesters as minor components. Skin surface samples contained mainly sterol esters and wax diesters, with smaller amounts of free sterol and only trace amounts of ceramides. GLC analysis of total hydrolyzed fatty acids from comedones showed similar patterns for the various lesions types, with 22 to 26 carbon acids comprising 55-65% of the total; these acids comprised only 19% of the total hydrolyzed skin surface samples. Analyses by argentation TLC and GLC/mass spectrometry showed the lesional lipids contained significant amounts of alpha-hydroxy-16:0, 16:1, 18:1 and 18:2, but only trace amounts of these appeared in the surface lipid. Fatty acid analysis of individual lipid classes show that the long chain, saturated fatty acids occur predominantly in the free fatty acid and polar lipid fractions and not in the wax diester of sterol ester fractions. Since wax diesters and sterol esters are products of sebaceous gland lipid synthesis, whereas free sterols, fatty acids, and ceramides are characteristic epidermal lipids, the data indicate that the lipids obtained from the acne lesions of dogs are primarily epidermal in origin and that sebaceous gland contribution is minimal in plugged follicles.

Changes in lipid composition during starvation and germ-tube formation in Candida albicans

The changes in the lipid components of Candida albicans have been determined during growth, starvation, and germ-tube formation. 14C-Labeled cells were used to determine the extent of synthesis and degradation of the different lipid fractions. On a dry weight basis the percentage of total lipid increased from 18% for blastospores to 22% after starvation but decreased to 11% after 4 h of germination. The major components of the lipid fraction were sterols (36–52%) and phospholipids (28–42%). The free and esterified sterol fractions both increased approximately 45% during starvation. The free sterol content continued to increase over the initial stage of germ-tube formation, then decreased with time. The sterol ester fraction decreased throughout germination to the concentration found in growing blastospores. The changes in specific activity (cpm/μg sterol) of these fractions indicated that sterol esters were precursors for free sterols during germination. The total phospholipid fraction increased during starvation but there was a decrease in both the cellular concentration (60%) and the specific activity during germination. There were only minor changes in the relative concentrations of phosphatidylinositol, phosphatidylserine, phosphatidylcholine, and phosphatidylethanolamine which indicated coordinate synthesis and degradation of these components. Free fatty acids and triacylglycerides are only minor components of the total lipid pool.

615 ACCELERATED DEGRADATION OF ESSENTIAL FATTY ACIDS (EFA) IN PREMATURE INFANTS ON PHOTOTHERAPY (PT)

We have previously demonstrated, in vitro (Ped. Res. 10:429, 1976) by measuring O2 consumption and the products of lipid peroxidation(thiobarbituric acid reactants or TBA and diene conjugates) that the oxidation of EFA (linoleic and (linolenic a.) is accelerated by exposure to light (460 nm), O2 and photosensitizing agents (bilirubin or methylene blue). This report describes the phenomenon to also occur, in vivo, in premature infants on PT. METHODS: Seven premature infants while on PT for treatment of jaundice were serially tested during the first 3 days of PT for the concentration of linoleic acid (C18:2) and triene/tetraene ratio in the phospholipid and sterol ester fractions of the serum by gas liquid chromatography. Serum TBA and diene conjugates were measured spectrophotometrically. RESULTS: During PT, there was a continuous fall in C18:2 concentration both in the phospholipid (−0.190±0.252 mg/dl/h) and sterol (−0.372±0.580 mg/dl/h) fractions of their serum and the decay was greatest during the first 24 h of PT (−0.259 mg/dl/h in phospholipid and −0.543 mg/dl/h for sterol). The rate of decay of C18:2 was doubled during PT, as compared to its spontaneous decay before PT (−0.088 mg/dl/h before, vs. −0.176 mg/dl/h during PT). There was also a simultaneous rise in triene/tetraene ratio during PT, from 0.014 to 0.086, but none achieved critical EFA deficiency ratio level of 0.4. During PT, there was a rise in the conc. of products of lipid peroxidation: TBA= +0.005 OD/mg C18:2 and diene conjugates= +0.075 OD/mg C18:2. None of the infants however showed clinical evidence of EFA despite chemical evidence of EFA decay. Furthermore, the decrease in conc. of C18:2 during PT was prevented or corrected by the feeding of the infant. CONCLUSION: This study shows that chemical evidence of accelerated degradation of EFA (specifically C18:2) occurs in premature infants on PT which is similar to what has been observed in vitro. Since the premature infant had been shown to be susceptible to the early development of EFA deficiency due to poor nutritional intake, the possibility that the EFA deficiency can be further accelerated if PT is used should be seriously considered.

Potential Organ- or Tumor-Imaging Agents XX: Ovarian Imaging with 19-Radioiodinated Cholesterol

Cholesterol is stored in the ovaries where it is a precursor in the biosynthesis of the female sex hormones progesterone and estradiol. The purpose of this study was to determine whether a radioiodinated analog of cholesterol, 125I-labeled 19-iodocholesterol, would mimic cholesterol in this capacity and thus offer a means for imaging the ovaries of intact animals. Aside from the thyroid, the adrenal glands and ovaries of the female rat retained the highest levels of radioactivity at 4days following the intravenous administration of 125I-labeled 19-iodocholesterol. Moreover, the levels of radioactivity were sufficient to obtain clear images of the adrenal glands and ovaries with a small animal scanner. Folch analysis of these tissues revealed that >80% of the radioactivity was associated with the sterol ester fraction.

Sterols in the Trophosomes of the Mermithid Nematodes Neomesomermis flumenalis and Romanomermis culicivorax Relative to Sterols in the Host Hemolymph

The sterols in the trophosomes of the mermithid nematodes Romanomermis culicivorax and Neomesomermis flumenalis were identified tentatively and compared with the sterols in the hemolymph of their larval insect hosts, Aedes aegypti and Simulium venustum, respectively. The C26 sterol 22-trans24-norcholesta-5, 22-dien-33,-ol was predominant in the free sterol and sterol ester fractions of both nematodes. 22-dehydrocholesterol was a major component of esterified and nonesterified sterols in the trophosomes of R. culicivorax and of free sterols in the trophosomes of N. flumenalis. Cholesterol was not a major trophosomal component in either of the nematodes. The host hemolymph contained cholesterol and 38-sitosterol as the principal free sterols in A. aegypti and as the only detectable free sterols in S. venustum. The evidence suggests that the mermithids have some capacity to interconvert sterols supplied by the hosts. Mermithid nematodes parasitize the hemocoel of insects during a portion of the larval development of the insects. Nutrients available in the host's hemolymph are transported across the cuticle of the nematode (Rutherford et al., 1977), then stored in a structure known as a trophosome for subsequent utilization by nonfeeding, free-living stages. Lipids, apparently in the form of a lipid-protein complex, constitute the predominant storage product of Agamermis decaudata (Chitwood and Jacobs, 1938) and Mermis nigrescens (Denner, 1968), mermithid parasites of grasshoppers. In Romanomermis culicivorax and Neomesomermis flumenalis, mermithid parasites of larval mosquitoes and blackflies, respectively, trophosomes contain substantial amounts of lipids (Ittycheriah et al., 1977; Gordon et al., 1979); in decreasing order of prevalence, these are in the form of triacylglycerols, phospholipids, sterol esters, and free sterols (Gordon et al., 1979). The fatty acid composition of the triacylglycerol and sterol ester fractions was investigated and related to metabolites available in the host hemolymph (Gordon et al., 1979), but no information was presented concerning the sterol components of the trophosomes and their derivation from the host hemolymph. Nematodes thus far investigated require sterols as essential dietary components (DutReceived for publication 31 July 1979. ky et al., 1967b; Hieb and Rothstein, 1968; Cole and Dutky, 1969; Lu et al., 1977). Thus, as part of our continuing investigation for nutritional information pertinent to the in vitro culture of R. culicivorax and N. flumenalis, we examined the sterol composition of their trophosomes and precursors available in the host hemolymph. Nematodes studied thus far are unable to biosynthesize sterols de novo (Rothstein, 1968; Cole and Krusberg, 1968; Barrett et al., 1970; Willett and Downey, 1974). Thus, it is probable that the mermithids rely upon sterols in the host hemolymph for dietary sterol requirements. Although the sterol composition of whole insects has been investigated extensively (Thompson et al., 1972; Svoboda et al., 1975), there is a dearth of information concerning hemolymph sterols-no studies have been done on the sterol c mposition of culicid or simuliid hemolymph. Accordingly, the hemolymph sterol composition of larval Simulium venustum, a host in Newfoundland for N. flumenalis, and of larval Aedes aegypti, laboratory host for R. culicivorax, was examined to provide basic information on the availability of sterols to the

Isolation of 4α-methyl-5α-Ergosta-8, 24 (28)-dien-3β-ol from ester fractions of nutritionally deprived [formula omitted

A method of isolating pure fractions of 4α-methyl-5α-ergosta-8, 24 (28)-dien-3β-ol for sterol intermediate studies is described. Starvation cultures of Neurospora crassa readily incorporate exogenous mevalonic acid into the sterol ester fraction. Isolation involves a simple solvent extraction and two chromatograms. Only the ester fraction yielded the required purity. Radioactive 4α-methyl-5α-ergosta-8, 24 (28)-dien-3β-ol is readily produced from DL-[2- 14C] mevalonic acid.

Further Studies on Lipid Metabolism in the Insect Parasite, Exeristes roborator (Fabricius)

The fatty acid pattern of the parasite Exeristes roborator reared on chemically defined fatty acid free diets was composed almost entirely of palmitate, 25%; palmitoleate, 15%; stearate, 10%; and oleate, 50%. Dietary 2-'4C-acetate was readily incorporated into these fatty acids and their relative spe- cific acivities determined. Triglyceride supplements resulted in increased levels in the parasite of the corresponding fatty acids, but these increases were accompanied by decreased specific activities sug- gesting deposition of dietary fat rather than increased de novo metabolic activity. In contrast, altered dietary lipid composition in host reared parasites resulted in much more striking changes in the fatty acid composition and the specific activities of the individual fatty acids remained the same demonstrat- ing altered de novo metabolic activity. Marked alterations in the basal fatty acid composition were brought about by dietary phenylmethyl sulphonyl fluoride, demonstrated to be an inhibitor of fatty acid synthesis. This action was accom- panied by decreased survival and increased development time. Parasites readily incorporated radioactivity from radioactive precursors into their various lipids. Parasites reared on artificial diets supplemented with 2-14C-acetate incorporated the largest proportion of radioactivity into the phospholipid and hydrocarbon, sterol ester and wax fractions, whereas host reared parasites incorporated the largest proportion into the phospholipid and triglyceride fractions. The results suggest that triglyceride synthesis and deposition is minimal in parasites reared under the artificial nutritional regime tested as these parasites contained half the lipid of those reared on host insects. Phenylmethyl sulphonyl fluoride had no effect on the relative distribution of radioactivity in the vari- ous lipid classes. Exogenous lipid supplied as long chain acyl-CoA derivatives inhibited isolated fatty acid synthetase activity similarly in E. roborator and its host Galleria mellonella. Their action as effectors on this portion of the de novo synthesis system, therefore, fails to explain the increased metabolic activity observed in host reared parasites following alteration in dietary lipid composition.

Lipid composition and polyene antibiotic resistance of Candida albicans mutants

Four polyene-resistant mutants (C7, E4, C4, D10) of Candida albicans were derived by mutagenesis with N-methyl-N′-nitro-N-nitrosoguanidine followed by isolation on nystatin-containing medium. The mutants were cross resistant to amphotericin B, lucensomycin, and candicidin and showed the same order of increasing resistance to the four polyenes tested, i.e., C7 < E4 < C4 < D10. Free sterols, sterol esters, and phospholipid fatty acids were analyzed in the mutants and sensitive parent strain. The lipids of C7 were the same as those of the sensitive parent strain. Mutant E4 contained lichesterol and other Δ8-sterols indicating a block at the Δ8→ Δ7 isomerase, and most of the sterol ester fraction consisted of 4,14-desmethyl sterols. The most resistant mutants C4 and D10 had reduced growth rates, alterations in phospholipid fatty acids, and the absence of 4,14-desmethyl sterols. Mutants C4 and D10 had similar lipid compositions with 24-methylenelanosterol as the major sterol and lesser amounts of obtusifoliol and lanosterol. The proportion of the total sterol that was esterified was low and similar (19–34%) in cultures of the mutants and of the sensitive strain harvested in the same stage of stationary growth. Total sterol content, however, increased with resistance. Polyene resistance was better correlated with the type of sterols in the total sterol pools rather than with the degree of esterification of the individual sterols, i.e., resistance increased with the presence of Δ8- and 4,14-methyl sterols. Our data indicate that factors other than or in addition to alterations in sterol and phospholipid patterns account for polyene resistance.

Neutral lipids of Aedes aegypti and Aedes albopictus cells cultured in vitro

Neutral lipids were examined from spinner culture cells of two species of mosquitoes, Aedes aegypti and A. albopictus, in exponential and stationary phases of growth. The lipids were separated into constituent classes by thin-layer chromatography. The fatty acid profiles of the methyl esters of each class were determined by gas-liquid chromatography. There were changes in the fatty acid profiles and increases in the amount of polyenes in the 1,2- and 1,3-diglycerides, free fatty acids, and triglyceride fractions with aging of the mosquito cells. The sterol ester fraction was similar at the exponential phase of growth in both Aedes cells. Changes occurred in the fatty acid profiles, and there was a decrease in polyenes from the exponential to the stationary phase of growth.

Neutral lipid composition of Culex quinquefasciatus and Culex tritaeniorhynchus cells at two phases of growth.

The mosquito cells Culex quinquefasciatus and Culex tritaeniorhynchus were grown in spinner cultures. The fatty acid profiles of the neutral lipid classes were analyzed, and comparisons were made between the two species at logarithmic and stationary phases of growth and between the species and the medium. The results from the data suggest an increase in the average chain length of the fatty acids in the free fatty acid and sterol ester fractions of the Culex quinquefasciatus cells with aging. From the logarighmic to stationary phase, both Culex cells showed some increase in desaturation of acids in the di- and triglyceride and free fatty acid fractions. The Culex tritaeniorhynchus cells also showed some increase in desaturation of acids in the monoglyceride fraction. Differences between the two Culex species at the logarithmic phase of growth were observed in the fatty acid profiles of all the neutral lipid fractions examined and at the stationary phase of growth in the free fatty acid, triglyceride, and sterol ester fractions.

Fatty acids of diapause and nondiapause pink bollworm larvae, Pectinophora gossypiella (Saunders)

1. 1. A comparative examination of lipids in field-reared diapause, laboratory-reared diapause, and laboratory-reared nondiapause pink bollworm larvae showed that in the free fatty acid, triglyceride, and sterol ester fractions each group had its own characteristic distribution of fatty acids. 2. 2. Fatty acids occurring in the largest amounts in all lipid fractions were palmitic, oleic, and linoleic acids. Phospholipids also contained high amounts of stearic acid. 3. 3. Major differences in fatty acids of larval diets were in oleic acid-lima bean diet 8.0%, cottonseeds 15%; linoleic acid-lima bean diet 40.0%, cottonseeds 50%; and linolenic acid-lima bean diet 13.1%, cottonseeds 1.0%. 4. 4. Fatty acid distributions in larvae did not appear to reflect those of the diet.

Unique pathways of sterol metabolism in the Mexican bean beetle, a plant-feeding insect.

Radiolabeled sterols, 14C-cholesterol, 14C-cholestanol, 3H-stigmasterol, 3H-stigmastanol, and 3H-sitosterol, were fed to larvae of the Mexican bean beetle, Epilachna varivestis Mulsant, bu coating soybean leaves. Free sterol and sterol ester fractions from treated insects were isolated and analyzed, and in each case nearly 30% or more of total radiolabeled sterols retained by the insect were found in the sterol ester fraction after 8 days. delta5-Dietary sterols were readily reduced to stanols, and C29-stanols thus produced were dealkylated to cholestanol. Significant amounts of labeled lathosterol were formed from delta5-C29 sterols; little, if any, radiolabeled cholesterol was detected in insects fed either of the labeled delta5-phytosterols, stigmasterol or sitosterol. Sterol metabolism of this insect thus differs considerably from that found for most phytophagous insects.

Uptake and metabolism of cholesterol and cholesteryl oleate by Phytophthora cactorum

1. 1. Both cholesterol and cholesteryl oleate were absorbed when added to partially grown cultures of Phytophthora cactorum, a fungus heterotrophic for sterols. 2. 2. Cholesterol was absorbed much more rapidly than the oleate ester. 3. 3. Most of the cholesterol absorbed into the mycelium was readily extracted with acetone; a small proportion (approx. 10%) was not, but was released by hydrolysis. 4. 4. Acetone extracts of mycelium grown with added cholesterol contained free cholesterol, cholesteryl esters, and two unidentified metabolites more polar than cholesterol. The fatty acids occurring in the sterol ester fraction were present in the same relative proportions as m the triglycerides. 5. 5. The sterol content per unit weight of mycelium reached a constant value after 24 h when supplied as cholesterol, and the same constant value after 48 h when supplied as the oleate ester. This value was dependent upon the amount of sterol supplied in the medium. 6. 6. When cholesterol was supplied in the medium, the amount of ester per unit weight of mycelium in the acetone extract reached a peak at 12–36 h and then declined. With cholesteryl oleate supplied, the ester in the acetone extract was low at first and gradually rose to that finally attained when free cholesterol was supplied. 7. 7. The proportion of cholesterol esterified in fully grown cultures increased with the amount supplied in the medium.

Fatty acid composition of the sterol ester fraction of human adrenal cortex in Cushingś syndrome and after treatment with aminoglutethimide.

AbstractThe lipid that accumulated in the adrenal cortex of a patient who had been treated with aminoglutethimide has been compared with the lipid in normal human adrenal cortex and identified as esters of cholesterol with fatty acids. While the concentration of free cholesterol was normal, that of esterified cholesterol was three times greater than that in normal controls. Sterols were analyzed by gas chromatography and found to consist almost wholly of cholesterol. The fatty acid composition of the cholesterol esters in adrenal cortex from patients with abnormal steroid secretion rates was determined. An increased proportion of cholesteryl arachidonate (cholesteryl‐3β‐[allcis]‐eicosa‐5,8,11,14‐tetraenoate) was found in adrenal cortex from patients with decreased steroid secretion rates and a decreased proportion in adrenal cortex from patients with steroid secretion rates raised sufficiently to cause Cushing's Syndrome.

Triterpenoid and steroid constituents of florida spanish moss

Both free and esterified sterols and triterpenes of Spanish Moss ( Tillandsia usneoides L.; Bromeliaceae0 from Florida were examined. Besides the eight sterols and triterpenes previously reported by others as present in Spanish Moss from Mexico, cycloeucalenol, 24-methylenecycloartanol and two unidentified triterpenes of the cycloartane group were detected by GLC and GLC-Mass Spectroscopy. Campesterol and stigmasterol were detected by these techniques and cholesterol was detected by GLC. Attempts to determine the specific nature of the esters of both triterpenes and desmethyl sterols were thwarted by the extreme complexity of the ester mixture. However, saturated fatty acids from C 12 to C 30 were detected in the sterol and triterpene ester fraction by GLC, with palmitic acid (25%) stearic acids (20%) predominating as the fatty acid moieties.