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1.
In this study, the contents of total and individual phytosterols in sprouts made from seeds of seven canola (Brassica napus L.) lines (Acropolis, Banjo, Jetton, KS-7740, KSM3-1-124, Mussette and Virginia), grown at three locations in Virginia (Orange, Petersburg and Suffolk), were determined. Canola sprouts contained, on an average, 36.3 g sterols in 100 g of unsaponifiable matter (UNSAP), 10.7 mg sterols in 1 g of oil and 2.4 mg sterols in 1 g of dry sprouts. The contents of individual phytosterols (μg per g of oil) in canola sprouts were 1,162 brassicasterol, 3,799 campesterol, 34 stigmasterol, 5,359 β-sitosterol, 201 Δ5-avenasterol and 97 Δ7-stigmastenol. Canola lines had significant effects on the contents of oil, brassicasterol and campesterol. Locations had significant effects on the oil, UNSAP, total sterols, brassicasterol, stigmasterol and β-sitosterol. The oil content in canola sprouts was positively correlated with total sterols and Δ5-avenasterol, whereas oil content was negatively correlated with brassicasterol content. In general, the contents of campesterol and β-sitosterol increased with an increase in total sterol content. The concentrations of sterols were in the following decreasing order: β-sitosterol > campesterol > brassicasterol > Δ5-avenasterol > Δ7-stigmastenol > stigmasterol. These results indicate that canola sprouts may have the potential as a natural source of dietary sterols and might be desirable for human nutrition.  相似文献   

2.
The phytosterol, tocopherol, and tocotrienol profiles for mkukubuyo, Sterculia africana, manketti, Ricinodendron rautanenni, mokolwane, Hyphaene petersiana, morama, Tylosema esculentum, and moretologa-kgomo, Ximenia caffra, seed oils from Botswana have been determined. Normal-phase HPLC analysis of the unsaponifiable matter showed that among the selected oils, the most abundant tocopherol and tocotrienol were γ-tocopherol (2232.99 μg/g) and γ-tocotrienol (246.19 μg/g), detected in manketti and mkukubuyo, respectively. Mokolwane oil, however, contained the largest total tocotrienol (258.47 μg/g). Total tocol contents found in manketti, mokolwane, mkukubuyo, morama, and moretologa-kgomo oils were 2238.60, 262.40, 246.20, 199.10, and 128.0 μg/g, respectively. GC–MS determination of the relative percentage composition of phytosterols showed 4-desmethylsterols as the most abundant phytosterols in the oils, by occurring up to 90% in moretologa-kgomo, mkukubuyo, and manketti seed oils, with β-sitosterol being the most abundant. Mokolwane seed oil contained the largest percentage composition of 4,4-dimethylsterols (45.93%). Besides 4-desmethylsterols (75%), morama oil also contained significant amounts of 4,4-dimethylsterols and 4-monomethylsterols (15.72% total). GC–MS determination of the absolute amounts of 4-desmethylsterols, after SPE fractionation of the unsaponifiable matter, confirmed that β-sitosterol was the most abundant phytosterol in the test seed oils, with manketti seed oil being the richest source (1326.74 μg/g). The analysis showed total 4-desmethylsterols content as 1617.41, 1291.88, 861.47, 149.15, and 109.11 μg/g for manketti, mokolwane, mkukubuyo, morama, and moretologa-kgomo seed oils, respectively.  相似文献   

3.
Genotype and growing location effects on phytosterols in canola oil   总被引:1,自引:3,他引:1  
There is little information available about phytosterols in canola (Brassica napa L.) oil and the effects of genotype and growing locations from Virginia and the mid-Atlantic region of the United States, a potential area for the establishment of domestic production to provide edible oil. Our objectives were to characterize the phytosterols, phospholipids, unsaponifiable matter, and FA in oil from Virginia-grown canola. Among 11 canola genotypes grown at two locations during 1995–1996 significant variations existed for oil content and FA profiles, but not for contents of phospholipids, unsaponifiable matter, total phytosterols, campesterol, stigmasterol, and β-sitosterol, Total phytosterol content in the oil of Virginia-grown canola varied from 0.7 to 0.9% with a mean of 0.8%. This concentration compared favorably with oil from Canadian canola, which typically contains 0.5 to 1.1% total phytosterols. The mean contents of brassicasterol, campesterol, stigmasterol, β-sitosterol, Δ5-avenasterol, and Δ7-stigmatenol as percentages of total phytosterols in Virginia-grown canola were: 9.7, 32.0, 0.6, 49.3, 4.99, and 3.5%, respectively. Growing location did not affect phytosterols in Virginia-grown canola oil but had significant effects on contents of phospholipids, and saturated (myristic, stearic, and arachidic) and unsaturated (palmitoleic, linoleic, linolenic, eicosenoic, and erucic) FA.  相似文献   

4.
Intravenous lipid constituents have different effects on various biological processes. Some of these effects are protective, while others are potentially adverse. Phytosterols, in particular, seem to be implicated with parenteral nutrition-associated cholestasis. The aim of this study is to determine the amount of plant and animal sterols present in lipid formulations derived from different oil sources. To this end, animal (cholesterol) and plant (β-sitosterol, campesterol, and stigmasterol) sterols in seven different commercially available intravenous lipid emulsions (ILEs) were quantified by capillary gas chromatography after performing a lipid extraction procedure. The two major constituents of the lipid emulsions were cholesterol (range 14–57% of total lipids) and β-sitosterol (range 24–55%), followed by campesterol (range 8–18%) and stigmasterol (range 5–16%). The fish oil-derived formulation was an exception, as it contained only cholesterol. The mean values of the different sterols were statistically different across ILEs (P = 0.0000). A large percentage of pairwise comparisons were also statistically significant (P = 0.000), most notably for cholesterol and stigmasterol (14 out of 21 for both), followed by campesterol (12 out 21) and β-sitosterol (11 out 21). In conclusion, most ILEs combined significant amounts of phytosterols and cholesterol. However, their phytosterols:cholesterol ratios were reversed compared to the normal human diet.  相似文献   

5.
This study was conducted to determine effects of genotypes and growing environment on phytosterols, triterpene alcohols, and phospholipids (PL) in lupin (Lupinus albus L.) oil from seven genotypes grown in Maine and Virginia. The unsaponifiable lipid (UNSAP) and phospholipid (PL) fractions ranged from 2.1 to 2.8% and from 2.6 to 2.8% of oil, respectively. UNSAP in lupin oil contained 19.9 to 28.7% sterols and 17.3 to 22.0% triterpene alcohols. Growing location significantly affected contents of total PL, PS, phosphatidylglycerol, β-sitosterol, campesterol, and β-amyrin. Genotypic effects were significant for stigmasterol. PC (32.6 to 46.3% of PL), PE (21.6 to 32% of PL), and PS (11.2 to 17.9% of PL) were the major PL in lupin oil. The concentration of PL classes in lupin oil were in the following descending order: PC>PE>PS>PI>phosphatidic acid > lysophosphatidylcholine > phosphatidylglycerol > diphosphatidylglycerol. In descending order of abundance, the sterols present in lupin oil were: β-sitosterol > campesterol > stigmasterol > Δ5-avenasterol > Δ7-stigmastenol Lupeol was the most prominent triterpene alcohol in lupin seed oil. In general, growing environment had a much greater influence on lupin oil characteristics than the genotypes.  相似文献   

6.
The unsaponifiable lipid constituents, hydrocarbons, triterpene alcohols and sterols of ten seed oils (Catharanthus roseus, Nymphaea nelumbo, Casuari-na equisetifolia, Lagerstroemia therolli, Prosopisjuliflora, Mimusops elengi, Mimusops hexandra, Ponga-miapinnata, Acrocarpus fraxinifolius, and Bauhinia retusa) were investigated by gas liquid chromatography. Total unsaponifiables ran from 4–14%. Some of the seed oils contained large quantities of jβ-amyrin, α-amyrin and cycloartenol. Acrocarpus fraxinifolius was found to contain 84% of lupeol. Stigmasterol (24-ethyl-22ε-dehydrocholesterol), β-sitosterol (24-ethyl-cholesterol) and campesterol (24-methyl-cholesterol) were the common constituents in all the seed oils. Besides these constituents, tirucallol, taraxerol, ψ-taraxasterol, fucosterol, isofucosterol, avenasterol and cholesterol also were detected in small quantities.  相似文献   

7.
Characterization and supercritical carbon dioxide extraction of walnut oil   总被引:9,自引:0,他引:9  
Walnut (Juglans regia L.) oil was extracted with compressed carbon dioxide (CO2) in the temperature range of 308 to 321 K and in the pressure range of 18 to 23.4 MPa. The influence of particle size was also studied at a superficial velocity of 0.068 cm/s, within a tubular extractor of 0.2 L capacity (cross-sectional area of 16.4 cm2). FFA, sterol, TAG, and tocopherol compositions were not different from those of oil obtained with n-hexane. The main FA was linoleic acid (56.5%), followed by oleic acid (21.2%) and linolenic acid (13.2%). The main TAG was LLL (linoleic, linoleic, linoleic) (24.4%), followed by OLL (oleic, linoleic, linoleic) (19.6%) and LLLn (linoleic, linoleic, linolenic) (18.4%). The main component of sterols was β-sitosterol (85.16%), followed by campesterol (5.06%). The amount of cholesterol was low (0.31 and 0.16% for oils extracted by n-hexane and supercritical fluid extraction, respectively. The CO2-extracted oil presented a larger amount of tocopherols (405.7 μg/g oil) when compared with 303.2 μg/g oil obtained with n-hexane. Oxidative stability determined by PV and the Rancimat method revealed that walnut oil was readily oxidized. Oil extracted by supercritical CO2 was clearer than that extracted by n-hexane, showing some refining. A central composite, nonfactorial design was used to optimize the extraction conditions using the software Statistica, Version 5. The best results were found at 22 MPa, 308 K, and particle diameter (Dp) −0.1 mm.  相似文献   

8.
Plant sterols were found by gas liquid chromatography in the sterols of five species of aquatic vertebrates; mackerel (Scomber japonicus), rainbow trout (Salmo gairdnerii), smelt (Osmerus dentex), sardine (Sardinops melanosticta) and chimera (Chimera phantasma). The sterols of chimera liver, sardine flesh and sardine viscera contained 9.0, 2.4 and 3.1% of C28 and C29 sterols in addition to 86.7, 96.6 and 95.2% of cholesterol. The occurrence of norcholestandienol, campesterol, β-sitosterol and C28 stanol was shown by combined gas chromatography-mass spectrometry. Sperm whale (Physeter catodon) sterols consisted of more than 99% cholesterol with only traces of 22-dehydrocholesterol.  相似文献   

9.
Niger seed samples were collected from different regions in Ethiopia for determination of oil content, and of fatty acid, tocopherol and sterol composition in the seed oil by gas-liquid chromatography and high-performance liquid chromatography methods. There was a large variation in oil content, ranging from 29 to 39%. More than 70% of the fatty acids was linoleic acid (18∶2) in all samples analyzed. The other predominant fatty acids were palmitic (16∶0), stearic (18∶0) and oleic (19∶1) at a range of 6 to 11% each. Total polar lipids recovered after preparative thin-layer chromatography comprised a small fraction of the total lipids. They had higher 16∶0 and lower 18∶2 contents than the triacylglycerols.α-Tocopherol was the predominant tocopherol in all samples, 94–96% of the total amounting to 630–800 μg/g oil. More than 40% of the total sterols wasβ-sitosterol,ca. 2000μg/g oil. The other major sterols were campesterol and stigmasterol, ranging from 11 to 14%. The Δ5- and Δ7-avenasterols were in the range of 4 to 7%. From the samples studied, no conclusion could be drawn regarding the influence of altitude or location on oil content, tocopherol and/or sterol contents. The results of the present study on niger seed oil are discussed in comparison with known data for common oils from Compositae,viz, safflower and sunflower.  相似文献   

10.
The deodoriser distillate (DOD) of Indian soybean oil obtained from two industries processing soybean oil was investigated for its physicochemical characteristics, its composition of tocopherols, phytosterols, fatty acids and recovery of phytosterols for use in nutraceutical products. It was found that the two DOD samples studied were dark in color and had higher amounts of free fatty acids (22.7 and 49.9%), unsaponifiable matter (11.8 and 21.9%) (5–10 times found in soybean oil), total tocopherols (1957–2256 mg/100 g) (20 times the amount in soybean oil), and 6–10% of phytosterols (12–20 times the soybean oil). The fatty acids found were palmitic (23.2–25.5%), stearic (1.4–2.4%), oleic (23.8–26.1%), linoleic (40.4–41.1%) and linolenic (2.7–3.2%) acids. The unsaponifiable matter (21.9%) and phytosterols (8.7%) content of DOD-2 were higher than in DOD-1 and hence was more suited for isolation of phytosterols. Using hexane and water for crystallisation, the DOD-2 yielded a phytosterol fraction with lower recovery of 13.2–17.8% while treatment with alkali to remove FFA and the glycerides followed by organic solvent extraction yielded unsaponifiable matter containing phytosterols with a recovery of 74.6%. Later the unsaponifiable matter was purified by double crystallisation into a mixture of phytosterols of 87% purity containing β-sitosterol (34.3%), stigmasterol (3.1%) and campesterol (50.1%). The product may find use in foods, pharmaceuticals, cosmetics and allied industries probably as a nutraceutical.  相似文献   

11.
Igel M  Lindenthal B  Giesa U  von BK 《Lipids》2002,37(2):153-157
In the present study, the effect of leptin on intestinal cholesterol absorption was investigated in C57 BL/6 OlaHsd Lepob/Lepob obese (ob/ob) mice and lean C57 BL/6 (wild-type) mice. Animals were treated either with or without recombinant leptin for 2 wk. Cholesterol absorption was measured by the constant isotope feeding method and indirectly by the ratio of campesterol to cholesterol in serum. In ob/ob mice, cholesterol absorption was significantly higher compared to wild-type mice [83.4±2.3% (SD) vs. 77.6±1.5%, P<0.01]. Treatment with leptin significantly reduced cholesterol absorption in both ob/ob and wild-type mice by 8.5 (P<0.001) and 5.2% (P<0.05), respectively. Serum concentrations of campesterol and the ratio of campesterol to cholesterol in ob/ob mice were significantly higher compared to wild-type mice (2.2±0.3 mg/dL vs. 1.2±0.3 mg/dL, P<0.001; and 36.8±2.8 μg/mg vs. 28.0±3.3 μg/mg, P<0.001). After treatment of ob/ob mice with leptin, concentrations of campesterol and its ratio to cholesterol were significantly lower (2.2±0.3 mg/dL vs. 1.0±0.2 μg/mg, P<0.001; and 36.8±2.8 μg/mg vs. 13.2±2.2 μg/mg, P<0.001, respectively). In wild-type mice, the ratio of campesterol to cholesterol in serum was also significantly lower after treatment with leptin (28.0±3.3 μg/mg vs. 22.6±5.0 μg/mg, P<0.05). A significant positive correlation (r=0.701, P<0.01) between cholesterol absorption and the ratio of campesterol to cholesterol, in serum was found. It is concluded that leptin contributes to intestinal cholesterol absorption in ob/ob mice and lean wild-type mice.  相似文献   

12.
Panagrellus redivivus was propagated in media containing three structurally different sterols: 7-dehydrocholesterol, campesterol or stigmastanol. Nematodes propagated with 7-dehydrocholesterol contained mostly lathosterol and 7-dehydrocholesterol. Nematodes propagated with campesterol contained mostly cholesterol and cholestanol. Nematodes propagated with stigmastanol contained mostly cholestanol. The sterol ester fraction was enriched with 4α-methylsterols and contained the same sterols as the free sterol fraction except for nematodes propagated with 7-dehydrocholesterol, where no dietary sterol was found in the ester fraction.P. redivivus is capable of reducing the Δ5-bond, C−24 dealkylation and methylating the sterol nucleus at C−4.  相似文献   

13.
4-Demethylsterol and triterpene alcohol compositions of two Vanilla bean species (V. fragrans and V. tahitensis) were investigated. From retention times and gas chromatography-mass spectrometry, nine 4-demethylsterols were identified in V. fragrans and seven in V. tahitensis. The 4-demethylsterol fraction of V. fragrans was characterized by a high content of 24-methylene cholesterol (27–40%) and of β-sitosterol (35–46%). The 4-demethylsterol fraction of V. tahitensis was characterized by a high content of stigmasterol (27%) and of β-sitosterol (57.5%), and a lower amount of 24-methylene cholesterol (5%). Vanilla tahitensis was also characterized by the presence of ergosta-5,25-dien-3β-ol (2%) and the absence of campesterol, stigmasta-5,22,25-trien-3β-ol, and ergosta-7,24(28)-dien-3β-ol. The beans’ age modified the ratio 24-methylene cholesterol/β-sitosterol in V. fragrans. Combining liquid chromatography and gas chromatography allowed the identification of four other demethylsterols in V. fragrans (brassicasterol, 0.02%; stigmasta-5,23-dien-3β-ol, 1.43%; stigmasten-22-ol, 0.1%; and fucosterol, 0.5%) from the 4-demethylsterol fraction. 24-Methylene cholesterol and β-sitosterol were isolated, and their structures were confirmed by 1H and 13C nuclear magnetic resonance. Four triterpene alcohols were identified in V. fragrans, including cycloartenol (0.9–1.6%) from the triterpene alcohol fraction, 24-dihydrotirucallol (17–23%) from the triterpene alcohol fraction, tirucall-7-en-3β-ol (6–7.5%) from the triterpene alcohol fraction, and in a higher content cyclosadol (66–69%) from the triterpene alcohol fraction. The content ranges were studied as a function of the beans’ age. Demethylsterol and triterpene alcohols profile could be used for origin differentiation.  相似文献   

14.
To assess the potential of traditional selection breeding to develop varieties with increased phytosterol content, we determined concentrations of those sterols in canola, sunflower, and soybean seed oils produced from breeding lines of diverse genetic backgrounds. Seed oils were extracted and saponified, and the nonsaponifiable fractions were subjected to silylation. The major phytosterols brassicasterol, campesterol, stigmasterol and β-sitosterol, were quantified by capillary gas chromatography with flame-ionization detection. Canola contained approximately twice the amount of total phytosterols (4590–8070 μg g−1) as sunflower (2100–4540 μg g−1) or soybean (2340–4660 μg g−1) oils. Phytosterol composition varied among crops as expected, as well as within a crop. Both genetic background and planting location significantly affected total phytosterol concentrations. Soybean plants were maintained from flower initiation to seed maturity under three temperature regimes in growth chambers to determine the effect of temperature during this period on seed oil phytosterol levels. A 2.5-fold variability in total phytosterol content was measured in these oils (3210–7920 μg g−1). Total phytosterol levels increased with higher temperatures. Composition also changed, with greater percent campesterol and lower percent stigmasterol and β-sitosterol at higher temperatures. In these soybean oils, total phytosterol accumulation was correlated inversely with total tocopherol levels. Owing to the relatively limited variability in phytosterol levels in seed oils produced under field conditions, it is unlikely that a traditional breeding approach would lead to a dramatic increase in phytosterol content or modified phytosterol composition.  相似文献   

15.
Two samples of virgin olive oil and one sample of hexane-extracted husk oil coming from Iran were examined. The analyses included physical and chemical characteristics, the composition of total fatty acids and fatty acids at the glyceride 2-position by gas liquid chromatography (GLC) of methyl esters, the triglycerides composition calculation according to Vander Wal theory, the separation of the alcoholic fractions (sterols, 4-methylsterols, triterpene alcohols, triterpene dialcohols and aliphatic alcohols) of the unsaponifiable matter by thin layer chromatography (TLC), the quantitation and the composition of these fractions by GLC of TMS derivatives. The results were in line with data from literature for olive oils of different origin, with the exception of: a high content of unsaponifiable matter (1.75 and 1.95% for virgin oils, 5.33% for husk oil); a high amount of sterols for husk oil (562 mg/100 g oil); a low content of SE 30 apparent β-sitosterol for husk oil (91.1%); a low amount of triterpene dialcohols (1 mg/100 g oil) and triterpene alcohols (78 and 91 mg/100 g oil) for virgin oils; a content of cycloartenol (60.2–66.9%) higher than the 24-methylenecycloartanol one (22.8–26.6%; a content of C24 linear saturated alcohol (33.9–38.0%) slightly higher than the C26 alcohol one (29.3–32.8%).  相似文献   

16.
A method is presented for the preparation of 2,4-3H-sterols (stigmasterol, β-sitosterol, campesterol, fucosterol and 7-dehydrocholesterol) via the technique of exchange-labeling of keto steroids and their subsequent conversion to sterols. The preparation of tritium-labeled 3β-hydroxy-24-norchol-5-en-23-oic acid and the synthesis of 2,4-3H-24-azacholesterol are reported. Some advantages of the exchange-labeling method over the conventional catalytic exchange method are discussed. One of 12 papers to be published from the “Sterol Symposium” presented at the AOCS Meeting, New Orleans, April 1970.  相似文献   

17.
Evening primrose (Oenothera spp.) seed contains ca. 15% protein, 24% oil, and 43% cellulose plus lignin. The protein is unusually rich in sulphur-containing amino acids and in tryptophan. The component fatty acids of the oil are 65–80% linoleic and 7–14% ofγ-linolenic, but noα-linolenic acid. The 1.5–2% unsaponifiable matter has a composition very similar to that of cottonseed oil. The sterol fraction contains 90%β-sitosterol and the 4-methyl sterol fraction contains 48% citrostadienol;γ-tocopherol dominates its class, with someα- but no other tocopherols.  相似文献   

18.
A preliminary investigation of the bulk properties of the oil from the edible mophane caterpillar (phane), Imbrasia belina, showed a significant difference in the iodine values of the oils from mature and young phane. Detailed analysis of the fatty acid composition of the two oil samples was thus carried out by capillary gas chromatography (GC) and complemented with 1H and 13C nuclear magnetic resonance (NMR) studies to investigate the degree of unstauration in the two oil samples. While these studies showed that the oil samples from the mature and young mophane caterpillar were much the same in fatty acid composition, the data revealed a significant divergence from a literature report on phane oil. This earlier report puts the ratio of total saturated to total unsaturated fatty acids at approximately 1:1 (48.2:48.8, in percentages) and estimates the fatty acid composition for the major fatty acids as 16:0 (31.9%), 18:0 (15.2%), 18:1 (20.4%), 18:2 (9.9%), and 18:3 (19%). The data collected from the present work, however, showed the fatty acid composition for total saturated and total unsaturated fatty acids to be 40.5 and 57.0%, respectively. This work estimated the fatty acid composition for the major fatty acids as 16:0 (27.2%), 18:0 (12.3%), 18:1 (16.1%), 18.2 (10.7%), and 18:3 (29.0%). Thus, linolenic acid was the most abundant fatty acid in the phane oil. The GC results of the present analysis were largely corroborated by studies of the composition of fatty acid classes in the phane oil estimated from integrals of 1H and 13C NMR signals. Oils from other edible Lepidoptera larvae are also known to be much richer in unsaturated than saturated fatty acids.  相似文献   

19.
Semecarpus anacardium (family Anacardiaceae) has many applications in the Ayurvedic and Siddha systems of medicine in India. Detailed knowledge on the composition of S. anacardium oil, in consideration of potential utilization, is of major importance. In this investigation, column chromatography, gas chromatography, thin layer chromatography and liquid chromatography techniques were performed to analyze lipid classes, fatty acids and fat-soluble bioactives of S. anacardium crude seed oil. The amount of neutral lipids in the crude seed oil was the highest, followed by glycolipids and phospholipids, respectively. Linoleic followed by palmitic and oleic were the major fatty acids. The ratio of unsaturated fatty acids to saturated fatty acids was higher in neutral lipid classes than in the polar lipids. The main sterol compounds were β-sitosterol, campesterol and stigmasterol. δ-Tocopherol followed by β-tocopherol were the main tocopherols. When S. anacardium seed oil and extra virgin olive oil were compared for their radical scavenging activity toward 1,1-diphenyl-2-picrylhydrazyl radical and galvinoxyl radical (by electron spin resonance spectrometry), S. anacardium seed oil exhibited a stronger RSA.  相似文献   

20.
Effects on the metabolism of campesterol and stigmasterol inCaenorhabditis elegans were investigated using N,N-dimethyldodecanamine, a known inhibitor of growth, reproduction and the Δ24-sterol reductase of this nematode. 7-Dehydrocholesterol was the predominant sterol (51%) ofC. elegans grown in stigmasterol-supplemented media, whereas addition of 25 ppm amine resulted in a large decrease in the relative percentage of 7-dehydrocholesterol (23%) and the accumulation of a substantial proportion (33%) of Δ24-sterols (e.g., cholesta-5,7,24-trienol) and Δ22,24-sterols (e.g., cholesta-5,7,22, 24-tetraenol) but yielded no Δ22-sterols. Dealkylation of stigmasterol byC. elegans proceeded in the presence of the Δ22-bond; reduction of the Δ22-bond occurred prior to Δ24-reduction. Addition of 25 ppm amine to campesterol-supplemented media altered the sterol composition ofC. elegans by increasing the percentage of unmetabolized dietary campesterol from 39 to 60%, decreasing the percentage of 7-dehydrocholesterol from 26 to 12%, and causing the accumulation of several Δ24-sterols (6%).C. elegans also was shown to be capable of dealkylating a Δ24(28)-sterol as it converted 24-methyl-enecholesterol to mostly 7-dehydrocholesterol. The proposed role of 24-methylenecholesterol as an intermediate between campesterol and 7-dehydrocholesterol was supported by the results.  相似文献   

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