分子短程蒸馏和重结晶分离银杏叶甾醇类化合物的研究

以银杏叶为原料,制备其石油醚提取软膏,通过皂化、萃取和冷冻,除去脂肪酸及其酯、蜡质等杂质,分离甾醇类集分.采用分子蒸馏分离技术和溶剂重结晶纯化甾醇类化合物,银杏叶甾醇收率为0.03%～0.08%.利用GC-MS联用技术鉴定银杏叶甾醇结晶物的化学组成,共分离出17种化合物,其中8种是甾醇类化合物,占所有峰面积的97.633%,依次为β-谷甾醇(67.984%)、8-烯-3β-麦角甾醇(10.624%)、3β-豆甾烷醇(10.065%)、5,24-二烯-3β-豆甾醇(5.255%)、4,22-二烯-3β-豆甾醇(1.926%)、5,8,22 E-三烯-3β-麦角甾醇(0.618%)、岩藻甾醇(0.595%)、α-谷甾醇(0.566%);酮类化合物占1.066%,分别为17,19-二乙酰氧基-4,4-二甲基-3α-雄-5,7-二烯-3-烷酮(0.336%)和17α-乙酰氧基孕烯醇酮(0.730%).除β-谷甾醇外,其它银杏叶甾醇均为首次报道.     

The effect of calcium nutrition on the sterol content of tobacco roots and their susceptibility to Phytophthora parasitica var. nicotianae

The influence of nutrient solutions containing low (25 mg/1) and high (250 mg/1) calcium (Ca) concentrations on the total lipid, free sterol, sterol glycoside and steryl ester content and on the subsequent susceptibility of three flue‐cured tobacco cultivars to black shank, incited by Phytophthora parasitica var. nicotianae was investigated. The total lipid, total sterol and free sterol content differed appreciably among root systems of the three cultivars grown at high Ca. Roots of plants grown at low Ca contained relatively higher proportions of steryl glycosides and lower proportions of free sterols than roots of plants grown at high Ca, although the absolute sterol concentrations also differed significantly among the roots of cultivars grown at low Ca. Black shank disease development was significantly lower in roots of susceptible plants grown at low Ca than in roots of the same cultivar grown at high Ca. The innate susceptibility of the cultivars were not related to the lipid or sterol content. The reduced disease development of plants grown at low Ca appeared to be associated with changes in membrane permeability, which may be correlated with changes in the various sterol fractions.     

猴头菌小分子活性成分研究进展

综述猴头菌(Hericium erinaceus)小分子活性成分的研究进展,旨在为这类物质的进一步开发利用提供参考。     

Sterol Composition of Sponges,Cnidarians, Arthropods,Mollusks, and Echinoderms from the Deep Northwest Atlantic: A Comparison with Shallow Coastal Gulf of Mexico

Triterpenoid biosynthesis is generally anaerobic in bacteria and aerobic in Eukarya. The major class of triterpenoids in bacteria, the hopanoids, is different to that in Eukarya, the lanostanoids, and their 4,4,14-demethylated derivatives, sterols. In the deep sea, the prokaryotic contribution to primary productivity has been suggested to be higher because local environmental conditions prevent classic photosynthetic processes from occurring. Sterols have been used as trophic biomarkers because primary producers have different compositions, and they are incorporated in primary consumer tissues. In the present study, we inferred food supply to deep sea, sponges, cnidarians, mollusks, crustaceans, and echinoderms from euphotic zone production which is driven by phytoplankton eukaryotic autotrophy. Sterol composition was obtained by gas chromatography and mass spectrometry. Moreover, we compared the sterol composition of three phyla (i.e., Porifera, Cnidaria, and Echinodermata) collected between a deep and cold-water region and a shallow tropical area. We hypothesized that the sterol composition of shallow tropical benthic organisms would better reflect their photoautotrophic sources independently of the taxonomy. Shallow tropical sponges and cnidarians from environments showed plant and zooxanthellae sterols in their tissues, while their deep-sea counterparts showed phytoplankton and zooplankton sterols. In contrast, echinoids, a class of echinoderms, the most complex phylum along with hemichordates and chordates (deuterostomes), did not show significant differences in their sterol profile, suggesting that cholesterol synthesis is present in deuterostomes other than chordates.     

The Role of Spongia sp. in the Discovery of Marine Lead Compounds

A comprehensive review on the chemistry of Spongia sp. is here presented, together with the biological activity of the isolated compounds. The compounds are grouped in sesquiterpene quinones, diterpenes, C21 and other linear furanoterpenes, sesterterpenes, sterols (including secosterols), macrolides and miscellaneous compounds. Among other reports we include studies on the intraspecific diversity of a Mediterranean species, compounds isolated from associated sponge and nudibranch and compounds isolated from S. zimocca and the red seaweed Laurentia microcladia. Under biological activity a table of the reported biological activities of the various compounds and the biological screening of extracts are described. The present review covers the literature from 1971 to 2015.     

Effects of rapeseed oil replacement in fish feed on lipid composition and self‐selection by rainbow trout (Oncorhynchus mykiss)

Increased use of plant oils with different origins and quality in fish feed needs to be approached from a food safety and fish welfare point of view. Plant oils contain a number of bioactive minor lipid compounds that may affect the fish’s metabolism and taste perception. This study focuses on the effect of replacing fish oil (FO) with different levels of cold‐pressed rapeseed oil (RO) on the lipid composition in muscle and liver as well as on the preference by the fish. Rainbow trout (Oncorhynchus mykiss) were fed diets with a FO : RO ratio of 100 : 0, 75 : 25, 50 : 50 and 25 : 75 until twofold weight increase. In self‐selecting feed trials of single rainbow trout, fish preferred the diet composed of only FO compared with the diets with RO but did not discriminate between different levels of RO. Plant sterols and their metabolites were found in liver of the fish fed RO diets, suggesting an effect on the sterol metabolism different from fish fed a 100% FO diet. The largest effects were seen in the fatty acid composition of the edible tissue of the fish with a decrease in 22:6n‐3 and 20:5n‐3 and an increase in 18:2n‐6 and 18:1n‐9.     

Stress response and lipid composition in shrimp Litopenaeus vannamei fed diets enriched with squid or scallop viscera meal

We substituted 10% of fishmeal with scallop (Argopecten ventricosus) or squid (Dosidiscus gigas) by‐product meal in a feed for shrimp (Litopenaeus vannamei) growth assay that lasted 60 days and then shrimps were submitted to handling stress. Shrimp fed the control diet had smaller weight gain and lower recovery after stress. Prostaglandins in gills were affected by diet and stress, with significant differences in shrimp fed the control diet before and after the stress. Hydroperoxides were increased after stress, while isoprostanoids were higher in shrimp fed the control diet. The gene expression of Glutathione peroxidase and Catalase was increased on the stressed shrimp fed the scallop diet, with no differences among diets for Superoxide dismutase or Cyclooxygenase. Arachidonic acid in the phospholipid fraction of muscle was the only fatty acid affected by stress and diet. Cholesterol oxidation products were significantly higher in shrimp fed the scallop diet compared to shrimp fed the control diet before applying the stress. A PCA analysis grouped in one‐factor growth variables, as well as Superoxide dismutase, esterified astaxanthin and isoprostane, while another factor was determined by stress, prostaglandin and hydroperoxide levels in gills. The partial substitution of fishmeal with scallop of squid by‐product meals affected growth and stress differently, indicating shrimp that grew up more were not necessarily more tolerant to handling stress, which can have a strong repercussion in aquaculture, particularly during density control, recording of growth and harvest.     

Fatty acid,fat‐soluble vitamin and sterol contents in testis and semen,testis‐somatic index and spermatologic values of broodstock rainbow trout (Oncorhynchus mykiss) fed with different levels of omega‐3 fatty acids under regular stripping conditions

In this study, the testis and semen fatty acid, fat‐soluble vitamin and sterol levels, testis‐somatic index and spermatological values were investigated in the broodstock rainbow trout fed with the different levels of omega‐3 polyunsaturated fatty acid (PUFA) under the regular stripping conditions. For this purpose, a control and three test diets were prepared. The control, D1, D2 and D3 diets were contained the omega‐3 PUFA at 3.14%, 7.84%, 13.63% and 20.54% as a percentage of the total fatty acids respectively. The fish in the experimental groups were fed with these diets for 60 days. The testis‐somatic index (3.81–4.50), semen volume (9.30–18.5 ml) and pH (8.05–8.99), initial sperm motility (68.1%–93.7%), duration of 50% sperm motility (141.3–258.9 s), total duration of sperm motility (268.7–489.6 s) and sperm density (9.95–17.5 cells × 10⁹ ml^?1) values of the fish fed the control diet were significantly decrease (p < 0.05) depending on decline of the omega‐3 PUFA, fat‐soluble vitamin and sterol contents in the testis and semen. The omega‐3 PUFA (3.40%–14.76% and 3.96%–16.31%), vitamin A (33.9–61.2 ml/mg and 9.12–26.7 ml/mg), D₂ (0.10–0.19 ml/mg and 0.04–0.10 ml/mg), D₃ (0.75–1.30 ml/mg and 0.06–0.24 ml/mg), alpha‐tocopherol (30.1–60.4 ml/mg and 8.93–25.3 ml/mg), K₁ (0.30–0.94 ml/mg and 0.03–0.08 ml/mg) and K₂ (2.0–3.19 ml/mg and 0.25–0.34 ml/mg) vitamins, cholesterol (1,201–1,588 ml/mg and 330–596 ml/mg), ergosterol (3.12–6.40 ml/mg and 2.10–4.08 ml/mg), stigmasterol (5.57–10.4 ml/mg and 10.2–12.6 ml/mg) and beta‐sitosterol (0.20–0.60 ml/mg and 0.14–0.41 ml/mg) contents in the testis and semen of the fish were significantly affected (p < 0.05) by the dietary omega‐3 PUFA supplementation. The highest values for these parameters were provided from the fish fed the D2 and D3 diets (p > 0.05), followed by the fish fed the D1 diet (p < 0.05). These results showed that the dietary omega‐3 PUFA at 13.63% of the total fatty acids could increase the omega‐3 PUFA, fat‐soluble vitamin and sterol contents in the testis and semen, the testis‐somatic index and spermatologic values of the broodstock rainbow trout under the regular stripping conditions.     

Sterol composition in polyene antibiotic-sensitive and resistant strains ofMalassezia pachydermatis

The membrane sterol compositions of ten strains ofMalassezia pachydermatis were analysed by gas-liquid chromatography. Six of these were wild-type strains from clinical sources that were sensitive to polyene antibiotics, whereas the other four strains were resistant mutants that had arisen after treatment withN-methyl-N-nitrosoguanidine or UV radiation.The wild-type strains contained 838.8 to 1291.7 µg of sterol per gram of freeze-dried mycelium. The sterols were composed of 79% ergosterol, 19% fecosterol and 2% lichesterol. The mutant strains contained 277.1 to 348.8 µg/g of sterols composed of 76% ergosterol and 24% fecosterol.Abbreviations MIC minimum inhibitory concentration - UV ultraviolet     

冠瘤海鞘化学成分研究

[目的]研究海洋动物冠瘤海鞘的化学成分。[方法]采用硅胶柱色谱、Sephadex LH-20柱色谱、气相色谱等方法对冠瘤海鞘的化学成分进行分离纯化;运用波谱分析并结合文献鉴定化合物的结构。[结果]从冠瘤海鞘分离纯化得到白色针状晶体和无色油状物;白色针状晶体具有典型甾醇类化合物特征,其GC总离子流谱图与文献报道相似;无色油状物Rf值为0.5,10%浓硫酸显紫红色,核磁共振测定与文献报道的油酸甲酯相等。[结论]从冠瘤海鞘中分得混合甾醇和油酸甲酯,油酸甲酯为首次从该动物中分得。