凝胶色谱-气相色谱法测定11种动植物油脂中角鲨烯的含量

动植物食用油经环己烷-乙酸乙酯（1∶1,V/V）萃取后,用凝胶色谱法对油样品进行净化处理,去除样品中大分子的油脂,再采用气相色谱法对动植物食用油中角鲨烯进行测定,以建立多种动植物油中角鲨烯的凝胶色谱-气相色谱（GPC-GC-FID）测定方法。在一定的实验条件下,角鲨烯在9.40⁹40μg·m L-1范围内呈现良好线性关系,相关系数R2为0.9999,方法回收率为95.7%,RSD为3.0%。该方法处理后的食用油样品中干扰基质少,灵敏度高,可有效避免检测过程中仪器的污染,广泛应用于动植物食用油中角鲨烯的检测,为评判动植物食用油标准提供依据。      

甜瓜种子性状及甜瓜籽油中角鲨烯含量研究

采用气相色谱法等对黄色马泡瓜、包瓜等30个甜瓜品种角鲨烯含量进行测定。种子形态特征及相关性分析得知百粒重与面积比和角鲨烯含量均成极显著相关水平,但百粒重与面积比的极显著关系为负相关,即面积比越大,百粒重越小,而角鲨烯含量却随着百粒重的增加有所增加。这30个品种甜瓜籽油中角鲨烯的含量较高(641.7~2 858.3 mg/kg),经主成分分析表明,共有4个主成分对其贡献率较大。在此基础上进行聚类分析可以将其分为4类,其中第一、二类群,面积比和单个重量较小,但角鲨烯含量较高,第三、四类群则长/宽均值较大,角鲨烯含量较高。     

Synthesis,Computational Studies and Assessment of in Vitro Activity of Squalene Derivatives as Carbonic Anhydrase Inhibitors

We report novel molecules incorporating the nontoxic squalene scaffold and different carbonic anhydrase inhibitors (CAIs). Potent inhibitory action, in the low-nanomolar range, was detected against isoforms hCA II for sulfonamide derivatives, which proved to be selective against this isoform over the tumor-associate hCA IX and XII isoforms. On the other hand, coumarin derivatives showed weak potency but high selectivity against the tumor-associated isoform CA IX. These compounds are interesting candidates for preclinical evaluation in glaucoma or various tumors in which the two enzymes are involved. In addition, an in silico study of inhibitor-bound hCA II revealed extensive interactions with the hydrophobic pocket of the active site and provided molecular insights into the binding properties of these new inhibitors.     

提取方法对茶油中活性成分角鲨烯含量的影响

采用不同的工艺和溶剂从油茶籽中提取茶油,并对经甲酯化处理的茶油进行气相色谱分析、GC-MS联用分析、标准物质共同色谱比对等方法,研究了不同的提取方法对茶油中生物活性物质角鲨烯含量的影响。结果表明,茶油中含有比较多的角鲨烯,其含量随提取方法而不同,直接压榨法、己烷提取法、石油醚提取法、丙酮提取法和三氯甲烷提取法等所得到的茶油中角鲨烯的含量分别为2.98%、7.62%、0.94%、0.29%和0.54%。     

Partitioning of predominant lipophilic bioactives (squalene, α-tocopherol and β-sitosterol) during olive oil processing

The partitioning of predominant lipophilic olive bioactives (squalene, β-sitosterol and α-tocopherol) in olive oil processing was studied for the first time using common integrated olive milling plant. 7% of the oil and 5% of the squalene present in the olives was lost in the last pomace. β-sitosterol and α-tocopherol, which are mainly concentrated in the seed of the olive fruit, was recovered in virgin olive oil to a lesser extent (66%, 67%) while 10% were lost in last pomace. Thus, the loss of β-sitosterol and α-tocopherol was higher than that of squalene and oil, due to nonrecovered bound forms. 19% of the α-tocopherol and 21% of the β-sitosterol loss was unaccounted for, which can be attributed to degradation of α-tocopherol and incomplete recovery of sterols from the olive and pomace matrices. This study provides a basis for process development studies.     

A Novel Function of the Triterpene Squalene in a Tritrophic System

Changes in apple leaf chemistry after infestation by leafminers and their effect on both host location and host habitat location of the generalist parasitoid Pholetesor bicolor were investigated. Chemical analysis of leaf solvent extracts from healthy and leafminer-damaged leaves revealed that herbivory increased the amount of the triterpene squalene (C₃₀H₅₀), whereas quantities of all other identified compounds were similar in both plant treatments. To assess the response of parasitoids to host location cues, contact bioassays were conducted with naïve females. Results showed that parasitoids performed a characteristic ovipositional probing more often on the mine-damaged than on the healthy leaf. This behavior was triggered by a hexane extract of the mine-damaged leaf, but not by a healthy leaf extract. A synthetic mixture of the compounds identified in the extract triggered a similar response. A mixture devoid of squalene was not active, whereas squalene alone elicited the probing behavior. To assess the use of the identified compounds in habitat location, Y-tube olfactometer experiments were conducted with naïve and experienced females. Results showed that squalene is not involved in habitat location and has no priming effect on P. bicolor. While other triterpenes are known to mediate habitat location of parasitoids, this is the first report in which a plant triterpene is shown to mediate host location of a parasitoid. The biological and ecological functions of squalene on all three trophic levels are discussed.     

Extraction of Teucrium manghuaense and Evaluation of the Bioactivity of Its Extract

The ethanol extract of Teucrium manghuaense grown in Hainan province (China) was analysed by GC and GC/MS. Of the constituents 84–96% were identified on the basis of their GC retention times and their mass spectra in regard to authentic compounds. The results revealed that it contained 9-methyl-9-azabicyclo[4.2.1]nonane (7.43%), 2-methylpyrrolidine (19.42%), 3,7,11,15-tetramethyl-2-hexadecen-1-ol (10.84%), and squalene (28.55%), as major components, constituting 66.24% of the extract. The chemical characterization of the ethanol extract by GC/MS also allowed identification of 1-octen-3-one (3.41%), 2-pentyl-piperidine (2.25%), 1-(2-methyl-1-propenyl)-piperidine (4.63%), 2,2′-diethoxy-5,5′-bi-1-pyrroline (0.41%), (Z,Z,Z)-9,12,15-octadecatrieniic acid, 2,3-dihydroxypropyl ester (1.56%), vitamin E (2.95%) and stigmasterol (1.39%). Finally, the antioxidant and anti-tumor activities of the ethanol extract have been evaluated. Results show that the extract of Teucrium manghuaense leaf possesses strong DPPH⁻, hydroxyl radical scavenging activity and anti-tumor activity.     

Dietary evaluation of Mediterranean fish and molluscs pan‐fried in virgin olive oil

The effect of domestic pan‐frying in virgin olive oil (VOO) on the proximate composition, energy content, cholesterol, squalene and fatty acids in the edible portion of six species of finfish, common squid and mussels just caught from several regions of the Aegean Sea (Mediterranean Sea) was investigated. The species selected are traditionally consumed pan‐fried in VOO by the Greeks. On a fresh weight basis, pan‐frying caused significant water loss and increase of total fat, crude protein and energy content. The amount of VOO absorbed during frying ranged from 4.5 to 14.2% of fresh matter, showing a non‐linear negative correlation with initial fat, fish length and fish weight. Cholesterol content increased from 25 to 106 mg 100 g^?1 fresh weight (fw) to 33–130 mg 100 g^?1 fw after frying. VOO absorbed during frying resulted in a 20–78 times increase of squalene content and in significant alteration of fatty acid composition, the major change being the increase of monounsaturated fatty acids which became predominant in all fried samples. The intakes of fat and major fatty acid classes by consuming the pan‐fried seafood were comparable with the respective average Greek values. Frying in VOO resulted in a two to three times decrease of the atherogenic index and a slightly less decrease of the thrombogenic index. Both indices remained lower than 0.45 in all fried samples. The cholesterol‐saturated fat index and the cholesterol index increased up to twice after frying, ranging between 3.4–9.9 and 2.9–9.3, respectively. From the results obtained it is concluded that fish and shellfish pan‐fried in VOO present a healthy lipid profile in terms of the n‐6/n‐3 ratio, major fatty acid classes and total fat content. Copyright © 2004 Society of Chemical Industry     

Optimisation of enzymatic hydrolysis for concentration of squalene in palm fatty acid distillate

BACKGROUND: Squalene was concentrated from palm fatty acid distillate (PFAD) in this study using commercial immobilised Candida antarctica lipase (Novozyme 435^®). The PFAD was neutralised (NPFAD) using an alkali to liberate the free fatty acids and then hydrolysed at 65 ± 1 °C. The enzymatic hydrolysis on NPFAD was optimised using response surface methodology (RSM) before being neutralised again to obtain a concentrated squalene fraction. RESULTS: A five‐level, three‐factor central composite rotatable design was adopted to evaluate the effects of the enzymatic hydrolysis parameters reaction time (4–12 h), water content (50–70% w/w) and enzyme concentration (1.5–3.5% w/w) on the percentage yield of squalene concentration. The optimal reaction parameters for maximum yield of squalene concentration were identified from the respective contour plots. The optimal enzymatic hydrolysis conditions were a reaction time of 7.05 h, a water content of 61.40% w/w and an enzyme concentration of 2.23% w/w. CONCLUSION: RSM was used to determine the optimal conditions for enzymatic hydrolysis of NPFAD with C. antarctica lipase for maximum recovery of squalene which could be implemented on an industrial scale. Copyright © 2008 Society of Chemical Industry