韧革菌Stereum sp.YMF1.1660的化学成分研究

对韧革菌属真菌Stereum sp.YMF1.1660发酵液的乙酸乙酯和正丁醇萃取物以及菌丝的甲醇提取物的化学成分进行了研究,从中分离得到6个化合物,经波谱数据分析鉴定为butyl-β-D-glucopyranoside(Ⅰ)、(3,4-dimethoxyphenyl)methanol(Ⅱ)、butyl-β-D-glucofuranoside(Ⅲ)、dibutyl phthalate(Ⅳ)、5α,8α-epidioxyergosta-6,22-dien-3-ol(Ⅴ)和6,9-epoxy-ergosta-7,22-dien-3-ol(Ⅵ),其中化合物Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅵ是首次从韧革菌属真菌中分离得到。     

枸橼果实化学成分研究

研究枸橼Citrusmedica L.果实的化学成分,采用硅胶柱色谱、Sephadex LH-20、ODS等方法分离纯化化合物,应用波谱方法鉴定其结构。从枸橼果实中分离得到13个化合物,分别为:柠檬内酯(Ⅰ)、东莨菪亭(Ⅱ)、β-谷甾醇(Ⅲ)、奥巴叩酮(Ⅳ)、诺米林(Ⅴ)、柠檬苦素(Ⅵ)、异奥巴叩酸(Ⅶ)、橙皮素(Ⅷ)、胡萝卜苷(Ⅸ)、1-O-(β-D-葡萄糖基)-(2S,3S,4E,8E)-2-[(2′R)-2′-羟基十六酰氨基]-4(E),8(E)-十八二烯-1,3-二醇(Ⅹ)、柚皮素-7-O-β-D-葡萄糖苷(Ⅺ)、柚皮苷(Ⅻ)、橙皮苷(■)。     

忍冬根的正丁醇萃取物化学成分研究

采用反相C18柱色谱、硅胶柱色谱、制备型高效液相色谱成功地从忍冬根的正丁醇萃取物中分离得到6个高纯度单体,通过核磁共振波谱和质谱鉴定其为:绿原酸(Ⅰ)、獐芽菜苷(Ⅱ)、马钱苷(Ⅲ)、断氧化马钱子苷(Ⅳ)、4-O-(4′-O-咖啡酰葡萄糖基)-5-O-咖啡酰奎宁酸(Ⅴ)、3,5-O-二咖啡酰奎宁酸(Ⅵ)。其中,马钱苷(Ⅲ)为首次从忍冬根中分离得到,4-O-(4′-O-咖啡酰葡萄糖基)-5-O-咖啡酰奎宁酸(Ⅴ)为首次从该种属植物中分离得到。该研究为进一步开发利用忍冬植物资源,深入了解其药用活性成分奠定了基础。     

莲子心中二种黄酮类化合物的分离与鉴定

结合溶剂萃取和聚酰胺反复柱层析、纯化,从莲子心的95%乙醇溶液的提取物中分离得到2种黄酮类化合物,通过核磁共振的波谱方法鉴定为金丝桃苷(Ⅰ)和山奈酚-7-O-β-D-葡萄糖苷(Ⅱ)。其中化合物Ⅱ为首次从莲子心中分离得到。     

氮苷1-(2'''',3'''',4'''',6''''-O-四乙酰基-β-D-吡喃葡萄糖基)-咪唑的制备

以D-葡萄糖(Ⅰ)、醋酸酐为原料,在无水吡啶中制得中间体1,2,3,4,6-O-五乙酰基-D-葡萄糖(Ⅱ),收率为87.5%.在HBr/CH3COOH条件下对Ⅱ异头碳上的乙酰基进行溴代,制得1-溴-2,3,4,6-O-四乙酰基-D-葡萄糖(Ⅲ),不经分离,在相转移催化剂TEBA催化下,Ⅲ直接与2,4-二硝基苯酚反应得到酚苷1-O-(2',4'-二硝基苯)-2,3,4,6-O-四乙酰基-β-D-葡萄糖苷(Ⅳ),最后Ⅳ与1-三甲基硅基-咪唑在无水四氯化锡的催化下,室温反应52 h制得氮苷1-(2',3',4',6'-O-四乙酰基-β-D-吡喃葡萄糖基)-咪唑(Ⅴ),此步反应收率为90%.     

铜藻Sargassu Horneri的化学成分研究

本文报道了从海南铜藻Sargassu horneri中分离得到4个甾醇类化合物,结构分别鉴定为:2,4-羟基-2,4-乙烯基-胆甾醇(Ⅰ),岩藻甾醇(Ⅱ),5α,8α-过氧麦角甾-6,2,2-二烯-3β-醇(Ⅲ),β-谷甾醇(Ⅳ)。     

氮苷1-(2,′3,′4,′6′-O-四乙酰基-β-D-吡喃葡萄糖基)-咪唑的制备

以D-葡萄糖(Ⅰ)、醋酸酐为原料,在无水吡啶中制得中间体1,2,3,4,6-O-五乙酰基-D-葡萄糖(Ⅱ),收率为87.5%。在HB r/CH3COOH条件下对Ⅱ异头碳上的乙酰基进行溴代,制得1-溴-2,3,4,6-O-四乙酰基-D-葡萄糖(Ⅲ),不经分离,在相转移催化剂TEBA催化下,Ⅲ直接与2,4-二硝基苯酚反应得到酚苷1-O-(2,′4′-二硝基苯)-2,3,4,6-O-四乙酰基-β-D-葡萄糖苷(Ⅳ),最后Ⅳ与1-三甲基硅基-咪唑在无水四氯化锡的催化下,室温反应52 h制得氮苷1-(2,′3,′4,′6′-O-四乙酰基-β-D-吡喃葡萄糖基)-咪唑(Ⅴ),此步反应收率为90%。     

麦芽酚-β-D-葡萄糖苷的便捷合成及其加香应用

为了改进糖苷化反应的合成工艺,以D-葡萄糖为原料,合成了溴代四乙酰葡萄糖(Ⅱ),化合物Ⅱ与麦芽酚(Ⅰ)分别经相转移催化和Koenigs-Knorr糖苷化反应合成了麦芽酚-2,3,4,6-四-O-乙酰基-β-D-葡萄糖苷(Ⅲ),化合物Ⅲ脱乙酰基得到目标产物麦芽酚-β-D-葡萄糖苷(Ⅳ)。产物结构经1HNMR、13CNMR、IR、HRMS确证。考察了糖苷Ⅳ的热裂解和加香评吸效果。结果表明,对于糖苷化反应,相转移催化法优于Koenigs-Knorr法。相转移催化法的反应条件为:丙酮为溶剂,无水K_2CO_3为缚酸剂,四丁基溴化铵(TBAB)为相转移催化剂,n(麦芽酚)∶n(溴代四乙酰葡萄糖)=1.0∶1.2,室温反应4h,化合物Ⅲ的产率为75.6%。化合物Ⅲ在甲醇钠/甲醇体系进行水解得到化合物Ⅳ。糖苷Ⅳ受热裂解能释放出麦芽酚等特征香味成分,将其添加于卷烟中能够改善香气品质。     

洋甘菊中黄酮类成分的分离与结构确定

对洋甘菊中黄酮类活性成分进行分离纯化和结构确定。经过聚酰胺反复柱色谱进行分离、纯化,并经核磁共振确定其结构。从洋甘菊的乙醇(95%)提取物中分离得到2个黄酮类化合物,其结构被确定为芹菜素-7-O-β-D-葡萄糖苷(Ⅰ)和木犀草素-7-O-β-D-葡萄糖苷(Ⅱ)。芹菜素-7-O-β-D-葡萄糖苷和木犀草素-7-O-β-D-葡萄糖苷很可能为洋甘菊的主要黄酮活性成分。     

6-烃氧基-2-烷硫基腺苷化合物的合成及抗血小板凝聚活性

以鸟嘌呤核苷(Ⅰ)为原料,经羟基保护得到2',3',5'-三-O-乙酰基鸟嘌呤核苷(Ⅱ),Ⅱ与三氯氧磷反应得到2-氨基-6-氯-9-(2',3',5'-三-O-乙酰基-β-D-呋喃核糖基)嘌呤(Ⅲ),Ⅲ再进行重氮-烷硫化反应,生成2-烷硫基-6-氯-9-(2',3',5'-三-O-乙酰基-β-D-呋喃核糖基)嘌呤(Ⅳ),Ⅳ与醇进行亲核取代反应同时脱去糖环保护得到8个6-烃氧基-2-烷硫基嘌呤腺苷化合物(Ⅴ)。化合物的结构经1HNMR、13CNMR、IR和HRMS表征,同时对合成的目标化合物进行了体外抗血小板凝聚活性测试。结果表明,在测试浓度为10μmol/L时,6-(2-呋喃甲基)氧基-2-丙硫基腺苷具有较高的抗血小板凝聚活性。     

一种从富含多酚多糖的西葫芦组织中快速提取RNA的方法

对比研究了一步法、尿素／氯化锂法、热酚法、LUG法等4种方法,建立了一种适合西葫芦组织RNA提取的改进的CTAB方法。用该方法从西葫芦叶中提取的RNA在琼脂糖凝胶电泳上清楚显示出28S和18S两条链．A250／280值为2.08、A250/280值为2．0,表明提取的RNA没有多酚、多糖、蛋白质污染;RNA产量为210μg·g^-1鲜质量;对RT—PCR的结果进行测序,通过NCBI—BLAST比对可知,与印度南瓜的同源性达89％。用该方法从西葫芦果肉中也获取了高质量的RNA。改进的CTAB法全程只需2h,不用液氮、亚精胺、二硫苏糖醇、蛋白酶K等试剂。     

Seeds and oil of the Styrian oil pumpkin: Components and biological activities

Cucurbita pepo subsp. pepo var. Styriaca is a phylogenetically young member of the Cucurbita spp. since the mutation leading to dark green seeds with stunted outer hulls arose only in the 19^th century. This mutation defined the so‐called Styrian oil pumpkin and facilitated the production of Styrian pumpkin seed oil. It is a regional specialty oil in the south‐eastern part of Europe. In this article, we describe the production and economic value of this edible oil as well as its composition on a molecular basis, including fatty acids, vitamins, phytosterols, minerals, polyphenols, and the compounds responsible for its pigments, taste and flavor. We also describe contaminants of Styrian pumpkin seed oil and the most relevant field pests of the Styrian oil pumpkin plant. Finally, we review the putative beneficial health effects of Styrian oil pumpkin seeds and of their products.     

Production technology and characteristics of Styrian pumpkin seed oil

Cucurbita pepo subsp. pepo var. Styriaca, the so‐called Styrian oil pumpkin, is a phylogenetically young member of the Cucurbita spp. A single mutation occurred only in the 19^th century and led to dark green seeds with stunted outer hulls. This mutation facilitated the production of Styrian pumpkin seed oil that became a regional specialty oil in the south‐eastern part of Europe during the last few decades. We describe in this article the production and economic value of this edible specialty oil as well as the most important parameters relevant for its quality. Furthermore, we report on its molecular composition including fatty acids, vitamins, phytosterols, minerals, polyphenols, and those compounds that are responsible for its color, taste and flavor. Finally, information is provided on potential contaminants of Styrian pumpkin seed oil as well as its putative beneficial health effects.     

Stability of pumpkin seed oil

In Austria pumpkins are grown primarily for the production of pumpkin seeds that can be used for eating or the production of salad oil. Pumpkin seed oil is dark green and its fatty acid composition consists typically of linoleic acid and oleic acid as the dominant fatty acids. The saturated fatty acids palmitic and stearic acid occur at lower levels. The samples for this study were taken from a breeding program that intends to increase the seed and oil productivity. 15 samples with different contents of linoleic acid (40—57%) and vitamin E (100—600 μg/g) were selected. The stability of the oil was measured in a Rancimat that oxidizes the oil at 120 �C and measures the induction time that is needed for the oxidation. The correlation analysis showed that only the ratio of linoleic acid to oleic acid had a significant influence on the oxidative stability of the oil. Vitamin E did not show any correlation. When α‐tocopherol was added to the oil a strong pro‐oxidative effect was observed.     

Biologically Active Digests from Pumpkin Oil Cake Protein: Effect of Cross-linking by Transglutaminase

The objective of this study was to show that biologically active hydrolysates can be obtained by simulated human gastrointestinal digestion (HGD) of transglutaminase cross-linked pumpkin oil cake protein (Tg-C) which was previously reported as a potential functional food additive. A two-stage in vitro digestion model system (by pepsin and α chymotrypsin and trypsin, simultaneously) was used to simulate the process of HGD on native and Tg-C major storage pumpkin oil seed/cake protein, cucurbitin (C). The biologically active potential of the digests was evaluated, measuring the angiotensin-converting-I enzyme (ACE) inhibitory and anti-oxidant capacity. The ACE inhibitory activity was determined in both final digests, with IC₅₀ = 0.30 ± 0.04 mg/ml for C and IC₅₀ = 0.28 ± 0.01 for Tg-C. The anti-oxidant potency of the examined proteins was enhanced by the digestion process. The 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical cation activities and reducing power testing showed that all the hydrolysates act as a radical quencher and reducing agents. Overall, the results showed that the cross-linking by Tg did not influence the digestion process, as well as having no effect on the biological activity of the hydrolysates. These also indicate that Tg-C, if used as functional food additive, after food consumption can be digested and become a source of peptides exerting positive effects on human health.     

A new cucurbitacin profile forCucurbita andreana: A candidate for cucurbitacin tissue culture

In addition to previously reported cucurbitacins B,1, and D,2, cucurbitacin E,3, and I,4, aglycones and their glucosides 2-O--glucopyranosyl-cucurbitacin E,5, and 2-O--glucopyranosyl-cucurbitacin I,6, were isolated and identified as constituents ofCucurbita andreana on the basis of MS, FD-MS, 1 H NMR and¹³C NMR spectroscopy. Also, 2-O--glucopy-ranosyl-cucurbitacin B, 7, cucurbitacin B glucoside was isolated and identified.     

Cucurbitacins fromCucurbita texana: Evidence for the role of isocucurbitacins

In addition to cucurbitacins E andI, cucurbitacins D,1, 3-epi-isocucurbitacin D,2, and B,3, were isolated from the fruits ofCucurbita texana and structurally identified by UV, IR,¹H NMR,¹³C NMR, and MS, and 2-O--glucopyranosylcucurbitacin I was identified. These compounds have not been reported previously as constituents of this species. The isolation of 3-epi-isocucurbitacin D2 together with normal cucurbitacins suggests that isocucurbitacins occur naturally. Evidence is also discussed that isocucurbitacins are biosynthesized one step ahead of normal cucurbitacin.     

Reducing fertilizer requirements for hybrid squash (Cucurbita maxima L.) with localized applications of phosphorus and potassium and use of partially acidulated phosphate rock

Two experiments examined options for reducing the inputs of P and K fertilizers for hybrid squash (Cucurbita maxima L.) at Pukekohe, New Zealand. The first experiment examined the effects of elevating the NaHCO₃-soluble P from 32 to 130 mg kg^–1 and the exchangeable K from 140 to 350 mg kg^–1 within strips from 0 to 0.75 m around rows of hybrid squash planted 1.5 m apart. From both P and K, crop yield increased as the width of the fertilized strip was increased up to 0.25 m, while wider fertilized strips had no further effect. These results followed similar effects on plant dry matter and tissue P or K concentration during early growth, and are explained in terms of the P and K accumulation by the crop, the decline during growth of the sensitivity of the crop to soil P and K fertility associated with declining rates of P and K uptake per unit length of root. Implications for fertilizer management for hybrid squash are also discussed.The second experiment compared the effects of partially acidulated phosphate rock and triple-superphosphate on soil P fertility, growth and yield of hybrid squash. Partially acidulated phosphate rock had smaller effects than those of triple-superphosphate on NaHCO₃-soluble P levels in the soil, plant dry weight and tissue P concentration soon after emergence, and subsequently crop yield. On average, partially acidulated phosphate rock increased crop yield by about 70% of that following the application of the same quantity of P as triple-superphosphate. This lower effectiveness of partially acidulated phosphate rock for hybrid squash is explained in terms of its lower solubility and hence smaller effect on NaHCO₃-soluble P in the soil during early growth, when the crop is most sensitive to soil P fertility.