香椿属中三萜类化学成分及生物活性研究进展

香椿属植物在我国民间应用广泛,自1846年香椿属建立以来,不少学者已经对本属植物进行各方面的研究,包括植物生态学和植物化学方面。但到目前为止还不曾见到对该属植物中化学成分和生物活性方面的研究进展进行综述报道。目前对香椿属植物化学成分及生物活性的报道相对集中在三萜类成分,此类成分也是香椿属所在的楝科其他植物特征性成分,该科植物中存在特有的新奇的三萜类成分,不论是化学成分还是生物活性方面都是是当前的研究热点。鉴于此作者对目前国内外报道的香椿属植物中三萜类成分的化学成分及其生物活性研究进行归纳总结,特别是香椿属中三萜的类型以及不同类型三萜代表性的生物活性进行系统归纳,以便为以后研究香椿属其他植物或进一步深入研究开发提供文献支持。     

米仔兰属化学成分及生物活性研究进展

米仔兰属植物在我国民间应用较多,已有不少学者从植物生态学和植物化学等方面对本属植物进行了广泛研究,但相关进展综述迄今尚未见报道。目前对米仔兰属植物化学成分及生物活性的报道较多集中于三萜类成分,该成分因其结构新奇成为米仔兰属所在楝科植物的特征性成分,因此其化学成分及生物活性均为当前研究热点。鉴于此,作者对国内外已报道的米仔兰属植物中化学成分及其生物活性研究进行归纳总结,特别关注其中三萜的不同类型及代表性活性,拟为进一步深入、系统地研究开发米仔兰属其它植物提供参考。     

鹅掌楸属植物化学成分及其生物活性研究进展

本文综述了鹅掌楸属植物化学成分以及该属植物及其部位成分的生物活性,其化学成分包括生物碱、倍半萜、苯丙素、黄酮类等化合物。生物活性包括抗菌、抗疟疾、抗肿瘤等活性。     

胡椒属化学成分的研究

本文对胡椒属植物生物碱和黄酮等类化学成分及其生物活性的研究进行了综述。     

蚤草属植物化学成分及生物活性研究进展

蚤草属植物的化学成分类型丰富,主要包括倍半萜、二萜、黄酮、单萜、挥发油、酚类等。该属植物具有抗菌、细胞毒、抗癌等生物活性。对国内外有关该属植物的化学成分和生物活性的研究进行了综述,为该植物资源的进一步研究和开发利用提供依据。     

海桑属红树植物及其内生真菌化学成分及生物活性研究进展

海桑属(Sonneratia)是重要的红树植物,近年来对其化学成分研究不断增加,揭示了其多种多样的化合物类型,以及抗肿瘤、抗炎、抗氧化等生物活性。对其共附生真菌次生代谢产物的研究始于2009年,短短几年,发现了大批结构新颖、活性显著的化合物。因此本文按照化合物来源对海桑属植物及其内生真菌的化学成分及生物活性作全面回顾,为后续研究提供参考。     

杜茎山属植物的三萜皂苷及其生物活性

综述了紫金牛科杜茎山属植物的三萜皂苷类化学成分及其生物活性;为植物的系统分类提供化学依据,并为全面评价该属植物的药用价值提供参考.     

无患子属植物的化学成分及生物活性研究进展

本文对近30年来无患子属植物的化学成分和生物活性研究进展进行了综述,为该属植物的进一步开发利用提供参考.无患子属植物的化学成分主要包括挥发油、三萜皂苷、倍半萜苷类化合物等,这些化合物具有抑菌、抗肿瘤、保肝和表面活性等多方面的生物活性.     

鸢尾属植物的化学成分及其生物活性

鸢尾科鸢尾属植物的主要化学成分是黄酮类化合物,这类化合物具有广泛的生物活性。本文对近年来该属植物的分布,化学成分的分类及生物活性进行了综述。     

药用山蚂蝗属植物的化学成分和药理活性研究进展

由于在中药中的广泛应用,近年来对豆科Leguminosae山蚂蝗属Desmodium Desv.植物的研究已成为热点。山蚂蝗属植物的化学成分主要包括黄酮类、生物碱类、萜类、甾醇类、烷类及各种烷衍生物等,具有抗氧化性、抗炎、镇痛解热、抗菌、抗虫、抗心脑血管疾病等药理活性。本文对山蚂蝗属中小槐花、广东金钱草、三点金、小叶三点金、假地豆、大叶山蚂蝗、饿蚂蝗等药用植物的研究进行总结,综述其化学成分及生物活性的研究进展,旨在为该属植物的进一步研究与利用提供参考。     

光度法检测核桃青皮中类胡萝卜素含量

以核桃青皮为原料,浸提法获得萜类,用光度计对常温保存和冷冻贮藏下的类胡萝卜素含量进行分析。结果显示,常温保存和冷冻贮藏下,核桃青皮中类胡萝卜素含量差异很大。其中,常温保存时核桃青皮中类胡萝卜素含量为0．8％;冷冻贮藏时核桃青皮中类胡萝卜素含量为1．4％。结果表明,冷冻状态更有利于核桃青皮中类胡萝卜素的保存。     

核桃青皮分解对小白菜生长及生理特性的影响

采用盆栽试验,研究了不同剂量核桃(Juglans regia L.)青皮在土壤中分解过程中对受体植物小白菜(Brassica rapa L.var.chinensis)幼苗生长及其生理特性的影响,探讨核桃青皮的化感作用机理。结果表明:(1)核桃青皮在施入土壤的75d内,显著抑制了小白菜地上部分生物量的积累。(2)各剂量青皮处理小白菜叶片的叶绿素含量在施入20d时均较CK降低,且随着处理时间延长总体呈减少趋势。(3)各剂量青皮处理小白菜叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)活性在施入20d和75d时大多比对照显著升高,且有随剂量增加而增强的趋势,但过氧化氢酶(CAT)活性则随添加量增大或处理时间延长多无显著变化。(4)小白菜叶片可溶性糖(SS)含量在施入20d时随青皮添加量的增加而增加,后期则表现为显著下降,而可溶性蛋白(SP)和脯氨酸(Pro)含量在整个处理期则呈减少趋势。研究认为,核桃青皮在土壤中分解可能对小白菜的生长和抗性生理指标产生了明显的化感作用,其化感作用强度随其分解时间延长呈先强后弱的变化趋势,且高添加量产生的效应比低添加量快而且强。     

Thermostabilities of plant phenol oxidase and peroxidase, determining the technology of their use in food industry

Stabilities of phenol oxidase and peroxidase from tea plant (Camellia sinensis L.) clone Kolkhida leaves, apple (Malus domestica L.) cultivar Kekhura fruits, walnut (Juglans regia L.) green pericarp, and horseradish (Armoracia lapathifolia Gilib) roots were studied using different storage temperature modes and storage duration. It was demonstrated that both enzymes retained residual activities (approximately 10%) upon 20-min incubation at 80 degrees C. Phenol oxidases from tea, walnut, and, especially, apple, as well as tea peroxidase were stable during storage. A technology for treatment of plant oxidases was proposed, based on the use of a natural inhibitor phenol oxidase and peroxidase, isolated from tea leaves, which solving the problem of residual activities of these enzymes, arising during pasteurization and storage of beverages and juices. It was demonstrated that browning of apple juice during pasteurization and beer turbidity during storage could be efficiently prevented using the natural inhibitor of these enzymes.     

Extractability and biological activity of tannins from various tree leaves determined by chemical and biological assays as affected by drying procedure

Leaf samples of Juglans regia (walnut), Rhus typhina (sumach), Aesculus hippocastanum (chestnut) and Salix alba (willow) were either freeze dried or oven dried and the amount of tannins was determined by two chemical assays (Folin Ciocalteau and ferric chloride method). In addition, the biological activity of these tannins was determined by their protein precipitation capacity and by a bioassay based on the incubation to the leaves in vitro in buffered rumen fluid with and without polyethylene glycol. Generally, oven drying is recognised to decrease the extractability and/or the biological activity of tannins. Our results however do not indicate a general decrease in extractability of tannins due to oven drying. The effects observed were plant specific with negative effects of oven drying in walnut and willow leafs, positive effects in chestnut leaves and no effects were observed for the sumach. No negative effects of oven drying were detected for the biological activity of the tannins. The specific protein precipitation capacity was nearly identical for the freeze dried and the oven dried tannins. Oven drying however decreased the solubility of the cell contents and the plant cell wall, which led to changes in fermentation end products, but the biological activity of the tannins was not negatively affected by the oven drying. Although some differences in the extractability and activity of the individual plant species were observed, we conclude from this work that the drying procedure has no negative effect on the biological activity of the tannins examined.     

胡桃楸提取液对肿瘤细胞增殖的抑制作用

目的考察胡桃楸提取液对肿瘤细胞Hela、K562的抑制作用和相关机制。方法用MTT方法分析胡桃楸提取液对Hela、K562细胞增殖的影响。采用端粒酶PCR ELISA试剂盒分析胡桃楸提取液对Hela、K562细胞端粒酶的影响。结果 Hela细胞24、48和72 h的LD50分别为406.18μg/mL、319.48μg/mL和112.84μg/mL。K562细胞24 h LD50为154.50μg/mL。HLF细胞LD50为918.69μg/mL。胡桃楸提取液可抑制Hela细胞和K562细胞的端粒酶活性,而对HLF细胞端粒酶活性影响不大。结论胡桃楸提取液对Hela细胞、K562细胞有抑制作用,在低浓度下对HLF细胞杀伤不大。对肿瘤细胞抑制作用可能与抑制端粒酶活性相关。     

胡桃楸不同营养器官 POD 同工酶的动态变化

对胡桃楸树根、树皮（茎皮）、枝皮、树枝（当年生枝条）、树叶5个营养器官过氧化物酶（POD）同工酶进行生长期动态测定比较,结果显示：胡桃楸POD同X-．酶表达具有发育阶段性和器官特异性;胡桃楸不同器官共有酶带B1,该酶带可能是胡桃属的特征性酶带;胡桃楸pod同工酶分析宜采用根、茎皮、枝皮部。试验结果为胡桃楸进一步食药用开发利用、引种栽培提供生化水平参考。     

Characterization and Localization of a Novel Protein (HFN 40) in Maize Genotypes Without Husk Leaf Blades

Some maize (Zea mays L.) genotypes produced husk leaves without leaf blades. However, the physiological implication of this leaf deformity is unclear. Difference in protein pattern was observed between maize with and without husk leaf blades. A clear band around 38[sim ]40 kDa in seeds of maize genotypes without husk leaf blades appeared, while it was not detected in ones with husk leaf blades. These protein might be involved in leaf blade intiation.     

胡桃楸提取液对肿瘤细胞细胞周期的影响

目的考察胡桃楸提取液对Hela和K562细胞周期的影响。方法用流式细胞仪分析胡桃楸提取液对Hela、K562细胞细胞周期的影响。结果胡桃楸提取物体外作用于Hela细胞可引起细胞周期在S期的停滞,这种效果随药物浓度和作用时间的增加而增加,胡桃楸提取物体外作用于K562细胞,可引起细胞周期在G1期的停滞,随药物浓度的增加而增加。结论胡桃楸提取液对Hela细胞的生长抑制作用可能通过S期阻滞实现,对K562细胞抑制作用可能通过G1期阻滞实现。     

Assessing Nezara viridula (Hemiptera: Pentatomidae) feeding damage in macadamia nuts by using a biological stain

Damage caused by southern green stink bug, Nezara viridula (L.), to macadamia nuts, Macadamia integrifolia Maiden & Betche, is normally determined after nuts are harvested and processed, which may be many months after damage occurred in the field. We developed a method using ruthenium red dye to stain stink bug feeding probes and indirectly assess feeding activity in macadamia nuts. By using the staining method, feeding probes were easily detected on the husk, shell, and kernel. Husk probing was highly correlated (0.80-0.90) with feeding and damage to the kernel. Failure rate to detect kernel damage from stained husk probes was generally <6%. The staining method was equally effective for immature and mature nuts; therefore, N. viridula feeding activity can be monitored throughout the season to evaluate pest management tactics and forecast outbreak populations.     

Crude tea extracts decrease the mutagenic activity of N-methyl-N'-nitro-N-nitrosoguanidine in vitro and in intragastric tract of rats

The effects of tea extracts and their ingredients, catechins and L-ascorbic acid (AsA), on the mutagenicity of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) were examined in vitro and in the stomachs of rats using E. coli WP2 and S. typhimurium TA100. The extracts of green tea and black tea leaves decreased the mutagenic activity of MNNG to E. coli WP2 in vitro in a desmutagenic manner. Catechins such as (-)-epigallocatechin from green tea leaves and the low-molecular-weight tannin fraction isolated from black tea extract with HP-20 resin also exhibited inhibitory effects against the mutagenic activity of MNNG. A desmutagenic effect of AsA on MNNG-induced mutagenicity was observed depending on the dose, though it was complicated. The effects were also demonstrated in the stomachs of rats by assaying the bacterial mutagenic in vitro; the tea extracts previously given orally to rats reduced the mutagenic activity of MNNG remarkably, though simultaneous administration showed less effect. The effectiveness of tea extracts for the decrease of MNNG-induced mutagenesis in vitro and in vivo suggests that the habitual drinking of tea may reduce the tumor-initiating potency of MNNG-type nitrosoureido compounds if they are formed in the stomach.