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1.
大萼香茶菜乙素和己素的化学结构   总被引:2,自引:0,他引:2  
从大萼香茶菜[Rabdosia m acrocalyx(Dunn) Hara]叶的乙醇提取物中又分得两种二萜类成分,经IR、MS、1 H-1H COSY、13C-1 H COSY 和NOE等光谱分析及衍生物制备,确证其化学结构为新型二萜,分别命名为大萼香茶菜乙素和己素  相似文献   

2.
新雷公藤内酯四醇的研究   总被引:1,自引:0,他引:1  
从雷公藤(Tripterygium w ilfordiiHook. f.)的叶和根中分离到一个新的环氧二萜内酯化合物,据其理化性质,UV、IR、MS、1H-NMR、13C-NMR、13C-NOE、2D-COSY、2D-NOESY 和选择性远程DEPT谱等光谱数据分析,并结合分子图形学和分子力学计算确定了它的化学结构,命名为新雷公藤内酯四醇(neotriptetraolide). 该产物为首次从植物中分得的新化合物  相似文献   

3.
大萼香茶菜庚素的化学结构   总被引:2,自引:0,他引:2  
从大萼香茶菜(Rabdosia m acrocalyx (Dunn) Hara)叶的乙醇提取物中又分离到3 个二萜成分(结晶Ⅰ、Ⅱ、Ⅲ),通过IR、MS、1H-1H COSY、13C-1H COSY和NOE等光谱分析及衍生物的制备,确定结晶Ⅰ的结构为ent-7β-20-epoxy-6α, 7α,14α,15α,16α-pentahydrokaurane-17-ac-etate,为新的二萜化合物,命名为大萼香茶菜庚素;结晶Ⅱ和Ⅲ为已知化合物rabdophyllin H和ponicidin。  相似文献   

4.
土壤重金属作物效应的区域分异   总被引:4,自引:0,他引:4  
夏增禄 《生态学报》1994,14(1):102-108
土壤重金属作物效应的区域分异REGIONALDIFFERENTIATIONOFEFFECTOFHEAVYMETALSINSOILONPLANT关于土壤重金属的作物效应已有大量报道 ̄[1-3]。但关于土壤重金属作物效应区域分异的研究结果,却极少见到报道...  相似文献   

5.
利用自编的脉冲程序,采用预饱和和自旋锁定对水峰进行双重抑制的方法,得到了^15N标记蛋白GAL4(62)的2D^1H-^15NHSQC、HSQC-NOESY、HSQC-TOCSY谱,并对这几个谱在蛋白质^1H谱的归属中所到的作用作了讨论。  相似文献   

6.
白头叶猴的性比与社会结构   总被引:3,自引:1,他引:2  
白头叶猴的性比与社会结构STUDYONSEXRATIOANDSOCIO-STRUCTUREOFFWHITE-HEADEDLEAFMONKEYKeywordsWhite-headedleafmonkey;Sexratio;Socio-structure...  相似文献   

7.
描述了从虎纹捕鸟蛛毒液分离的凝集素SHL-I的核磁共振氢谱谱峰的完全归属。通过分析二维DQF-COSY,COSY,TOCSY和NOESY谱,鉴别出全部32个氨基酸残基自旋体系。然后由COSY,NOESY谱指纹区的dαN连系推测出序列专一归属,并得到了TOCSY和NOESY谱中dαN,dNN的验证。从而明确分辨了除Cys2外所有主链质子和大于96%的侧链质子。这一结果为最终确定SHL-I的溶液构象奠定了基础。  相似文献   

8.
目的:研究云南红豆杉中四种紫杉烷类二萜成分化合物(2-去乙酰氧基紫杉宁E、7-去乙酰氧基紫杉宁J、2-去乙酰氧基去肉桂酰基紫杉宁、巴宁亭酸)的安全性。方法:采用Alarmblue检测采用四种紫杉烷类二萜成分化合物在CHL细胞上的细胞毒性,采用CHL细胞染色体畸变实验和Ames试验,观察云南红豆杉中四种紫杉烷类二萜成分化合物遗传毒性作用。结果:四种紫杉烷类二萜成分化合物在CHL细胞株上IC500.5 mg/m L;未对鼠伤寒沙门氏杆菌组氨酸缺陷型菌株回复突变数产生影响;未使得CHL染色体畸变率增加。结论:在本实验条件下,未观察到2-去乙酰氧基紫杉宁E、7-去乙酰氧基紫杉宁J、2-去乙酰氧基去肉桂酰基紫杉宁、巴宁亭酸对CHL细胞有明显的细胞毒性以及未观察到体外遗传毒性。  相似文献   

9.
从羊红膻(PimpinelathelungianaWolf)根的75%乙醇提取物的乙醚萃取部分,分得一化合物。经光谱(UV、IR、1HNMR、13CNMR、1H1HCOSY、1H13CCOSY和MS)分析,确定为新化合物2(1甲氧基2羟基)丙基4甲氧基苯酚,命名为羊红膻素E(thelungianinE)。  相似文献   

10.
紫外线对大豆胚芽化学发光的影响   总被引:1,自引:0,他引:1  
范立通 《植物学通报》1995,12(1):44-46,48
紫外线对大豆胚芽化学发光的影响范立通(山西大学分子科学研究所,太原03006)EFFECTOFUTRAVIOLETRAYONTHECHEMILUM-INESCENCEOFSOYBEANEMBRYONICSHOOT¥Fanli-tong(Institu...  相似文献   

11.
The paper reviewed the 13C-NMR features of natural taxane diterpenoids according to their carbon-skeleton types. In the 13C-NMR it is easy to distinguish the 6/8/6 and 5/7/6 membered rings by observation of the 13C-NMR data of C-1 and C-15. The remarkable differences of the resonance of C -13 and C-12 were found. In addition, based on various chemical environments man y obscured chemical shifts of carbons can be distinguished, such as the oxygenat ed tertiary carbons of C-2, C-5, C-7, C-9 and C-13, and sometimes between C-9 an d C-10, as well as between aliphatic quaternary carbons of C-8 and C-15, and sec ondary carbons of C-6 and C-14. All the above-mentioned characteristics are helpful for structural elucidation and assignments of the carbon signals of taxoids.  相似文献   

12.
In many organisms, various enzymes mediate site-specific carotenoid cleavage to generate biologically active apocarotenoids. These carotenoid-derived products include provitamin A, hormones, and flavor and fragrance molecules. In plants, the CCD1 enzyme cleaves carotenoids at 9,10 (9',10') bonds to generate multiple apocarotenoid products. Here we systematically analyzed volatile apocarotenoids generated by maize CCD1 (ZmCCD1) from multiple carotenoid substrates. ZmCCD1 did not cleave geranylgeranyl diphosphate or phytoene but did cleave other linear and cyclic carotenoids, producing volatiles derived from 9,10 (9',10') bond cleavage. Additionally the Arabidopsis, maize, and tomato CCD1 enzymes all cleaved lycopene to generate 6-methyl-5-hepten-2-one. 6-Methyl-5-hepten-2-one, an important flavor volatile in tomato, was produced by cleavage of the 5,6 or 5',6' bond positions of lycopene but not geranylgeranyl diphosphate, zeta-carotene, or phytoene. In vitro, ZmCCD1 cleaved linear and cyclic carotenoids with equal efficiency. Based on the pattern of apocarotenoid volatiles produced, we propose that CCD1 recognizes its cleavage site based on the saturation status between carbons 7 and 8 (7' and 8') and carbons 11 and 12 (11' and 12') as well as the methyl groups on carbons 5, 9, and 13 (5', 9', and 13').  相似文献   

13.
The biosynthetic pathways to abscisic acid (ABA) were investigated by feeding [1-(13)C]-D-glucose to cuttings from young tulip tree shoots and to two ABA-producing phytopathogenic fungi. 13C-NMR spectra of the ABA samples isolated showed that the carbons at 1, 5, 6, 4', 7' and 9' of ABA from the tulip tree were labeled with 13C, while the carbons at 2, 4, 6, 1', 3', 5', 7', 8' and 9' of ABA from the fungi were labeled with 13C. The former corresponds to C-1 and -5 of isopentenyl pyrophosphate, and the latter to C-2, -4 and -5 of isopentenyl pyrophosphate. This finding reveals that ABA was biosynthesized by the non-mevalonate pathway in the plant, and by the mevalonate pathway in the fungi. 13C-Labeled beta-carotene from the tulip tree showed that the positions of the labeled carbons were the same as those of ABA, being consistent with the biosynthesis of ABA via carotenoids. Lipiferolide of the tulip tree was also biosynthesized by the non-mevalonate pathway.  相似文献   

14.
以固氮菌和解磷菌筛选拮抗作物病害的细菌组合   总被引:1,自引:0,他引:1  
用选择性培养基从土壤分离筛选了22 种具有固N或解P能力的细菌,不进行纯化,分组混合接种于15种液体培养基,进行继代培养,每代培养48 h.第12代时,各细菌组合的菌类数目及比例达到稳定状态,共获得15个细菌组合,各组合均含有2~3种细菌.对茄黄萎病病原菌(Verticillium dahliae)、棉花立枯病病原菌(Rhizoctonia solani)和黄瓜角斑病病原菌(Pseudomonas syringae)等9种植物病原菌进行平皿抑菌试验,筛选出7个具有抑菌作用的细菌组合,进一步从植株盆栽试验中筛选出6个有防病作用的组合,其中C7和C15表现出最明显的抑菌防病效果.C15保持了固N能力,C4、C5、C7、C9、C14和C15保持了解P能力.结果表明,这是一条可获得具有协同作用的、稳定的多功能生防菌剂的途径.  相似文献   

15.
摘要: 【目的】初步搞清一株蛹拟青霉(Paecilomyces militaris )菌株RCEF0927在发酵罐发酵条件下发酵液的抗中国仓鼠卵巢瘤(CHO)细胞活性及活性成分的具体组成。【方法】用刃天青(Resazurin)法测定样品对CHO细胞的抑制率;用高效液相色谱-高分辨质谱和活性测定联用的方法进行活性成分分析和鉴定。【结果】活性测定结果表明菌株RCEF0927经发酵罐发酵的发酵液具有较强的抗CHO细胞活性;提取实验结果表明抗肿瘤活性物质能较好地被乙酸乙酯提取出来;液相色谱-质谱-活性测定分析表明  相似文献   

16.
The synthesis of 9 alpha,11 alpha-epoxy-5 alpha-cholest-7-ene-3 beta,5,6 beta-triol (1), a highly oxygenated marine sterol containing a 9,11-epoxide moiety in the nucleus, is described. Epoxy sterol 1 was synthesized from cholesta-5,7-dien-3 beta-ol. Oxidation of this sterol with m-chloroperbenzoic acid followed by hydrolysis and acetylation furnished 5 alpha-cholest-7-ene-3 beta,5,6 alpha-triol 3,6-diacetate (2). Mercuric acetate dehydrogenation of diacetate 2, followed by oxidation with manganese dioxide and epoxidation with m-chloroper-benzoic acid, afforded 9 alpha,11 alpha-epoxy-3 beta,5-dihydroxy-5 alpha-cholest-7-en-6-one (5). Reduction of 5 with lithium aluminum hydride gave the desired compound 1. The structures of all synthetic intermediates were confirmed by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. A reassignment of resonances for carbons 1, 8, and 15 in the 13C NMR spectrum of 1, based on 2D-NMR correlation spectroscopy, has been accomplished.  相似文献   

17.
A swine resource family was constructed at the National Institute of Animal Industry, Japan, in order to determine the genetic regions responsible for economically important traits, including fetus development. To identify genes expressed in the early stage of embryo development, we cataloged and mapped genes expressed in a 28-day-old normal pig embryo. In this effort, we have mapped 64 genes, which have map information in human genome onto a swine radiation hybrid (RH) map, IMpRH. These mappings provided additional chromosomal homologies between swine and human to improve the comparative map between the two species. The distribution of the genes assigned to swine chromosomes are as follows: 9 genes were assigned on SSC6; 6 genes each assigned on SSC5 and SSC14; 5 genes each assigned on SSC3, SSC4, and SSC8; 4 genes each assigned on SSC1, SSC7, SSC9, and SSC15; 3 genes each assigned on SSC2, SSC13 and SSCX; and 1 gene each assigned on SSC10, SSC11, and SSC16. Moreover, the present findings revealed 18 new chromosomal homologies between pig and human. Briefly, SSC3 regions were indicated to correspond with HSA1 and HSA10; SSC4 with HSA6; SSC5 with HSA2, HSA15, and HSA16; SSC6 with HSA3, HSA6, and HSA20; SSC7 with HSA11; SSC8 with HSA3, HSA6, and HSA7; SSC9 with HSA8; SSC13 with HSA1; SSC14 with HSA13; SSC15 with HSA19; SSC16 with HSA9. Received: 19 December 2000 / Accepted: 13 March 2001  相似文献   

18.
19.
落叶松落叶病的生态因子及其生态模型的研究   总被引:4,自引:0,他引:4  
通过1987-1991年在吉林省磐石等3个县(市17)个林场300余块长白落叶松(Larix olgensis)人工林标准地调查、定点观察试验和统计分析表明,落叶松落叶病(Mycosphaerella Larici-leptolepis)的林分病情指数与林分密度、林分类型、平均枝下高、土壤种类、林龄和林分地形有密切关系;对1990年103块标准地的数量化理论1分析,其偏相关系数分别为0.723、0  相似文献   

20.
Solvolytic rearrangement of the C/D ring system of the tetracyclic diterpenoid stemodinone (2) afforded the compounds 15(13-->12)abeo-13beta-hydroxystemaran-2-one (5) and 15(8-->9)abeo-8beta(H)-12beta-hydroxystachan-2-one (10). Terpene 5 possesses a novel diterpene skeleton. Oxidation of these compounds yielded their respective diketones. Bioconversion of 5 by Rhizopus oryzae yielded 15(13-->12)abeo-7beta,13beta-dihydroxystemaran-2-one (18) while microbial transformation of 10 provided 15(8-->9)abeo-8beta(H)-6alpha,12beta-dihydroxystachan-2-one (19), 15(8-->9)abeo-8beta(H)-7beta,12beta-dihydroxystachan-2-one (20) and 15(8-->9)abeo-8beta(H)-6alpha,12beta,14beta-trihydroxystachan-2-one (21). A rationale for the formation of the rearranged compounds is proposed.  相似文献   

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