含酯糖链皂甙的负离子快原子轰击质谱分析

本实验用负离子快原子轰击(FAB)法测定了8个含酯糖链的双糖链皂甙样品,给出了明显的脱质子分子离子峰,由碎片离子峰可推测糖基的连接顺序;不仅对难挥发、热不稳定和极性大的样品可直接进样分析,而且对在酯糖链皂甙中出现以酯裂解为基峰的碎片,还可初步确定糖链在甙元上的连接位置。     

β—（酚酯基）乙基锗倍半氧化物的合成及对体外培养细胞的作用

β-羧基乙基锗倍半氧化物(即Ge-132)是一种无毒和具较强抗癌活性的有机锗化合物。为了进一步提高其抗癌活性。已对Ge-132进行了化学结构修饰。本文介绍8种未见报导的Ge-132衍生物,β-酚酯基乙基锗倍半氧化物的合成和体外培养细胞实验结果。     

3-丁烯酮-吲哚衍生物的合成

吲哚类化合物广泛存在于植物界中, 且具有多种生理活性。其中, 月橘烯碱具有抗生育活性。本文以合成月橘烯碱的中间体3-(1-丁烯酮-3)吲哚为起始物, 并设计了10个与其结构类似的单吲哚化合物, 并做了小鼠的药理实验。     

O~6-METHYLGUANINE-DNA METHYLTRANSFERASE AND HUMAN CANCER CHEMOTHERAPY

Two kinds of human tumor cell strains having different activity of O~6-methylguanine-DNA methyltransferase (O~6-MT) were transplanted into nude mice. Then the mice were inject-ed intraperitoneally with bifunctional alkylating agent 1--(4--amino--2-methyl--5--pyrimidinyl)methy1-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU). The tumors with low O~6-MTactivity were quickly suppressed or cured. The result suggests that some tumors, if previ-sionally determined with low O~6-MT activity, might be efficiently cured by treatment withACNU. This probably opens a new way for human cancer chemotherapy.     

A Novel Protoilludane Sesquiterpene from the Wood of Xanthoceras sorbifolia

In the course of our searching for anti-HIV agents from natural sources, we have isolated a triterpene and a doubly linked proanthocyanidin dimer as HIV-1 protease inhibitors from the wood of Xanthoceras sorbifolia Bunge (Sapindaceae)1. Further investigation of this plant has led to the isolation of a protoilludane sesquiterpene (1). The present paper describes the isolation and structural determination of this novel sesquiterpene. The EtOH eluate of a MeOH extract of the wood of X. so…     

A New Cyclic Bisdesmoside from Tubers of Bolbostemma paniculatum

The structure of tubeimoside V (1), a new cyclic bisdesmoside, isolated from tubers of Bolbostemma paniculatum (Tu Bei Mu), was established by means of 2D NMR spectral and chemical methods. Compound 1 has inter-saccharide chain bridging by a dicrotalic acid to form aunique macrocyclic structure.     

An Unusual Formation of Cyclic Sulfite at C-4 and C-5 Positions of Taxane

An unusual formation of cyclic sulfite at C-4 and C-5 positions of taxane was accomplished by treatment of compound 1 with excess MeSOEC1/Et3N and a possible mechanism was proposed.     

双氢埃托啡的^1H, ^1^3C NMR和立体化学

双氢埃托啡(1)为合成的高效镇痛剂。药理实验结果表示,其镇痛作用优于吗啡。该化合物的~1H和~(13)C NMR谱都较为复杂,尚未见报道,并且多数谱峰采用一般方法难以指定。     

The Synthesis of α-DDB, β-DDB and Theoretical Study with AM1

Biphenyl units are present in a wide range of compounds both natural and synthetic, and many of them have pharmacological activity1. Xie Jingxi et al. found that dimethyl 4,4'-dimethoxy-5,6,5',6'-dimethylenedioxybiphenyl-2,2'-dicarboxylate((-DDB) as an important intermediate for the synthesis of Schizandrin C analogue which is effective in lowering elevated SGPT level2-3. Two isomers dimethyl 6,6'-dimethoxy-4,5,4',5'-dimethylenedioxybiphenyl-2,2'-dicarboxylate ((-DDB) and 6,4,-dimethoxy-4…     

Study on the Ring Eulargment Reaction: Synthesis of 7,8,13, 13a-tetrahydroisoindolo[1,2-b][3]benzazepine and 5,6,8,9,14,14a-hexahydroisoquino[1,2-b][3]benzazepine

In our research on the ring enlargement of certain N-heterocycles, a general procedure for the ring enlargement with the insertion of an extra -CH2- was improved and shown in Scheme I1.Scheme IThe procedure had been carried out with such N-heterocycles as 2-methyl-1,2,3,4-tetrahydroisoquinoline2, tetrahydroberberine and strychnine3 with expected results. Thus, the procedure shown in Scheme I provides a new approach to the synthesis of larger N-heterocycles.Isoindolo[1,2-b][3]benzazepines a…