15-芳亚甲基脱水穿心莲内酯的合成与抗菌活性

以脱水穿心莲内酯为原料与2个取代苯甲醛缩合得到2个15-芳亚甲基取代的脱水穿心莲内酯,进一步对其C-3,19位羟基衍生化,共得到14个衍生物,所有合成化合物均通过核磁共振仪(NMR)和高分辨质谱仪(HRMS)表征。在合成实验中,初步考察了C-3,19位乙酰化、C-3位羟基氧化和C-19位脱保护的方法。抗菌活性筛选实验研究发现,化合物G2对粪肠球菌的抑制能力优于脱水穿心莲内酯,有一定的研究价值。     

(1R,2S,3R,4S,6R)-2,3,4-三羟基-2-(苄氧羰基氨基)-环己烷甲酸苄酯的高立体选择性合成

多羟基环己基手性β-氨基酸及其衍生物具有重要的药物、生物和合成用途.本文对从内消旋cis-1,2,3,6-四氢邻苯二甲酸酐经去对称化得到的内酯关键中间体(2)的绝对构型进行了确定,并通过邻二羟基化和内酯开环,经两步反应以45%的产率从化合物(2)高立体选择性地合成了光学活性的(1R,2S,3R,4S,6R)-2,3,4-三羟基-2-(苄氧羰基氨基)-环己烷甲酸苄酯(6).     

马齿苋乙酸乙酯萃取物化学成分研究

采用硅胶柱色谱及HPLC等分离方法对干燥马齿苋全草甲醇浸提液乙酸乙酯萃取物进行分离纯化,共分离得到6个单体化合物,其中4个内酯类化合物,2个紫罗兰酮类化合物,通过分析波谱数据并根据其理化性质等确定其结构,分别为:羟基二氢博伏内酯⑴、黑麦草内酯(2)、异黑麦草内酯(3)、脱氢地芰普内酯(4)、3-羟基-5,6-环氧-β-...     

银杏萜内酯A、B、C和白果内酯的热特征分析

研究银杏萜内酯A、B、C和白果内酯的热特征并探讨鉴定这些化合物的新方法.用热重分析法(TGA)和差示扫描量热法(DSC)分别对银杏萜内酯A、B、C和白果内酯进行热特征分析.所有样品的热重(TG)和微商热重(DTG)曲线都有各自的谱图特征,其DSC曲线的峰形、峰位置和峰值也有特征;银杏萜内酯A、B、C的稳定性较差,不能准确测得其熔点;白果内酯受热稳定,能够测得其熔点.利用TGA和DSC法容易鉴定银杏萜内酯A、B、C和白果内酯.用TG-DTG法对银杏萜内酯A、B、C和白果内酯在非等温条件下进行热分解动力学研究,把从TG-DTG曲线中得到的数据和30个不同的方程采用Achar微分法和Madhusudanan-Krishnan-Ninan(MKN)积分法对其进行非等温分解动力学研究,得到动力学参数活化能(E和指前因子A)和分解动力学机理及方程.     

8,8-二取代-2-氧杂双环[3.2.1]-辛-3-酮类化合物的合成

以2-甲基-1,3-环戊二酮为原料,经过烷基化,Wittig-H orner反应,催化氢化,硼氢化钠还原,酸催化下分子内酯交换反应,合成了相应的双环内酯,共十六个化合物,其中十二个未见报道.通过IR,1NHMR,元素分析或质谱分析确定了化合物的结构.通过1NHMR确定了6个顺反异构体的构型.     

24-亚甲基胆甾-4-烯-3β,6β-二醇的合成

从豆甾醇出发,先合成了胆甾-5-烯-24-酮-3β-乙酸酯(2);再用过甲酸将2的5,6位双键氧化为环氧化物,后者在碱性条件下立体专一地开环得胆甾-3β,5α,6β-三羟基-24-酮(3),用醋酐将化合物3的C3-βOH和C6-βOH乙酰化保护后用亚硫酰氯脱水得胆甾-4-烯-24-酮基-3β,6β-二乙酸酯(4),4在碱性条件下脱去乙酰基得胆甾-4-烯-3β,6β-二羟基-24-酮(5);化合物5通过Wittig反应将C-24羰基亚甲基化得到目标化合物24-亚甲基胆甾-4-烯-3β,6β-二醇1,总产率为26%.合成化合物1的光谱数据与分离得到的天然物完全一致.     

蒿属植物中倍半萜α—亚甲基γ—内酯圆二色谱的研究

本文用园二色谱(cD)对七个倍半萜内酯中B、c环的稠合方式、及化合物的绝对构型进行了研究.     

新型C12吡唑啉酮酮内酯的合成与抗菌活性

根据酮内酯的构效关系和生物电子等排原理,设计、合成了新型C12吡唑啉酮酮内酯(1).1以吡唑啉酮结构单元替代泰利霉素11,12 - 氨基甲酸内酯环,以克拉霉素衍生物为原料合成 1. 1对红霉素敏感菌和耐药菌的体外活性测试表明:1对金黄色葡萄球菌(ATCC 6538p)和表皮葡萄菌(ATCC 12228)有良好的抑菌活性.     

天然岩藻糖苷酶的抑制剂L-deoxygulojirimycin关键中间体的不对称合成

报道一种合成天然氮杂糖L-deoxygulojirimycin关键中间体及全保护L-gulono-1,5-lactam的方法.其关键反应之一为二碘化钐(SmI2)促进下对硅基保护的3-羟基戊二酰亚胺10的C-2位的区域和立体选择性不对称羟甲基化,区域选择性为80:20,立体选择性为93:7;另一关键反应为采用OsO4-NMO体系对18进行不对称双羟基化反应,立体选择性单一,并通过NOE确定产物的立体化学.     

臭椿中新苦木苦素的结构鉴定

采用现代色谱和波谱技术 ,对采自甘肃省甘谷县的臭椿 (Ailanthusaltissima)根皮进行化学成分研究。从其乙醇提取物中分离得到 2个化合物 ,确定了它们的化学结构。二者均为未见报道的新臭椿苦内酯 ,命名为1α ,11α_epoxy_2 β ,11β ,12 β ,2 0_tetrahydroxypicrasa_3,13_ (2 1)_dien_16_one和 1α ,11α_epoxy_2 β ,11β ,12α ,2 0_tetrahydroxypicrasa_3,13_ (2 1)_dien_16_one。并对其抗癌活性进行了初步测试。     

黄檗不同家系子代生长性状比较

通过不同子代幼苗苗高和地径对比,分析黄檗种源间、家系间和家系内个体间生长性状变异规律.结果表明:不同种源间苗高差异不显著,地径差异显著(F=41.22~(**)),临江黄檗幼苗苗高和地径均值均大于黑龙江黄檗;种源内不同家系间苗高的差异均达到极显著水平(F=34.74~(**)和F=34.48~(**)),黑龙江种源12号(H-12)在所有家系中苗高表现最好,临江种源中优良家系数量较多.两个种源内不同家系间地径的差异也达到极显著水平(F=9.19~(**)和F=15.40~(**)),临江种源1号家系(L-1)幼苗地径最大,黑龙江种源12号家系(H-12)幼苗地径最大;黄檗幼苗苗高与地径呈极显著正相关(相关系数为0.67~(**)).在优良家系内苗高最优良单株是黑龙江种源12号家系第1号单株(H-12-1),苗高为95 cm;地径最优良的单株是临江种源第22号家系第17号单株(L-22-17),地径为10.47 mm.     

人肿瘤细胞株中细小病毒H—1的DNA扩增与非结构蛋白NS—1基因的表达

研究三株人癌细胞和两株对照细胞对细小病毒Ｈ－１杀伤作用敏感性的分子机制．表明了在感染复数ｍｏｉ（ｍｕｌｔｉｐｉｃｉｔｙｏｆｉｎｆｅｃｔｉｏｎ）为５ｐｆｕ（ｐｌａｑｕｅｆｏｒｍｉｎｇｕｎｉｔ）／细胞的情况下，作为Ｈ—１病毒复制受纳细胞的人肝癌细胞株ＯＧＹ－７７０３和人胃癌细胞株ＳＧＣ—７９０１，能够支持病毒ＤＮＡ扩增和非结构蛋白ＮＳ—１基因的表达，这和作为阳性对照的由ＳＶ４０转化的新生儿肾细胞株ＮＢ—Ｋ一样，但对Ｈ—１病毒感染有抗性的人肾癌细胞株ＯＵＲ—１０和它的对照人胎肾细胞株ＨｕＫ—１，并不支持病毒ＤＮＡ扩增和ＮＳ—１蛋白的表达．本文结果指出，细小病毒Ｈ—１的杀伤作用与细胞中的病毒ＤＮＡ扩增及ＮＳ—１基因表达的程度相关．     

Inversion in the H-2 complex of t-haplotypes in mice

Mouse t-haplotypes demonstrate strong linkage disequilibrium between t-lethal genes and specific H-2 types, presumably a result of recombination suppression between t and normal chromosomes. The observation of free recombination occurring between two complementary t-haplotypes suggested a chromosomal mismatch between t and normal chromosomes. Recent data showing the H-2 complex to be misplaced relative to two other markers, T and tf, in t-haplotypes suggested that chromosomal rearrangement in t-haplotypes might be the basis for their 'mismatch' with the normal chromosome. Here, to analyse the molecular nature of the rearrangement, we have cloned a polymorphic H-2 class I restriction fragment, which had previously been shown to map centromeric to the serologically defined H-2 complex in t-haplotypes. Genetic mapping studies show that this cloned t-DNA is homologous to the H-2 D region of wild-type chromosomes, and that the E alpha Ia gene maps telomeric to this DNA fragment in t-haplotypes, in contrast to its orientation in wild-type chromosomes. These results give molecular evidence for an inversion of H-2 in t-haplotypes, which may be at least partially responsible for recombination suppression and thus for linkage disequilibrium.     

一类Hopf路余代数的不可约表示

设D2是二面体群,H是群代数kD2上的一个Hopf路余代数,则H是非交换非余交换的.设T是H的Hopf理想,从而形成商代数H-=H/T.文中讨论了H-上的模表示,给出了H-上1维不可约模与2维不可约模,它们是H-上的互不同构所有不可约模.     

Recognition of H-2 domains by cytotoxic T lymphocytes

The polymorphic major histocompatibility antigens (H-2) have a crucial role in the activation of antigen-specific T lymphocytes. Thus, H-2 antigens are not only recognized by allogenic lymphocytes leading to generation of cytotoxic T lymphocytes (CTLs), but it has also been demonstrated that in syngeneic systems most T cells are only able to recognize foreign antigens in conjunction with their own MHC (major histocompatibility complex) antigens. This phenomenon, termed H-2 restriction, may be the key to our understanding to the biological function of MHC antigens. It is not clear whether recognition by T cells of H-2 on a molecular level is confined to particular domains on the H-2 molecule, nor whether the same polymorphic H-2 sites, which are characterized by antibodies, are recognized by allogeneic as well as by H-2 restricted syngeneic CTLs. Previous findings indicate the existence of at least two major polymorphic domains on the H-2Kk molecule as defined by antibodies. Here we show the existence of CTLs with specifity for these polymorphic domains, and the preferential recognition of a particular domain by both alloreactive as well as H-2 restricted CTLs.     

A potential donor gene for the bm1 gene conversion event in the C57BL mouse

The mammalian major histocompatibility complex (MHC; H-2 complex in mouse) is a large multigene complex which encodes cell-surface antigens involved in the cellular immune response to foreign antigens. Class I polypeptides expressed at the H-2K and H-2D loci of numerous mouse strains exhibit an unusually high degree of genetic polymorphism, which is assumed to be related to their function as primary recognition elements in the immune response. We suggested that this H-2 polymorphism may arise by gene conversion-like events between non-allelic class I genes. This is supported by our recent comparison of the DNA sequences of the normal H-2Kb gene sequence, from the C57BL/10 mouse, and a mutant form of this gene called H-2Kbm1: the mutant allele differs from the H-2Kb gene in seven bases out of a region of 13 bases in exon 3 of the class I gene (which encodes alpha 2 (C1) the second highly polymorphic protein domain), suggesting that this region of new sequence had been introduced into the H-2Kb sequence following unequal pairing of two class I genes in the genome of the C57BL mouse. Schulze et al. have obtained similar results. Here we report work identifying a potential donor gene in our library of 26 class I genes cloned from the C57BL/10 mouse.     

Positive and negative selection of an antigen receptor on T cells in transgenic mice

The T-cell repertoire found in the periphery is thought to be shaped by two developmental events in the thymus that involve the antigen receptors of T lymphocytes. First, interactions between T cells and major histocompatibility complex (MHC) molecules select a T-cell repertoire skewed towards recognition of antigens in the context of self-MHC molecules. In addition, T cells that react strongly to self-MHC molecules are eliminated by a process called self-tolerance. We have recently described transgenic mice expressing the alpha beta T-cell receptor from the cytotoxic T lymphocyte 2C (ref. 11). The clone 2C was derived from a BALB.B (H-2b) anti-BALB/c (H-2d) mixed lymphocyte culture and is specific for the Ld class I MHC antigen. In transgenic H-2b mice, a large fraction of T cells in the periphery expressed the 2C T-cell receptor. These T cells were predominantly CD4-CD8+ and were able to specifically lyse target cells bearing Ld. We now report that in the periphery of transgenic mice expressing Ld, functional T cells bearing the 2C T-cell receptor were deleted. This elimination of autoreactive T cells appears to take place at or before the CD4+CD8+ stage in thymocyte development. In addition, we report that in H-2s mice, a non-autoreactive target haplotype, large numbers of CD8+ T cells bearing the 2C T-cell receptor were not found, providing strong evidence for the positive selection of the 2C T-cell receptor specificity by H-2b molecules.     

Identity of cells that imprint H-2-restricted T-cell specificity in the thymus

The thymus has two important roles in controlling the specificity of T lymphocytes. First, T cells differentiating in the thymus are rendered tolerant of 'self' antigens, particularly antigens encoded by the major histocompatibility complex, the H-2 complex in mice. Second, the thymus imbues T cells with the property of H-2-restricted recognition of antigen, that is, the capacity of T cells to react with foreign antigens presented in association with self H-2 gene products. Until recently it has generally been assumed that self-tolerance and H-2-restricted specificity both reflect early T-cell contact with self H-2 determinants expressed on thymic epithelial cells. Recent evidence suggests, however, that intrathymic cells of the macrophage/dendritic cell (Mphi/DC) lineage also have a role in shaping T-cell specificity. In particular, it has been found that the tolerance to graft-type H-2 determinants which normally ensues when T cells differentiate in an H-2-different thymus fails to occur when the thymus is pretreated with deoxyguanosine (dGuo), a procedure that selectively destroys Mphi/DC but spares epithelial cells. In contrast to these findings on tolerance induction, evidence is presented here that dGuo-treated thymus grafts do imprint T cells with H--2-restricted specificity for antigen. It appears, therefore, that induction of tolerance and H--2 restriction are controlled by different cells in the thymus.     

几种低温微生物菌株及其组合对北方农村生活污水处理效果

针对北方地区农村厕改废水冬季处理效率低的问题,从低温驯化的活性污泥中分离筛选出8株在10 ℃下具有较高降解能力的耐冷菌株,研究其混菌作用效果并制成菌剂。结果表明：单一菌处理时,假单胞菌H-30对模拟农村生活污水的化学需氧量（chemical oxygen demand,COD）去除率最高,为88.6%;8株耐冷菌H-7、H-10、H-29、H-30、H-33、H-36、H-40、H-54按最优体积比2：1：4：4：4：1：1：1混合后对实际农村生活污水COD去除率可达94.1%,按此比例制成的菌剂在10℃下对实际农村生活污水的COD去除率为83.6%,出水COD为92.45 mg/L,达到我国农田灌溉水质标准。