卵叶娃儿藤中的抗癌活性生物碱

从卵叶娃儿藤(Tylophora ovata (Lindl.) Hook. ex Steud.)根中分离得到 4个菲骈吲哚里西丁类生物碱,分别为tylophoridicine A (1)、娃儿藤宁(2)、氧甲基娃儿藤定(3)和娃儿藤定(4).经波谱分析并结合化学方法鉴定,其结构分别为:(13aR)-6-羟基-3,7-二甲氧基菲骈吲哚里西丁、 (13aS ,14R)-14-羟基-3,6,7-三甲氧基-菲骈吲哚里西丁、(13aS, 14S)-14-羟基-3,6,7-三甲氧基-菲骈吲哚里西丁和(13 aS,14S)-6,14-二羟基-3,7-二甲氧基-菲骈吲哚里西丁.化合物1为新化合物,化合物2-4为首次从该植物得到的化合物.经药理筛选,化合物1、3和4显示很强的抗癌活性.     

具抗癌活性的菲并吲哚里西丁类生物碱构效关系及不对称全合成研究进展

菲并吲哚里西丁类生物碱最引人瞩目的生物活性是抗肿瘤活性,本文对这类天然小分子化合物的构效关系和主要不对称全合成路线做了综述,以期为有机化学工作者开发高抗癌活性的菲并吲哚里西啶类生物碱提供参考。     

白花银背藤中的生物碱及其细胞毒活性研究

为研究白花银背藤(Argyreia seguinii)的生物碱类成分及其细胞毒活性,该研究采用硅胶、ODS、Sephadex LH-20及半制备HPLC等柱色谱法对白花银背藤的75%乙醇提取物进行分离纯化,根据理化性质及波谱数据鉴定化合物的结构,并通过MTS法检测化合物对5种肿瘤细胞的增殖抑制活性。结果表明：从白花银背藤中分离得到9个生物碱类化合物,分别鉴定为N-反式桂皮酰对羟基苯乙胺(1)、N-反式对香豆酰基酪胺(2)、N-反式阿魏酰酪胺(3)、N-顺式阿魏酰酪胺(4)、1H-吲哚-3-甲醇(5)、金色酰胺醇酯(6)、8-氧-四氢巴马亭(7)、8-oxypalmatine(8)和12,13-dihydro-8-oxoberberine(9)。其中,化合物1、4-9均为首次从该植物中分离得到,化合物7和化合物8对肝癌SMMC-7721细胞显示细胞毒活性,半抑制浓度(IC₅₀)值分别为(15.50±0.76)、(14.24±0.72)μmol·L^-1。该研究结果为进一步探讨白花银背藤的化学成分和药理活性奠定了基础,为厘清壮药“一匹绸”的药材基原...     

Alkaloids from Tylophora hirsuta

Five novel phenanthroindolizidine alkaloids, namely tylohirsutinine, 13a-methyltylohirsutine, 13a-methyltylohirsutinidine, tylohirsutinidine and 13a-hydroxysepticine, isolated from Tylophora hirsuta together with two unidentified bases are described. Structural studies indicate that the first four alkaloids possess the dibenzo [f, h]-pyrrolo-[1,2b]isoquinoline skeleton present in other Tylophora species, but differ in the presence of unsaturation in ring E or in the presence of an angular methyl function. The fifth alkaloid has been shown to be the 13a-hydroxy analogue of septicine.     

Progress in the Total Synthesis of Antitumor Tetrahydroisoquinoline Alkaloids

Among the tetrahydroisoquinoline(THIQ) of natural products, a family of THIQ alkaloids has the characteristics of similar biosynthetic pathway. Such THIQ alkaloids family mainly include Renieramycins, Ecteinasicdins, Tetrazaomine, Lemonomycin, etc. Most of these natural compounds have strong antitumor activities, and its family member Ecteinasicdins743 (ET-743, Trabectedin) has been marketed in the European Union and the United States for the treatment of advanced soft tissue tumors and ovarian cancer. Because of the excellent biological activity and complex chemical structure of this kind of THIQ products, it has aroused great interest of biologists and chemists, and many synthetic chemists have paid considerable efforts to their total synthesis over the past decade. Based on this, the recent advances in the total synthesis of such THIQ alkaloids are reviewed.     

C19-、C20-二萜生物碱抗肿瘤活性研究进展

二萜生物碱具有较高的药理活性和药用价值,一直以来为药理学家和临床医生所重视,但对于其抗肿瘤作用的报道却并不多见,主要集中于 C19-、C20- 二萜生物碱。综述近 10 年来 C19-、C20- 二萜生物碱抗肿瘤作用的基础及临床研究进展,并对当前研究存在的不足提出见解,为进一步研究及应用提供参考。     

脉叶虎皮楠的生物碱成分研究

从脉叶虎皮楠(Daphniphyllum paxianum)的枝干中分离并鉴定了四个生物碱,分别为daphnilactone A(1)、daphnicyclidin D(2)、daphniphylline(3)、daphnicyclidin H(4).其中首次对化合物1的碳谱数据进行了归属.     

Two Novel Diterpenoid Alkaloids Isolated from the Roots of Aconitum brevicalcaratum

Two new diterpenoid alkaloids were isolated from the roots of Aconitum brevicalcaratum Diels. They were acobretine D ( Ⅰ )and acobretine E ( Ⅱ ), and the structures of which were identified on the basis of spectroscopic evidences (IR, MS, 1 H and 13C-NMR) and confirmed by chemical transformations. The 1 H and 13C chemical shifts of the hydrochloride of Ⅰ were assigned in relation to of 1 H-1 H COSY and 13C-1 H COSY.     

Two New Buxus Alkaloids from Buxus Microphylla Sieb. et Zucc.

Five compounds were isolated from Buxus microphylla Sieb. et Zucc. Based on the physico-chemical constants and spectral analysis (IR, MS, 1H-NMR and 13C-NMR), they were identified as cycloprotobuxinamine ( Ⅰ ), buxmicrophylline A ( Ⅱ ), buxtauine M ( Ⅲ ), isoscopoletin (Ⅳ) and epi-lupeol ( Ⅴ ). ( Ⅰ ) and ( Ⅱ ) were new compounds. The structure of buxmicrophylline ( Ⅱ ) was confirmed by X-ray crystallographic analysis.     

Genetic Diversity of Ostreopsis ovata (Dinophyceae) from Malaysia

The genus Ostreopsis is an important component of benthic and epiphytic dinoflagellate assemblages in coral reefs and seaweed beds of Malaysia. Members of the species may produce toxins that contribute to ciguatera fish poisoning. In this study, two species have been isolated and cultured, Ostreopsis ovata and Ostreopsis lenticularis. Analyses of the 5.8S subunit and internal transcribed spacer regions ITS1 and ITS2 of the ribosomal RNA gene sequences of these two species showed that they are separate species, consistent with morphological designations. The nucleotide sequences of the 5.8S subunit and ITS1 and ITS2 regions of the rRNA gene were also used to evaluate the interpopulation and intrapopulation genetic diversity of O. ovata found in Malaysian waters. Results showed a low level of sequence divergence within populations. At the interpopulation level, the rRNA gene sequence distinguished two groups of genetically distinct strains, representative of a Malacca Straits group (isolates from Port Dickson) and a South China Sea group (isolates from Pulau Redang and Kota Kinabalu). Part of the sequences in the ITS regions may be useful in the design of oligonucleotide probes specific for each group. Results from this study show that the ITS regions can be used as genetic markers for taxonomic, biogeographic, and fine-scale population studies of this species. Received September 15, 2000; accepted December 15, 2000     

Oviposition-stimulatory activity of phenanthroindolizidine alkaloids of host-plant origin to a danaid butterfly, Ideopsis similis

Oviposition response of Ideopsis similis (L.) (Lepidoptera: Danaidae) was examined for 12 phenanthroindolizidine alkaloids present in its host plant, Tylophora tanakae (Maxim.) (Asclepiadaceae). At least five alkaloids, i.e. (+)‐isotylocrebrine (3,4,6,7‐tetramethoxyphenanthroindolizidine; l ), (+)‐3‐demethyliso‐ tylocrebrine ( 3 ), (+)‐isotylocrebrine N‐oxide ( 5 ), (+)‐6‐demethyltylocrebrine ( 8 ) and (–)‐7‐demethyltylophorine ( 10 ), were found to individually stimulate oviposition by females. Of these, compounds 1, 3 and 10 were regarded as key components most responsible for host recognition or preference. However, female egg‐laying was much higher in response to a mixture of the five alkaloids. In two‐choice bioassays, more eggs were deposited on samples comprising the five alkaloids than on samples consisting of a single alkaloid. This suggests strongly that host selection by the butterfly is mediated by the synergistic action of several phenanthroindolizidine alkaloids present in the host plant.     

茶树花多糖免疫调节与抗肿瘤活性的研究

茶树花富含多糖,是茶树生长过程中的产物,然而目前茶树花多糖(tea plant flow polysaccharide, TFP)尚未被充分利用．因此,认为茶树花多糖有着和茶叶中的多糖相似的功能效果．研究目的是通过系列的体内和体外实验系统来评价茶树花多糖的抗肿瘤以及免疫调节的活性．利用S180(sarcoma 180)荷瘤小鼠模型,系统地研究了灌胃不同剂量茶树花多糖对荷瘤小鼠的肉瘤抑制率、存活率以及细胞免疫的影响．结果显示,连续灌胃10天茶树花多糖,能显著抑制S180肉瘤的生长,延长荷瘤小鼠的存活时间,增强迟发型超敏作用(delayed-type hypersensitivity, DTH),促进血液白介素-2(IL-2)、γ-干扰素(IFN-γ)的分泌,增强巨噬细胞的吞噬作用,改善T淋巴细胞亚群CD4⁺数量以及CD4⁺/CD8⁺的比值,表明茶树花多糖能增强机体对肿瘤的防御,在一定程度上归功于其对免疫调节作用．