New taxanes from the needles of Taxus canadensis

Nine minor taxanes were identified for the first time in the Canadian yew needles. Four of these metabolites are new: 5-epi-cinnamoylcanadensene (1), 2,9,10, 13-tetraacetoxy-20-cinnamoyloxy-taxa-4(5),11(12)-diene (2), 2'-acetyl-epi-taxol (3), and 9-deacetyltaxinine E (4).     

New taxane analogues from the needles of Taxus canadensis

Eight minor taxanes have been identified for the first time in Taxus canadensis needles. Four of these metabolites are new taxane analogues: 7-acetyl-10-deacetyltaxol (1), 2'-acetyl-7-epi-cephalomannine (2), 10-deacetyl-10-oxo-7-epi-cephalomannine (3), and 10-acetylglycollylbaccatin VI (4).     

New minor taxane derivatives from the needles of Taxus canadensis

Seven minor taxane derivatives were isolated for the first time from the needles of Taxus canadensis. Four of these natural taxanes are O-glycosylated (1-4), with 4 being the only reported taxane with a glucose on ring C, and two have a dimethylamino-C-5 side chain (5 and 6). An unusual double bond at C-5(6) has been identified in taxane 7.     

Rearranged taxanes from the bark of Taxus yunnanensis

Five new 11(15-->1)-abeo-taxane diterpenoids, taxuyunnanines K-O (1-5), were isolated from an ethanol extract of the bark of Taxus yunnanensis, and their structures were determined using MS and NMR techniques. Compounds 1/2 and 4/5 are rearranged taxane diterpenoids possessing an opened oxetane ring moiety at C4(20). Compounds 4/5 are rearranged taxoids lacking an oxygenated functionality at C-4.     

New taxanes with an opened oxetane ring from the roots of Taxus mairei

Two novel taxoids, taxumairols N (1) and O (2), have been isolated from extracts of the roots of Taxus mairei. The structures of 1 and 2 were identified as 7beta,9alpha,10beta,13alpha-tetraacetoxy-2alp ha, 4alpha,5alpha,20-tetrahydroxytax-11-ene and 7beta,9alpha,10beta, 13alpha-tetraacetoxy-1beta,2alpha,4alpha,5alp ha, 20-pentahydroxytax-11-ene on the basis of 1D and 2D NMR techniques including COSY, HMQC, HMBC, and NOESY experiments.     

加拿大红豆杉针叶的化学成分(英文)

目的:对加拿大红豆杉(Taxus Canadensis)针叶的化学成分进行研究。方法:采用多种色谱手段进行分离,通过波谱解析确定化合物结构。结果:从加拿大红豆杉针叶中分离并鉴定了6个化合物:对羟基苯甲酸(p-hydroxybenzoic acid,1),putraflavone(2),sequoiavone(3),7,13-dideacetyl-9,10-debenzoyltaxchinin C(4),baccatin Ⅵ(5),taxumairone A(6)。结论:化合物1-2为首次从该属植物中分离得到,化合物3-6均为首次从该植物中分离得到。     

Taxanes from rooted cuttings of Taxus canadensis

A 3,11-cyclotaxane (1), a new epoxytaxane (2), an abeo-taxane (3), and 26 known taxanes were isolated in rooted cuttings of the Canadian yew (Taxus canadensis) for the first time. Their chemical structures were characterized as 1 beta,2 alpha,9 alpha-trihydroxy-10 beta-acetoxy-5 alpha-cinnamoyloxy-3,11-cyclotaxa-4(20)-en-13-one (1), 2 alpha,9 alpha,10 beta-triacetoxy-11,12-epoxy-20-hydroxytaxa-4-en-13-one (2), and 7 beta,9 alpha,10 beta,13 alpha-tetraacetoxy-11(15-->1)abeo-taxa-4(20),11-diene-5 alpha,15-diol (3). Metabolite 2 is a new taxane, metabolite 1 has been reported previously in the needles of Taxus baccata, and metabolite 3 was previously discovered as a biotransformation product but is now reported as a natural product for the first time.     

New regio- and stereoselective O-deacetylated and epoxy products of taxanes isolated from Taxus mairei

Deacylation of a taxoid mixture isolated from the roots of Taxus mairei followed by chromatographic fractionation resulted in the isolation of three new taxoid derivatives, 2alpha,9alpha,10beta-triacetoxy-5alpha,14beta-dihydroxy-4(20),11(12)-taxadiene (1), 9alpha,10beta-diacetoxy-2alpha,5alpha,14beta-trihydroxy-4(20),11(12)-taxadiene (2), and 9alpha,10beta-diacetoxy-2alpha,5alpha,14beta-trihydroxy-4,20-epoxy,11(12)-taxene (3). Epoxidation of 2 afforded 9alpha,10beta-diacetoxy-2alpha,5alpha,14beta-trihydroxy-4,20:11,12-diepoxytaxane (6), while epoxidation of 4 yielded 9alpha,10beta-diacetoxy-5alpha,13alpha-dihydroxy-4,20-epoxy,11(12)-taxene (7) and 9alpha,10beta-diacetoxy-5alpha,13alpha-dihydroxy-4,20:11,12-diepoxytaxane (8). The structures were elucidated by detailed analysis of their NMR spectra. The structure and relative stereochemistry of 7 was confirmed by X-ray crystallography.     

Three new C-14 oxygenated taxanes from the wood of Taxus yunnanensis

Three new C-14 oxygenated taxane-type diterpenes, hongdoushans A-C (1-3), were isolated from the wood of Taxus yunnanensis together with four known diterpenes and two lignans. The absolute stereochemistry of the 2-methylbutyryloxy group attached at C-14 of the taxane skeleton was determined to be S by GC analysis of the methyl ester of 2-methylbutyric acid obtained after alkaline hydrolysis of 1 and 4 followed by treatment with CH(2)N(2). The complete stereostructure of the known compound 2alpha,5alpha,10beta-triacetoxy-14beta-[(S)-2-methylbutyryloxy]-4(20),11-taxadiene (4) was established for the first time. The isolates obtained were evaluated for their antiproliferative activity toward murine colon 26-L5 carcinoma and human HT-1080 fibrosarcoma cell lines.     

东北红豆杉针叶中两个双重排紫杉烷内酯化合物的结构鉴定

目的研究东北红豆杉Taxuscuspidata针叶中的化学成分。方法采用硅胶柱色谱及制备薄层色谱法分离、纯化化学成分,用一维和二维核磁共振技术鉴定化合物结构。结果从东北红豆杉针叶的甲醇提取物中分离出两个罕见的双重排紫杉烷内酯类化合物wallifoliol()和tasumatrolH()。结论此两种化合物为首次从东北红豆杉中分离得到,在氘代氯仿溶液中化合物在室温下可以转化成5α-乙酰基-2α-苯甲酰氧基-4α,7β,9α,13α,20-五羟基-11(15→1),11(10→9)双重排紫杉烷-11-烯-10,15-内酯()。     

云南红豆杉中紫杉烷类化合物的分离与鉴定

目的 为了进一步研究红豆杉中的紫杉烷二萜类化合物,对生长在我国的云南红豆杉Taxus yunnanensis进行深入的化学研究。方法 云南红豆杉枝叶的乙醇提取物,经萃取、硅胶柱层析、PTLC、制备HPLC等方法分离,从乙醇提取物的二氯甲烷萃取部分分离得到5个化合物,采用波谱解析（UV,IR,ESI－MS,^1HMNR,^13CNMR)等方法确定了它们的结构。结果 分别为1－acetoxy-baccation I(I),7-epi-taxol(Ⅱ）,taxchinia A(Ⅲ）,cephalemannine(Ⅳ）和taxol（Ⅴ）。结论 化合物I为新化合物,化合物Ⅱ、Ⅲ为首次从该植物分得。     

超临界CO2萃取云南红豆杉枝叶中紫杉醇的研究

目的:采用超临界CO2从云南红豆杉枝叶中萃取紫杉醇。方法:以云南红豆杉枝叶为原料,先以纯CO2做萃取溶剂,除去原料中的脂类,再加入甲醇为夹带剂提取紫杉醇。用HPLC法检测萃取物中紫杉醇的含量。结果:紫杉醇的最佳萃取条件为:红豆杉枝叶粉碎至直径0.6~0.8 mm,萃取压力34 MPa,萃取温度40℃,甲醇为夹带剂。结论:SPE法较传统溶剂法,提取率有所提高,且使用有机试剂少,有利于环境保护,耗时少,生产周期短,效率高。     

东北红豆杉中三种紫杉烷类化合物体外抗癌活性研究

目的：通过观察东北红豆杉中三种紫杉烷二萜类化合物2，9-diacetyl-5-cinnamoyl-phototaxicinⅡ（1）、5-acetyhaxuspineW（2）及10-acetyhaxuspineB（3）对人乳腺癌细胞生长的影响，探讨这三种紫杉烷类化合物的抗癌作用及各化合物结构与活性之间的构效关系。方法：以人乳腺癌细胞为研究对象，采用MTT法检测3种紫杉烷类化合物对乳腺癌细胞生长的抑制率。结果：上述三个化合物对乳腺癌细胞均有不同程度的抑制作用，其中2，9-diacetyl-5-cinnamoyl-phototaxicinⅡ（1）及10-acetyltaxuspineB（3）的作用优于5-acetyhaxuspineW（2）；前两者有效浓度范围是20μmol／L-100μmol/L，后者的有效浓度为60μmol／L-100μmol／L。结论：从东北红豆杉中得到的三种紫杉烷类化合物2，9-diacetyl-5-cinnamoyl-phototaxicinⅡ（1）、5-acetyhaxuspineW（2）及10-acetyhaxuspineB（3）对人乳腺癌细胞具有较强的体外抗肿瘤活性，侧链肉桂酰基可能是有效基团之一。     

Taxus spp. needles contain amounts of taxol comparable to the bark of Taxus brevifolia: analysis and isolation

New sources for the antitumor natural product taxol [1] are needed as demands for this promising cancer chemotherapeutic agent increase. Presently, supplies of taxol for clinical studies are obtained from the bark of Taxus brevifolia, a potentially limited source. Using analytical methods, the needles and stems of six Taxus species have been examined for taxol [1] and 10-deacetylbaccatin III [5], a related compound that can be converted to taxol through a semi-synthetic route. Amounts of taxol comparable to quantities reported from the bark of T. brevifolia were found in the needles of four of the Taxus species investigated. In addition, taxol was isolated from the needles of one Taxus species. Thus, Taxus needles may provide a renewable source of this valuable compound.     

New taxane diterpenoids from the leaves and twigs of Taxus sumatrana

Two new taxoids, taxumairol Q (1) and 13-O-acetyl wallifoliol (2), have been isolated from the leaves and twigs of Taxus sumatrana. Taxuspine F and wallifoliol (10) have been isolated for the first time from the yew T. sumatrana. Seventeen known taxoid diterpenoids have also been isolated. The new derivatives, 9,13-diacetyltaxumairol W (3), 10,13-dibenzoyltaxacustin (4), 7,13-diacetylwallifoliol (5), 7,13-dibenzoylwallifoliol (6), and 7,9-dibenzoyltaxumairol P (7), have been prepared by acylation of a crude mixture of taxoids. All structures were established primarily on the basis of 1D and 2D NMR techniques, including DEPT, COSY, and HMBC experiments, as well as chemical correlation with known compounds. Wallifoliol (10) exhibited significant cytotoxicities against both Hepa 59 T/VGH (human liver carcinoma) and KB (human oral epidermoid carcinoma) tumor cells. Taxuspine F and compound 5 possessed moderate activity against Hepa cells only, while 3, 6, 7, and 10-deacetylbaccatin III showed only marginal activity against Hepa cells.     

Taxoids from Taxus chinensis

Two new taxoids, 13,15-epoxy-13-epi-taxayunnasin A (1) and taxchinin N (2), were isolated from the leaves and stems of Taxus chinensis. Compound 2 is the first taxoid to be reported with an alpha,beta-unsaturated lactone at C-4, C-5, C-20, and C-2. The structure of 1 was elucidated by spectroscopic analysis and confirmed by semisynthesis from taxayunnasin A, while 2 was determined structurally using spectroscopic methods and by single-crystal X-ray diffraction.     

小飞蓬化学成分研究

目的:研究小飞蓬的化学成分。方法:采用HP20大孔树脂、硅胶、Sephadex LH-20和十八烷基硅烷键合硅胶(ODS)等多种色谱技术,对小飞蓬进行分离纯化;根据理化常数和波谱数据鉴定所分离化合物的结构。结果:从小飞蓬醇提物的水部位分离了6个化合物,分别鉴定为:Eugenyl-βPsd(1)、野黄芩苷(2)、木犀草素-7-O--βD-葡萄糖醛酸苷(3)、槲皮素(4)、异槲皮素苷(5)和木犀草素(6)。结论:化合物1、3、5和6为首次从小飞蓬中分离得到。     

加拿大杨树芽中的苷类成分

目的：研究杨树芽的化学成分,探明蜂胶和杨树芽内在成分差异。方法：采用溶剂提取和柱层析色谱分离,根据化合物理化性质和光谱数据鉴定其结构。结果：从加拿大杨树芽的正丁醇提取物和水提取物中分离得到3个苷类化合物和1个黄酮类化合物,分别为高良姜素（1）、乔松素-5-O-β-D-葡萄糖苷（2）、紫丁香苷（3）和水杨苷（4）。结论：化合物2和3为首次从杨属植物中分离得到,同时首次报道了化合物2的1H-NMR和13C-NMR数据。     

In vitro susceptibility of Helicobacter pylori to isoquinoline alkaloids from Sanguinaria canadensis and Hydrastis canadensis

Methanol extracts of the rhizomes of Sanguinaria canadensis, and the roots and rhizomes of Hydrastis canadensis, two plants used traditionally for the treatment of gastrointestinal ailments, were screened for in vitro antibacterial activity against 15 strains of Helicobacter pylori. The rhizome extracts, as well as a methanol extract of S. canadensis suspension-cell cultures inhibited the growth of H. pylori in vitro, with a MIC50 range of 12.5-50.0 microg/ml. Three isoquinoline alkaloids were identified in the active fraction. Sanguinarine and chelerythrine, two benzophenanthridine alkaloids, inhibited the growth of the bacterium, with an MIC50 of 50.0 and 100.0 microg/ml, respectively. Protopine, a protopine alkaloid, also inhibited the growth of the bacterium, with a MIC50 of 100 microg/ml. The crude methanol extract of H. canadensis rhizomes was very active, with an MIC50 of 12.5 microg/ml. Two isoquinoline alkaloids, berberine and beta-hydrastine, were identified as the active constituents, and having an MIC50 of 12.5 and 100.0 microg/ml, respectively.