Cytotoxic clerodane diterpenoids from Casearia membranacea

Bioassay-guided fractionation of the EtOAc extract of Casearia membranacea leaves and twigs afforded three new clerodane diterpenes, caseamembrins M-O (1-3), and the known rel-(2S,5R,6R,8S,9S,10R,18S,19R)-2-(2-methylbutyryloxy)-6-hydroxy-18,19-di-O-acetyl-18,19-epoxycleroda-3,13(16),14-triene (4) and caseamembrin D (5). The structures of 1-3, including the relative configurations, were established by extensive NMR spectroscopic analyses. The cytotoxic activities of the isolated diterpenoids against human oral epidermoid (KB), medulla (Med), and colon (DLD-1) cancer cell lines were evaluated.     

Novel bioactive clerodane diterpenoids from the leaves and twigs of Casearia sylvestris

Fractionation of a methanol extract of the leaves and twigs of Casearia sylvestris, as directed by activity against KB cell cytotoxicity, led to the isolation of three novel clerodane diterpenoids, casearvestrins A-C (1-3). The structures of 1-3 were deduced from one- and two-dimensional NMR experiments, including relative stereochemical assignments based on ROESY correlations and COSY coupling constants. All three compounds displayed promising bioactivity, both in cytotoxicity assays against a panel of tumor cell lines and in antifungal assays via the growth inhibition of Aspergillus niger in a disk diffusion assay.     

New bioactive clerodane diterpenoids from the bark of Casearia grewiifolia

Bioactivity-guided fractionation of hexane and dichloromethane extracts of the bark of Casearia grewiifolia afforded four new clerodane diterpenes, caseargrewiins A-D (1-4), and two known clerodane diterpenes, rel-(2S,5R,6R,8S,9S,10R,18S,19R)-18,19-diacetoxy-18,19-epoxy-6-methoxy-2-(2-methylbutanoyloxy)cleroda-3,13(16),14-triene (5) and rel-(2S,5R,6R,8S,9S,10R,18S,19R)-18,19-diacetoxy-18,19-epoxy-6-hydroxy-2-(2-methylbutanoyloxy)cleroda-3,13(16),14-triene (6). The structures of 1-4 were established on the basis of the interpretation of their 1D and 2D NMR spectral data. The absolute configuration of 4 was determined by the modified Mosher's method. All compounds exhibited promising antimalarial and antimycobacterial activities but also cytotoxicity against three cancer cell lines.     

Cytotoxic clerodane diterpenoids from fruits of Casearia grewiifolia

Bioactivity-guided fractionation of the ethyl acetate-soluble fraction of a methanol extract of the fruits of Casearia grewiifolia afforded eight new clerodane diterpenes, caseargrewiins E-L (1-8), and a known clerodane diterpene, esculentin B (9). The structures of 1-8 were established on the basis of 1D and 2D NMR spectroscopic data. Most of these compounds exhibited cytotoxicity against three cancer cell lines with IC50 values in the range 0.15-6.00 microg/mL.     

Structure and stereochemistry of new cytotoxic clerodane diterpenoids from the bark of Casearia lucida from the Madagascar rainforest

Bioassay-guided fractionation of a CH(2)Cl(2)/MeOH extract of the bark of Casearia lucida resulted in the isolation of 11 new clerodane diterpenes, namely, casearlucins A-K (1-11), and three known clerodane diterpenoids, rel-(2S,5R,6R,8S,9S,10R,18S,19R)-diacetoxy-18,19-epoxy-6-hydroxy-2-(2xi-methylbutanoyloxy)cleroda-3,13(16),14-triene (12), rel-(2S,5R,6R,8S,9S,10R,18S,19R)-18,19-diacetoxy-18,19-epoxy-6-methoxy-2-(2xi-methylbutanoyloxy)cleroda-3,13(16),14-triene (13), and rel-(2S,5R,8S,9S,10R,18S,19R)-18,19-diacetoxy-18,19-epoxy-2-(2xi-methylbutanoyloxy)cleroda-3,13(16),14-triene (14). The structures of compounds 1-11 were established on the basis of extensive 1D and 2D NMR spectroscopic data interpretation. All compounds exhibited cytotoxicity activity against the A2780 ovarian cancer cell line, but none of the six compounds selected for testing in multiple cell lines showed significant selectivity.     

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.     

Cytotoxic clerodane diterpenoids and their hydrolysis products from Casearia nigrescens from the rainforest of Madagascar

Bioassay-guided fractionation of the cytotoxic leaf and flower extract of Casearia nigrescens led to the isolation of four new clerodane diterpenoids, designated caseanigrescens A-D (1-4). These compounds were subject to hydrolysis to dialdehydes when stored in CDCl3. The structures of compounds 1-4 were determined using 1D and 2D NMR spectroscopy. All four compounds showed moderate cytotoxicity to the A2780 human ovarian cancer cell line, with an IC50 range of 0.83-1.4 microM.     

Cytotoxic clerodane diterpenes from Casearia rupestris

Four new clerodane diterpenes, casearupestrins A-D (1-4), were isolated from the leaves of Casearia rupestris. Compounds 1 and 4 were acetylated to yield 2,7-di-O-acetylcasearupestrin A (5) and 2,6-di-O-acetylcasearupestrin D (6). All compounds were evaluated for cytotoxicity against a small panel of human cancer cell lines. Casearupestrin A (1) exhibited the most potent activity against MDA/MB-435 (human melanoma) and SF-295 (human glioblastoma) cells, superior to that of the standard drug doxorubicin.     

Four new clerodane diterpenoids from Callicarpa pentandra

Leaf extracts of Callicarpa pentandra provided four new clerodane-type diterpenoids (1-4), of which 1, 2, and 4 have ring-A-contracted structures. Their structures and stereochemistry were established by spectral data interpretation, and for 3 also by single-crystal X-ray diffraction.     

New cytotoxic lupane triterpenoids from the twigs of Coussarea paniculata

Bioassay-guided fractionation of a CH(2)Cl(2)-MeOH extract of the twigs of Coussarea paniculata using a yeast-based assay for potential DNA-damaging agents resulted in the isolation of three new lupane triterpenoids, 1-3, in addition to eight known triterpenoids, lupeol (4), lupeyl acetate (5), betulin (6), betulinic acid (7), 3-epi-betulinic acid (8), 3-epi-betulinaldehyde (9), oleanolic acid (10), and ursolic acid (11). The structures of the new compounds were established as lup-20(29)-en-3beta,25-diol (1), lup-20(29)-en-11alpha-ol-25,3beta-lactone (2), and 3-deoxybetulonic acid (3), on the basis of extensive 1D and 2D NMR spectroscopic data interpretation and chemical conversion.     

Novel cytotoxic diterpenes from Casearia arborea

Cytotoxicity-guided fractionation of the dichloromethane-methanol extract of the roots of Casearia arborea yielded five novel clerodane diterpenes, casearborins A-E (1-5), as well as cucurbitacin B. The presence of cucurbitacins glycosides was also detected. The absolute configuration of casearborin E was determined by X-ray crystallography.     

Echinophyllins C-F, new nitrogen-containing clerodane diterpenoids from Echinodorus macrophyllus

Four new nitrogen-containing clerodane diterpenoids, echinophyllins C-F (1-4), were isolated from the leaves of the Brazilian medicinal plant Echinodorus macrophyllus ("Chapéu-de-couro"), and their structures and relative stereochemistry were elucidated from their spectroscopic data. Compounds 1-4 possess an alpha,beta-unsaturated gamma-lactam ring consisting of a clerodane diterpene unit and an amine moiety.     

New cytotoxic xenia diterpenoids from the Formosan soft coral Xenia umbellata

Seven new cytotoxic xenicane-type diterpenoids, 9-deoxyxeniloide-E (1), 9-deoxy-7,8-epoxyxeniloide-E (2), xeniolide-G (3), 9-deoxyxenialactol-C (4), xenibecin (5), xeniolide-H (6), and xenitacin (7), were isolated from the methylene chloride solubles of the Formosan soft coral Xenia umbellata. The structures were elucidated by 1D and 2D NMR spectral analysis, and their cytotoxicity against selected cancer cells was measured in vitro.     

Porwenins A and B, new clerodane diterpenoids from Portulaca okinawensis.

Two new clerodane-type diterpenes, porwenins A (1) and B (2), were isolated from Portulaca okinawensis, and the structures were elucidated by spectroscopic data.     

普约狗牙花枝叶的生物碱类成分研究

目的 研究夹竹桃科普约狗牙花Tabernaemontana sananho枝叶的化学成分.方法 利用硅胶、ODS、SephadexLH-20等柱色谱技术及薄层色谱、制备液相色谱等方法进行分离、纯化,根据化合物的理化性质及波谱学数据鉴定其化学结构.结果 从普约狗牙花枝叶的总生物碱部位中分离得到12个生物碱类成分,分别鉴定...     

苦木生物碱的化学研究

目的研究苦木生物碱的化学成分。方法用硅胶和Sephadex LH-20进行色谱柱分离,通过理化性质、光谱数据鉴定结构。结果鉴定了16个生物碱,分别是:5-甲氧基-铁屎米酮(Ⅰ)、11-羟基-铁屎米酮(Ⅱ)、铁屎米酮(Ⅲ)、4,5-二甲氧基-铁屎米酮(Ⅳ)、4-甲氧基-5-羟基-铁屎米酮(Ⅴ)、3-甲基-铁屎米-2,6-二酮(Ⅵ)、1-甲酰-4-甲氧基-β-咔巴啉(Ⅶ)、1-甲氧基-β-咔巴啉(Ⅷ)、1-乙基-4,8-二甲氧基-β-咔巴啉(Ⅸ)、1-甲氧甲酰-4-羟基-β-咔巴啉(Ⅹ)、1-甲基-4-甲氧基-β-咔巴啉(Ⅺ)、1-乙氧甲酰-β-咔巴啉(ⅩⅡ)、1-甲酰-β-咔巴啉(ⅩⅢ)、1-甲氧甲酰-β-咔巴啉(ⅩⅣ)、1-乙基-4-甲氧基-β-咔巴啉(ⅩⅤ)和1,2,3,4-tetrahydro-1,3,4-trioxo-β-carboline(ⅩⅥ)。结论化合物Ⅺ是首次从自然界植物中分离得到,化合物Ⅱ、Ⅷ、ⅩⅤ是首次从该属植物中分离得到。     

Cytotoxic styryl-lactones from the leaves and twigs of Polyalthia crassa

Four new styryl-lactones, crassalactones A-D (1-4), were isolated from a cytotoxic ethyl acetate-soluble extract of the leaves and twigs of Polyalthia crassa, together with seven known compounds, (+)-3-acetylaltholactone, (+)-altholactone, aristolactam AII, cinnamic acid, (+)-goniofufurone, (+)-goniopypyrone, and (+)-howiinol A. Their structures were determined on the basis of spectroscopic methods. The absolute configuration of 1-3 was established by chemical conversions. Single-crystal X-ray analysis and the Mosher ester method were used to confirm the absolute stereochemistry of 4. Cytotoxic evaluation against several mammalian cancer cell lines was performed on all new isolates, aristolactam AII, and the modified (+)-tricinnamate derivative 11 obtained from 1.     

柳杉枝叶化学成分的研究

目的研究柳杉Cryptomeria fortunei Hooibrenk ex Otto et Dietr.枝叶的化学成分。方法柳杉枝叶95%乙醇提取物的乙酸乙酯部位采用硅胶、中压液相(MCI)、Sephadex LH-20柱进行分离纯化,根据理化性质及波谱数据鉴定所得化合物的结构。结果从中分离得到11个化合物,分别鉴定为异海松酸(1)、山达海松酸(2)、乙酰基异柏酸(3)、复瓦杉酸(4)、异柏酸(5)、松叶酸(6)、13-表柏油酸(7)、19-acetylagathadiol(8)、agatadiol(9)、植醇(10)、榄香醇(11)。结论化合物1~10为二萜,化合物11为倍半萜;化合物2、3、6~11为首次从该植物中分离得到。     

岩生翠柏枝叶化学成分的研究

目的研究岩生翠柏Calocedrus rupestris枝叶的化学成分。方法岩生翠柏枝叶95%乙醇提取物采用硅胶、TLC、HPLC进行分离纯化,根据理化性质及波谱数据鉴定所得化合物的结构。结果从中分离得到11个化合物,分别鉴定为pinusolidic acid(1)、isocupressic acid(2)、isoagatholal(3)、16-hydroxy-8(17),13-labdadien-15,16-olid-19-oic acid(4)、15-hydroxypinusolidic acid(5)、8(17),13-ent-labdadien-15→16-lactone-19-oic acid(6)、cupressuflavone(7)、amentoflavone(8)、sequoiavone(9)、taiwaniaflavone(10)、hinokiflavone(11)。结论所有化合物均为首次从该植物中分离得到。     

壮药干花豆枝叶化学成分研究

目的研究干花豆Fordia cauliflora枝叶中的化学成分。方法采用硅胶、C18、Sephadex LH-20等色谱手段对干花豆枝叶的95%乙醇提取物中醋酸乙酯萃取部分进行化学成分分离,通过波谱学技术和理化性质确定化合物的结构。结果从干花豆中分离得到11个成分,分别鉴定为羽扇豆醇(1)、羽扇豆醇乙酸酯(2)、水黄皮素(3)、呋喃-[4″,5″,8,7]-黄酮(4)、7-甲氧基-8-异戊烯基黄烷酮(5)、7-甲氧基-8-(3″-羟基-3″-甲基-1″-丁烯基)-黄酮(6)、豆甾醇(7)、豆甾醇-3-O-β-葡萄糖苷(8)、胡萝卜苷(9)、齐墩果酸(10)、β-谷甾醇(11)。结论化合物2、4、6～9为首次从该植物中分离得到。