Monoterpenoid indole alkaloids from Gardneria ovata

Eight new monoterpenoid indole alkaloids, gardfloramine-9-O-β-D-glucopyranoside (1), 19(E)-18-demethoxygardfloramine-N(4)-oxide (2), gardfloramine-N(4)-oxide (3), 18-demethylgardfloramine (4), 19(E)-9,18-didemethoxygardneramine (5), 19(E)-11-methoxy-9,18-didemethoxygardneramine (6), 9-demethoxy-18-demethylgardneramine (7), and minfiensine-N(4)-oxide (8), along with six known alkaloids, were isolated from Gardneria ovata. The structures of the new alkaloids were established by means of spectroscopic methods. None of the compounds were cytotoxic to five human cancer cell lines.     

Isolation of gelsedine-type indole alkaloids from Gelsemium elegans and evaluation of the cytotoxic activity of gelsemium alkaloids for A431 epidermoid carcinoma cells

Four new gelsedine-type indole alkaloids (1-4) were isolated from the leaves of Gelsemium elegans, together with 11 known alkaloids. The structures were determined as 14-acetoxygelsenicine (1), 14-acetoxy-15-hydroxygelsenicine (2), 14-hydroxy-19-oxogelsenicine (3), and 14-acetoxygelselegine (4), respectively, by spectroscopic analysis. The cytotoxic effects of 14 Gelsemium alkaloids including two new compounds (1, 2) were evaluated using the A431 human epidermoid carcinoma cell line. Of these, the gelsedine-type alkaloids 14-acetoxy15-hydroxygelsenicine (2) [corrected] 14,15-dihydroxygelsenicine (5), gelsedine (7), and gelsemicine (8) showed potent cytotoxic effects.     

New cytotoxic terpenoids from the wood of Vepris punctata from the Madagascar Rainforest

Continuation of the chemical examination of the cytotoxic constituents of the wood of Vepris punctata resulted in the isolation of the two new terpenoids 1 and 2 and eight known compounds, glechomanolide (3), isogermafurenolide, (E,E)-germacra-1(10),4,7(11)-triene, alpha-amyrin, lupeol, lupeyl acetate, taraxerol, and 3-epi-taraxerol, in addition to the alkaloids reported reported previously. The structures of the two new compounds were established on the basis of 1D and 2D NMR spectroscopic data interpretation and chemical modifications. All the isolated compounds were tested against the A2780 human ovarian cancer cell line; the four sequiterpenoids showed moderate cytotoxic activity, while the six triterpenoids were inactive.     

Nuttingins A-F and malonganenones D-H, tetraprenylated alkaloids from the Tanzanian gorgonian Euplexaura nuttingi

Six new tetraprenylated purine alkaloids, designated nuttingins A-F (1-6), were isolated together with three known malonganenones, A-C (12-14), and five new closely related malonganenones, D-H (7-11), from the gorgonian Euplexaura nuttingi collected in Pemba Island, Tanzania. The structures of the compounds were elucidated by interpretation of 1D and 2D NMR data including 15N chemical shifts obtained from 1H-15N HMBC spectra. Nuttingins A-E (1-5) and malonganenones D-G (7-10) displayed inhibitory activity against both K562 and UT7 tumor cell lines, compounds 3-5 being the most active ones, approximately 3-fold more potent than the others. Compounds 1-5 and 7-11 also induce apoptosis in transformed mammalian cells at a concentration of 1.25 microg/mL.     

Alkaloids from Gelsemium elegans

Three new alkaloids, gelsebanine (1), 14alpha-hydroxyelegansamine (2), and 14alpha-hydroxygelsamydine (3), and a new extraction artifact , gelsebamine (4), together with 12 known alkaloids, were isolated from the stems and leaves of Gelsemium elegans. The structures of 1-4 were determined by spectroscopic methods, especially 2D NMR techniques. Compounds 1-4 were evaluated for cytotoxic activity against four tumor cell lines, and gelsebamine (4) selectively inhibited the A-549 human lung adenocarcinoma cell line.     

Cytotoxic dolabellane diterpenes from the Formosan soft coral Clavularia inflata

Six new cytotoxic dolabellane diterpenes, (1R,12R)-dolabella-4(16),7,10-triene-3,13-dione (1), (1R*,7R*,8S*,12R*)-dolabella-4(16),10-diene-7,8-epoxy- 3,13-dione (2), (1R*,10R*,11S*,12R*)-dolabella-4(16),7-diene-10,11-epoxy-3,13-dione (3), (1R)-dolabella-4(16),7,11(12)-triene-3,13-dione (4), (1R*,3R*)-3-hydroxydolabella-4(16),7,11(12)-triene-3,13-dione (5), and (1R*,7R*)-7-hydroperoxydolabella-4(16),8(17),11(12)-triene-3,13-dione (6), have been isolated from the Formosan soft coral Clavularia inflata. The structures of compounds 1-6 were determined by 1D and 2D spectral analysis, and their cytotoxicity against selected cancer cells was measured in vitro.     

Triterpenoids and steroids from the fruits of Melia toosendan and their cytotoxic effects on two human cancer cell lines

Ten new triterpenoids, named meliasenins I-R (1-10), one new steroid (11), and 11 related known compounds (12-22) were isolated from fruits of Melia toosendan. The structures of the new compounds were established on the basis of spectroscopic methods, including 2D NMR techniques and mass spectrometry. The relative configuration of 1, (20R*,23E)-25-hydroperoxyeupha-7,23-diene-3β,16β-diol (meliasenin I), was confirmed by single-crystal X-ray diffraction analysis. All isolated triterpenoids (1-10, 12-15) and two steroids (11, 20) were tested for their cytotoxicity against U20S human osteosarcoma and MCF-7 human breast cancer cells using the MTT assay, and some of them were significantly cytotoxic (IC(50) <10 μg/mL). The insecticidal properties of compounds 1-15 and 20 were also briefly evaluated.     

Highly hydroxylated triterpenes from Salvia kronenburgii

The three new triterpenes (1-3) and five known triterpenes and a sterol were isolated from the acetone extract of a Turkish collection of Salvia kronenburgii. The structures of the new triterpenes were established as 1beta,2alpha-dihydroxy-3beta-acetoxy-11-oxours-12-ene (1), 2alpha,20beta-dihydroxy-3beta-acetoxyurs-9(11),12-diene (2), and 1beta,2alpha-dihydroxy-3beta-acetoxyurs-9(11),12-diene (3) on the basis of spectral analyses, including 1D and 2D NMR and mass spectroscopy. It is probable that compounds 2 and 3 are artifacts from dehydration of the corresponding allylic alcohols. 1beta,2alpha,3beta,11alpha-Tetrahydroxyurs-12-ene (5), the most abundant compound in the extract, was found to be highly cytotoxic to renal, non-small cell lung, and breast cancer cell lines.     

New alkaloids of the sarpagine group from Rauvolfia serpentina hairy root culture

Three new monoterpenoid indole alkaloids, 19(S),20(R)-dihydroperaksine (1), 19(S),20(R)-dihydroperaksine-17-al (2), and 10-hydroxy-19(S),20(R)-dihydroperaksine (3), along with 16 known alkaloids 4-19 were isolated from hairy root culture of Rauvolfia serpentina, and their structures were elucidated by 1D and 2D NMR analyses. Taking into account the stereochemistry of the new alkaloids and results of preliminary enzymatical studies, the putative biosynthetical relationships between the novel alkaloids are discussed.     

铁棒锤及其炮制品中二萜生物碱化学成分研究

目的研究铁棒锤及其水煮炮制品的化学成分。方法采用硅胶柱色谱等方法对铁棒锤及水煮炮制品的化学成分进行分离纯化,根据化合物的理化常数和波谱数据鉴定其结构。结果从铁棒锤及其水煮炮制品中共分离得到12个化合物,经鉴定为去氧乌头碱(1)、3-乙酰乌头碱(2)、乌头碱(3)、15α-OH-neoline(4)、8-acetyl-15-hydroxyneoline(5)、尼奥灵(6)、14-benzoyl-8-O-methylaconine(7)、苯甲酰乌头原碱(8)、多裂乌头碱D(polyschistineD,9)、苯甲酰去氧乌头碱(10)、polyschistineA(11)、乌头原碱(12)。结论二萜生物碱是铁棒锤块根的主要化学成分,其中化合物4～8为首次从该植物中分离得到。与生品相比,铁棒锤水煮炮制品中二萜生物碱成分发生了一定的变化,其中化合物9～12为炮制品新增的成分,这些成分的鉴定为铁棒锤水煮炮制法炮制原理的揭示提供了依据。     

皮孔葱臭木化学成分的研究

目的对皮孔葱臭木Dysoxylum lenticellatum茎干的化学成分及其细胞毒活性进行研究。方法利用正相硅胶、RP-18柱色谱、葡聚糖凝胶Sephadex LH-20等手段进行分离纯化,根据波谱数据鉴定化合物的结构,采用MTT法进行细胞毒活性测定。结果分离鉴定了12个化合物,分别为β-谷甾醇(1)、豆甾醇(2)、3-oxo-24,25,26,27-tetranortirucall-7-ene-23(21)-lactone(3)、3α-hydroxy-24,25,26,27-tetranortirucall-7-ene-23(21)-lactone(4)、laxiracemosin H(5)、laxiracemosin B(6)、24,25-epoxy-tirucall-7-ene-3,23-dione(7)、丁酰鲸鱼醇(8)、齐墩果酸(9)、蒲公英赛酮(10)、蒲公英赛醇(11)和8-hydroxy-6-methoxy-3-pentylisocoumarin(12)。结论 12个化合物均为首次从该种植物中分离得到,化合物8、10～12为首次从该属植物中分离得到,化合物5、6是甘遂烷型生物碱,化合物3具有明显体外肿瘤细胞生长抑制活性。     

Indole alkaloids and quassinoids from the stems of Brucea mollis

Seven new indole alkaloids, bruceollines H-N (1-7), three new quassinoids, yadanziolides T-V (10-12), and four known analogues, bruceolline E (8), bruceolline F (9), bruceine D (13), and yadanziolide B (14), were isolated from an ethanol extract of the stems of Brucea mollis. The absolute configurations of compounds 2 and 5 were determined by comparison of their experimental and calculated ECD spectra. The absolute configuration of the known compound 9 was determined by using Mo2(OAc)4-induced CD analysis for the first time. Compounds 10, 13, and 14 exhibited cytotoxic activities with IC50 values of 3.00-5.81 μM.     

Terpenoid indole alkaloids from Winchia calophylla

Three new indole alkaloids, N(4)-demethyl-12-methoxyalstogustine (1), 17-carboxyl-N(4)-methylechitamidine chloride (2), and 17-carboxyl-12-methoxy-N(4)-methylechitamidine chloride (3), along with 15 known alkaloids, were isolated from the ethanolic extract of the stem bark of Winchia calophylla. The structures of 1-3 were elucidated on the basis of spectroscopic means and chemical methods. The determination of relative configurations at C-19 and C-20 for 1-3 was aided by 13C NMR spectroscopic data. The absolute configurations of alkaloids 1-3 were determined by direct comparison of their CD spectra with those of known alkaloids. All the alkaloids were tested in cytotoxic assays against P-388 and A-549 tumor cell lines, and only two of them showed weak activity against the A-549 cell line.     

Cytotoxic sesquiterpene lactones from Eupatorium lindleyanum

Ten new guaiane type sesquiterpene lactones, namely, eupalinilides A-J (1-10), as well as nine known compounds, eupachinilide C (11), eupachifolin D (12), eupachinilide E (13), 2alpha-hydroxyeupatolide (14), 3-deacetyleupalinin A (15), heliangine (16), 8beta-tigloyloxy-2,3-seco-6betaH,7alphaH-helianga-4Z,11(13)-diene-3,10beta;6, 12-diolid-2-oic acid (17), 8beta-(4'-hydroxytigloyloxy)-3beta,14-dihydroxy-6betaH,7alphaH-germacra-1(10)Z,4Z,11(13)-trien-6,12-olide (18), and 8beta-tigloyloxy-3beta,14-dihydroxy-6betaH,7alphaH-germacra-1(10)Z,4E,11(13)-trien-6,12-olide (19), were isolated from the whole plant of Eupatorium lindleyanum. Eupalinilides B (2), C (3), E (5), F (6), and I (9) have been tested for cytotoxicity against P-388 and A-549 tumor cell lines. The results showed that eupalinilides B (2) and E (5) demonstrated potent cytotoxicity. The structures of these compounds were determined by spectroscopic methods including 1D and 2D NMR spectra.     

Cytotoxic and antimalarial beta-carboline alkaloids from the roots of Eurycoma longifolia

Three new [n-pentyl beta-carboline-1-propionate (1), 5-hydroxymethyl-9-methoxycanthin-6-one (2), and 1-hydroxy-9-methoxycanthin-6-one (3)] and 19 known beta-carboline alkaloids were isolated from the roots of Eurycoma longifolia. The new structures were determined by comprehensive analyses of their 1D and 2D NMR and mass spectral data and by chemical transformation. These compounds were screened for in vitro cytotoxic and antimalarial activities, and 9-methoxycanthin-6-one (4) and canthin-6-one (5) demonstrated significant cytotoxicity against human lung cancer (A-549) and human breast cancer (MCF-7) cell lines.     

Five new iboga alkaloids from Tabernaemontana corymbosa

Five new indole alkaloids of the ibogan type (1-5), in addition to 12 other known iboga alkaloids, were obtained from the leaf and stem-bark extract of the Malayan species Tabernaemontana corymbosa, viz., 19(S)-hydroxyibogamine (1), 19-epi-isovoacristine (2), isovoacryptine (3), 3R/S-ethoxyheyneanine (4), and 3R/S-ethoxy-19-epi-heyneanine (5). The structures were determined using NMR and MS analysis and comparison with known related compounds.     

Xanthanolides, germacranolides, and other constituents from Carpesium longifolium

Three new xanthanolides, 1-3, along with nine known compounds, were isolated from the aerial parts of Carpesium longifolium. The structures of the new compounds were elucidated as 1beta,4beta-epoxy-5beta-hydroxy-10alphaH-xantha-11(13)-en-12,8beta-olide (1), 1beta,4beta,4alpha,5beta-diepoxy-10alphaH,11alphaH-xantha-12,8beta-olide (2), and 4-acetoxy-1beta,5beta-epoxy-10alphaH-xantha-11(13)-en-12,8beta-olide (3) by spectroscopic methods including IR, EIMS, HRESIMS, and 1D and 2D NMR experiments. Parthenolide and michelenolide exhibited significant cytotoxic activity against cultured SMMC-7721 (human hepatoma) and HO-8910 (human ovarian carcinoma) cells.     

Triterpenoidal alkaloids from Buxus natalensis and their acetylcholinesterase inhibitory activity

Acetylcholinesterase (AChE) inhibition-directed phytochemical studies on the methanolic extract of Buxus natalensis, collected in South Africa, resulted in the isolation of 12 compounds: O(2)-natafuranamine (1), O(10)-natafuranamine (2), cyclonataminol (3), 31-demethylbuxaminol A (4), buxaminol A (5), buxafuranamide (6), buxalongifolamidine (7), buxamine A (8), cyclobuxophylline K (9), buxaminol C (10), methyl syringate (11), and p-coumaroylputrescine (12). Compounds 1-4 were new alkaloids, and compound 5 was isolated for the first time as a natural product. Their structures were elucidated with the aid of extensive NMR and mass spectroscopic studies. Compounds 1 and 2 are members of a rarely occurring class of Buxus alkaloids, having a tetrahydrofuran ring incorporated in their structures. Compounds 1-12 exhibited strong to moderate AChE inhibitory activity.     

Indole alkaloids from Cephalanceropsis gracilis

Purification of CHCl3 and EtOAc solubles of the MeOH extract of Cephalanceropsis gracilis afforded seven new indole alkaloids, cephalinones A (1), B (2), C (3), and D (4) and cephalandoles A (5), B (6), and C (7), besides eight known compounds. The structures of the new compounds were determined by spectroscopic analysis. All 15 indole alkaloids were evaluated for their cytotoxic effects on MCF-7, NCI-H460, and SF-268 cell lines by the MTT method. Only cephalinone-F (6) showed significant cytotoxicity.     

New cytotoxic alkaloids from the wood of Vepris punctata from the Madagascar rainforest

Bioassay-guided fractionation of a CH(2)Cl(2)/MeOH extract of the wood of Vepris punctata resulted in the isolation of three new furoquinoline alkaloids, 5-methoxymaculine (1), 5,8-dimethoxymaculine (2), and 4,5,6,7,8-pentamethoxyfuroquinoline (3), in addition to the four known alkaloids flindersiamine (4), kokusaginine (5), maculine (6), and skimmianine (7). The structures of the new alkaloids 1-3 were established on the basis of extensive 1D and 2D NMR spectroscopic data interpretation. All the isolated compounds were tested against the A2780 human ovarian cancer cell line, and all seven alkaloids showed weak cytotoxic activity.