Paxiphyllines A and B, new alkaloids from Daphniphyllum paxianum

Two new Daphniphyllum alkaloids with daphnicyclidin-type skeleton, paxiphyllines A (1) and B (2) were isolated from the twigs and the leaves of Daphniphyllum paxianum. Paxiphylline A (1) has an unprecedented additional carbon from a biogenetic perspective. The structures and relative configurations were elucidated on the basis of spectroscopic data.     

Notes concerning the isolation of quaternary alkaloids from Pleiocarpa tubicina Stapf

The following quaternary indole alkaloids have been isolated from the root bark of the Apocynaceae species Pleiocarpa tubicina Stapf: huntrabrine methochloride, kopsinic acid methochloride, N_(a)-methyl-sarpagine methochloride and macusine B chloride.     

Aconapelsulfonines A and B,seco C20-diterpenoid alkaloids deriving via Criegee rearrangements of napelline skeleton from Aconitum carmichaelii

Two sulfo nated seco C₂₀-diterpenoid alkaloids,aconapelsulfonines A(1) and B(2),were isolated from an aqueous extract of the raw material of "Fu Zi"(the Aconitum carmichaelii lateral roots),of which the structures were elucidated by various spectroscopic data,combined with X-ray crystallogra phic analysis.The unprecedented skeletons are biogenetically proposed to be derived via Criegee rearrangements of the napelline-type architecture.The two compounds exhibited dose-depended analgesic activities on an acetic acid-induced mice writhing test.     

Constituents of regenerated plants of Ophiorrhiza pumila; formation of a new glycocamptothecin and predominant formation of (3R)-deoxypumiloside over (3S)-congener

The regeneration of plantlets was successful from Ophiorrhiza pumila callus cultures, from which a new glucosyloxy camptothecin, 9-β-glucosyloxycamptothecin, together with 15 metabolites including six camptothecin-related alkaloids was isolated. (3S)-Deoxypumiloside, one of the plausible biogenetic precursors of camptothecin, could not be found, whereas the (3R) epimer was isolated from the regenerated plants.     

Manadomanzamines A and B: a novel alkaloid ring system with potent activity against mycobacteria and HIV-1

Two novel alkaloids, named manadomanzamines A (1) and B (2), were isolated from an Indonesian sponge Acanthostrongylophora sp. (Haplosclerida: Petrosiidae). Their structures were elucidated and shown to be a novel organic skeleton related to the manzamine type alkaloids. Their absolute configuration and conformation were determined by CD, NOESY, and molecular modeling analysis. The microbial community analysis for the sponge that produces these unprecedented alkaloids has also been completed. Manadomanzamines A (1) and B (2) exhibited strong activity against Mycobacterium tuberculosis (Mtb) with MIC values of 1.9 and 1.5 mug/mL, respectively. Manadomanzamines A and B also exhibit activities against human immunodeficiency virus (HIV-1) and AIDS opportunistic fungal infections.     

中国乌头之研究: 一枝蒿戊素和己素的结构

作者曾从雪上一枝蒿中分离出二个生物: 一枝蒿戊素和一支蒿己素. 本文报导了用质子核磁共振, 碳十三核磁共振, 质谱, X-射线衍射研究和化学转化等方法鉴定了它们的结构. 证明一枝蒿己素为15β-羟基尼奥灵. 一枝蒿戊素实为丙酮与15β-羟基尼奥灵的8-OH和15-OH的缩合物.     

Two New C19-Diterpenoid Alkaloids from Delphinium davidii Franch.

Two new C19-diterpenoid alkaloids, davidisines A (1) and B (2) along with thirteen known alkaloids were isolated from the whole herb of Delphinium davidii Franch. Their structures were established by spectral methods, especially 2D NMR techniques.     

Puberunine and puberudine, two new C18-diterpenoid alkaloids from Aconitum barbatum var. puberulum

Two C(18)-diterpenoid alkaloids, puberunine (1) and puberudine (2), together with four other new alkaloids, including the first examples having β-oriented substitution at C-3 and a rare chloro-substituent were isolated from Aconitum barbatum var. puberulum. Their structures were elucidated by spectroscopic methods. Puberunine and puberudine, which possess a unique rearranged E ring and an opened A ring, respectively, represent new subtypes of the C(18)-diterpenoid alkaloids. A plausible biosynthetic pathway of 1 and 2 was proposed.     

Alkaloids, diarylheptanoid and naphthalene carboxylic acid ester from Rhoiptelea chiliantha.

Two pyrrolidine alkaloids (1, 2) were isolated from the fruits of Rhoiptelea chiliantha Diel et Hand.-Mazz. (Rhoipteleaceae). A diphenyl ether-type diarylheptanoid (3), and a naphthalene carboxylic acid methyl ester (4) which is biogenetically-related to juglone were isolated from the branches of the same plant. Their chemical structures were elucidated on the basis of spectroscopic analysis and chemical evidence.     

Isolation and structure of rosicine from Catharanthus roseus

An investigation of the alkaloidal constituents of the leaves of Catharanthus roseus has led to the isolation of a new alkaloid, “rosicine”, to which structure (1) has been assigned on the basis of spectroscopic studies. Two other alkaloids isolated have been identified as 14, 15-dehydroepivincadine and 19-hydroxytabersonine.     

Alkaloids from stemmadenia species-I The alkaloids of S. Donnell-Smithii and S. Galeottiana

—From Stemmadenia Donnell-Smithii and S. Galeottiana, the following new alkaloids were isolated: (+)-quebrachamine (IV), an optical isomer of the known (−)-quebrachamine; isovoacangine (IIIa), a position isomer of voacangine (Ia), voacamine, tabernanthine (IIIb) and ibogamine.     

Steroidal alkaloids from the bulbs of Fritillaria monatha

Two new Steroidal alkaloids, named pengbeisine A and pengbeisine B, were isolated from the fresh bulbs of Fritillaria monatha Migo. along with a known alkaloid. The structures were characterized as 22,26-imino-17, 23-oxido-5α-jerv-6-oxo-2α,3β-diol and 22, 26-imino-17, 23-oxido-5α-jerv-6-oxo-2β,3α-diol on the basis of spectroscopic methods.     

Two new alkaloids from Crinum asiaticum var. sinicum

Two new alkaloids (1, 2) were isolated from the whole plants of Crinum asiaticum var. sinicum together with seven known alkaloids. The structures of the new alkaloids were elucidated by spectroscopic analyses and chemical conversions from known alkaloids. New alkaloid 1 was isolated for the first time as a natural product, although it has been prepared as a synthetic product.     

1,2,3,4-tetrahydro-8-hydroxymanzamines, alkaloids from two different haplosclerid sponges

The isolation and characterization of two new sponge alkaloids, 1,2,3,4-tetrahydro-2-N-methyl-8-hydroxymanzamine A (2) and 1,2,3,4-tetrahydro-8-hydroxymanzamine A (3), is described. These compounds were obtained from Papua New Guinea sponges of the genera Petrosia and Cribochalina, which are in different families of the order Haplosclerida. These new manzamines are close in structure to 8-hydroxymanzamine (4) recently reported from Pachypellina, a Haplosclerid sponge belonging to a different family than that of the two preceding sponges. The cytotoxicity of 2 is described and the biogenetic relationship of 2 or 3 to manzamine A (1) and to nine other related polycyclic diamine and one monoamine type alkaloids is described.     

Two New Cytotoxic Alkaloids from Mappianthus iodoides Hand.‐Mazz.

Two new alkaloids, mappine A ( 1 ) and mapposidic acid ( 2 ), together with eleven known compounds, were isolated from the stems of Mappianthus iodoides Hand.‐Mazz. Their structures were elucidated by means of spectroscopic and mass‐spectrometric analyses, particularly 1D‐ and 2D‐NMR spectroscopy. The cytotoxic activities of the two new alkaloids were also evaluated.     

三尖彬属植物中生物碱的研究:VI.三尖杉中两种高刺桐类型的新生物碱的结构

本文报导从安徽产三尖杉弱碱部份分得五种高刺桐类型生物碱, 其中两种新生物碱经UV, IR光谱分析分鉴定为:2-O-乙基表福建三尖杉碱(2-O-ethglepicephalofortuneine)和2-O-乙基福建三尖杉碱(2-O-ethylcephalofortuneine)。     

Two New Alkaloids from Stemona tuberosa

Two new alkaloids, named tuberostemoninol A ( 1 ) and tuberostemoninol B ( 2 ), along with the known compounds tuberostemoninol ( 3 ) and bisdehydroneotuberostemonine ( 4 ), were isolated from Stemona tuberosa Lour . The structures were elucidated by means of spectroscopic analyses, including 1D‐ and 2D‐NMR experiments. The four alkaloids 1 – 4 were analyzed by on‐line high‐performance liquid chromatography/electrospray‐ionization mass spectrometry (HPLC/ESI‐MS), and their fragmentation pathways were found to be similar. Compounds 1, 2 , and 3 are isomers with the same molecular mass but which eluted at different retention times.     

STUDIES ON GLYCOSIDES ⅤⅢ.TOTAL SYNTHESIS OF NEW ALKALOID GLYCOSIDES FROM SELAGINELLA DOEDERIENII

Two new alkaloids,hordenine-O- -L-rhamnopyranoside(Ⅰ)and hordenine-0-(6′-trans-cinnamoyl)-4′-O-β-D-glucopyranosyl- -L-rhamnopyranoside(Ⅲ)isolated from Selaginella doederleinii have been synthesized the first time.A new method,in which trifluoroacetoxyl group was used both as a good leavinggroup and a protecting group for synthesis of O-glycosides with high stereo-selectivity was reported.     

Determination of ephedrine alkaloids by capillary electrophoresis

A simple and rapid method for the simultaneous determination of six ephedrine alkaloids (ephedrine, pseudoephedrine, norephedrine, norpseudoephedrine, methylephedrine and methylpseudoephedrine) in Ephedrae herba by capillary electrophoresis was developed. A buffer solution that contained 0.005 M barium hydroxide and 0.02 M isoleucine and adjusted to pH 10.0 with ammonia solution was found to be the most suitable electrolyte for this separation. The contents of the six alkaloids in the crude drug of Ephedrae herba could be easily determined.     

New Diterpenoid Alkaloids from Aconitum recemulosum Franch.

Two new diterpenoid alkaloids, racemulosines A ( 1 ) and B ( 2 ), were isolated from the roots of Aconitum racemulosum Franch . The structures of the new alkaloids were elucidated by analysis of physical and spectroscopic data, and the structure of 1 was further confirmed by a single‐crystal X‐ray diffraction analysis. Furthermore, compound 1 , at 2.25?10^?4 mol/l, showed moderate activity against platelet aggregation induced by PAF (platelet‐activation factor).