Alcaloïdes de l' Isopyrum thalictroïdes—bases quaternaires des feuilles—isolement et identification de quatre pseudoprotoberberines

Besides the known magnoflorine, four new protoberberines were isolated from leaves of Isopyrum thalictroïdes. Their structures were deduced from spectral data. The names pseudoberberine, pseudocoptisine, pseudocolumbamine and dehydropseudocheilanthifoline are proposed for them.     

The alkaloids of Stephania sasakii: Structure of five new alkaloids

Five new alkaloids, dehydrocrebanine, 4,5-dioxodehydrocrebanine, stesakine, dehydrostesakine, bisaknadinine and four known alkaloids, lirodenine, lanuginosine, 1-tetrahydropalmatine, d-isocorydine with a few alkaloids of unknown structure were newly isolated from Stephania sasakii. The structures of the new alkaloids were determined from spectral data and chemical evidence.     

Alkaloids from Alstonia angustifolia

Six new alkaloids, viz., alstolactone, affinisine oxindole, lagumicine, N(4)-demethylalstonerine, N(4)-demethylalstonerinal, and 10-methoxycathafoline N(4)-oxide, in addition to 36 other known alkaloids, were obtained from the leaf extract of Alstonia angustifolia var. latifolia. The structures of the new alkaloids were determined using NMR and MS analysis.     

Melohenryines A and B,two new indole alkaloids from Melodinus henryi

Two new monoterpenoid indole alkaloids, melohenryines A and B (1 and 2), along with six known indole alkaloids, were isolated from the twigs and leaves of Melodinus henryi. Structures of the new alkaloids were established by extensive spectroscopic techniques including NMR spectroscopy and mass spectrometry. Melohenryine A (1) represents the first example of monoterpenoid indole alkaloids characterized an ester carbonyl group at C-19 position. All of the new compounds were evaluated for in vitro cytotoxicity against several human cancer cell lines.     

Venalstonine and dioxokopsan derivatives from Kopsia fruticosa

Two new venalstonine derivatives, viz., venacarpines A and B, and one new dioxokopsan derivative, kopsorinine, in addition to the kopsifolines A-F, and 11 other known alkaloids, were isolated from a Malayan Kopsia species. The structures of the new alkaloids were determined using NMR and MS analysis.     

Alkaloids from Crinum moorei

Thirteen alkaloids were isolated from Crinum moorei two of which are new. These are 3-[4'-(8'-aminoethyl)phenoxy] bulbispermine and mooreine. The structures of the new alkaloids were determined by spectroscopic methods.     

New skeletons and new concepts in Amaryllidaceae alkaloids

The Amaryllidaceae alkaloids, represent a group of isoquinoline alkaloids, which are produced almost solely by members of the Amaryllidaceae family. The alkaloids of this family have attracted considerable amount of interest due to some important pharmacological activities they were shown to possess. In the last decade, our phytochemical studies on four Galanthus (Amaryllidaceae) species of Turkish origin have yielded quite a number of new alkaloids with diverse structures. Among these alkaloids, gracilines and plicamines constitute two new subgroups for the Amaryllidaceae alkaloids. The gracilines contain an incorporated 10b,4a-ethanoiminodibenzo[b,d]pyrane skeleton. The plicamines are dinitrogenous compounds, where the oxygen atom in position 7 of a tazettine skeleton is replaced by a nitrogen atom substituted by a pendant 4-hydroxyphenethyl moiety. One of the new alkaloids, galanthindole, which possesses a nonfused indole ring, unlike the already known subgroups of Amaryllidaceae alkaloids, may be considered as the prototype of a third new subgroup of the Amaryllidaceae alkaloids. Additionally, two known isoquinoline alkaloids which do not possess one of the established skeletons of the Amaryllidaceae alkaloids, namely ( − )-capnoidine and (+)-bulbocapnine, have been isolated from a Turkish Galanthus species. Totally, 21 new, 20 known alkaloids and 2 known lignans have been characterized. In this review, the isolation and structure elucidation of these compounds with interesting chemical structures are described.     

The alkaloids and other constituents from the root and stem of Aristolochia elegans

Two new aristolactams, aristolactam E (1) and aristolactam-AIIIa-6-O-beta-D-glucoside (2), three novel benzoyl benzyltetrahydroisoquinoline ether N-oxide alkaloids, aristoquinoline A (3), aristoquinoline B (4), and aristoquinoline C (5), and a new biphenyl ether, aristogin F (6), together with 62 known compounds have been isolated from the root and stem of Aristolochia elegans Mast. The structures of the new natural products were established on the basis of spectral evidence. Some of the isolated compounds were examined for their antioxidative and antityrosinase activities. Occurrence of the isoquinolones, biphenyl ethers, and benzoyl benzyltetrahydroisoquinoline ether alkaloids in the same plant indicated the definite possibility of these metabolites as biotransformation intermediates of bisbenzyltetrahydroisoquinoline alkaloids. This can be useful to solve the catabolic process of bisbenzyltetrahydroisoquinoline alkaloids.     

Imidazole alkaloids from Cynometra hankei

Two new and two known imidazole alkaloids, N₁-demethyl cynometrine, N₁-demethyl cynodine, cynometrine and cynodine, respectively, have been isolated from the stem bark and seed of Cynometra hankei. The structures of the new alkaloids were elucidated by chemical evidence and spectral data. No alkaloids could be detected in C. mannei stem bark.     

Trois nouveaux alcaloïdes bis-indoliques de Flindersia fo urnieri

Three new bis-indole alkaloids were isolated from Flindersia fournieri. Their structures were elucidated by spectral analysis and chemical correlation with the major alkaloids of the plant.     

Comparative study of the alkaloids in tribe Datureae and their chemosystematic significance

Sixty-six tropane alkaloids from crude leaf and root alkaloid mixtures of 12 different species and their varieties and subspecies from tribe Datureae were determined by GC–MS. The alkaloids 3β-hydroxy-6β-acetoxytropane, 3-propionyloxy-6-hyroxytropane, 3β-hydroxy-6β-tigloyloxytropane, 3β-tigloyloxy-6β-acetoxytropane and 3-tigloyloxy-7-isobutyryloxytropane are new reported tropane alkaloids.     

深裂黄草乌二萜生物碱研究

深裂黄草乌(Aconitum vilmorinianum var.altifidum W. T.Wang)又名西南乌头、紫乌头、藤乌,主要分布于云南东北部、贵州西部和四川西部(泸定、天全)海拔2800m的山地。块根可祛风散寒、除湿止痛,民间也用于解乌头中毒。其化学成分未见报道。本文从深裂黄草乌全草中分离鉴定了3个二萜生物碱,一个为C-19骨架类型,两个为C-20骨架类型。其中一个为新化合物,是C-20骨架类型二萜生物碱,命名为深裂黄草乌碱vilmorinianine(Ⅰ),另两个化合物是denudatine(Ⅱ)和deoxyaconitine(Ⅲ),均首次从该植物中得到。     

Neodihydrothebaine and bractazonine,two dibenz[d,f]azonine alkaloids of Papaver bracteatum

Two new dibenz[d,f]azonine alkaloids, neodihydrothebaine and bractazonine were isolated from Papaver bracteatum. Their possible biosynthesis from thebaine is discussed. The structures of both new alkaloids are proven by synthesis. An isomeric dibenz[d,f]azonine compound was also prepared.     

Two New C19-Diterpenoid Alkaloids from Delphinium shawurense

Shawurenine C ( 1a ) and D ( 1b ), a new pair of regioisomeric C₁₉-diterpenoid alkaloids, and five known C₁₉-diterpenoid alkaloids ( 2 – 6 ) were isolated from the aerial part of Delphinium shawurense W. T. Wang. The chemical structures of new compounds were established based on spectroscopic analyses: HR-ESI-MS, and 1D, 2D NMR spectroscopic data. The anti-inflammatory and cytotoxic activities of these diterpenoid alkaloids were also evaluated.     

Cytotoxic 7S-oxindole alkaloids from Gardneria multiflora

Seven new oxindole alkaloids, gardmutines A–F (1–6) and 18-hydroxy-chitosenine (7), along with 15 known alkaloids, were isolated from the aerial parts of Gardneria multiflora Makino. The structures of the alkaloids were established by spectroscopic methods. Alkaloids 1–6 are the first Gardneria alkaloids possessing a 7S configuration. Gardmutines D and E were cytotoxic to HeLa, MCF-7 breast, and SW-480 colon cancer cell lines.     

Pyrrolizidine alkaloids from seeds of Crotalaria scassellatii

Three pyrrolizidine alkaloids were isolated from the seeds of Crotalaria scassellatii. Axillaridine and axillarine were the two major alkaloids whereas the third minor alkaloid was a new compound. Its structure was determined as desoxyaxillarine.     

Alkaloids from Haplophyllum tuberculatum

Two new alkaloids, haplotubinone (3) and haplotubine (4), were isolated from the aerial parts of Haplophyllum tuberculatum together with the known lignan diphyllin. The structures of the new alkaloids were established by spectroscopic methods in conjunction with X-ray crystallographic analysis of 3. In addition, the amide N-(2-phenylethyl)-benzamide has been identified in this source for the first time.     

Methyl chanofruticosinates from leaves of Kopsia flavida Blume

Three new indole alkaloids with methyl chanofruticosinates skeletal system, viz., methyl 12-methoxy-N1-decarbomethoxychanofruticosinate, methyl 12-methoxychanofruticosinate and methyl 11,12-dimethoxychanofruticosinate, in addition to methyl 11,12-methylenedioxy-N1-decarbomethoxychanofruticosinate, have been isolated from the leaves of Kopsia flavida Blume. The structures of these three new indole alkaloids were assigned by NMR spectral data using various 2D-techniques.     

New class of steroidal alkaloids from Fritillaria imperialis

Two members of a new class of C-nor-D-homo steroidal alkaloids, impranine (1). and dihydroimpranine (2). along with a new pyridyl-pregnane-type steroidal alkaloid, fetisinine (3). and a known base, korsevine (4). were isolated from the bulbs of Fritillaria imperialis. The structures of the compounds were established on the basis of spectroscopic techniques and some chemical transformations. Compounds 1 and 2 form a new class of steroidal alkaloids, named as "impranane."     

Alkaloids from Sri Lankan curry-leaf (Murraya koenigii) display melanogenesis inhibitory activity: Structures of karapinchamines A and B

A methanolic extract and its ethyl acetate-soluble fraction from Sri Lankan curry-leaf, the leaves of Murraya koenigii, inhibited melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells. Two new carbazole alkaloids, karapinchamines A and B, were isolated from the ethyl acetate-soluble fraction together with 12 known carbazole alkaloids. The structures of karapinchamines A and B were determined by physicochemical analyses. The principal alkaloid constituents were found to display potent melanogenesis inhibitory activity. The structural requirements of the carbazole alkaloids for melanogenesis inhibitory activity were discussed.