Constituents from Siparuna apiosyce

The isolation and spectral data of the aporphine alkaloid asimilobine (1) from the aerial parts of Siparuna apiosyce are reported.     

Aporphine alkaloids from Enantia chlorantha

Two novel aporphine alkaloids, named 6a,7-dehydro-1,2-dimethoxy-7-hydroxy-N-methylaporphine (1) and 6a,7-dehydro-1,2-dimethoxy-7-hydroxyaporphine (2), have been isolated from the stem bark of E. chlorantha.     

Isolation and X-ray crystal structure of a new isoquinoline-N-oxide alkaloid from Calycotome villosa subsp. intermedia

A new isoquinoline-N-oxide alkaloid was extracted from the alkaloid fraction of a methanol extract of the seeds of Calycotome villosa subsp. intermedia. Its structure was established as 1-hydroxymethyl-6,7-dimethoxyisoquinoline-N-oxide (1) by spectroscopic techniques and X-ray diffraction analysis.     

A new dimeric aporphine from the roots of Artabotrys spinosus

A new dimeric aporphine, artabotrysine along with five known compounds was isolated from the roots of Artabotrys spinosus. Their structures were fully established on the basis of spectral evidence. All isolated compounds were evaluated for their cytotoxicity on HeLa and KB cells.     

New bisbenzylisoquinoline alkaloid from Laureliopsis philippiana

Phytochemical investigation of Laureliopsis philippiana resulted in isolation of a new bisbenzylisoquinoline alkaloid (1) named laureliopsine A. The structure was established by spectroscopic methods, including 2D homo- and heteronuclear NMR experiments. This finding of a bisbenzylisoquinoline alkaloid in Laureliopsis supports its close relationship to Atherosperma and its taxonomic segregation from Laurelia.     

Alkaloids from Sophora flavescens Aition

Although the quinolizidine alkaloids and flavonoids, the main active components of the traditional Chinese medicine Sophora flavescens, have been largely investigated, a new matrine alkaloid derivative 9α-hydroxy-7,11-dehydromatrine (1) and a rare 1,4-diazaindan-type alkaloid flavascensine (17), together with 15 known alkaloids, were isolated from S. flavescens. The structures were established on the basis of spectroscopic techniques.     

Antitumor alkaloid from Glycosmis pentaphylla

Arborinine, an acridone alkaloid obtained from Glycosmis pentaphylla, exhibited significant inhibition of crown gall tumors produced by Agrobacterium tumefaciens in a potato disc bioassay.     

Aporphine alkaloids,clerodane diterpenes,and other constituents from Tinospora cordifolia

Phytochemical investigation of the methanol extract of Tinospora cordifolia aerial parts led to the isolation of four new and seven known compounds. The structures of two new aporphine alkaloids, N-formylasimilobine 2-O-β-d-glucopyranosyl-(1 → 2)-β-d-glucopyranoside (tinoscorside A, 1) and N-acetylasimilobine 2-O-β-d-glucopyranosyl-(1 → 2)-β-d-glucopyranoside (tinoscorside B, 2), a new clerodane diterpene, tinoscorside C (3), and a new phenylpropanoid, sinapyl 4-O-β-d-apiofuranosyl-(1 → 6)-O-β-d-glucopyranoside (tinoscorside D, 6) were determined by extensive spectroscopic methods including FTICR-MS and 1D and 2D NMR.     

New amide alkaloid from the aerial part of Piper capense L.f. (Piperaceae)

Together with apigenine dimethylether and piperchabamide A, a new amide alkaloid, Kaousine and the Z form of antiepilepsirine were isolated from the aerial part of Piper capense L.f (Piperaceae). Their structures were elucidated by spectrometric methods and their in vitro antiparasitic activities were evaluated on Plasmodium falciparum.     

A new proaporphine alkaloid from Meconopsishorridula

A new proaporphine alkaloid, 8, 9-dihydroprooxocryptochine (1), together with three known alkaloids, was isolated from the aerial parts of Meconopsishorridula Hook. f. & Thomson (Papaveraceae), a traditional Tibetan medicine. The structure of 1 was determined by spectroscopic methods.     

Cassine, an antimicrobial alkaloid from Senna racemosa

The leaves of Senna racemosa yielded the piperidine alkaloid cassine and an inositol methyl ether. Antimicrobial screening of the compounds revealed antibacterial activity of cassine with minimum inhibitory concentrations of 2.5 mg/ml for Staphylococcus aureus and Bacillus subtilis and 5.0 mg/ml for Candida albicans.     

Bismurrayafoline E: a new dimeric carbazole alkaloid from Murraya koenigii

The ethanolic extract of the leaves of M. koenigii afforded a new carbazole alkaloid, which was identified as bismurrayafoline E (1) on the basis of spectroscopic analysis.     

Alkaloid production from regenerated Solanum plants

Production of Solanum nigrum and S. nigrum var. judaicum plants with a high power of alkaloid accumulation was the aim of in vitro regeneration trials followed by in vivo plant acclimatization. MS-basal medium containing BA and NAA (0.5 mg/ml each) was the best for both plants. A series of in vitro and in vivo plants were successfully produced and chemical analysis revealed contents of glycoalkaloids higher than those reported for intact field plants.     

Sinoscrewtine,an alkaloid with novel skeleton from the roots of Sinomenium acutum

An alkaloid with novel skeleton, sinoscrewtine (1), has been isolated from the roots of Sinomenium acutum. Its structure was established by spectral analysis and X-ray crystallographic study, and its possible biosynthetic pathway was delivered. In vitro experiments, 1 showed weak injurious effects against H₂O₂/Aβ_25–35 induced oxidative injury in PC-12 cells and DPPH radical scavenging activity with IC₅₀ of 32.6 μM.     

Four new fluorenone alkaloids and one new dihydroazafluoranthene alkaloid from Caulophyllum robustum Maxim

Four new fluorenone alkaloids, caulophylline A-D (1-4), and one new dihydroazafluoranthene alkaloid, caulophylline E (5) were isolated from the roots of Caulophyllum robustum Maxim. Their structures were elucidated by spectroscopic analysis. Among the isolated alkaloids, Caulophylline E showed good scavenging effects against DPPH radical with IC₅₀ of 39 μM.     

Two novel dimeric indole alkaloids from the leaves and twigs of Psychotria henryi

Two novel dimeric indole alkaloids were isolated from the leaves and twigs of Psychotria henryi. Their structures were established by chemical and spectroscopic methods. Compound 1 was a novel dimeric tryptamine-related alkaloid that contained an unprecedented decacyclic ring system, and compound 2 featured a pyrido[3,4-b]indole moiety adjacent to a pyrrolidinoindole skeleton. The absolute configurations of compounds 1 and 2 were determined by calculation of electronic circular dichroism (ECD) using density functional theory (DFT).     

New isoquinolinequinone alkaloids from the South China Sea nudibranch Jorunna funebris and its possible sponge-prey Xestospongia sp.

Two new renieramycin-type bistetrahydroisoquinolinequinone alkaloids, fennebricins A (1) and B (5), and one new isoquinolinequinone alkaloid, N-formyl-1,2-dihydrorenierol (7), were isolated from the skin of the South China Sea nudibranch Jorunna funebris and its possible sponge-prey Xestospongia sp., together with eight known metabolites, including three bistetrahydroisoquinolinequinones (2–4) and five isoquinolinequinones (8–12). Their structures were elucidated by analysis of spectroscopic data including 1D and 2D NMR and high-resolution electrospray ionization mass spectrometry (HRESIMS) and by comparison with data for related known compounds. All the metabolites except for 7 occurred simultaneously in the two animals, supporting recent ecological studies that the nudibranch J. funebris preys on the sponge of the genus Xestospongia.     

Dysoxylum binectariferum Hook.f (Meliaceae), a rich source of rohitukine

Rohitukine, a chromane alkaloid, is a precursor of flavopiridol, a promising anti-cancer compound. Currently in Phase III clinical trials, flavopiridol is a potent inhibitor of several cyclin-dependent kinases (CDKs). Rohitukine was first reported from Amoora rohituka (0.083% dry weight) followed by that in Dysoxylum binectariferum (0.9% dry weight), both belonging to the family Meliaceae. Here, we report incredibly high yields of rohitukine (7% dry weight) in trees of D. binectariferum from the Western Ghats, India. Crude extracts of the tree were found to be highly effective against ovarian and breast cancer lines tested.     

A new indole alkaloid from Ervatamia yunnanensis

The stems of Ervatamia yunnanensis have afforded a new indole alkaloid, ervataine (1), whose structure was determined by spectroscopic analysis. Five known compounds, ibogaine (2) coronaridine (3), heyneanine (4), voacangine hydroxyindolenine (5) and coronaridine hydroxyindolenine (6), were also isolated.     

Bisindole alkaloids and secoiridoids from Alstonia macrophylla Wall. ex G. Don

The ethanolic extract from stems of a Thai medicinal plant, Alstonia macrophylla Wall. ex G. Don (Apocynaceae) showed a significant inhibitory effect on acetylcholinesterase (AChE) determined by using Ellman assay. Four compounds i.e., a bisindole alkaloid, macralstonine (1), a new bisindole alkaloid, thungfaine (2), a secoiridoid glycoside, sweroside (3) and a new secoiridoid glycoside, naresuanoside (4) were isolated. Compound 4 showed moderate AChE and butyrylcholinesterase (BChE) inhibitory effects. Interestingly, compound 4 inhibited cell growth on human androgen-sensitive prostate cancer cell line (LNCaP) but no effect on viability of human foreskin fibroblast cells (HF).