Isolation and structure of buxaminol-G,an alkaloid from Buxus papilosa

A new alkaloid, buxaminol-G, has been isolated from the alcoholic extract of the leaves of Buxus papilosa, and its structure assigned on the basis of spectroscopic studies.     

(−)-12-Cytisineacetic acid,a new lupin alkaloid in Euchresta japonica

A new lupin alkaloid, methyl 12-cytisineacetate 1, was isolated from the MeOH extract of Euchresta japonica. Its structure was confirmed by spectrometric data and by direct comparison with a synthetic sample. However, 1 is an artifact product and 12-cytisineacetic acid (2) is assumed to be the principal source of 1.     

Na-formylechitamidine,an alkaloid from Alstonia boonei

A known alkaloid, echitamidine, and a new alkaloid, N_a-formylechitamidine, have been isolated from the stem bark of Alstonia boonei. The structure of this new alkaloid was assigned on the basis of chemical and spectroscopic data.     

Emiline,a new alkaloid from the aerial parts of Emilia sonchifolia

A new pyrrolidine alkaloid, Emiline (1), was isolated from the 90% EtOH extract of the aerial parts of Emilia sonchifolia. Its structure was established by various spectroscopic methods, including NMR, IR, HR-ESI-MS and X-ray crystallography. It was characterized by its skeleton derived from a bicyclo-[2.2.2]-oct-5-one ring and a pyrrolidine unit. The racemic mixture, (±)-Emiline, displayed good neuroprotective effect against the corticosterone-induced apoptosis in PC12 cells.     

A benzopyrroloisoquinoline alkaloid from Ficus fistulosa

A new benzopyrroloisoquinoline alkaloid, fistulosine (1), was isolated from the stem-bark of Ficus fistulosa (Moraceae) collected in Singapore, along with three known phenanthroindolizidine alkaloids, (?)-13aα-antofine (2), (?)-14β-hydroxyantofine (3) and (?)-13aα-secoantofine (4). (?)-13aα-Antofine (2) accounted for the antifungal activity against Aspergillus fumigatus and Candida albicans originally observed in the crude alkaloid extract.     

Effects of an alkaloid-rich extract from Mitragyna speciosa leaves and fluoxetine on sleep profiles,EEG spectral frequency and ethanol withdrawal symptoms in rats

BackgroundMany antidepressants are effective in alleviating ethanol withdrawal symptoms. However, most of them suppress rapid eye movement (REM) sleep. Thus, development of antidepressants without undesirable side effects would be preferable. Previously, crude alkaloid extract from Mitragyna speciosa (MS) Korth was found to produce antidepressant activities. It was hypothesized that the alkaloid extract from MS may attenuate ethanol withdrawal without REM sleep disturbance.MethodsAdult male Wistar rats implanted with electrodes over the frontal and parietal cortices were used for two separated studies. For an acute study, 10 mg/kg fluoxetine or 60 mg/kg alkaloid extract from MS were administered intragastrically. Electroencephalographic (EEG) signals were recorded for 3 h to examine sleep profiles and EEG fingerprints. Another set of animal was used for an ethanol withdrawal study. They were rendered dependent on ethanol via a modified liquid diet (MLD) containing ethanol ad libitum for 28 days. On day 29, fluoxetine (10 mg/kg) or alkaloid extract from MS (60 mg/kg) were administered 15 min before the ethanol-containing MLD was replaced with an isocaloric ethanol-free MLD to induced ethanol withdrawal symptoms.ResultsThe sleep analysis revealed that alkaloid extract from MS did not change any REM parameters which included average duration of each REM episode, total REM time, number of REM episode and REM latency whereas fluoxetine significantly suppressed all REM parameters and delayed REM latency. However, power spectral analysis revealed similar fingerprints for fluoxetine and alkaloid extract from MS characterized by decreasing powers in the slow frequency range in frontal and parietal cortical EEG. Neither treatment affected spontaneous motor activity. Finally, both alkaloid extract from MS and fluoxetine were found to significantly attenuate ethanol withdrawal-induced hyperexcitability (increases gamma activity) in both cortices and to reduce locomotor activity.ConclusionThe present study demonstrated that the alkaloid extract from MS alleviates ethanol withdrawal severity with no side effect on REM sleep. In addition, these data suggest that suppressive effects on slow frequency powers but not REM sleep may be hallmarks of effective antidepressants for ethanol withdrawal treatment.     

19-hydroxycoronaridin und 19-hydroxyibogamin,zwei antibiotisch wirksame alkaloide vom ibogamin-typ

During the separation of an extract from Tabernaemontana glandulosa, small amounts of a new alkaloid were obtained for which the structure 19-hydroxycoronaridine was deduced. This new alkaloid and 19-hydroxyibogamine, which can be obtained from it, show marked antibiotic activity in the agar plate diffusion test.     

Seco-tabersonine alkaloids from Tabernaemontana corymbosa

Two seco-tabersonine alkaloids, jerantiphyllines A and B, in addition to a tabersonine hydroxyindolenine, jerantinine H, and a recently reported vincamine alkaloid 7, were isolated from the leaf extract of the Malayan Tabernaemontana corymbosa and the structures were established using NMR and MS analysis. Biomimetic conversion of jerantinines A and E to their respective vincamine and 16-epivincamine derivatives were also carried out.     

Nummularine-O,a cyclopeptide alkaloid from Zizyphus nummularia

In addition to the known peptide alkaloid jubanine-B, a new peptide alkaloid, nummularine-O, has been isolated from the stem bark of Zizyphus nummularia and their structures have been elucidated by chemical and spectroscopic methods.     

Iso-erysopinophorine,a new quaternary alkaloid from the seeds of Erythrina arborescens

The ethanolic extract of the seeds of Erythrina arborescens yielded a new quaternary alkaloid provisionally named as iso-erysopinophorine besides the other alkaloids reported previously. The new alkaloid was characterised by chemical and spectral studies.     

1,2-dehydroaspidospermidine-N-oxide,an alkaloid from Rhazya stricta

A new alkaloid, 1,2-dehydroaspidospermidme-N-oxide, has been isolated from the roots of Rhazya stricta.     

Tylophorinicine,a phenanthroindolizidine alkaloid from tylophora asthmatica and pergularia pallida

Tylophorinicine, a minor alkaloid isolated from the roots of Tylophora asthmatica and Pergularia pallida has been characterized as 14-hydroxytylophorine from physical and chemical evidence.     

Glycarpine,a new alkaloid from Glycosmis cyanocarpa

Glycarpine, a new furoquinolone alkaloid and evolitrine have been isolated from Glycosmis cyanocarpa.     

Gramodendrine,a bipiperidyl-indole alkaloid from Lupinus arbustus subsp. calcara tus

A new bipiperidyl-indole alkaloid, gramodendrine, was isolated from Lupinus arbustus subsp. calcaratus. Its structure was determined from spect     

An aporphinoid alkaloid from Pseuduvaria macrophylla

Chromatographic separation of the alkaloid fraction of the methanol extract from the stem bark of Pseuduvaria macrophylla resulted in the isolation of a new aporphinoid alkaloid, 1,2,3-trimethoxy-4,5-dioxo-6a,7-dehydroaporphine, together with possibly the known O-methylmoschatoline.     

A novel tryptophan-derived alkaloid and other constituents from Guettarda speciosa (Rubiaceae: Cinchonoideae–Guettardeae)

Phytochemical examination of two Thai accessions of the widespread paleotropical Guettarda speciosa (Rubiaceae: Cinchonoideae–Guettardeae) led to the isolation of the hitherto undescribed tryptophan-derived alkaloid 5α-carboxystrictosidinic acid together with 5α-carboxystrictosidine, the iridoid glucoside loganic acid and 5-O-caffeoylquinic acid from the root bark extract. The leaf extract further yielded 3-O-caffeoylquinic acid and 4,5-di-O-caffeoylquinic acid. The structures of the isolated compounds were established by NMR and MS techniques and compared to other species of Guettarda. In addition, the structural differentiation of alkaloids within this genus is discussed with special emphasis on 5α-carboxy derivatives suggesting a pathway apart from the strictosidine biosynthetic route.     

Acanthothamine,a sesquiterpenoid alkaloid from Acanthothamnus aphyllus

Acanthothamine, a new sesquiterpene alkaloid, with an iso-evoninic acid residue, was isolated from Acanthothamnus aphyllus and characterized by chemical and spectroscopic data as 8-epieuonyminol tetraacetate iso-evoninate.     

Ervatinine,an indole alkaloid from Ervatamia coronaria

An indole alkaloid, ervatinine, has been isolated from the leaves of Ervatamia coronaria and its structure has been elucidated.     

3-methoxy-4,6-dihydroxymorphinandien-7-one,an alkaloid from Croton bonplandianum

A new alkaloid, 3-methoxy-4,6-dihydroxymorphinandien-7-one, and norsinoacutine have been isolated from extracts of Croton bonplandianum.     

Stapfinine,an indole alkaloid from Ervatamia coronaria

A new indole alkaloid, stapfinine, was isolated from the leaves of Ervatamia coronaria and its structure determined by spectroscopic means.