Monoterpenoid Indole Alkaloids with Promoting Neurite Growth from Tabernaemontana divaricata

Main observation and conclusion Phytochemical investigations on Tabernaemontana divaricata led to the isolation of seven undescribed monoterpenoid indole alka-l...     

Vobasonidine and Vobatricine,Novel Bisindole Alkaloids from a Malayan Tabernaemontana

Two novel bisindole alkaloids of the vobasine‐vobasine and vobasine‐strychnan type, viz., vobasonidine ( 2 ) and vobatricine ( 3 ) were obtained from the leaf and stembark extracts, respectively, of the Malayan species Tabernaemontana corymbosa, and their structures were established by spectroscopic analysis.     

Two New Indole Alkaloids from Tabernaemontana hystrix Steud. (Apocynaceae)

Two new monoterpene indole alkaloids named ibogamine‐7,8‐dione ( 1 ) and 12‐methoxyvoachalotine ( 2 ), and eight known ones, coronaridine ( 3 ), coronaridine hydroxyindolenine ( 4 ), 5‐oxocoronaridine ( 5 ), 3‐oxocoronaridine hydroxyindolenine ( 6 ), 3‐oxocoronaridine ( 7 ), vobasine ( 8 ), ibogamine ( 9 ), and olivacine ( 10 ), were isolated from a CH₂Cl₂ extract of the root bark from Tabernaemontana hystrix. The structures of the compounds were elucidated on the basis of spectroscopic data analyses, mainly ¹H‐ and ¹³C‐NMR, including 2D experiments (¹H,¹H‐COSY, HMBC, and HMQC).     

Studies on Natural Products from Cuban Plants. Alkaloids from Tabernaemontana citrifolia

A detailed study of the alkaloids from Tabernaemontana citrifolia, a species growing in Cuba is presented. Thirteen alkaloids were isolated and characterized. One of these, (?)-19-oxovoacristine ( 7 ), is a new compound isolated for the first lime from a natural source.     

Analgesic components from bornean medicinal plants, Tabernaemontana pauciflora Blume and Tabernaemontana pandacaqui Poir.

The analgesic components were isolated from a Bornean medicinal plant, Tabernaemontana pauciflora Blume (syn. Ervatamia blumeana Mark gr.), and the major components were identified as coronaridine and 3-(2-oxopropyl)coronaridine. Four minor components were estimated to be 5R- and 5S-(2-oxopropyl)coronaridine, 3-(2-oxopropyl)voacangine and 3,3'-(oxopropyl)dicoronaridine, which might be produced during the isolation process. Voacangine was also isolated as a major component of T. pandacaqui Poir. Coronaridine and voacangine exhibited significant analgesic and hypothermic effects in mice at a dose of 25 mg/kg, p.o., while 3-(2-oxopropyl)coronaridine was less effective. The former two compounds also revealed a surface anesthesia.     

Antimicrobial activities of indole alkaloids from Tabernaemontana catharinensis

Tabernaemontana catharinensis root bark ethanol extract, EB2 fraction and the MMV alkaloid (12-methoxy-4-methylvoachalotine) were evaluated for their antimicrobial activities. T. catharinensis ethanol extract was effective against both strains of the dermatophyte Trichophyton rubrum at concentrations of 2.5 mg/mL (wild strain) and 1.25 mg/mL (mutant strain), while the EB2 fraction and MMV alkaloid showed a strong antifungal activity against wild and mutant strains with MIC values of <0.02 and 0.16 mg/mL, respectively. The EB2 fraction showed a strong antibacterial activity against ATCC strains of S. aureus, S. epidermidis, E. coli and P. aeruginosa with MICs from <0.02 to 0.04 mg/mL, as well as against resistant clinical isolates species of Enterococcus sp, Klebsiella oxytoca, Citrobacter, K. pneumoniae, P. mirabilis, S. aureus, S. epidermidis, E. coli and P. aeruginosa with MIC values ranging from 0.04 to 0.08 mg/mL. The MMV alkaloid presented a MIC of 0.16 mg/mL against the strains of S. aureus and E. coli ATCC. For the resistant clinical isolates Enterococcus sp, Citrobacter, S. aureus, S. epidermidis, E. coli and P. aeruginosa the MIC of MMV ranged from 0.08 to 0.31 mg/mL. The chromatography analysis of the EB2 fraction revealed the presence of indole alkaloids, including MMV, possibly responsible for the observed antimicrobial activity.     

Two new monoterpenoid indole alkaloids from Tabernaemontana divaricata

Two new monoterpenoid indole alkaloids, tabervarines A (1) and B (2), along with seven known monoterpenoid indole alkaloids, were isolated from the methanol extract of the twigs and leaves of Tabernaemontana divaricata. The structures including the absolute configurations of the new alkaloids were elucidated based on MS, NMR, and ECD calculation. The in vitro cytotoxic activities of the isolated alkaloids against several human cancer cell lines were also evaluated.     

A new stereoisomer of stemmadenine alkaloid from Tabernaemontana heyneana

A new alkaloid, 15‐β‐stemmadenine, was isolated from the fruits of Tabernaemontana heyneana Wall. from the ethanolic extract. The complete ¹H and ¹³C NMR assignments of the compound were carried out using COSY, HMQC and HMBC. Stereochemistry at C‐15 and C‐16 was established using ROESY and temperature‐dependent ¹H NMR studies. Copyright © 2002 John Wiley & Sons, Ltd.     

Die Alkaloide von Gabunia eglandulosa STAPF 155. Mitteilung über Alkaloide

From the root bark of the Apocynaceae Gabunia eglandulosa STAPE seven indole alkaloids were isolated. Besides the known indole alkaloids (?)-isovoacangine ( 1 ), (?)-coronaridine ( 2 ), voacamine ( 3 ), vobasine ( 4 ), and perivine ( 5 ), two new bases (?)-19-hydroxy-isovoacangine ( 6 ) and 19-hydroxy-coronaridine ( 15 ) were isolated. Compound 6 was obtained by oxidation of isovoacangine with iodine. Similar oxidation reactions with voacangine ( 12 ) were studied.     

Biologically active indole and bisindole alkaloids from Tabernaemontana divaricata

The ethanol extract of the leaves of Tabernaemontana divaricata (double flower variety) provided a total of 23 alkaloids, including the new aspidosperma alkaloids, taberhanine, voafinine, N-methylvoafinine, voafinidine, voalenine and the new bisindole alkaloid, conophyllinine in addition to the previously known, biologically active bisindole, conophylline and its congener, conofoline. The structures of the new alkaloids were established by spectroscopic methods. The preparation and characterization of the corresponding quinones of the biologically active bisindoles are also described in relation to a structure-activity study of these compounds with respect to their action in stimulating insulin expression.     

Tacamine-type alkaloids from Tabernaemontana bovina together with their configuration determination

Eleven undescribed tacamine type alkaloids, named tabercamines A–K were isolated from leaves of Tabernaemontana bovina, together with six known alkaloids. The planar structure of the undescribed alkaloids were determined by comprehensive spectroscopic data analysis. Their absolute configuration were established based on the combination of the electronic circular dichroism and single X-ray crystal diffraction analysis. The NMR rules (in acetone-d₆) of identifying of the stereo-configuration at C-20/16 was established.     

Alkaloids ofDicentra

Methanolic extraction ofDicentra spectabilis L., collected in the flowering period in the botanical garden of Pyatigorsk Pharmaceutical Institute, has yielded 0.17% of combined alkaloids from the epigeal part and 0.25% from the roots. By the separation of these materials, dihydrosanguinarine, sanguinarine, scoulerine, cheilanthifoline, corydine, and protopine have been obtained.Dicentra peregrina Rudolph, collected in the flowering period on the island of Sakhalin, has yielded 1.8% of combined alkaloids from the epigeal part and 1.51% from the roots. From these combined materials have been isolated isocorydine, corydine, dicentrine, protopine, dihydrosanguinarine, sanguinarine, cheilanthifoline, bicuculline, lederine, scoulerine, isoboldine, predicentrine, reticuline, and allocryptopine.Institute of the Chemistry of Plant Substances. Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 79–81, January–February, 1984.