A. Hadi

Lapidilectine A and lapidilectine B, two new alkaloids from Kopsia lapidilecta

Abstract Bark and leaves of Kopsia lapidilecta Van der Sleesen were extracted. Two new indole alkaloids were afforded: lapidilectine A 1 (bark) and lapidilectine B 2 (leaves). Both possess a novel skeleton with a five membered unsaturated ring. The structures of these alkaloids were elucidated especially by 2D NMR analysis.

A PRELIMINARY CHEMOTAXONOMIC REVIEW OF KOPSIA (APOCYNACEAE)

The present paper is the result of a botanical and chemical study of the Indo-Pacific genus Kopsia (Plumerioideae-Rauvolfieae) Apocynaceae. Some of the species of this genus possess medicinal uses. A survey of the accepted taxa and their synonymy, based on the study of types, is presented. Studies on alkaloids provides chemotaxonomic information. Indeed, in some cases, chemical relationships occur between species belonging to the same botanical group.

Bisnicalaterines B and C, atropisomeric bisindole alkaloids from Hunteria zeylanica, showing vasorelaxant activity.

Two new bisindole alkaloids, bisnicalaterines B and C (1 and 2) consisting of an eburnane and a corynanthe type of skeletons, were isolated from the bark of Hunteria zeylanica. Their absolute structures were determined by combination of NMR, CD, and computational methods, and each of them was shown to be in an atropisomeric relationship. Bisnicalaterines B and C (1 and 2) showed potent vasorelaxant activity on isolated rat aorta.

Bisnicalaterine A, a Vobasine-Vobasine Bisindole Alkaloid from Hunteria zeylanica

A new bisindole alkaloid, bisnicalaterine A (1), consisting of two vobasine-type skeletons, and 3-epivobasinol (2) and 3-O-methylepivobasinol (3), with vobasine-type skeletons, were isolated from the leaves of Hunteria zeylanica, and their structures were elucidated on the basis of spectroscopic data and chemical correlation. Bisnicalaterine A showed moderate cytotoxicity against various human cancer cell lines.

6-Acylcoumarins from Mesua racemosa

Abstract Two new 6-acylcoumarins, racemosol 1 and mammea A/AC cyclo F 2 were isolated by fractionation of a leave extract of Mesua racemosa (Planch. ex Triana and Planch.) Kostermans. Their structures were solved by extensive spectroscopic analysis as 5,7-dihydroxy-8- (2‴-hydroxy-3‴-methylbut-3‴-ene)-6- (1″-oxobutyl)-4-phenyl-2 H -benzo [ b ]pyran-2-one 1 and 5-hydroxy-8- (1‴-hydroxy-1‴-methylethyl)-6- (1″-oxobutyl)-4-phenyl-8,9-dihydro-2 H -furo [2′,3′:5,6]benzo [1,2-b]pyran-2-one 2. Five known compounds namely mammea A/AC 3, mammea A/AC cyclo D 4, mammea A/AD cyclo D 5, mammea A/BB 6 and mammea A/AA 7 were also isolated from the same source.

Antibacterial Evaluation of Some Schiff Bases Derived from 2-Acetylpyridine and Their Metal Complexes

A series of Schiff bases derived from 2-acetylpyridne and their metal complexes were characterized by elemental analysis, NMR, FT-IR and UV-Vis spectral studies. The complexes were screened for anti-bacterial activity against Methicillin-resistant Staphylococcus aureus (MRSA), Acinetobacter baumanni (AC), Klebsiella pneumonie (KB) and Pseudomonas aeruginosa (PA) using the disc diffusion and micro broth dilution assays. Based on the overall results, the complexes showed the highest activities against MRSA while a weak antibacterial activity was observed against A. baumanii and P. aeruginosa.

Phoebegrandines A and B, proaporphine-tryptamine dimers, from Phoebe grandis

Abstract Four known aporphine alkaloids, boldine, norboldine, laurotetanine and lindecarpine were isolated from the bark of Phoebe grandis. The leaves yielded two new alkaloids belonging to the proaporphine-tryptamine dimers series, phoebegrandines A and B. The structure of the new compounds was elucidated by spectral methods.

Bisleuconothine A, an eburnane-aspidosperma bisindole alkaloid from Leuconotis griffithii

A new bisindole alkaloid, bisleuconothine A (1) consisting of an eburnane-aspidosperma type skeleton, was isolated from the bark of Leuconotis griffithii. The structure including absolute stereochemistry was elucidated on the basis of 2D NMR data and X-ray analysis. Bisleuconothine A (1) showed cell growth inhibitory activity against various human cancer cell lines.

Eucophylline, a Tetracyclic Vinylquinoline Alkaloid from Leuconotis eugenifolius

Eucophylline (1), a new tetracyclic vinylquinoline alkaloid, was isolated from the bark of Leuconotis eugenifolius together with leucophyllidine (2). The structure and absolute configuration of 1 were elucidated on the basis of 2D NMR correlations and simulated CD analysis. Leucophyllidine (2) showed iNOS inhibitory activity and decreased the iNOS protein expression dose-dependently.

Aporphine Alkaloids from the Leaves of Phoebe grandis (Nees) Mer. (Lauraceae) and Their Cytotoxic and Antibacterial Activities

The oxoaporphine alkaloid lysicamine (1), and three proaporphine alkaloids, litsericinone (2), 8,9,11,12-tetrahydromecambrine (3) and hexahydromecambrine A (4) were isolated from the leaves of Phoebe grandis (Nees) Merr. (Lauraceae). Compounds 2 and 3 were first time isolated as new naturally occurring compounds from plants. The NMR data for the compounds 2–4 have never been reported so far. Compounds 1 and 2 showed significant cytotoxic activity against a MCF7 (human estrogen receptor (ER+) positive breast cancer) cell line with IC50 values of 26 and 60 µg/mL, respectively. Furthermore, in vitro cytotoxic activity against HepG2 (human liver cancer) cell line was evaluated for compounds 1–4 with IC50 values of 27, 14, 81 and 20 µg/mL, respectively. Lysicamine (1) displayed strong antibacterial activity against Bacillus subtilis (B145), Staphylococcus aureus (S1434) and Staphylococus epidermidis (a clinically isolated strain) with inhibition zones of 15.50 ± 0.57, 13.33 ± 0.57 and 12.00 ± 0.00 mm, respectively. However, none of the tested pathogenic bacteria were susceptible towards compounds 2 and 3.