Syntheses, structures, and luminescent properties of dipyridylamine-functionalized anthracene and its complexes.

A novel multidentate ligand with 2,2'-dipyridylamine functionalities, 1,8-bis[4-(2,2'-dipyridylamino)phenylacetylenyl]anthracene (1), has been synthesized through a double Sonogashira coupling reaction and characterized by NMR spectroscopic, elemental, and X-ray diffraction analyses. Compound 1 can bind to either one metal center as a tetradentate ligand or two metal centers as a double-bidentate ligand. In the double-bidentate mode, the distance between the two metal centers may vary significantly.

Triterpenoidal alkaloids from Buxus natalensis and their acetylcholinesterase inhibitory activity.

Acetylcholinesterase (AChE) inhibition-directed phytochemical studies on the methanolic extract of Buxus natalensis, collected in South Africa, resulted in the isolation of 12 compounds: O(2)-natafuranamine (1), O(10)-natafuranamine (2), cyclonataminol (3), 31-demethylbuxaminol A (4), buxaminol A (5), buxafuranamide (6), buxalongifolamidine (7), buxamine A (8), cyclobuxophylline K (9), buxaminol C (10), methyl syringate (11), and p-coumaroylputrescine (12). Compounds 1-4 were new alkaloids, and compound 5 was isolated for the first time as a natural product. Their structures were elucidated with the aid of extensive NMR and mass spectroscopic studies.

Microbial reactions on 7alpha-hydroxyfrullanolide and evaluation of biotransformed products for antibacterial activity.

7alpha-Hydroxyfrullanolide (1), a known sesquiterpenoid, was isolated from Sphaeranthus indicus using an antibacterial-activity-directed fractionation method. This compound had exhibited a significant antibacterial activity against Gram-positive bacteria. Chemical and microbial reactions were performed to prepare eight different analogues of compound 1 in order to evaluate these newly synthesized compounds for antibacterial activity.