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Study on the Chemistry and Antimicrobial Activity of Psychotria reevesii Wall

The high accumulation of tannins may be responsible for the antibacterial activities of the polar fractions against Staphylococcus aureus, Pseudomonas aeruginosa, Shigella sonnei, and Shigella flexneri. However, they did not exhibit any inhibitory effect against Escherichia coli, Candida albicans, and Candida stellatoides. | Journal of Chemistry, Vol. 45 (5), P. 628 - 633, 2007 Study on the Chemistry and Antimicrobial Activity of Psychotria reevesii Wall. (Rubiaceae) Received 28 August 2006 Phan Minh Giang, Ha Viet Son, Phan Tong Son Laboratory of Chemistry of Natural Products, College of Natural Science, VNU Hanoi Summary The first chemical investigation on Vietnamese medicinal plant Psychotria reevesii Wall. (Rubiaceae) led to the isolation and structural determination of -sitosterol and stigmasterol as a mixture, 1-octacosene, and asperglaucide from n-hexane- and CHCl3-soluble fractions of MeOH extract from the aerial parts of P. reevesii. Phytochemical screening based on color reactions, HPLC analysis, and NMR spectroscopy revealed the concentration of condensed tannins in EtOAc- and n-BuOH soluble fractions. The high accumulation of tannins may be responsible for the antibacterial activities of the polar fractions against Staphylococcus aureus, Pseudomonas aeruginosa, Shigella sonnei, and Shigella flexneri. However, they did not exhibit any inhibitory effect against Escherichia coli, Candida albicans, and Candida stellatoides. Keywords: Psychotria reevesii; Rubiaceae; asperglaucide; antibacterial activity; antifungal activity. I - Introduction Psychotria reevesii Wall. (syn. Psychotria rubra (Lour.) Poir.) of the family Rubiaceae is a medicinal plant known as Lau or Bo chat in Vietnam [1, 2]. P. reevesii is a plant of 1 - 9 m high, widely distributed in Vinh Phu, Thai Nguyen, Lang Son,. The roots and leaves of P. reevesii (Radix et Folium Psychotriae Rubrae) are used in the treatment of throat inflammation, dysentery, and rheumatic fever; leaves are also used externally to cure wounds. This paper deals with the chemical study and the investigation of antimicrobial activity of the aerial parts of P. reevesii. II - Experimental General Melting points were recorded on a Boetius micromelting point apparatus without correction. Optical rotations were measured on a 628 Union Giken