SECONDARY METABOLITES PRODUCED DURING THE GERMINATION OF STREPTOMYCES COELICOLOR AND FROM THE LEAVES OF OXALIS DEBILIS

Asif Ali, Mohammed Ali*, Showkat Rassol Mir, Md. Kamaruz Zaman and Shahnaz Sultana

ABSTRACT

Streptomyces coelicolor produces various type of compounds by means of specialized biosynthetic pathways. This paper reports the isolation and identification of chemical constituents found in a fermentation broth of S. coelicolor. A methanol extract of the cells of S. coelicolor was chromatographed over a silica gel column. The column was eluted with various solvent mixtures of increasing polarity to isolate the chemical constituents. Elution of the column with petroleum ether - chloroform (1:1) yielded a new 2,3-dihydro-1-benzopyran-4-one identified as 2α-methyl-8-hydroxy-4-chromanone (1). Elution of the column with chloroform gave yellow crystals of a new alkylated β-naphthol carboxylic acid characterized as 1-(2'-pentanyl-1'-aldehyde)-2-hydroxy-8-naphthoic acid (2). Lawsonyl-1,3-dimethyl-2α-(10,14-dimethyl nonan-7β-olyl)cyclohexan-1-oate (3), a new diterpenic ester with lawsone, was isolated when the column was eluted with chloroform-methanol (19:1) mixture. Elution of the column with chloroform-methanol (9:1) furnished red crystals of 3-[1-(2'-hexan-1'-al-4'-one)-2-hydroxy-8-naphthoic acid]-3''-[1''-(2'''-hexan-1'''-al)-2''-hydroxy-8''-naphthoic acid]-hydroxy methine (4), a new dinaphthol-1, 1''-dihexanal-8, 8''-dioic acid carbinol derivative. The leaves of Oxalis debilis Kunth (Oxalidaceae) possess analgesic, anodyne, antiscorbutic, astringent, diuretic, emmenagogue, expectorant and stomachic properties and are used to treat earache, fevers and to quench the thirst. Phytochemical investigation of the leaves of O. debilis furnished a known phytosterol, stigmasterol (5) and a higher aliphatic alcohols identified as 1-heptatriacontanol (6). The structures of these natural products were elucidated on the basis of spectral data analysis and chemical reactions.

Keywords: Streptomyces coelicolor, spore germination, Oxalis debilis leaves, chemical constituents, isolation, identification.