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A novel actinomycete producing 2-allyloxyphenol, designated strain MS1/7(T), was isolated from sediments of the Sundarbans mangrove forest, India. Growth on International Streptomyces Project (ISP) media 2, 3, 4, 5 and 7 produced olive green to grey aerial hyphae that carried smooth-surfaced spores in a flexuous (Rectiflexibiles) arrangement. The strain contained ll-diaminopimelic acid, but no diagnostic sugars in whole-cell hydrolysates. Hexa-, octa- and a minor amount of tetra-hydrogenated menaquinones with nine isoprene units [MK-9 (H(4), H(6), H(8) and H(10))] were present as isoprene analogues. Diagnostic phospholipids were phosphatidylethanolamine and diphosphatidylglycerol. The predominant fatty acids were anteiso-C(15 : 0) (34.80 %), iso-C(16 : 0) (16.45 %), C(16) (10.53 %) and anteiso-C(17 : 0) (10.92 %). The strain showed greater than 99 % 16S rRNA gene sequence similarity to the type strains of several recognized species of the genus Streptomyces, but in the phylogenetic tree based on 16S rRNA gene sequences it formed a distinct phyletic line and demonstrated closest relationships to viomycin-producers (Streptomyces californicus NRRL B-1221(T), Streptomyces floridae MTCC 2534(T) and Streptomyces puniceus NRRL B-2895(T)). However, strain MS1/7(T) could be distinguished from these and other closely related species based on low levels of DNA-DNA relatedness (<44 %) and disparate physiological features, principally amino acid utilization and growth in NaCl. Strain MS1/7(T) is therefore suggested to represent a novel species of the genus Streptomyces, for which the name Streptomyces sundarbansensis sp. nov. is proposed. The type strain is MS1/7(T) ( = MTCC 10621(T) = DSM 42019(T)).

A marine actinobacterium isolated from the Bay of Bengal, India and previously found to be producing an antimicrobial and cytotoxic terpenoid was further investigated for antimicrobial metabolites. The bacterium was preliminarily identified as a new species of the genus Streptomyces (strain MS1/7). The cell-free culture broth was extracted with n-butanol and purified using silica gel column chromatography and high-performance liquid chromatography. Molecular characterization was done using ESI mass, IR and 1H and 13C NMR spectrometry. 2-Allyloxyphenol (MW 150; C9H10O2), a synthetic drug and chemical intermediate, was obtained as a natural product for the first time. Serendipitous natural occurrence provided new insights into the synthetic molecule. 2-Allyloxyphenol was found to be inhibitory to 21 bacteria and three fungi in the minimum range 0.2-1.75 mg mL(-1) determined by agar dilution method. 2-Allyoxyphenol possesses strong antioxidant property (IC(50) 22 microg mL(-1), measured by 1, 1-diphenyl-2-picryl hydrazyl scavenging activity). Hydroxyl and allyloxy groups in 2-allyloxyphenol were responsible for antimicrobial and antioxidant activities. 2-Allyloxyphenol has marked resemblance to smoky aroma and is two to three times more active as an antimicrobial than some commercial smoke-flavour compounds. Absence of hemolytic toxicity, potential carcinogenicity, cytotoxicity and reports of toxic reactions in literature suggest possible application of 2-allyloxyphenol as a food preservative and an oral disinfectant.