.DELTA.-Indomycinone: A New Member of Pluramycin Class of Antibiotics Isolated from Marine Streptomyces sp.

Abstract

In a continuation of our investigation for bioactive secondary metabolites from marine microorganisms1}, we have isolated a new pluramycin type metabolite 5-indomycinone (2), along with the known antibiotic /?-indomycinone (1)2). Both compounds were extracted from the culture broth of a Streptomyces strain (B 8300), obtained from the collection of marine actinomycetes at Alfred-Wegener-Institute for Polar and Marine Research, Bremerhaven, Germany. Pluramycin metabolites containing the 4tf-anthra[l ,2-Z>]pyran-4,7, 1 2-trione nucleus to which amino sugars typically are attached at C-8 and C-10 positions, were most commonly isolated from terrestrial Streptomyces sp. The pluramycin analogues which lack any carbohydrate substitution are the pluramycinones such as indomycinones3). The pluramycins are a group of highly structurally evolved DNA reactive agents and found to have antimicrobial and OCT. 1997 anticancer activity40. We would now like to describe the taxonomy of the producing strain and the fermentation, isolation and structure determination of the new metabolite (5-indomycinone (2). Taxonomy of Strain B 8300The actinomycete strain B 8300 was isolated from sediment of the Laguna de Terminos at the Gulf of Mexico using cellulose medium5) containing 50% seawater at an incubation temperature of 18°C. The pure culture was maintained on yeast extract-malt extract agar6) (YMA). The strain forms extensive yellow aerial mycelium, with straight to flexuous (Rectiflexibiles) spore chains of about 20jum length. Spores are cylindrical about 1.1/mi long and 0.4 to 0.5/im in diameter with a smooth surface. The non fragmenting vegetative mycelium is reddish brown forming a reddish brown, diffusible pigment. The strain cannot grow at 4°C and 45°C on YMA. Poor growth occurs at 10°C and 37°C after 4 weeks. The temperature optimum is at about 30°C. Growth is obtained in the presence of 0.4 and 7% (w/v) sodium chloride but not in the presence of 10 or 13% sodium chloride on YMA. Further physiological characteristics are compiled in Table 1.The cell wall peptidoglycan of the strain contains major diagnostic amounts of L-diaminopimelic acid (l-DAP) and glycine corresponding with wall chemotype

Research on marine actinobacteria in India

“…Since environmental conditions of the sea are extremely different from terrestrial conditions, they produce different types of antibiotics. Several antibiotics have been isolated from marine actinobacteria by many researchers [20][21][22][23][24][25][26][27][28][29][30] . The isolated antibiotics are entirely new and unique when compared to those from the terrestrial ones 31 .…”

MC21-A, a Bactericidal Antibiotic Produced by a New Marine Bacterium, Pseudoalteromonas phenolica sp. nov. O-BC30 T , against Methicillin-Resistant Staphylococcus aureus

“…Antibiotics from marine microorganisms have been reported, including loloatins from Bacillus (14), agrochelin and sesbanimides from agrobacterium (1,2), pelagiomicins from Pelagiobacter variabilis (23), ␦-indomycinone from a Streptomyces sp. (6), and dihydrophencomycin methyl ester from Streptomyces (36). In particular, some species of the genus Pseudoalteromonas (formerly Alteromonas) (11) produce both antibiotics and several bioactive substances (12,13,18,25,29,38,39,45).…”

Natural marine products with antifouling activities

“…An antimicroalgal substance, 2-[methyl-(3-phenylproprionyl)amino]-benzoic acid, isolated from a culture of the marine Streptomyces sp. strain B7747, showed activity against Chlorella vulgaris, C. sorokiniana and Scenesdesmus subspicatus (Minimum Inihibitory Concentration (MICs) ≥ 20 μg ml −1 ) (Biabani et al, 1997). The activity is lower than the commercially available antibiotics but could be potentially improved by slight modifi cation of the chemical structure during synthesis.…”