In our systematic screening programme for marine actinomycetes, a bioactive Streptomycete was isolated from marine sediment samples of Bay of Bengal, India. The taxonomic studies indicated that the isolate belongs to Streptomyces chibaensis and it was designated as S. chibaensis AUBN1/7. The isolate yielded a cytotoxic compound. It was obtained by solvent extraction followed by the chromatographic purification. Based on the spectral data of the pure compound, it was identified as quinone-related antibiotic, resistoflavine (1). It showed a potent cytotoxic activity against cell lines viz. HMO2 (Gastric adenocarcinoma) and HePG2 (Hepatic carcinoma) in vitro and also exhibited weak antibacterial activities against Gram-positive and Gram-negative bacteria.

In our systematic screening programme for marine actinomycetes, a bioactive streptomycete was isolated from marine sediment samples of the Bay of Bengal, India. The isolate yielded a new cytotoxic compound. This was obtained by solvent extraction followed by chromatographic purification. The pure compound was identified from spectroscopic data as a quinone-related antibiotic, 1-hydroxy-1-norresistomycin (1). It showed a potent cytotoxic activity against cell lines viz. HMO2 (gastric adenocarcinoma) and HePG2 (hepatic carcinoma) in vitro. It also exhibited antibacterial activities against Gram-positive and Gram-negative bacteria.Keywords Streptomyces, cytotoxic activity, antibacterial activity, quinone, 1-hydroxy-1-norresistomycin Marine actinomycetes remain an important source in the search for novel bioactive compounds. So far terrestrial substrates have been predominantly exploited as sources of actinomycetes, where as the marine habitat has received much less attention. There are a few reports on bioactive compounds from marine actinomycetes in recent times [1ϳ6]. The marine environment may be an important source of novel anti-cancer, anti-viral, antibacterial and antifungal antibiotics as well as industrially important enzymes.Taxonomic characteristics of the isolate were determined by cultivation on various media as described by Shirling and Gottlieb [7], Waksman [8] and Arai [9]. Cell wall composition was analyzed by the method of Lechevalier and Lechevalier [10], using thin layer chromatography plates as described by Staneck and Roberts [11]. The taxonomic studies indicated that the isolate belongs to Streptomyces chibaensis and it was designated as S. chibaensis AUBN 1 /7.The cytotoxicities of 1 were assessed based on their effects on the growth of tumor cells in vitro according to the NCI guide lines [12]. The cell lines used were HMO2 (gastric adenocarcinoma) and HePG2 (hepatic carcinoma). Cells were grown in 96-well microtitre plates of RPMI 1640 tissue culture medium supplemented with 10% fetal calf serum at 37°C in a humidified atmosphere of 50% CO 2 in air. After 24 hours of incubation 1 (0.1ϳ10.0 mg/ml) was added to the cells. After 48 hours incubation, the cells were fixed by addition of trichloracetic acid and cell protein was assayed with sulforhodamine B [13]. For each concentration tested, the GI 50 (drug concentration causing 50% growth inhibition), TGI values (drug concentration causing 100% growth inhibition) and LC 50 (minimum concentration which reduces the initial cell number to half) were determined (Table 2).A full grown slant culture of the strain AUBN 1 /7 on

Urokinase (UK) [EC 3.4.99.26] is a serine protease that activates plasminogen to plasmin, which in turn degrades fibrin clots. Hence, UK finds its value as an important anti-thromboembolic drug. Plasmin has diverse physiological roles apart from its fibrinolytic role in the regulation of blood clotting. It has been implicated in complement activation, cell migration, wound healing, and generation of localized extracellular proteolysis during tissue remodelling, pro-hormone conversion, carcinogenesis and neoplasia. Among the plasminogen activators, UK provides a superior alternative for the simple reasons of its being more potent as compared to tissue-plasminogen activator and non-antigenic by virtue of its human origin unlike streptokinase. Based on these observations, UK is a very popular cardiovascular agent. Hence, UK, as one of the most potent plasminogen activators is attracting a great deal of attention. We will summarize recent patents related to the occurrence, mechanism of action, structure and function, physico-chemical properties, in vitro production, cloning and expression, purification and applications of UK.

Antibiotics U 1200 1-Hydroxy-1-norresistomycin, a New Cytotoxic Compound from a Marine Actinomycete, Streptomyces chibaensis AUBN1/7. -(GORAJANA, A.; KURADA, B. V. V. S. N.; PEELA, S.; JANGAM, P.; VINJAMURI, S.; POLURI*, E.; ZEECK, A.; J. Antibiot. 58 (2005) 8, 526-529; Dep. Pharm. Sci., Andhra Univ., Visakhapatnam 530 003, India; Eng.) -A. Forchert 09-223

Gas Chromatography Mass Spectrometry (GCMS) analysis of the plants leaf and stem extract confirmed the presence of six and four major compounds in leaves and stem respectively. The presence of these compounds is a scientific indication that the plant can be used for therapeutic purposes. Further study in this regard is in progress to understand the complete potential of the bioactive compounds in this plant.