Streptomyces achromogenes

Other examples of natural drugs may be pointed out streptozotocin (from streptomyces achromogenes), bleomycin (from streptomyces verticillus), adriamy-cin and daunomycin (from streptomyces pencetius), mitomycin C (from streptomyces caesipitosus), vincristine, vinblastine and vindoline (from catharanthus roseus or vinca rosea L.). 

Streptozocin (Zanosar), a water-soluble nitrosourea produced by the fungus Streptomyces achromogenes, acts through methylation of nucleic acids and proteins. In addition, it produces rapid and severe depletion of the pyridine nucleotides nicotinamide adenine dinucleotide (NAD) and its reduced form (NADH) in liver and pancreatic islets. 

The biosynthesis of tomaymycin and anthramycin has been studied in submerged batch cultures of Streptomyces achromogenes var. tomaymyceticus (11-demethyltomaymycin and oxotomaymycin) and Streptomyces refuines var. ther-motolerans (anthramycin and derivatives). Feeding of several labeled amino acids and subsequent degradation of the formed alkaloids established L-tryp-tophan, L-tyrosine, and one or two carbon units derived via methionine as the direct precursors (22-25) (see Fig. 7). 

Some antibiotics are alkylating agents. A prominent example is streptozotocin, an antibiotic produced by the soil bacterium Streptomyces achromogenes. This compound is a 2-deoxy-D-glucose derivative of the potent alkylating agent methylnitrosourea (MNU). 

Lomustine (CCNU) is used to treat lymphomas and some solid tumors, particularly brain tumors, often in combination with procarbazine and vincristine (2). Nimustine (ACNU) is used to treat mahgnant glioma (3). Streptozocin (streptozotocin) is produced by Streptomyces achromogenes. It is used to treat metastatic islet cell carcinoma of the pancreas, but because of its high nephrotoxic and emetogenic potential should be reserved for patients with symptomatic or progressive disease. 

Streptozocin (streptozotocin) is produced by Streptomyces achromogenes. It is used to treat metastatic islet cell carcinoma of the pancreas, but because of its high nephrotoxic and emetogenic potential it should be reserved for patients with symptomatic or progressive disease. 

Escherichia coll Haemophilus Influenzae Klebsiella pneumonia Provldencla stuartll Streptomyces achromogenes Streptomyces albue Serratia marcescens Streptomyces phaeochromogenes Xanthomonas badiil... 

Streptozotocin is unique both in origin and pharmacology. It is an antibiotic obtained from Streptomyces achromogenes and contains a glucosamine component in its structure, which may contribute to its tendency to be taken up into the P-cells of the islets of Langerhans of the pancreas. Where it was initially used to induce diabetes in experimental animals, it is now used to treat pancreatic islet cell carcinoma, resulting in about a 50% response rate, but few survivors past 1 year. 

Rubradirin (70) was isolated from the fermentation broth of Streptomyces achromogenes var. rubradiris [109-114]. Rubradirin (70) possesses pH indicator properties. Namely, it is red in acidic or neutral solutions and green in basic solutions, or in salt form. It is an extremely potent inhibitor of Gram-positive bacteria in vitro, and is effective in the treatment of experimental bacterial infections in mice [114]. The mechanism of the... 

As examples of other naphthalenoid ansamycin antibiotics, rubradirin (70) and protorubradirin (71) were isolated from the fermentation broth of Streptomyces achromogenes var. rubradiris [109-114,117]. As indicated previously, protorubradirin (71) is the C-nitroso-analogue of 70, and it seems that 71 is the true secondary metabolite produced by S. achromogenes var. rubradiris. Thus, rubradirin (70), reported earlier, is the photo-oxidation product of protorubradirin (71). The ansa moiety of these compounds possesses a C9 chain, instead of a C or a C23 chain. 

Streptomyces Stanford (SstI)] (3.1.23.34) is produced and catalyzes the reaction G AGCTC. [Isolated from Streptomyces achromogenes. ]... 

CgHijNjOy 265.222 Aminoglycoside antibiotic. Prod, by Streptomyces achromogenes. Antineo-plastic agent. Pointed platelets or prisms (EtOH). 

Streptozotocin, a broad spectrum antibiotic with anitumour activity produced by Streptomyces achromogenes [163], has been shown to be the A -methyl-A -nitrosourea derivative of glucosamine (XLa) by chemical degradation and spectroscopic studies [164], Two syntheses have confirmed the structure, one of which is suitable for the commercial preparation of the drug [165]. Treatment of glucosamine with 7V-methylisocyanate has afforded the A -methylurea derivative (XLb), which gave streptozotocin on treatment with nitrogen trioxide. 

A few antitumor antibiotics whose use is strictly limited to a single indication deserve a brief mention. Streptozotocin, produced by Streptomyces achromogenes, is selectively active against P-cells of pancreatic islets. It was approved by FDA in 1982. Pentostatin (deoxycoformycin), a product of Streptomyces antibioticus, although rather toxic, is used to treat some forms of leukemia. The FDA granted approval for pentostatin in 1993. 

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