Streptomyces rishiriensis

Mycotrienins I (95) and II (96) were isolated from the fermentation broth of Streptomyces rishiriensis [154-158] and their structures determined. Mycotrienin II (96) corresponded to the mycotrienin isolated from the fermentation broth of a Streptomyces sp. [159]. 

CioHisClNfiOfiS 380.768 From Streptomyces rishiriensis. Blood platelet aggregation inhibitor. Active against gram-positive and -negative bacteria. Herbicide. Needles. 

In nature, the alkylation of aromatic rings most commonly proceeds using 5-adenosyhnethionine ( SAM, 31a) as the source of an electrophilic methyl group. Such alkylations are catalyzed by C-methyltransferase enzymes and are analogous to Friedel-Crafts alkylations. Two C-methyl-transferases, NovO and CouO (from Streptomyces spheroides and Streptomyces rishiriensis, respectively), have been expressed in recombinant E. coli and have been shown to have a synthetically useful substrate scope. Not only are they able to catalyze the regioselective alkylation of various coumarins 32 (X=0), 2-quinolones 32 (X=NH), and naphthalenediols 34-36, but in addition, they are able to accept nonnatural cofactors 31b-f in place of SAM and so can transfer various alkyl groups other than methyl to the substrates (Scheme 32.4) [26]. 

Matsumoto N, Tsuchida T, Maruyama M, Sawa R, Kinoshita N, Homma Y, Takahashi Y, linuma H, Naganawa H, Sawa T, Hamada M, Takeuchi T. Lactonamycin, a new antimicrobial antibiotic produced by Streptomyces rishiriensis. J. Antibiot. 1996 49 953-954. 

Recently, a somewhat similar antibiotic, coumermycin (52), was isolated from Streptomyces hazelienses [381, 382] and fromS fr. rishiriensis [383,384] and found to be active against Gram-positive as well as some Gram-negative bacteria [383, 385]. Its action against some Mycobacterium species has also... 

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