Seldomycin

Analogous deoxygenations were carried out with antibiotics such as nargenicin,[42] fortimicin,[43] seldomycin,[44 erythromycin,[45H47] with baccatin (taxol group),[48] the triquinane hirsuten,[49] the tuberculosis inhibitor a-C-mannobioside,[49a] and the steroids alisol,[50] and progesterone.[51]... 

With primary or nonsterically hindered secondary alcohols, method A led exclusively to the formation of chlorinated sugars [68]. The mildness and efficiency of this chlorination method was used to advantage in the synthesis of a dichloro aminoglycoside, a precursor of seldomycin factor 2 [68] (Scheme 7). 

Seldomycin factor 2, 131 Selectins, 358, 366, 420 Shikimate pathway, 471 (-)-Shikimic acid, 572 Showdomycin, 530 Sialyi dimeric Le 324 Sialyl glycosides, 357 p-acetonitrilium ion, 362 anomeric effect, 362 benzeneselenyl triflate, 359 biology, 366, 419, 421, 436, 445... 

The synthesis of 3 -epi-seldomycin 5 from seldomycin 5 (56) is achieved by a reaction sequence similar to that shown in F. 51. Reaction of the N-protected seldomycin 5 with 0-nitrobenzene-sulfonylchloride gives in one step the epiryclic carbamate 244, which is then hydrolyzed to the 3 -epimer (Fig. 52). The synthesis of 3 -deoxyseldomycin 5 is accomplished by known deoxygenation proce-dures Both compounds show, as expected, an improved antibacterial activity against resistant strains which phosphorylate the 3 -hydroxyl group. 

Aminoglycoside antibiotic. Isol. from Streptomyces hofunensis. Shows antibacterial activity similar to Seldomycin 1, S-21. Amorph. powder. Sol. H2O fairly sol. MeOH poorly sol. butanol, hexane, EtOH. 

The occurrence of 2-amino-2-deoxy-D-ribose and 2-amino-2-deoxy-D-xylose in a nucleoside antibiotic and seldomycin, respectively, is noted in Chapter 18, while a synthesis of 2-amino-2-deoxy-D-ribose is reported in Chapter 19. 

The occurrence of 2,3-diamino-2,3-dideoxy-4-0-methyl-D-xylopyranose and 2,6-diamino-2,6-dideoxy-D-glucopyranose as constituents of the seldomycin antibiotic complex is noted in Chapter 18. 

Several components have been separated from the seldomycin complex elaborated by Streptomyces hofunensis. Seldomycin factors 1 and 2 were identified as 6-0-(2-amino-2 deoxy-a-D-xylopyranosyl)paromamine (494) and 4 -deoxynea-mine, respectively factor 3 as, probably, (495) (i.e. the 6 -amino-6 -deoxy analogue of factor 1) and factor 5, which is the most active of these antibiotics, as 6-0-(2,3-diamino-2,3-dideoxy-4-0-methyl-a-D-xylopyranosyl)-4 -deoxyneamine (496 ... 

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