H. Kase, T. Iida, Y. Odakura
Oct 1, 1980
Citations
0
Influential Citations
17
Citations
Journal
The Journal of antibiotics
Abstract
Sir: 2-Deoxystreptamine (DOS) is a component of many clinically important aminoglycoside antibiotics. A biosynthetic pathway for DOS has been proposed by REINHART and coworkers1) on the basis of the incorporation of [6-13C] glucose into the aminocyclitol (Fig. 1). The route involves initial oxidation and amination at C-3 of the aminocyclitol ring (which is derived from C-5 of glucose), followed by similar reactions at C-1 of the aminocyclitol ring (from C-1 of glucose). An alternative route (also shown in Fig. 1), involving the reverse sequence-oxidation-amination at the ring's C-1 first, followed by oxidation-amination at its C-3-cannot be ruled out. Feeding of putative biosynthetic intermediates to DOS idiotrophs2,3) and cell free enzymic studies4) have suggested 2-deoxy-scylloinosose (2,3,4,5-tetrahydroxycyclohexanone 3,5/ 2,4, compound III, X=H, or its enantiomer) and 2-deoxy-scyllo-inosamine (2,3,4,5-tetrahydroxycyclohexylamine 3,5/2,4, compound IV, X=H, or its enantiomer, compound VII, X=H) (DOI) as intermediates in the biosynthetic pathway for DOS. However, it should be noted that no intermediates in DOS biosynthesis were isolated in any of above studies. In this communication, we described the isolation of DOI in the culture broth of a DOSrequiring idiotrophic mutant of Micromonospora sagamiensis which produces the DOS-containing antibiotic, sagamicin. We will also present data which will support the route (a) in Fig. 1. The DOS idiotrophic mutant, KY11509, was derived from a sagamicin producer, M. sagamiensis KY11505. Mutant KY11509 was grown in 150 liters of a medium consisting of 4% Stabilose K (soluble starch), 1 % soy bean meal, 2 % Pharmamedia (cottonseed flour), 0.1 % corn oil, 0.5% casein, 0.2% phytate, 0.015% FeSO4 7H2O, 0.05% MgSO4 • 7H2O and 0.025% KH2PO4. The fermentation was carried out in a 300-liter tank by stirring at 180 rpm at 34°C with aeration of 150 liters/min. Mutant KY11509 produced a number of aminocyclitols. One of them, K14-1 had a similar chromatographic behavior to DOI. K14-1 was isolated from the fermentation broth by an ion exchange procedure. The fermentation broth was harvested at 73 hours and the pH was adjusted to 2.0. After filtration, the filtrate was neutralized, applied to an Amberlite IRC-50 resin (NH4+) column and eluted with aqueous ammonia. The eluate was concentrated to dryness and then applied to an Amberlite CG-50 resin (NH,+) column. The resin was eluted with a linear gradient of 0 to 0.08 N ammonium hydroxide and fractions containing K14-1 were collected. Lyophilization of the pooled fractions gave a crude powder of K14-1. The crude K14-1 was further chromatographed on Bio-Rex 70 (NH4+) column. Fig. 1. Possible biosynthetic pathway from glucose to 2-deoxystreptamine. (RINEHART et al.1)) (a) Postulated oathwav: