RIFAMYCINS

摘要

1470426 Rifamycins GRUPPO LEPETIT SpA 20 Aug 1975 [30 Aug 1974] 37913/74 Headings C2A and C2C A process for producing rifamycin P, rifamycin Q, rifamycin R and rifamycin U comprises cultivating a mutant Nocardia mediterranea strain selected from Nocardia mediterranea ATCC 31064, Nocardia mediterranea ATCC 31065 and Nocardia mediterranea ATCC 31066 and mutants and equivalents thereof under aerobic conditions in a nutrient medium containing an assimilable carbon source, an assimilable nitrogen source and essential mineral salts until substantial antibiotic activity is present and recovering the rifamycins. The rifamycins may be recovered by extracting the fermentation broth with a water-immiscible solvent at a pH lower than 5. The rifamycins may be separated by column chromatography. The new mutants may be prepared by treating a suspension of spores of Streptomyces mediterranei ATCC 13685 with a mutagenic agent, incubating the treated spores and isolating the surviving colonies which are able to inhibit the growth of Bacillus subtilis Rifamycin P has the following characteristics:- (1) Elemental analysis (per cent) C = 60À6, H= 6À2, N=3À8, O=25À2, S=4À1, (2) U.V. spectrum indicated in Fig. 1 (not shown), (3) I.R. spectrum indicated in Fig. 2 (not shown), (4) A mass spectrum at 70 eV showing the M+ peak at the m/e value of 738, (5) N.M.R. spectrum indicated in Fig. 3 (not shown) and (6) Rf value of 0À57. Rifamycin R has the formula Rifamycin Q has the following characteristics (1) Elemental analysis (per cent) C=60À7, H= 6À3, N=3À6, O=25À3, S=4À2, (2) U.V. and visible absorption bands:- # max. (mÁ) E 1% 1 cm. 406 178 350 (shoulder) 297 305 257 405 224 518 (3) I.R. spectrum indicated in Fig. 4 (not shown), (4) N.M.R. spectrum indicated in Fig. 7 (not shown) and (5) Rf value of 0À32. Rifamycin U has the following characteristics (1) U.V. and visible absorption bands:- # max. (mÁ E 1% 1 cm. 412 163 353 (shoulder) 299 265 258 389 220 451 (2) the most significant absorption peaks in Nujol occur at the following frequencies (cm.-1): 3700-3100 (m, br); 3060 (vw); 3040-2740 (vs), 2720 (vw), 1460 (s), 1378 (m); Nujol; 1750-1705 (m, br) ; 1680-1620 (m, br) ; 1600 (s); 1558 (s); 1490 (w, shoulder); 1308 (w) ; 1270 (w, shoulder); 1245 (m, shoulder); 1225 (m); 1160(m); 1120(w); 1090(vw); 1070 (w); 1030 (vw); 1020 (vw); 1000 (vw); 975 (w); 960 (w, shoulder); 905 (m); 850 (m) ; 802 (w) ; 800 (vw, shoulder); 777 (vw); 760 (vw); 720 (vw); 685 (vw); 670 (vw) and (3) Rf value of 0À63.