A new antibiotic SF-7331) gave neamine2) and methyl D-riboside on acid methanolysis and a furanoside nature of the ribose moiety was determined by periodate oxidation of tetra-N-acetyl SF-733. The site of linkage was determined by the formation of di-N-acetyl-6-O-methyl-2-deoxystreptamine after acid hydrolysis of tetra-N-acetyl-hexa-O-methyl SF-733. The NMR spectrum of tetra-N-acetyl SF-733 was compared with those of N-acetylated neomycin group of antibiotics and it was concluded that the ribofuranosyl linkage was β. Thus, the chemical structure of antibiotic SF-733 was determined to be O-β-D-ribofuranosyl-(1→5)-O-[α-2, 6-diamino-2, 6-dideoxy-D-glucopyranosyl-(1→4)] -2-deoxystreptamine.
The antigenicity of cefazolin and its cross reactivity with benzylpenicillin, ampicillin and cephaloridine were studied. Cefazolin showed a sensitizing activity, as evidenced by the elicitation of specific precipitin antibodies and of hemagglutinating antibodies in experimental animals immunized with protein conjugates of this antibiotic, as do conjugates of penicillins and cephalosporins. Cefazolin gave a minimal cross reactivity, not only with benzylpenicillin but also with ampicillin and cephaloridine. Quantitative hapten inhibition of precipitation, against anti-benzylpenicillin antibodies, by haptens of 7-aminocephalosporanic acid and 6-aminopenicillanic acid was only minimal. This finding suggests the possibility that the cross reaction between cephalosporin derivatives and related penicillins against benzylpenicillin is mediated mainly by the acyl side chain of the molecules.
A new subspecies of Streptomyces hygroscopicus was isolated from a peatysoil collected in Bibai, Hokkaido, Japan in July, 1965, and numbered as 325-17. The isolate has been named Streptomyces hygroscopicus (JENSEN) WAKSMAN et HENRICI subsp. aabomyceticus SEINO. Freeze-dried cultures of the type strain 325-17 have been deposited in the Fermentation Research Institute, Chiba, Japan and the American Type Culture Collection, Rockvill, Maryland, U. S. A. where they have been assigned accession numbers as FERM-P No. 166 and ATCC 21449, respectively.
The biosynthetic pathways involved in the formation of four everninomicin antibiotics were studied. Carbon-14 labelled substrates added to liquid cultures of Micromonospora carbonacea var. aurantiaca revealed that acetate, malonate and glucose were good precursors. Degradation of the antibiotics revealed the primary importance of acetate and malonate for the synthesis of the dichloroisoeverninic acid, an aromatic moiety common to all of the four everninomicins studied, thus indicating its relationship to the biosynthesis of orsellinic acid. The incorporation of the methyl group of methionine into the methoxy group of dichloroisoeverninic acid could also be demonstrated. The remainder of the everninomicin molecule is apparently derived principally from glucose.
Disagreements in serum and urine cephaloglycin determinations by Sarcina lutea with those by Bacillus subtilis or Streptococcus hemolyticus after oral administration of the antibiotic have been clarified by the present studies, attention being focussed on the formation of an active metabolite, desacetylcephaloglycin. The formation of desacetylcephaloglycin was detected by paper and thin-layer chromatography. Desacetylcephaloglycin was 0.1 to 0.5 as active as cephaloglycin against B. subtilis and S. hemolyticus but of comparable activity- against S. lutea PCI-1001.