. The actinomycetes. Actinomycetales. 52 NATURE, FORMATION. AND ACTIVITIES CHs CH, \ / N N "^N^^N-" OH- -CH,OH NH—CO—CH(—CH, I OCH3 Puromycin is active against bacteria (mainly gram-positive), protozoa, and tumors. Re- moval of the methyltyrosine moiety from the molecule caused a loss in antibacterial activity. The resulting aminonucleoside was, however, acti\-e against protozoa and tumors. Nudeocidin is another meml^er of this group of purine-containing compounds. It is active against bacteria and protozoa. It con- tains a G-aminopurine moiety, a carbohy- drate moiety, and sulfu
. The actinomycetes. Actinomycetales. 52 NATURE, FORMATION. AND ACTIVITIES CHs CH, \ / N N "^N^^N-" OH- -CH,OH NH—CO—CH(—CH, I OCH3 Puromycin is active against bacteria (mainly gram-positive), protozoa, and tumors. Re- moval of the methyltyrosine moiety from the molecule caused a loss in antibacterial activity. The resulting aminonucleoside was, however, acti\-e against protozoa and tumors. Nudeocidin is another meml^er of this group of purine-containing compounds. It is active against bacteria and protozoa. It con- tains a G-aminopurine moiety, a carbohy- drate moiety, and sulfur. Three antibiotics, amicetin, amicetin B, and bamicetin, are formed of four cyclic moieties, one of which is a pyrimidine: (1) p-aminobenzoic acid, (2) cytosine, (3) a six-carbon sugar-like unit in the furan form, and (4) a dimethylamino sugar, amosamine (C8Hn04N): CH3 N OH OHCH, 'CH, nw ^O' \ / \ ^'^^ N />—NHCO / \ O / -N^' In the molecules of both amicetin and bamicetin, CH, ! R = XHCOC— I NHo The two antibiotics differ in that l)amicetin has one less —CHo group in the glycosidic moiety than does amicetin. In amicetin B, R = XH2. These three antibiotics are ac- tive mainly against gram-positive bacteria and mycobacteria. It is interesting to note that bamicetin is more active against gram- negative bacteria than are the amicetins. It has been suggested that amicetin B might be a precursor of amicetin. Tetracyclines The tetracyclines ha\'e in common a naph- thacene nucleus; their range of biological activity approximates that of chlor- amphenicol; they are active against gram- positive and gram-negative bacteria, ricket- tsiae, and the psittacosis-lymphogranuloma group of organisms. The three commonly used antibiotics of this group are tetracycline, chlortetracycline, and They have the following formulas:. OH 0 OH 0 TetnifvcliiK': R, = R, = H Oxytetiacvfline: Ri = H; R,. = OH Chlortetracycline: Ri = CI; Ri = H When chlortetracyclin
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