Anthramycin, sibiromycin and tomaymycin are structurally related antibiotics produced by various actinomycetes. Anthramycin was originally isolated from the fermentation broth of a thermophilic actinomycete, Streptomyces refruineus var. thermotolerans found in a compost heap in the 1950's by M. D. TENDLER1). The active compound, originally called "refuin" (from the Hebrew "refuah" meaning a medicine), was isolated as a pure crystalline antibiotic by LEIMGRUBER2, 3) in 1965. This antibiotic was subsequently shown to have antibiotic, antitumor, antiprotozoal and chemosterilant activity against houseflies. Tomaymycin, a Japanese antibiotic, produced by Streptomyces achromogenes var. tomaymyceticus, was isolated from a soil sample collected in Musashikoganei-city. The isolation and properties of this antibiotic were first reported by ARIMA and coworkers4) in 1972. The structure of tomaymycin and the structurally related but biologically inactive compound, oxotomaymycin, were reported by KARIYONE5) in 1971. Tomaymycin has been shown to have antitumor, antiviral and antibiotic activities. Sibiromycin, the most recent of the three antibiotics to be fully characterized, is produced by the actinomycete, Streptosporangium sibiricum and was first reported by GAUSE and coworkers6) at the Moscow Institute for New Antibiotics. The isolation and partial characterization of this antibiotic was published in 1972.7) However, its full structure was not published until 1974 by MESENTEV and coworkers.8) Sibiromycin has been shown to have antitumor as well as antibiotic activity. In addition to anthramycin, sibiromycin and tomaymycin, three further structurally related antibiotics have appeared in the literature, although full structural information has not been published. The first of these compounds, dextrochrysin which is produced by Streptomyces calms var. dextrochrysus9), has been demonstrated to have antiviral as well as antibiotic activity. Most recently two isomeric anthramycin-related compounds, neothramycins A and B produced by Streptomyces No. MC916-C410) have been reported. These compounds have been shown to have weak antibiotic and antifungal activity as well as antitumor activity. Reviews on the mechanism of action of anthramycin11, 12) and sibiromycin have appeared.13-15)
Ambruticin represents a new class of antibiotics isolated from a strain of Polyangium cellulosum var. firlvum, a bacterium belonging to the class Myxobacteriales. This antibiotic is a cyclopropyl-polyene-pyran acid and is active in vitro against fungi.
A number of penicillins (2) have been synthesized from the α-hydrazinoarylacetic acids (4) via the activated chloride hydrochlorides (5) or via the mixed anhydride of the corresponding N2-benzyloxycarbonyl derivatives (6). The penicillins, 2b, e, j, show good activity against gram-positive and gram-negative bacteria and enhanced penicillinase resistance in comparison with ampicillin.
L-Alanine, L-threonine, L-valine, D-cystine and three derivatives of thiazole-4-carboxylic acid (thiostreptin, 2-aminomethylthiazole-4-carboxylic acid and thiostreptoic acid) were isolated from the acid-hydrolysate of thiopeptin B. In addition, the presence of dehydrobutyrine and dehydroalanine residues in the antibiotic was determined. Other components remain unidentified.
During chemical studies of bleomycin, many fragments and derivatives have been isolated and characterized. The 13C-NMR spectra of these compounds were taken and analyzed for structural information, and the complete assignment of the spectra was achieved. The 13C-chemical shift map thus obtained contains information about the structure and conformation and will be useful for studies on the chemistry and biology of bleomycin and related compounds.
The application of reverse phase high-performance liquid chromatography to the separation and analysis of cephradine and cephalexin is demonstrated. The procedure has been applied to chemicals, pharmaceutical formulations and reaction solutions. The preparation of samples is simple and rapid. Chromatographic conditions are described for both pellicular and small particle columns. The feasibility of determining cephradine and cephalexin in physiological fluids has also been demonstrated.
The treatment of Streptomyces bikiniensis with ethidium bromide or acriflavine resulted in the loss of the ability to produce streptomycin in 2-16% of the colonies isolated from the treated spores. These isolates had also lost their resistance to streptomycin. Treatment with the dyes caused partial to total loss of the ability to produce aerial mycelium by S. biki-niensis, but the isolates regained this ability upon repeated transfer to fresh medium. The dyes did not appear to effect pigment production by S. bikiniensis.
The interactions of a series of C3-substituted rifamycins with human and bovine serum albumins were studied in order to find possible correlations between the degree of binding and the structural features of the various molecules. The results obtained indicate some of the physicochemical properties and, therefore, of the structural requirements which appear to determine or influence the bonding mechanisms of this series of rifamycins. Two types of interaction were found to exist, ionic and hydro-phobic types. The findings suggest that the inhibition by protein of the antibacterial activities of these antibiotics depends on the type of bonding mechanism rather than the degree of binding.