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Biomedical subjects

N V Konstantinova

Publications and source records attributed to N V Konstantinova.

At least 19 recordsLinked to original sources

[Isolation and identification of the antibiotics amicetin and nebramycin formed by a Streptomyces coeruleoaurantiacus 4009 culture].

It was found that Str. coeruleoaurantiacus, strain 4009 produced antibiotics 4009-A and 4009-B belonging to different groups. Antibiotic 4009-A was identified as amicetin belonging to the group of pyrimidine bases and antibiotic 4009-B as the nebramycin complex belonging to the group of aminoglycosides. The identity of the antibiotics was confirmed by the physico-chemical constants, spectral and chromatographic characteristics and their chemotherapeutic activity.

Animals

The structure of nocamycin, a new antitumor antibiotic.

The structure of nocamycin, a new antitumor antibiotic, has been elucidated with the aid of mass- and PMR-spectroscopic investigation of the antibiotic and its various chemical transformation products. Nocamycin is structurally related to tirandamycins.

Antibiotics, Antineoplastic

[Physicochmemical characteristics of the new antineoplastic antibiotic, nocamycin].

Nocamycin is produced by Nocardiopsis syringae. It is recovered from the culture fluid by extraction with chloroform. The molecular weight of the crystalline antibiotic is 503, its melting point is 147--149 degrees, [alpha]20 degrees D = --50 degrees (c. 0.21, chloroform), lambdamax235 and 348 nm(E1%sm= = 150 and 420), the summation formula is C26 H33NO9, the biological activity is 100000 Units/mg with respect to Bacillus mycoides. Nocamycin forms salts with alkalies soluble in water. On hydrolysis with an alkali it forms carbonic acid having no ester bond (IP spectrum) and methoxylic group present in the antibiotic molecule. Nocamycin is a new natural substance.

Antibiotics, Antineoplastic

[Spontaneous and induced variability in Actinomyces rubiginosohelvolus, a new producer of the antibiotic rubomycin].

Mutants possessing 3 times higher activity as compared to the initial culture were obtained as a result of selection of active variants of Act. rubiginosonelvolus, a new organism producing rubomycin against the background of variation induced by N-methyl-N1-nitro-N-nitrozoguinidine, diethylsulphate and their combinations. Further selection among the mutants stable to 6-mercaptopurine and riboflavine resulted in obtaining an active culture No. 3912 at least 7 times more active with respect to rubomycin production than the initial soil culture.

Antibiotics, Antineoplastic

[Extraction of rifamycin B from native and aqueous solutions].

Optimal conditions for extraction of rifamycin B from aqueous solutions and fermentation broth filtrates at pH values within 2.0-7.0 were determined. When the antibiotic was extracted from the aqueous solutions, the highest yield was obtained at pH 2.0. When the antibiotic was extracted from the fermentation broth filtrates, it was found that chloroform was the most selective solvent with respect to rifamycin B, the chloroform selectivity being increased at pH 3.5-4.0. It was shown that rifamicin B passed from the buffer solutions with a concentration of 3-20 mg/ml to chloroform in amounts of 6-7 mg/ml and to ethylacetate and butanol in amounts of 20 mg/ml. Such conditions of chloroform and butanol (9 : 1) increased the rifamycin B contents in the extract up to 40 mg/ml.

Buffers

[Diagnosis of supravalvular stenosis of the aorta].

The authors analyzed the potentialities of combined radiodiagnosis of supravalvular stenosis (SS) and concomitant diseases of the heart and major vessels (Williams-Beuren syndrome) in 7 patients aged 7 mos. to 24 yrs. Polypositional chest and heart x-ray procedure, catheterization of the cardiac cavities, pulmonary artery and aorta, left ventriculography (6), right ventriculography (4) and angiopulmonography were used. The diagnostic potentialities of each method were defined. It was proved that SS practically in all patients was accompanied by major vascular changes in the pulmonary, vertebral, coronary, carotid, subclavicular, renal and other arteries, heart failure (atrial septal defect, and mitral incompetence).

Adolescent