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Biomedical subjects

R C Pandey

Publications and source records attributed to R C Pandey.

At least 37 records · Page 2Linked to original sources
PubMed1981

Fredericamycin A, a new antitumor antibiotic. I. Production, isolation and physicochemical properties.

A new antitumor antibiotic, fredericamycin A (FCRC-A48, NSC-305263), has been isolated from a strain of Streptomyces griseus (FCRC-48). Based on its unique ultraviolet-visible spectrum, infrared spectrum, proton and carbon-13 nuclear magnetic resonance spectra and mass spectra, it is judged to be a novel acid-base indicator type of compound. Its production, isolation and physicochemical properties are discussed. The isolation, ultraviolet-visible spectrum and some biological properties of two minor components, fredericamycin B and fredericamycin C, are also described.

Antibiotics, Antineoplastic↗
PubMed1981

Fredericamycin A, a new antitumor antibiotic. II. Biological properties.

Fredericamycin A is a novel antibiotic produced by a soil isolate of Streptomyces griseus (FCRC-48). In vitro, fredericamycin A exhibits antibacterial, antifungal, and cytotoxic activities. In vivo, fredericamycin A exhibits very good antitumor activity against P388 mouse leukemia as well as the CD8F mammary tumor and marginal activity against B16 melanoma. Fredericamycin A failed to demonstrate any interaction with DNA and inhibited protein and RNA synthesis preferentially to DNA synthesis in Bacillus subtilis and P388 cells.

Animals↗
PubMed1980

High-performance liquid chromatography and thin-layer chromatography of anthracycline antibiotics: separation and identification of components of the dauno-rubicin complex from fermentation broth.

A new solvent system composed of methanol-acidic water (pH 2.0 with phosphoric acid) has been developed for high-performance liquid chromatography of the daunorubicin complex from fermentation broth on a micro Bondapak C18 column. Application of this solvent system in conjunction with thin-layer chromatography in the identification of anthracycline antibiotics from the fermentation broth is discussed.

Chromatography, High Pressure Liquid↗
PubMed1980

Field desorption mass spectrometry in structural studies of polyene macrolide antibiotics: isolation and early identification of a pentaene macrolide antibiotic.

Isolation of a pentaene macrolide antibiotic (NSC-277813) from Streptomyces griseus (FCRC-21) fermentation broth is described. Using field desorption mass spectrometry and high resolution field desorption mass spectrometry on the intact and derivatized antibiotic and degradation products, the antibiotic was identified as fungichromin. The application of field desorption mass spectrometry in the identification of polyene antibiotics is discussed.

Antibiotics, Antineoplastic↗
PubMed1979

Classification of polyene antibiotics according to chemical structure and biological effects.

Fourteen polyene antibiotics and six of their semisynthetic derivatives were compared for their effects on potassium (K(+)) leakage and lethality or hemolysis of either Saccharomyces cerevisiae or mouse erythrocytes. These polyene antibiotics fell into two groups. Group I antibiotics caused K(+) leakage and cell death or hemolysis at the same concentrations of added polyene. In this group fungistatic and fungicidal levels were indistinguishable. Group I drugs included one triene (trienin); tetraenes (pimaricin and etruscomycin); pentaenes (filipin and chainin); one hexaene (dermostatin); and one polyene antibiotic with unknown chemical structure (lymphosarcin). Group II antibiotics caused considerable K(+) leakage at low concentrations and cell death or hemolysis at high concentrations. The fungistatic levels were clearly separable from fungicidal. This group included the heptaenes (amphotericin B, candicidin, aureofungin A and B, hamycin A and B), and five of their semisynthetic derivatives (amphotericin B methyl ester, N-acetyl-amphotericin B, hamycin A and B methyl esters, and N-acetyl-candicidin). Nystatin, classified as a tetraene, and its derivative, N-acetyl nystatin, also were in this group.

Animals↗
PubMed1977

Polyene antibiotics. VIII. The structure of rimocidin.

A structure is assigned to the tetraene antibiotic rimocidin, based in part on 13C NMR spectroscopy and field desorption mass spectrometry. The structure assigned revises a structure proposed in 1966 which was anomalous in relation to those of other polyene antibiotics.

Anti-Bacterial Agents↗
PubMed1977

Polyene antibiotics. IX. An improved method for the preparation of methyl esters of polyene antibiotics.

An improved general method for the preparation of methyl esters of polyene antibiotics is discussed. Using this method methyl esters of pimaricin, nystatin, eurocidin, hamycin, hamycins A and B, aureofungin, partricins A and B, candimycin, candicidin, and amphotericin B have been prepared and their physical properties are reported. The biological activities of hamycins A and B and their methyl esters are also described.

Anti-Bacterial Agents↗