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Biomedical subjects

R C Pandey

Publications and source records attributed to R C Pandey.

17 recordsLinked to original sources
PubMed1992

Antifungal anthracycline antibiotics, spartanamicins A and B from Micromonospora spp.

Spartanamicins A and B, two antifungal antibiotics, were produced by a culture of Micromonospora spp. strain No. MSU-43097 (ATCC 53803), isolated from a potted soil containing asparagus (Asparagus officinalis L.) plants. The antibiotics were isolated from the mycelial cake using organic solvents. The structures of spartanamicins A and B were determined by spectral and chemical means. Spartanamicin B is more active as an antifungal compound than it's analogue, A. The minimum inhibitory concentration for spartanamicin B on Candida albicans and Aspergillus, Cladosporium, Cryptococcus, Rhodotorula and Staphylococcus spp. ranged from 0.2 to 1 microgram/ml. It was not active against Staphylococcus aureus, Escherichia coli and Citrobacter spp. but some strains of S. aureus were sensitive.

Anthracyclines↗
PubMed1991

A clinico-radiological study of secondary mycoses in pulmonary tuberculosis.

Clinical and radiological differences were compared in Fungus positive (74) and negative (66) cases of pulmonary tuberculosis. Cough, expectoration, dyspnoea, and fever were marked in former group than that of latter. Anaemia, leucocytosis, raised ESR, abnormal radiological shadows and mycetoma in healed cavity were also noted in significant number in fungus positive cases.

Calcinosis↗
PubMed1990

Applications of thin layer chromatography, high performance liquid chromatography and mass spectrometry in the fermentation and isolation of the antibiotic nybomycin.

Thin layer chromatography (TLC), high performance liquid chromatography (HPLC) and mass spectrometry (MS) methods have been developed for the analysis of the antibiotic nybomycin, its derivatives deoxynybomycin and nybomycin acetate, during the fermentation and isolation of nybomycin. Using a quantitative HPLC based assay, the time course of nybomycin production (nybomycin titers) in 1000 liter fermentations was determined. Desorption chemical ionization mass spectrometry (DCI/MS) of standard nybomycin samples, fermentation broth samples and purified fractions suggested the co-production of deoxynybomycin which was not reported previously from this organism. TLC and HPLC were used to confirm the presence of deoxynybomycin in the crude extracts of fermentation broths.

Anti-Bacterial Agents↗
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↗
PubMed1976

Polyene antibiotics. VII. Carbon-13 nuclear magnetic resonance evidence for cyclic hemiketals in the polyene antibiotics amphotericin B, nystatin A1, tetrin A, tetrin B, lucensomycin, and pimaricin1,2.

Carbon magnetic resonance establishes conclusively that six polyene macrolide antibiotics containing keto groups (the heptaene amphotericin B, the tetraene-diene nystatin A1, and the tetraenes tetrin A, tetrin B, pimaricin, and lucensomycin) exist in the hemiketal form in solution. Their spectra all contain a hemiketal carbon's absorption near 97 ppm but lack a keto carbon's absorption near 210 ppm. The non-polyenic macrolide erythromycin, on the other hand, exists in the keto form.

Amphotericin B↗
PubMedDate not supplied

Some observations on human semen analysis.

Semen analysis of 66 unmarried medical students in the age group of 17-21 years was carried out. A higher liquefaction time pH, motility, lower sperm count and abnormal forms were observed compared to reported values. Liquefaction time, pH and sperm count was found significantly different in non-vegetarians and vegetarians, perhaps due to difference in their dietary proteins.

Adolescent↗