Joseph A. Marquez

KIJANIMICIN (Sch 25663), A NOVEL ANTIBIOTIC PRODUCED BY ACTINOMAD URA KIJANIATA SCC 1256

A novel antibiotic complex has been isolated form the fermentation broth of a new species of Actinomadura, A. kijaniata SCC 1256. The complex was separated form the broth by a solvent extraction procedure and consists of 1 major component, designated kijanimicin, and 3 minor components. Kijanimicin was isolated form the complex by column chromatography and/or preparative high pressure liquid chromatography. Structurally the compound is a unique, large acid enol antibiotic and possesses an unusual in vitro spectrum of activity against some Gram-positive and anaerobic microorganisms. In vivo it has also shown interesting activity against malaria.

Chromatographic separation of the components of the gentamicin complex

By means of paper and thin-layer chromatography using the lower phase of a solvent mixture consisting of chloroform—methanol—17 % ammonium hydroxide (2:1:1, v/v), the gentamicin antibiotic complex is shown to consist of three components, named C1, C1a and C2. Methods are given for preparative separation of these antibiotics by use of cellulose and Chromosorb W chromatographic column procedures utilizing the solvent system described for paper and TLC.

Antibiotic G-418, a New Micromonospora-Produced Aminoglycoside with Activity Against Protozoa and Helminths: Fermentation, Isolation, and Preliminary Characterization

Antibiotic G-418 is a new aminoglycoside produced as the major component by a new species of Micromonospora, M. rhodorangea NRRL 5326. The antibiotic is prepared by submerged fermentation in a soybean-dextrin medium. Antibiotic G-418 is adsorbed on a cationic-exchange resin and separated from other impurities by passing it down a Dowex (1 × 2) resin column. The antibiotic, which contains 2-deoxystreptamine, has broad-spectrum antibacterial activity and is highly active against protozoa, amoebae, tapeworm, and pinworm infections in mice. This report describes the taxonomy of the organism, and fermentation, isolation, and preliminary characterization of antibiotic G-418. Images

Verdamicin, a New Broad Spectrum Aminoglycoside Antibiotic

Verdamicin is a new aminoglycoside antibiotic isolated from fermentation broths of a species of the genus Micromonospora, M. grisea. It has been differentiated from other known related antibiotics by a variety of chemical and biological methods. Its in vitro and in vivo spectrum of activity appears to be similar to those of gentamicin and sisomicin.

A New Actinomycin Complex Produced by a Micromonospora Species: Fermentation, Isolation, and Characterization

A species of Micromonospora, Micromonospora floridensis NRRL 8020, has been found to produce an actinomycin complex consisting of at least 25 active components. After solvent extraction of the complex, separation of the individual components was carried out by preparative thin-layer chromatography. Hydrolysis and subsequent electrophoretic and chromatographic identification of the amino acid content of each of the isolated components have shown differences from known actinomycins, and the probability exists that these contain a number of amino or imino acids not previously found in other members of this group of antibiotics.

Biotransformation of Sisomicin to Gentamicin C2b

Sisomicin was transformed to gentamicin C2b by Micromonospora rhodorangea NRRL 5326. The mechanisms involved in the biotransformation are the 6′-N-methylation and the (4′-5′)-reduction. The progression of the methylation was followed by the isotope technique, but the reduction reaction was not monitored.

New Polyene Antifungal Antibiotic Produced by a Species of Actinoplanes

A new species of Actinoplanes, which has been deposited with the designation NRRL 5325 at the Northern Utilization Research and Development Division of the U. S. Department of Agriculture, produces a polyene antifungal complex designated as Sch 16656. The complex, consisting of one major and three minor components, is isolated from the fermentation broth by a solvent extraction procedure and purified by precipitation methods. The major component is a heptaene and is highly active in vitro and in vivo against Candida albicans. It is active also against strains of Torulopsis and is significantly more potent orally than candicidin in mice against Candida infections. Images

High-performance preparative isolation and purification of several mycinamicins

Abstract High performance preparative chromatographic systems are described which facilitate the isolation and purification of some naturally occurring, novel mycinamicins. Facile separation and excellent recovery of these macrolide antibiotics was obtained with a C-18 radially compressed Prep 500 cartridge using methanol/trifluoroacetic acid mobile phases. Semi-preparative chromatography on a C-8 reversed-phase sorbent incorporating a volatile ammonium acetate buffer was utilized in the final purification of an enriched mixture of intermediate components. Monitoring of isolated fractions with analytical HPLC provided direct support for the effectiveness of the preparative isolation.

A novel antifungal from an Actinomadurae with preferential activity against the mycelial phase ofCandida albicans

SummarySch 40873, a novel antifungal compound isolated from the fermentation broth of anActinomadura spp. was discovered in an assay designed to detect compounds with preferential activity against the invasive mycelial form ofCandida albicans. The geometric mean MIC of Sch 40873 against sevenCandida spp. in Sabouraud dextrose broth (yeast phase) was ≥58 μg/ml and in Eagles minimum essential medium (mycelial phase) was <0.03 μg/ml. Sch 40873 demonstrated slight in vivo topical activity in a hamster vaginal model.

Chapter 2 Hplc Detection Methods for Microbial Products in Fermentation Broth

Publisher Summary This chapter describes high-performance liquid chromatography (HPLC) detection methods for microbial products in fermentation broth. Several efforts have been directed toward the early identification of compounds in fermentation broths. One approach is to combine analytical methods such as an HPLC separation followed by spectroscopic detection. The development of photodiode-array (PDA) detector technology has allowed the use of on-line ultraviolet (UV)–visible (VIS) spectra as an aid to compound identification during HPLC separation. This technique has proven to be effective for discriminating known reference compounds and metabolites within complex matrices. Moreover, this technology allows detection of either structurally related compounds, or compounds with similar chromophores under non-optimized chromatographic conditions. This is of particular importance when analyzing a complex matrix such as biological fluid or fermentation broth. The technological advances in PDA have created the possibility of uninterrupted acquisition of UV–VIS absorption spectra of chromatographic peaks over a user defined time domain. The combination of chromatographic retention parameters and spectral characteristics provide dual criteria for component comparison and identification. With photodiode array detection, spectral data, obtained in digitized form, can be stored, retrieved, and transformed by a number of algorithms to reveal further characteristic physiochemical component features upon request.