Arginomycin. Production, isolation, characterization and structure.

Abstract

Arginomycinis a new nucleoside antibiotic produced by Streptomyces arginensis. Arginomycin, C18H28N8O5, which inhibits the growth of Gram-positive bacteria and fungi in vitro, is structurally related to blasticidin S and found to be relatively non-toxic.Cultures of Streptomyces arginensis UC8632, grown in a complex medium were found to contain an antibacterial agent which was characterized by its paper chromatographic and TLCbehavior and its antibacterial spectrum. This antibiotic which exhibited activity against both Gram-positive bacteria and fungi was isolated and designated arginomycin (U-72,026). The present communication deals with the production, isolation, characterization and the chemical structure of arginomycin. Experimental Assay and Testing ProceduresAntibiotic production and purification was measured by a microbiological disc-plate assay procedure with Micrococcus luteus or Penicillium oxalicum as the assay organism. Paper Chromatographic ProceduresThe production of arginomycin was followed by paper chromatography using a variety of mobile phases. The Rf values of arginomycin in the following solvents were: 0.00 [1-butanol -water (84 : 16) Thin-layer Chromatographic (TLC) ProceduresTLC's of arginomycin were run on cellulose (Brinkman Cell 300) plates using pH 7.0, 0.1 m phosphate buffer as the mobile phase. Bioautography was on M. luteus or P. oxalicum-seeded trays. Hydrolytic reactions on arginomycin were followed by TLCusing silica gel and chloroform -methanolcone ammoniumhydroxide (1 :4 : 1) as the mobile phase. Spots were developed by spraying with ninhydrin or using iodine vapors. UV absorbing materials were detected by a shortwave UV lamp.High Performance Liquid Chromatography (HPLC) All HPLCwas carried out using a C-18 reverse phase silica column on a Varian 5560 instrument equipped with an LKB-RSBphoto diode array UVdetector and operating in the dual pump mode.The mobile phase consisted of a 10 mMsolution of hexanesulfonic acid in acetonitrile -water (80 : 20) containing 0.2% glacial acetic acid. Flow rate 1.5 ml/minute. Sample volume 10 u\.

Biosynthesis of the β-Methylarginine Residue of Peptidyl Nucleoside Arginomycin in Streptomyces arginensis NRRL 15941

“…The reaction was carried out in the presence of L-arginine, ␣-ketoglutaric acid, L-aspartate, SAM, PLP, ArgM, and ArgN at 25°C for 3 h. Reactions were derivatized with DNS-Cl and quenched by 10% ethylamine, and reactions mixtures were subjected to an Agilent semipreparative column (Zorbax ODS, 5-m particle size, 9.4 by 250 mm). The same fragments of DNS-␤mArg were combined, concentrated, and analyzed for their 1 H NMR (500-MHz, methanol-d4) and 13 S11 to S12 in the supplemental material). Further COSY NMR clearly showed that the H · H protons of the ␣-carbon and ␤-methyl groups were correlated, thus proving the configuration of the (3R)-methyl group of DNS-␤mArg (Fig.…”

“…Although the overall skeleton of arginomycin is highly similar to that of blasticidin S (BS) (Fig. 1), a representative peptidyl nucleoside antibiotic exhibiting strong inhibitory activity against rice blast caused by Pyricularia oryzae Cavara (2), arginomycin showed much lower toxicity to mice (1). They differ from each other only in the modification of the L-arginine-derived guanidino side chain (Fig.…”

“…1) is a peptidyl nucleoside antibiotic isolated from Streptomyces arginensis NRRL 15941 that shows bioactivity against Gram-positive bacteria and fungi, such as Micrococcus luteus and Penicillium oxalicum (1). Although the overall skeleton of arginomycin is highly similar to that of blasticidin S (BS) (Fig.…”

Cytosylglucuronic acid synthase (cytosine: UDP-glucuronosyltransferase) from Streptomyces griseochromogenes, the first prokaryotic UDP-glucuronosyltransferase

“…Although BS is most potent as an antifungal agent, it also exhibits antibacterial (32), antiviral (16,17), and antitumor activities (39). Several other peptidyl nucleoside antibiotics have close structural similarities to BS (1,7,15,19,20,36,37); they all consist of a cytosine hexuronic nucleoside unit and a basic amino acid side chain.…”

“…As shown in Figure 2, SDS-PAGE of the purified CGA synthase from the last step (lanes 8 CGA synthase, isolated from S. griseochromogenes, catalyzes the formation of CGA from UDP-glucuronic acid and cytosine in the biosynthesis of the peptide-nucleoside antibiotic BS (14) and is also quite likely involved in the biosynthesis of a number of other known nucleoside antibiotics (1,7,15,19,20,36,37). Functionally, CGA synthase belongs to the family of UDPGTs; although UDP-GTs are common in mammalian metabolism and at least two have been reported for fungi (10,40), they have not been previously reported for a prokaryotic organism.…”