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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\.

The structure of ricellomycin, an antibiotic previously discovered by Argoudelis et ah, is elucidated as valyl-2-[4-guanidyl4-azabicyclo[3.1.0]hexan-2-yl]glycine(1) by NMR, MS, and derivatization studies. The l-azabicyclo[3.1.0]hexane moiety in 1 represents an unusual ring system making ricellomycin a unique natural product compound. 357In a previous report,1* Argoudelis et aL described the production, isolation, and chemical characterization of ficellomycin. Wenowwish to report the structure of ficellomycin. Experimenta l TLCProceduresTLC's were run on silica gel using ethanol -3 m ammoniumhydroxide (3 : 2) as the solvent system. The antibiotics were detected by bioautography on an agar mediumseeded with Staphylococcus aureus agar tray or spraying with ninhydrin reagent. NMR SpectroscopyXHand 13C NMRspectra were recorded on a Bruker AM-300spectrometer operated at 300 MHz for *H and 75 MHzfor 13C nuclei. D2Owas used as the solvent. 1H-lH correlation spectrum (COSY)2) was obtained from a 128 x2,048 data matrix, which resulted after zero filling in the Fl dimension in a 2K x2K data matrix. The spectral width was 1,400 Hz. Sixteen scans were recorded for each tx value with a delay time of 2 seconds between scans.^-"C COSY3)was obtained from a 128x4,096 data matrix. The spectral widths were 13,500Hz and 700 Hz in the F2 and Fl dimensions, respectively. For each tx value, 384 scans were recorded, and the delay time between scans was 1.5 seconds. The MLEVdecoupling method was used with the decoupler positioned in the center of the XHspectrum. Long-range C-H correlation (COLOC)4) spectrum was obtained with the same data size as the 1H-18Ccorrelation experiment. The number of scans of each experiment was 1,024. Composite decoupling was used during acquisition.Titration of Ficellomycin The pH of a D2Osolution of ficellomycin was adjusted with dropwise addition of 2 n DC1directly into the NMRtube containing the sample. The chemical shift value was referenced to internal dioxane (67.4ppm). Methyl Ester DerivatizationFicellomycin, 100 mg, was dissolved in 10 ml of 0.8 n methanolic HC1 and refluxed for 2.5 hours. The solution was added to a mixture of acetone and diethyl ether (200 ml/50 ml) to precipitate the HC1 salt. Fast atom bombardment (FAB)-MS gave a peak (M+H) at 327 amu confirming the formation of the methyl ester. Ester carbonyl absorbance was also observed in a Fourier transformation (FT)-IR spectrum of the methyl ester derivative of ficellomycin. Results and DiscussionThe physico-chemical properties of 1 were described in the previous report.1} It was established

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