Hydantocidin1, a new compoundwith potent non-selective herbicidal activity, was found in a submerged culture of Streptomyces hygroscopicus SANK63584. It was isolated from the culture filtrate by the following successive treatments comprised of activated carbon, Diaion HP-20, Dowex 50WX4,and Avicel column chromatographies. Finally it was crystallized as colorless needles from acetone.The molecular formula, C7H10N2O6, was determined by analyses of HRFABmass spectrum in conjunction with 13C NMRspectrometry. The structural elucidation revealed that it has a unique structure with a spiro-bond between ribose and hydantoin moieties in the molecule. The characteristic herbicidal activities against annuals as well as perennials, including monocotyledonous and dicotyledonous weeds, were observed. 293 In the course of screening for new herbicidal substances from culture broths of microorganisms, we found a new compound, hydantocidin, produced by a streptomycete identified as Streptomyces hygroscopicus SANK63584, which was isolated from a soil sample collected in Annaka, GunmaPrefecture, Japan.In this paper, we report the taxonomy, fermentation of the producing strain, isolation, physico-chemical and biological properties of hydantocidin. The detailed herbicidal activity and the structural elucidation of the compoundwill be reported elsewhere (under preparation).
Cornexistint, a new compound demonstrating promising herbicidal activity, was purified from the culture nitrate of a newly-isolated fungus identified as Paecilomyces variotii SANK 21086. The compoundwas extracted with organic solvents from the culture nitrate, purified using column chromatography on Sephadex LH-20 and finally crystallized from methylene chloride. Following analysis of its physico-chemical properties it was identified to be a new compound belonging to the nonadride group. Chemical structure elucidation was conducted by analyses of various spectral data and the structure was finally confirmed by means of X-ray crystallographic analysis. Based on its herbicidal characteristics cornexistin may be classified as a postemergence herbicide active against certain young annual and perennial monocotyledonous and dicotyledonous plants with selective protection for corn.
Mureidomycins (MRD's) A~D were specifically active against Pseudomonas aeruginosa. Amongthem, MRDC was most active, with MICs of 0.1 to 3.13 /^g/ml against many strains of the target organism. Its activity was comparable to that of cefoperazone, ceftazidime and cefsulodin. MRD C-resistant mutants of P. aeruginosa appeared spontaneously at a high frequency whencultured in the presence of the antibiotic. Nocross-resistance was observed with /3-lactam antibiotics. A rapid decrease of turbidity along with spheroplast formation and cell lysis was observed whencells of P. aeruginosa were grownin the presence of MRD C. The compoundsexhibited low toxicity and protected mice from experimental infection with P. aeruginosa. The urinary and fecal recoveries of MRDC given subcutaneously were 5 and 18%, respectively. Although many new /3-lactam antibiotics with activity against Pseudomonas aeruginosa have been synthesized, the infectious diseases caused by this species of bacteria still pose serious problems throughout the world.
Structures of new antibiotics,mureidomycins (MRD's) A~D, were deduced from spectroscopic analyses and degradation studies. Tworesidues of m-tyrosine, one residue of 2-amino-3-iV-methylaminobutyric acid (AMBA) and methionine are present in all components of the complex. Uracil is contained in MRD's A and C, while dihydrouracil in MRD's B and D. Methionine and m-tyrosine are connected through an ureido bond, and uracil or dihydrouracil is linked to AMBA via enamine sugar moiety. In addition, MRD's C and D contain a glycine residue at the iV-terminal.
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