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.

During the course of screening for inhibitors of trehalase, we found the pseudodisaccharide termed trehazolin1 (1) in a culture broth of Micromonospora, strain SANK 62390n. This paper describes the isolation, structure determination, and inhibitory activity of trehazolin. One loopful of the producing organism was aseptically transferred from an agar slant into baffled 500-ml Erlenmeyer flasks each containing 80ml of a primary seed medium.This mediumwas composed of glucose 1%, glycerol 1%, oatmeal 0.5%, sucrose 1%, soybean meal 2%, Casamino acids 0.5%, pressed yeast 1%, CaCO3 0.1%, and Disfoam CB-442 (Nippon Yushi Co.) 0.01%. After formulation, the pH was adjusted to 7.0 with aq NaOH, and the mediumwas sterilized. The incubation was performed on a rotary shaker at 220rpmat 28°C for 216 hours. Forty ml of the primary seed culture were aseptically transferred into baffled 2-liter Erlenmeyer flasks each containing 800ml of a secondary seed/production medium which was composed of glucose 2%, soluble starch 1 %, pressed yeast 0.9%, meat extract 0.5%, Polypepton 0.5%, NaCl 0.5%, CaCO3 0.3%, and Disfoam CB-442 0.01%. The medium was then adjusted to pH 7.2

Trehalamine, (3a^,4i?,55',65,6a5')-2-amino-4-(hydroxymethyl)-3a,5,6,6a-tetrahydro-4//-cyclopent[J]oxazole-4,5,6-triol (1) and D-glucose were obtained by acid hydrolysis of trehazolin (3), a trehalase inhibitor produced by actinomycetes. More vigorous hydrolytic treatment of trehazolin afforded an aminocyclitol, ( 1 R,2S,3R,4S,5R)-5-amino-l -(hydroxymethyl)cyclopentane-1 ,2,3,4-tetraol (2). Trehalamine, the aglycon of trehazolin, was also found in the culture broths of two trehazolin producing strains, Micromonospora sp. SANK62390 and Amycolatopsis sp. SANK60791. These trehazolin related compounds trehalamine (1) and 2 were poor inhibitors of trehalase (1; IC501.8 x 10~4 m, 2; > 5.0 x 10~4 m). On the other hand they inhibited more potently rat intestinal sucrase (1; IC50 6.8 x 10~5m) and sweet almond /?-glucosidase (2; IC50 5.6 x 10"6m) than trehazolin.In the previous paper, we reported the isolation and characterization of trehazolin (3), an inhibitor of trehalase produced by Micromonospora sp. SANK623901}. Trehazolin showed a specific and potent inhibitory activity against trehalase and was shown to have a glucosyl moiety and a unique aglycon part in its structure. Since the aglycon portion of trehazolin seems to account for the trehalase inhibitory activity, it will be informative to assess the enzyme inhibitory properties of the aglycon to understand the nature of the activity of trehazolin. Furthermore, in respect to the microbial biosynthesis of the unique metabolite, it is of interest if the aglycon itself is present in the broths of the trehazolin producing microorganisms. Therefore, we attempted to characterize the aglycon and related compounds by hydrolysis of trehazolin and further to discover them from culture broths of trehazolin producers.On the first attempt of acidic hydrolysis of trehazolin at 100°C, the sole product was a 5-membered Fig. 1. The structures of trehalamine (1), 2, and trehazolin (3).