No abstract

Okilactomycin, a novel antibiotic, was isolated from the culture filtrate of a strain of actinomycetes. The producing organism, strain YP-02908L, was identified as Streptomyces griseoflavus subsp. zamamiensis subsp. nov. The antibiotic was extracted with ethyl acetate and purified by silica gel column chromatography. It was obtained as colorless prisms from a dichloromethane solution. It exhibited weak antimicrobial activity against Grampositive organisms in vitro. It also exhibited antitumor activity against Ehrlich ascites carcinoma in vivo. The apparent molecular formula of okilactomycin was determined as C24H32O6.It is a new memberof the lactone group antibiotics. 1475 In the course of our screening for new antibiotics, a novel antibiotic, okilactomycin, was found. The antibiotic was produced by Streptomyces griseoflavus subsp. zamamiensis subsp. nov. It exhibited weak antimicrobial activity against Gram-positive organisms and antitumor activity agaist Ehrlich ascites carcinoma. In this paper, we describe the taxonomy of the producing organism, the fermentation, isolation and characterization of the antibiotic. Materials and Methods Chemicals Chemicals employed were as follows: Kieselgel 60 and TLC plates Silica gel 60 F254 (0.25 mm thickness) from E. Merck, Darmstadt, FRG; Sephadex LH-20 from Pharmacia Fine Chemicals, Sweden; mitomycin C from KyowaHakko Kogyo Co., Ltd., Japan. All other chemicals were of analytical grade. Components for Media Components for media employed were as follows :

Phospholine, an antitumor antibiotic, has the molecular formula of C25H40NO8P and posesses a

Phospholine was isolated as an antitumor antibiotic from the fermentation broth of Streptomyces hygroscopicus. Phospholine is an amphoteric compound which has an amino group and a phosphoric acid ester as functional groups. Phospholine shows strong activities against L1210, P388 and EL-4.In our screening program to find antitumor antibiotics, strain SCM-127indentified as Streptomyces hygroscopicus subsp. luteolus subsp. nov. was found to produce a new antitumor antibiotic, phospholine.In this paper, the taxonomy of the producing strain, isolation physico-chemical and biological properties of phospholine are described. Materials and Methods ChemicalsChemicals employed are as follows; Packed column of ODSfrom Yamamura Scientific Co., Ltd., Kyoto, Japan. Silica gel and TLC-plate Silica gel 60 F254 (0.25 mm thickness) from E. Merck, Darmstadt, FRG. All other chemicals are of analytical grade. Assay In vitro cytotoxicity assay was carried out against L1210 murine leukemia cells, P388 murine leukemia cells and EL-4 murine lymphoma cells. Each cells in RPMI-1640 medium containing 10% fetal calf serum and the test sample solutions were planted to the wells and incubated at 37°C for 72 hours with 5% CO2 under high humidity condition. The cytotoxicity of the test samples was determined by counting viable cells after staining with trypan blue. The percent inhibition was calculated by the formula, ((A-B) x l00/A), where A is the number of viable cells without the drug and B is that with the drug. Taxonomy A soil sample was collected at Katsuta-city, Ibaragi Prefecture, Japan. The taxonomic studies were carried out by the methods of International Streptomyces Project (ISP)0, along with several supplementary tests. Stock slant cultures were maintained on Bennett's agar. These slants, as well as subsequent cultures used in this study, wereincubated at 28°C. Microscopic observations were madeon cultures that were grownfor 7~21 days on sucrose -nitrate agar, glycerol -asparagine agar, inorganic salts -starch agar, yeast extract -malt extract agar, and oatmeal agar media.Taxonomic keys of Bergey's Manual of Determinative Bacteriology (8th Ed.), Actinomycete Taxonomy2) and other descriptions were used to compare with recognized genera and species of actinomycetes. Chemotaxonomic studies were carried out by the method of Lechevalier and

The synthesis and properties of five thiacyclobutenes (thietes) are described. Thietes are of theoretical interest because they have the potential of forming anions and cations isoelectronic with the anion and cation of cyclopentadiene. They are prepared by facile Hofmann eliminations from 3-aminothietane derivatives usually obtained via synthetic schemes which start with the addition of sulfene (CH2=S02) to enamines. Thietes, while relatively stable at low temperatures, show a marked tendency to polymerize or to otherwise decompose over a period of time. Thietes (4, 5), in which the sulfur-containing ring is fused to a sixor seven-membered carbocyclic ring, are less stable than thiete itself or thietes substituted with alkyl groups. Ring opening occurs when