The Preparation and Geometrical Isomerism of Substituted α-Methylthio-Cinnamic Acids

α-Methylthio-cinnamic acid and its substituted analogues (III) were synthesized from their respective β-aryl-α-thiopyruvic acids (II). In connection with the study on the tautomeric ene-thiol structure of β-aryl-α-thiopyruvic acids (II), 4-arylidenerl,3-oxathiolan-5-one (IV) were prepared from compounds II.     

Synthesis of 2-Acetamido-2-deoxy-1,6-dithio-d-glucose and its Derivatives

2-Acetamido-3,4-di-Oacetyl-2,6-dideoxy-6-S-acetyl-6-thio-d-glucopyranosyl chloride (III) was condensed with potassium thiolacetate, potassium ethylxanthate or thiourea to give three crystalline derivatives of 2-acetamido-2-deoxy-1,6-dithio-d-glucose. An attempt to prepare 2-acetamido-1,2,6-trideoxy-1,6-dimercapto-D-glucose (VII) from 2-acetamido-3,4-di-O-acetyl-1,2,6-trideoxy-1,6-di-S-acetyl-1,6-dithio-β-d-glucopyranose was described. 2-Acetamido-3,4-di-O-acetyl-1,2,6-trideoxy-1-mercapto-6-S-acetyl-6-thio-β-d-glucopyranose (VIII) was synthesized from the condensation product of III with thiourea.     

Isolation,Identification and Some Cultural Conditions of Streptomyces Species That Produce Water-insoluble Polyglucan Hydrolase

Cariogenic streptococci produce tenacious water-insoluble polysaccharides from sucrose and these form the structural intercellular matrix of dental plaque. Two Streptomyces species were isolated from soils on agar medium containing the water-insoluble polyglucan as a sole carbon source. They were identified as Streptomyces werraensis (strain F₁) and Streptomyces chartreusis (strain F₂). These strains produced extracellular enzymes which strongly solubilized the polyglucans from various strains of cariogenic streptococci. Strain F₂ produced polyglucanases under rather stationary cultural condition, while F₁ required vigorous aeration. The polyglucanases may provide a useful measure for the prevention and control of dental plaque formation,     

Production and Properties of Lipase from a Newly Isolated Chromobacterium

Out of some 750 strains of microorganisms, a potent bacterium for lipase production was isolated from soil and was identified as Chromobacterium viscosum.

The bacterium accumulates lipase in culture fluid when grown aerobically at 26°C for 3 days in a medium composed of soluble starch, soy bean meal, lard and inorganic salts.

Chromobacterium lipase had an optimum pH of 7.0 for activity at 37°C, and an optimal temperature of 65°C at pH 7.0. The enzyme retained 80% of the activity when heated for 10 min at 70°C. This lipase was capable of hydrolyzing a variety of natural fats and oils, and it was more active on lard and butter than on olive oil. The activity was stimulated by Ca²⁺, Mg²⁺, Mn²⁺ and inhibited by Cu²⁺, Hg²⁺ and Sn²⁺. It was not diminished but rather stimulated by a high concentration of bile-salts.     

Optical Resolution and Determination of Absolute Configurations of α-Isopropyl-4-substituted Phenylacetic Acids and Insecticidal Activities of Their 5-Benzyl-3-furylmethyl Esters

In connection with disclosure of a new class of insecticides, the modified phenylacetates, six new optically active α-isopropy-4-substituted phenylacetic acids whose substituents are respectively 4-methyl,4-methoxy, 4-fluoro, 4-chloro, 4-bromo and 3,4-methylenedioxy group were prepared by optical resolution and their absolute configurations were determined by comparative ORD with α-isopropylphenylacetic acid derivatives whose absolute configuration is known as (S)-(²). Esters of the (S)-(²)-acids with 5-benzyl-3-furylmethanol were nearly twice toxic to Musca domestica than those of the racemic esters. Optical purities of the resolved acids were determined by GLC and NMR (with Eu-FOD) as (?)-methyl esters.     

Fatty Acids as Inhibitors of Microbial Cell Wall Synthesis

The Maillard reaction of DNA with ketoses was investigated. Several days of incubation of d-fructose 6-phosphate with deoxyribonucleotides or with polymer DNA in an aqueous buffer resulted in the formation of chromophores and fluorophores. Aminoguanidine and sodium cvanoborohydride inhibited the formation of fluorophores. Transition metal ions such as Cu²⁺, Fe³⁺, Fe²⁺, or Mn^{2 +} promoted the formation of chromophores and fluorophores. Metal-chelating agents such as DETAPAC, citrate, and Desferal inhibited the formation of fluorophores. Superoxide dismutase and catalase also inhibited the formation of fluorophores. The transition metal ion-catalyzed autoxidation of d-fructose 6-phosphate or of the Heyns rearrangement products were to be partially involved in the glycation of DNA and subsequent formation of chromophores and of fluorophores.     

Extracellular Accumulation of Phospholipids,UDP-N-Acetylhexosamine Derivatives and L-Glutamic Acid by Penicillin-treated Corynebacterium alkanolyticum

The addition of penicillin to cells of Corynebacterium alkanolyticum No. 314 growing on n-paraffins medium caused the simultaneous excretion of phospholipids, UDP-N-acetylhexosamine derivatives and L-glutamic acid.

Among many antibiotics which inhibit cell wall synthesis, only the inhibitors of peptideglycan transpeptidase such as penicillin G and cephaloridine were effective for inducing the excretion of phospholipids, UDP-N-acetylhexosamine derivatives and L-glutamic acid, while the others promoted only the excretion of UDP-N-acetylhexosamine derivatives.

From the close relationship between the excretion of L-glutamic acid and the excretion of phospholipids, it was suggested that the action of penicillins and cephalosporins on the cell membrane resulted in the excretion of L-glutamic acid.