Michiharu Sugawara

Neurotrophic sesquiterpene-neolignans from magnolia obovata: structure and neurotrophic activity

Abstract Novel sesquiterpene-neolignans, eudesobovatos A (1) and B (2), eudesmagnolol (3), eudeshonokiols A (4) and B (5), clovanemagnolol (6), and caryolanemagnolol (7), have been isolated from the bark of Magnolia obovata. Their structures were elucidated to be sesquiterpenes (eudesmol, 4,4,8-trimethyltricyclo [6.3.1.02,5] dodecane-1,9-diol, and clovanediol) combined through ether bond with neolignans such as obovatol, honokiol, and magnolol on the basis of spectral data, degradation, and/or synthesis. Compounds 1, 6, and 7 were found to exhibit interesting neurotrophic activity on a neuronal cell culture system derived from fetal rat hemisphere.

Phthalides from the rhizome of Ligusticum wallichii

Abstract Three phthalides, 3-butylidene-7-hydroxyphthalide, and cis and trans -6,7-dihydroxyligustilides, along with a dimeric phthalide wallichilide have been isolated from the hot water extract of the rhizome of Ligusticum wallichii . Their structures were established mainly on the basis of spectroscopic data. 3-Butyl-4,5-dihydro-3-hydroxy phthalide and adenosine were identified as active principles of the extract which are responsible for increase of coronary blood flow in the dog heart.

Structure of K-76, a complement inhibitor produced by Stachybotrys complementi nov. Sp. K-76

The structure of ‘K-76’(1), a complement inhibitor containing a spirobenzofuran unit, obtained from Stachybotrys complementi nov. sp. K-76, is reported.

Illicinolides A and B, novel sesquiterpene lactones from the wood of Illicium tashiroi

Abstract A new type of sesquiterpenes, illicinolides A (1) and B (2) has been isolated from Illicium tashiroi. The structure of illicinolide A was established by X-ray analysis of the p-bromobenzoyl derivative. Illicinolide B was assigned the structure as 9α-hydroxyillicinolide A by spectral data compared with those of illicinolide A. They are biogenetically closely related to anisatin (3) and its derivative.

Isolation of a fosfomycin-hypersensitive mutant and production of α-d-glucose-l-phosphate from Bacillus sp. BA-3796 screened by its use

Abstract The development of a very sensitive and highly specific screening method for detection of new cell wall inhibitors of the fosfomycin type is described. A fosfomycin-hypersensitive mutant, f-360, was isolated from Staphylococcus aureus Newman by selection with fosfomycin, an antibiotic that inhibits synthesis of the bacterial cell wall. The mutant f-360 was 50-fold more sensitive than the parent strain to fosfomycin. The mutant was constitutive for the hexose phosphate transport system. Using the organism in screening, BA-3796, which had an antibacterial activity against mutant f-360 was found to be produced by a bacterium designated Bacillus sp. BA-3796. Starch and beef extract were the most suitable carbon and nitrogen sources for BA-3796 production and the amount of BA-3796 reached 3 g/ l at a maximum level. The purified BA-3796 was identified as α- d -glucose-l-phosphate by its various physiochemical properties. α- d -Glucose-1-phosphate showes an antibacterial activity against Staphylococci in the presence of a slight amount pf α- d -glucose-6-phosphate.