Hideo Shimamura

Volatile Components of the Rhizomes of Dioscorea japonica

Abstract The composition of the volatile oil from the rhizomes of Dioscorea japonica has been investigated by capillary GC, GC-MS. The oil contained 74 volatile components of which 1.29% were terpenoids and 0.89% were aldehydes. The main constituents were fatty acids, which were palmitic acid (41.00%), linoleic acid (28.76%), pentadecanoic acid (4.90%), oleic acid (3.03%), and (3.02%).

Suppression of the SOS-Inducing Activity of Trp-P-1 and Aflatoxin B1 by Meso-dihydroguaiaretic Acid from Machilus thunbergii in the Salmonella typhimurium TA1535/pSK1002 umu Test

The methanol extract from Machilus thunbergii showed a suppressive effect on umu gene expression of the SOS response in Salmonella typhimurium TA1535/pSK1002 against the mutagen, 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), which requires liver metabolizing enzymes. The methanol extract from M. thunbergii was successively re-extracted with chloroform, butanol and water. A suppressive compound in the chloroform extract fraction was isolated by SiO2 column chromatography and identified as meso-dihydroguaiaretic acid by GC-MS, and (1)H- and (13)C-NMR spectroscopy. Meso-dihydroguaiaretic acid inhibited of the SOS-inducing activity of Trp-P-1 in the umu test. Gene expression was suppressed by 62% at less than 0.18 μmol/ml, the ID50 value being 0.08 μmol/ml. Compound 1 was also assayed with aflatoxin B1 (AfB1) and showed a suppressive effect.

Suppression of SOS-Inducing Activity of Trp-P-1 by Fatty Acids from Cistanche Salsa in the Salmonella Typhimurium TA1535/pSK1002 umu Test

Abstract The methanol extract from Cistanche salsa showed a suppressive effect on umu gene expression of the SOS response in Salmonella thyphimurium TA1535/pSK1002 against the mutagen, 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1). The major suppressants in this plant were identified as palmitic acid oleic acid by GC and GC-MS.