Biomedical subjects
Publications and source records attributed to Noriko Sata.
A new metabolite, poipuol (1), was isolated from an undescribed marine sponge Hyrtios sp. collected in Kauai Island, Hawaii. The structure was determined from spectroscopic data.
A collection of an undescribed marine sponge of the genus Plakortis yielded four new "polyketide-derived" metabolites, lehualides A-D (1-4). The structures of compounds 1-4 were elucidated by interpretation of spectral data. Compound 2 demonstrated cytotoxicity against an ovarian cancer cell line, while compound 4 was active against both ovarian cancer and leukemia cell lines.
The new diterpene glucoside 3,15-dihydroxy-ent-labd-7-en-17-oic acid 3-O-beta-D-glucoside (1) and its aglycone (2) have been isolated from Eupatorium glutinosum. The structures were determined by IR, one- and two-dimensional NMR, high-resolution mass spectrometry, chemical transformations, and comparison of spectroscopic data with closely related diterpenes. Crude extracts showed antimicrobial and cytotoxic activities, but compounds 1 and 2 showed only antimicrobial activity. These results support the vernacular medicinal use of the plant as an antimicrobial.
A search for growth inhibitors in rice root exudates was undertaken in order to clarify the allelopathic system in rice (Oryza sativa L.). Rice seedlings inhibited the growth of cress (Lepidium sativum L.) and lettuce (Lactuca sativa L.) seedlings when the cress and lettuce were grown with rice seedlings. The putative compound causing the inhibitory effect of rice seedlings was isolated from their culture solution, and the chemical structure of the inhibitor was determined by spectral data as momilactone B. Momilactone B inhibited the growth of cress and lettuce seedlings at concentrations greater than 3 and 30 microM, respectively. The concentration of momilactone B was 3.4 and 1.1 nmol per seedling in the culture solutions of husked and non-husked rice seedlings, respectively. These results suggest that rice seedlings may release momilactone B into the environment and the stress caused by the husk-treatment may increase the amount of momilactone B released. Thus, momilactone B may play an important role in rice allelopathy.