|Budget Amount *help
¥7,900,000 (Direct Cost : ¥7,900,000)
Fiscal Year 1995 : ¥2,500,000 (Direct Cost : ¥2,500,000)
Fiscal Year 1994 : ¥5,400,000 (Direct Cost : ¥5,400,000)
1.Cell cultivation of Ophiorrhiza pumila
(1)Studies on metabolites of cultured callus : The cultured callus produced a group of anthraquinones instead of anticipated alkaloids. Structures of nine anthraquinones including two new molecules, 1-hydroxy-2-hydroxymethyl-3-methoxy anthraquinone and 2-butoxymethyl-1,3-dihydroxy anthraquinone, were elucidated.
(2)Induction of differentiated plants from callus of Ophiorrhyza pumila : Regenerated plants were formed from the callus. Studies on the constituents revealed occurrences of camptothecin, 9-methoxycamptothecin, pumiloside, and 3(R)-deoxypumiloside, proving expression of the same alkaloid-forming enzyme activities as the original plant.
2.A step toward biosynthesis-modeled synthesis of camptothecin : 3-epi-pumiloside tetraacetate was converted to the C-7 deoxy derivative. The resulting product proved to be identical with the acetate of natural deoxypumiloside ; an observation that required us to revise the proposed C-3 stereo chemistry of the above natural molecule form alpha to beta.
3.Synthesis of new camptothecin derivatives : Synthesis of five esters of 10-hydroxycamptothecin was made ; esters with saturated fatty acids of 10,12,16,18 and 20 carbons, respectively. Biological activity tests for mammalian esterases and for topoisomerase I are under progress.
4.Studies on the constituents of Vernonia cenerea and V.arborea : A study on the constituents of V.cinerea was unsuccessful because of scarece material amount. V.arborea native to South Thai gave a new lignan of unknown structure besides known 3-0-caffeoyl quinic acid.
5.Search for new medicinal resource plants : Studies on some Okinawan or Tropical Asian plant species of such genera as Morrinda (Rubiaceae), Hedyotis (Rubiaceae), Glycosmis (Rutaceae), Murraya (Rutaceae), or Acalypha (Euphorbiaceae), are in progress under close contact with scientists in the countries of South East Asia.