DISCOVERY OF NEW ANTITUMOR AGENTS FROM MEDICINAL PLANTS
Many types of compounds have been isolated from higher plants till now, that is, alkaloids, terpenes, lignans, steroids and so on. One of them, named as RA series Cyclic hexapeptides isolated from Rubia akane and R. cordijofia also have strong antineoplastic activity against various types of tumors. Till now 10 kinds ofRA series compounds were isolated and named as RA - I, II, III, IV, V, VI, VII, VIII, IX and X. Moreover,monogl-ucoside of RA - V newly Isolated from same plant. Many kinds of derivatives including natural RAcompounds were tested for QSAR, and one of them, RA - VII was screened up as a most suitable substance asan antitumor agent. RA - VII(=RA-700) has strong cytotoxic activity against KB cells, P388 Iymphocyticleukemia and MM2 mammary carcinoma cells. RA - VII has been under investigation for Phase I clinical trials.