Studies On The Chemical Constituents And Bioactivities Of Isodon Rubescens And Isodon Serra

Background Since1910, Japanese scholars had taken the lead in Genus Isodon plants, attributing to its rich ent-kauranoids and diversities biological activities. Nearly one century it has drawn phytochemists and pharmacologists’ interest. More than500diterpenoids have been obtained from80species of this genus, the biological activities involving antibacterial, anti-inflammation, cytotoxicities, antimmor, effects on cardiae-vascular system, inhibition activities on insects growth and oxidative phosphorylation of mitochondrion. Many researches about chemical constituents and biological activities of Isodon rubescens have been reported, but few reseach in Huixian of Henan province; the reports about Isodon serra also does not see more, so we chose this plant which had been collected from the Shennongjia Mountain, Hunan Province.Objective To study the constituents and biological activities of Isodon rubescens and Isodon serra (Burm.f.) Hara.Method The chemical constituents were separated by repeated silica gel column chromatography, Sephadex chromatography, preparative thin layer chromatography and recrystallization etc. The structures were identified by modern spectra technology such as IR, UV,1H-NMR,13C-NMR, DEPT, HMQC, HMBC,1H-1H COSY, NOESY, DEPT, EI-MS, HRESI-MS or directly comparison with the standard sample. The in vitro anti-tumour activities of the compounds from Isodon rubescens were studied by MTT assay.Result (1) Twenty compounds were isolated and identified from the extract of Isodon rubescens, fourteen compounds are diterpenoids consisting of two new diterpenoids. One is identified as15α-acetoxyl-6,11α-epoxy-6α-hydroxy-20-oxo-6,7-seco-ent-kaur-16-en-1,7-olide and named as rubescrystal A (1*), The other one is identified as15α-hydroxyl-20-oxo-6,7-seco-ent-kaur-16-en-1,7α (6,11α)-diolide and named as rubescrystal B (2*). Among the remaining eighteen compounds were as follows: Oridonin(3), Enmenin(4), Glaucocalactone(5), Rabdonervosin B(6), Ponicidin(7), Acetonide of rubescensin J(8), Maoyecrystal F(9), Rabdoternin A(10),1-a-O-β-D-glucopyranosyl-enmenol(11), Acetonide of maoyecrystal F (12),6α,15a-dihydroxy-20-aldehyde-6,7-seco-6,11α-epoxy-1,7-olide-ent-kaur-16-ent(13), Rubescensin C(14), Vanillic acid(15), o-hydroxy-benzoic acid(16), Ferulic acid(17), phenol(18), Apocynin(19), pedalitin(20). Oridonin(3) and Ponicidin(7) were demonstrated their significant effects to EC-1, MCF-7, Hela, K562and U87.(2) Twenty three compounds were obtained and identified from the extract of Isodon serra. One new compound was isolated and identified as15a-dihydroxy-6β-methoxy-6,7-seco-6,20-epoxy-1,7-olide-ent-kaur-16-ene and named as Serrin D(1*), The rest of the compounds are as follows:Isodoacetal(2), Parvifoline G (3), Longirabdolide C (4), Epinodosinol (5), Epinodosin (6), Taibaihenryiins B (7), Rabdonervosin A (8), Isodocarpin (9), Rabdonervosin B (10), Rabdosin B (11), Ememogin (12), Serrin C (13), Serrin B (14), Effusanin A (15), Lushanrubescensin F (16), Sculponeatin F (17), Nodosin (18), Lasiodonin (19), Enmein(20),6a,15a-dihydroxy-20-aldehyde-6,7-seco-6, lla-epoxy-1,7-olide-ent-kaur-16-ene (21),15β-hydroxy-6,7-seco-6,11β:6,20-diepoxy-1a,7-olide-ent-kaur-16-ene (22),6β,7β-13a-trihydroxy-1a-acetoxy-7a,20-epoxy-ent-kaur-16-en-15-one(23).Conclusion Two new diterpenoids are obtained from Isodon rubescens, what’s more, compounds15and19are separated from the genus of rubescens for the first time, and compounds3and7had a significant inhibitory effect on a few tumor cells; one new diterpenoid are obtained from Isodon serra.