Studies On The Chemical Constituents And Bioactivities From The Leaves Of Rubus Suavissimus S.Lee

Rubus suavissimus S. Lee (Rosaceae) is a perennial frutex deciduus whichis widely distributed in Guangxi, it has been used as a potable tea and sugarin folk for a long time. In addition, it is used as a traditional medicine foreliminating phlegm by cooling, expelling phlegm to arrest coughing and hemos-tatic elimination of stagnation.A series of pharmacological experiments and systematic analyses on the c-hemical constitutions of the leaves of Rubus suavissimus S. Lee have been co-nducted, which built a foundation for the further exploitation of Rosaceae. Thedried and powdered leaves of Rubus suavissimus S. Lee were refluxed with 95% ethanol and 50% ethanol respectively, then concentrated under reduced pre-ssure. The residue of 95% ethanol was subjected to silica-gel column chromat-ography, eluted in order with Petroleum ether, CHCl₃, EtOAc, acetone, 95%ETOH and MeOH. The residue of 50% ethanol was subjected to D101 column andwas eluted respectively by H₂O, 30%EtOH, 60%EtOH and 95%EtOH. All of t-hese portions, the EtOAc, 30%EtOH and 60%EtOH portions showed obvioushypoglycemic activities against PTP1B enzyme in the in vitro screen. Based onthe result, we studied the extract portions and tried to find the chemical comp-ounds related to above bioactivities.In this thesis, twenty-seven compounds were obtained from the EtOAc, ac-etone portions of the 95% ethanolic extract and 60% ethanolic portion of the50% ethanolic extract, in which six compounds are new compounds. Their str-uctures were elucidated by spectroscopic methods including IR, UV, MS, HRMS, 1D and 2DNMR and chemical methods. As a result, there are 10 diterpeno-ids (1, 16-17, 19, 22-27), 7 triterpenoids (4, 6-7, 9, 12-14), 4 flavonoids (2, 8,10-11), 3 lignans (18, 20-21), 3 other compounds (3, 5, 15). These compoundswere identified respectively as follows: Steviol (1), Quercetin (2),β-sitosterol (3),2α,3β,23-trihydroxy-urs-12-en-28-oic acid (4), Daucosterin (5), 2α,3β,19α,23-tet-rahydroxy-urs-12-en-28-oic acid (6), 2α,3β,19α,23-tetrahydroxy-olean-12-en-28-oicacid (7), kaempferol-3-O-(7-O-trans-p-coumaryol)-β-D-glucopyranoside (8), 2β,3β,19a,23,24-pentahydroxy-urs-12-en-28-oic acid (9), Quercetin-3-O-α-D-ribopyra-noside (10), Quercetin-3-O-β-D-glucopyranoside (11), 2,3-O-acetonide-2α,3β,19α,23- tetrahydroxy-urs-12-en-28-oic acid (12), 2,3-O-acetonide-2β,3β,19α,23,24-pentahy-droxy-urs-12-en-28-oic acid (13), 2α,3β-dihydroxy-urs-12-en-28-oic acid (14), Su-crose (15), Rubusoside (16), 3β,16α,17-trihydroxy-ent-kaurane (17), (7R,8S)-dih-ydrodehydrodiconiferyl alcohol (18), 7β-hydroxy-setviol (19), 7,8-dihydro-Buddle-nol B(erythro) (20), 7,8-dihydro-Buddlenol B (threo)(21), 16α,17,19-trihydroxy-ent-kaurane (22), ent-16α,17-dihydroxy-kauran-19-oic acid (23), 3β,16α,17,19-te-trahydroxy-ent-kaurane (24), Sugeroside (25), Suavioside A (26), Paniculosideâ…£(27). Among them, 9, 10, 12, 13, 19and 24 are new compounds; 4, 7, 8,11, 14, 17, 18, 20, 21, 22 and 23 are isolated from this plant for the fristtime.We also explored the pharmacological activities about the compounds iso-lated from Rubus suavissimus S. Lee. As a result, compound 19, 22 and 23 s-howed potent hepatoprotective activity.