Study On The Chemical Constituents Of Croton Laui

Croton laui belongs to the genus Croton (Euphorbiaceae), and is specially distributed in Hainan province of China. The genus Croton comprises about 800 species in tropical and subtropical regions worldwide. Many species in this genus have been used as a folk medicine to treat stomachache, inflammation, abscesses,malaria, etc. Previous phytochemical investigations have demonstrated that the plants of genus Croton are rich in diterpenoids. These diterpenoids not only possessed diverse structures, but also displayed so many significant biological activities. such as anti-tumour, anti-inflammatory, anti-microbial, and anti-tubercular activities. Previous studies have shown that there are few reports of C. laui about the chemical constituents and pharmacological activities. The research attempts to elucidate the chemical constituents and pharmacological activities of C. laui, and provide scientific basis for further development and use.The branches and leaves of C. laui were systematical investigated. By means of chromatographic separation, thirty-three compounds were isolated from petroleum ether and EtOAc extracts. They were identified as(11E)-14,15-bisnor-8α-hydroxy-11-labden- 13-one (ECL-1), sterebin D (ECL-2),crolaunine A (ECL-3), launine C (ECL-4), crolaunine B (ECL-5),3β-hydroxy-labd-8(17),12Z,14-triene (ECL-6), crolaunine C (ECL-7), crolaunine D(ECL-8), crotonolide I (ECL-9), crolaunine E (ECL-10), crolaunine F (ECL-11);crolaunine G (ECL-12), 7β,12α-dihydroxy manoyl oxide (ECL-13),7β,12a- dihydro xy-13 - epi- manoyl oxide (ECL-14),crolaunine H (ECL-15),dehydroabietic acid (ECL-16), crolaunine I (ECL-17), launine A (ECL-18),(5E,9E)-6,10,14-trimethylpentadeca-5,9,13-trien-2-one (ECL-19), sarcophytol T(ECL-20), crolaunine J (ECL-21), serratol (ECL-22), nephthenol (ECL-23),crolaunine K (ECL-24), (7R*)-opposit-4(15)-ene-1β,7-diol (ECL-25), torilenol(ECL-26), 3 ’- (4’’-hydro xy- 3"-metho xyp henyl)-propyl benzoate (ECL-27),3’-(4"-hydroxy-3",5"-dimethoxyphenyl)-propyl benzoate (ECL-28),7 - metho xyd ihy dro s y nap y l alcohol 9-O-benzoyl ester (ECL-29), crolaunine L(ECL-30), chrysophanol (ECL-31), 3 (3’-methoxy-5’-phenylfuran-2’-yl) propan-1-ol(ECL-32), and (±)-chromomoric acid B methyl ester (ECL-33). Among them,ECL-3, 5, 7, 8, 10～12, 15, 17, 21,24, and 30 are new compounds. ECL-2, 6, 13, 16,19, 20, 22, 23, 25～29, and 31～33 are isolated from this plant for the first time.ECL-1～15 were evaluated for their inhibitory activities against LPS-activated NO production in RAW 264.7 macrophage cells using the griess assay, and ECL-4,10～12, and 14 showed inhibitory activities against NO production.