Studies On The Chemical Constituents Of Terpenoids From Three Medicinal Plants

Natural products play an important role in the development of new drugs.Using modern science and technology to search for natural compounds with novel structures and wide biological activities from medicinal plants is one of the important ways to find lead compounds.The chemical constituents and biological activities of three medicinal plants,including Croton sublyratus,Clerodendrum chinense and Oroxylum indicum,were studied systematically in this dissertation.116 compounds,including 55 diterpenoids and 41 new compounds,were isolated and identified from the three medicinal plants by means of multiple separation materials and purification techniques,combined with spectroscopic methods,single crystal X-ray diffraction experiments and quantum chemical calculations.40 compounds(1-40)were isolated and identified from the EtOAc extract of the twigs and leaves of C.sublyratus,including 30 labdane diterpenoids and 25 new compounds.Among them,compounds 1-8,9-12,13-15,17-18,and 19-20 were stereoisomers,respectively.Compounds 25,26,28 and 30 were 14,15-dinor-labdane diterpenoids.Compound 29 was a 13,14,17-trinor-labdane diterpenoids.Compounds 9-12 exhibited significant antiproliferative activities against HL-60 cell lines with IC50 values of 2.79±0.95,2.56±0.01,1.49±1.32,and 2.37±0.37μM,respectively.However,the other compounds did not show good antiproliferative activities against A549 cell line.51 compounds(41-91)were purified and elucidated from the EtOAc extract of the roots of C.chinense.Among them,25 diterpenoids and 9 new compounds.These compounds mainly belonged to the rearranged abietane skeletons of 17(15→16)-abeo-abietane(42,43,45,46,55-57,59 and 60)and 17(15→16),18(4→3)-diabeo-abietane(44,47-49,53,54,58,and 61-64).At the same time,a series of lignans and amide alkaloids were also isolated from this species.Bioactivity screening showed that 11 compounds exhibited good antiproliferation activities against two tumor cell lines A549 and HL-60,with IC50 values ranging from 1.00 ± 0.10 to 16.34 ± 1.56μM.The bioactivity screening work of this compounds is still ongoing.25 compounds(92-116)were purified and elucidated from the EtOAc extract of the barks of O.indicum.Among them,compounds 92-98 were new compounds.Some of the compounds performed a variety of activity screening including INS-1E cell line apoptosis detection,ACLY inhibition(ATP Citrate Lyase),DAP Kinase-related apoptosis-inducing protein kinase 2 and SARS-CoV-2 3CLPro inhibitor model.The results indicated that compound 105 showed good pharmacological activities for the above activities.