Study On Chemical Constituents And Biological Activities Of Amomum Tsaoko

Terpenoids,with abundant skeleton types and extensive biological activities,were one of the important secondary metabolites in plants.Amomum has abundant plant resources,which possessed a wide variety of novel terpenoids with significant activity.Most of Amomum plant were spices,with the function of“Aromatic Resuscitation”,that can be used to alleviate Alzheimer’s disease（AD）.Furthermore,acetylcholinesterase（AChE）was one of the crucial targets acting on AD.Therefore,it is very necessary to find effective AChE inhibitors from natural aromatic plants.In the first chapter,the research progress of novel terpenoids and their biological activities in Amomum were reviewed.52 novel terpenoids were isolated and identified from Amomum in the past 40 years,and their extensive biological activities were summarized also,such as inhibition of NO production,anti-malaria,inhibition of nuclear factor NF-κB,inhibition ofα-glucosidase,etc.This review will provide scientific reference for the further study of terpenoids and their biological activities in Amomum.In the second chapter,the chemical constituents of Amomum tsaoko Crevost et Lemaire（from Baoshan,Yunnan）were systematically studied.26 compounds were isolated by using MCI,silica gel,reverse silica gel（RP-18,ODS）,Sephadex LH-20 and other column chromatography materials combined with MPLC,HPLC analysis and semi-preparative HPLC.A total of 26 compounds were isolated and identified from the fruit,of which 3 were new compounds.Their structures were identified by MS,1DNMR,2DNMR,UV,IR etc.These compounds included 1 flavanol-monoterpenoid hybrid（1）,3 flavonoids（2～4）,9 monoterpenoids（5～13）,3 aliphatic compounds（14～16）,2 phenolics（17 and 18）and 8 diphenylheptanoids（19～26）.Finally,the results of AChE inhibitory activity screen suggested that compounds 1,3,22,23 and 25 were effective AChE inhibitors with IC₅₀ values of 0.17,0.34,0.76,0.14 and 1.42μM,respectively.In addition,compounds 1 and 14 showed neuroprotective activity against SH-SY5Y neurons injured by H₂O₂.In the third chapter,the volatile components and AChE inhibitory activity of 8kinds of spices represented by Amomum tsaoko were studied.The results of GC-MS analysis indicated that the main components of the essential oil were oxygenated monoterpenoids,sesquiterpenes and phenylpropanoids.Furthermore,the resesrch results showed that the Black/White Piper nigrumL essential oil,A.tsao-ko Crevost et Lemaire essential oil,Cinnamomum cassia Presl essential oil,A.kravanh Pierre ex Gagnep essential oil and Curcuma longa L essential oil had significant AChE inhibitory activity with IC₅₀ values of 8.54,5.02,62.33,38.00,86.00,84.00μg/mL,respectively.In vitro enzymology verification was performed combined with molecular docking.Among them,3-carene,α-pinene andβ-pinene(IC₅₀=1.73,2.66,14.75μg/mL)were the main active components inhibiting AChE in the essential oils.The Lineweaver–Burk plotting showed that 3-carene andα-pinene were mixed-type inhibitors,andβ-pinene was non-competitive inhibitors.This thesis combined the research methods of natural product chemistry and molecular docking.In this paper,we not only studied the non-volatile components of Yunnan famous-region spices represented by Amomum tsaoko,but also the volatile components of Amomum tsaoko.From the non-volatile components,26 monomers were isolated from Amomum tsaoko,of which 3 were new compounds.Their structural types included monoterpenes,diphenylheptanoids and novel flavanol-monoterpenoid hybrids and other skeleton types.In addition,the volatile components of 8 famous-region spices in Yunnan Province,and their AChE inhibitory activities were tested,and three monomer molecules were identified which significantly inhibited AChE.The results of this study provided scientific reference for the sustainable utilization and development of the famous-region spices in Yunnan Province.