Font Size: a A A

Conformation Of Absolute Configuration Of Natural Products By Vibrational Circular Dichroism

Posted on:2017-01-27Degree:MasterType:Thesis
Country:ChinaCandidate:X L CaiFull Text:PDF
GTID:2311330512462438Subject:Chemical Engineering
Abstract/Summary:PDF Full Text Request
In the present study,Fourier Transform Infrared Spectrometer(FT-IR)and Vibrational Circular Dichroism Spectroscopy(VCD)were used to measure the spectra of several types of natural products which have kinds of biological activities.The density functional theory(DFT)was applied to research the theory spectra of the corresponding molecules.The absolute configuration and conformations can be determined after comparing the experimental and calculated spectra of each molecule which provides specific geometry for developing of new drugs.Followed the main points:1.Determination of absolute configuration of sophocarpine and sophocarpidine,the Matine-type alkaloids,by vibrational circular dichroism combined with quantum chemical calculation.The IR and VCD spectra of sophocarpine and sophocarpidine were measured in film,DMSO-d6 and CDCl3 respectively while sophocarpidine was measured in film.Sophocarpine was simulated in gas phase,polarized continuum model(PCM)and the combination of explicit and implicit solvation model(expli.+ PCM)and calculated at B3LYP/cc-p VTZ level.Sophcarpidine was simulated in gas phase and calculated both at B3LYP/cc-p VTZ and B3LYP/6-311+G(d,p)level.The results show that both of sophocarpine and sophocarpidine exist in a mixture of two relative conformers.The geometry of sophcarpine is: 5S 6S 7S 11 R,A-chair,B-chair,C-chair,D-sofa,A/B-trans,A/C-cis,B/C-cis.The geometry of sophcarpidine is: 5S 6S 7S 11 R,A-chair,B-chair,C-chair,D-sofa,A/B-trans,A/C-cis,B/C-cis.2.Determination of absolute configuration of artemisinin and artenimol,the artenmisinin-type molecules,by vibrational circular dichroism combined with quantum chemical calculation.The IR and VCD spectra of artemisinin and artenimol were measured in DMSO-d6.Artemisinin was simulated in PCM model and calculated at B3LYP/cc-p VTZ and B3LYP/6-31+G(d,p)level.Artenimol was simulated in PCM and expli.+ PCM model and calculated at B3LYP/cc-p VTZ and B3LYP/6-31+G(d,p)level.The results show that both of artemisinin and artenimol stay in one stable comformation.The geometry of artemisinin is: 1S 4S 5S 6R 7S 10 R 11R,A-chair,B-boat,C-chair,A/B-trans,B/C-cis,A/C-cis.The geometry of artenimol is: 1S 4S 5R 6R 7S 10 R 11R 12 S,A-chair,B-boat,C-chair,A/B-trans,B/C-cis,A/C-cis.3.Determination of absolute configuration of methyltestosterone,dehydroepiandrosterone and Aco-dehydroepiandrosterone,the steroid hormone,by vibrational circular dichroism combined with quantum chemical calculation.The IR and VCD spectra of methyltestosterone,dehydroepiandrosterone and Acodehydroepiandrosterone were measured in DMSO-d6.Methyltestosterone and dehydroepiandrosterone were simulated in PCM and expli.+ PCM model and calculated at B3LYP/cc-p VTZ and B3LYP/6-31+G(d,p)level.Aco-dehydroepiandrosterone was simulated in PCM model and calculated at B3LYP/cc-p VTZ and B3LYP/6-31+G(d,p)level.The results show that both of methyltestosterone and dehydroepiandrosterone exist in a mixture of three relative conformers.The geometry of methyltestosterone is: 8R 9S10 R 13S 14 S 17S,B-chair,C-chair,D-envelope,A/B-trans,B/C-trans,C/D-trans.The geometry of dehydroepiandrosterone is: 3S 8R 9S 10 R 13S 14 S,A-chair,B-twist chair,C-chair,D-envelope,A/B-trans(cis),B/C-trans,C/D-trans.The geometry of Acodehydroepiandrosterone is: 3S 8R 9S 10 R 13S 14 S,A-chair,B-twist chair,C-chair,D-envelope,A/B-trans,B/C-trans,C/D-trans.
Keywords/Search Tags:VCD, DFT, Matrine-type alkloids, artemisinin-type, steroid hormone, absolute configuration, conformation
PDF Full Text Request
Related items