Studies On The Preparation Process And The Related Substances Of Pseudo-sapogenin DQ

Pseudo-sapogenin DQ(PDQ) has a good anti-hemorrhagic shock pharmacological effect,which doesn’t exist in natural products.In this thesis，the chemistry synthesis technology and the related substances of pseudo-sapogenin DQ were studied. The preparation process of PDQ contains two steps: thesynthesis of20(S)-protopanaxadiol(PPD) crude products by alkaline degradation and oxida-tive cyclization.Through single factor tests, some best reaction conditions of alkaline degradationreaction including solvent, temperature, time and material ratios were discussed, and anoptimum about the alkaline degradation of20(S)-protopanaxdiol saponins from leaves andstems of Panax quinquefolium L.(PQDS) was preliminarily selected. PQDS were hydrolyzedto prepare PPD for155min at235℃in a glycerine solution, in which the mass ratio ofPQDS to NaOH is1to4and the quality and volume ratio of PQDS to glycerine is1to40.The best reaction conditions for oxidative-cyclization of crude PPD to prepare PDQwere confirmed: alkaline-degradation crude products containing a certain content of PPD asthe starting material; m-CPBA of1.2times the mass of PPD as acid catalyst;1,4-dioxane，the amount of10times the volume of crude PPD as solvent; mixing reaction for2h at80℃.Based on the conditions, the (20S,24S)-form target product was obtained and it accounted for78.3%of the (20S,24S)-PDQ and (20S,24R)-PDQ stereoisomers.10compounds from alkaline-degradation and oxidative-cyclization products wereisolated by silica gel column chromatography and recrystallization, and their structures wereelucidated by chemical methods and spectral techniques as follows: PPD(1), ginsenosideRh2(2), dammar-20(21),24-diene-3β,12β-diol(3), panaxadiol(4), stigmastane-3,5,6-triol(5),PDQ(6),24(R)-PDQ(7), Pseudo-ginsenoside HQ(8),(24R)-Pseudo-ginsenoside HQ(9),dammar-20S,25R-epoxy-3β,12β,26-triol(10). Among them, compound10is a new compo-und never reported and first obtained by synthesis method.The inhibiting effect of compound10on the apoptosis of human breast cancer MCF-7cells, human prostate cancer PC3M cells and human lung cancer NCI-H446cells wasinitially investigated. The results of pharmaceutical tests in vitro revealed that compound10had an obviously antitumor activity.