Research On Synthesis Of 6-ketone Spirostanol Saponins Brs And Their Biological Activity

Brassinosteroids?BRs?is acknowledged as non-toxic and widely used plant growth regulator which have a significant role in plant growth.BRs is widely existing in plants.But the minimal content?difficult to obtain?unstable chemical structure and synthetic difficulties provide greatly limit of application in agriculture.Studies have reported the screw steroid compounds have good effect in promoting seed germination?seedling growth?callus formation and differentiation of aspects?m.Nunez,et al.,2004,i.A.M.-A,et al,2002?,with rapeseed sterols chemical structure similar to that of plant hormones.Some 6-ketone type screw steroid compounds have a better activity than the BRs,La and BL at the same time processing rape seeds and seed germination rate La group was obviously higher than that of BL group?Guo Jie etc.,2010?.In order to obtain compound which is similar to BRs in promoting plant growth and having a stable structure.This experiment use diosgenin as raw materials through chemical synthesis method to getting a series of 6-ketone spirostanol saponins.Then we can get some compounds which have a good biological activity in promoting plant growth.This experiment provide material premise in developing the new plant growth regulator and also give a foundation for application of 6-ketone spirostanol saponins compounds in agriculture.We use the chemical synthesis methods for structural modification and using diosgenin as raw materials.The specificity of the hydroxide radical oxides to carbonyl group by Jones reagent and without affecting the structure of the double bond and triple bond.The NaBH₄ can reduces carboxide radical into hydroxide radical,then we use reduction product as raw material by NBS was selectively oxidized 6 hydroxide radical to carbonyl under acid condition.Finally we got the target product and identifying their structures by TLC?NMR?MS and iodine vapor.The target product was named 3,6-dione spirostane?3,6-dione-4-ene spirostane?Compoud1??3,6-dione spirostane?Compound8??3,6-diol spirostane?Compound2??laxogenin?Compound3??3,4-diol-5-ene-spirostane?Compound4??3,4,6-trione spirostane.?Compound5?.The method of carrot hypocotyl elongation ensures activity of each product.we measured the carrot hypocotyl?elongation of and weight gain of the cotyledon under different concentrations,comparing with distilled water as control group.The result shows that all compounds have highly biological activity.Compound1 give a better affection to hypocotyl elongation and enlargement than control group,while compound 2 and 8 are benefit to the growth of cotyledon.Above all,compounds 1 has the highest activity at 10^-1010 mg/mL,which gives a significant effection in promoting carrot hypocotyl elongation reached 85%and the thickening is 19%comparing with the control group?P<0.05?.