《中德双边会议-潘远江.ppt》由会员分享，可在线阅读，更多相关《中德双边会议-潘远江.ppt（78页珍藏版）》请在三一办公上搜索。
1、Yuanjiang PanZhejiang University,Stilbenes from Parthenocissus laetevirens:Isolation,Bioactivity and Implication of Chemical Defense System in Plant,PNAS,1999,96,13620.,diterpene,antifeedant activity for beetle,PNAS,2000,97,14406.,Males of the moth acquire by feeding on the excrescent fluids of cert
2、ain plants They incorporate the alkaloid systemically and as a result are protected against spiders.,pyrrolizidine alkaloid,Chemical Defense in Flower,In the flower of Hypericum calycinum,dearomatized isoprenylated phloroglucinols(DIPs)are responsible for the UV demarcations.DIPs fulfill both a visu
3、al and a defensive function.DIPs also serve for protection of female reproductive structures in other plants.,Gronquest M.,et.al.,Proc.Natl.Acad.Sci.U.S.A.,2001,98,13745,Chemical Defense in Catepillar,Pinoresinol,a lignan of wide distribution in plants,is found to occur as a minor component in the d
4、efensive secretion produced by glandular hairs of caterpillars of the cabbage butterfly,Pieris rapae.,Schroeder F.C.,et.al.,Proc.Natl.Acad.Sci.U.S.A.,2006,103,15497,ROS:reactive oxygen species,ROS include both radicals and non-radicals.They are generally very small molecules and are highly reactive
5、due to the presence of unpaired valence shell electrons.ROSs form as natural byproducts of normal metabolism of oxygen and play important roles in cell signaling.,Circu M.L.,et.al.,Free Radic.Biol.Med.,2010,48,749-762,Endogenous Sources of ROS,Exogenous Sources of ROS,Radiation UV light,x-rays,-rays
6、 Chemicals that react to form peroxides ozone,singlet oxygen Chemicals that promote superoxide formation quinones,nitroaromatics,bipyrimidiulium herbicides Chemicals that are metabolized to radicals polyhalogenated alkanes,aminophenols Chemicals that release iron ferritin,ROS&Protein Damage,Chang C.
7、J.,et.al.,Nat.Chem.Biol.,2011,7,504-511,A one-electron reduction of molecular oxygen,either from the electron transport chain(ETC)or through the action of NADPH oxidases(NOX),yields superoxide(O2).Superoxide is converted to hydrogen peroxide(H2O2)by superoxide dismutase(SOD)or by dismutation in aque
8、ous solution.,ROS&Cell Damage,Finkel T.,Holbrook N.J.,Nature 2000,408,239-246,ROS damages&related diseases,Related Diseases Inflammation Atherosclerosis Cancer Aging,ROS damages Activation of cellular pathways Stimulation of cell proliferation Damage to proteins,DNA and lipids,Antioxidant,an antioxi
9、dant is a molecule capable of slowing or preventing the oxidation of other molecules.,Natural Antioxidants,flavonoids黄酮类化合物,tannins单宁类化合物,stilbenoids茋类化合物,Quideau S.,et.al.,Angew.Chem.Int.Ed.,2011,50,586,化妆品SOD蜜 Maquillage,海藻类Laminaria japonica,人参Ginseng,茶Tea,水果Fruits,Natural Stilbenes as antioxidan
10、ts,Frech Paradox&Cardioprotection“法国异常”与保护心血管活性,Antitumor抗肿瘤活性,Antioxidant&Anti-aging抗氧化与抗衰老作用,Type II diabetes抗II型糖尿病,Some plantphenols may activate the gene for lengthening the life,Guarante et al Nature,430,686，2004),Inhibition of lipid peroxidation,The production of MDA is an index of the occurr
11、ence of lipid peroxidation and the development of oxidative stress.,Resveratrol prevents superoxide-dependent inflammatory induced by ischemia/reperfusion,Free Radical Biology&Medicine(5.6),2003,Vol.34,810817.,Antioxidant Effects of Resveratrol and its Analogues against the Free-Radical-Induced Pero
12、xidation of Linoleic Acid in Micelles,Chem.Eur.J.(4.5)2002,8,No.18:4191-4198,Stilbenes from Parthenocissus laetevirens:Isolation,Bioactivity and Implication of Chemical Defense System in Plant,Family:Vitaceae 葡萄科Genus:Parthenocissus 爬山虎属Species:Parthenocissus laetevirens Rehd.English name:Shinygreen
13、 CreeperChinese name:绿爬山虎,Japanese Creeper,Ref.1:A resveratrol dimer from Parthenocissus tricuspidataPhytochemistry 1991,30,3144-3146,A stilbene dimerA resveratrol dimer,Resveratrol白藜芦醇,Stilbene,Ref.2:A resveratrol dimer from Parthenocissus tricuspidataPhytochemistry 1998,48,1241-1243,Resveratrol,An
14、tifungal,Ref.3:Stilbene derivatives in the stem of Parthenocissus quinquefoliaPhytochemistry 1998,48,1045-1049,Ref.4:Two new antioxidant stilbene dimers,parthenostilbenins A and B from Parthenocissus tricuspidataPlanta Medica 2005,71,973-976,Isolation of resveratrol oligomers from Parthenocissus lae
15、tevirens,Structure elucidation of 5Molecular formula,Negative HR-ESIMS(m/z):451.1178 M-H Calcd.for C28H19O6:451.1187,ResveratrolC14H12O3MW=228,Molecular formula:C28H20O6(MW=452),Structure elucidation of 5 13C NMR spectrum,Structure elucidation of 5 1H NMR spectrum,Structure elucidation of 5 1H NMR s
16、pectrum(H:6.0 8.0),Structure elucidation of 5 2D NMR Data:Deduction of Structure Unit A,Structure elucidation of 5 2D NMR Data:Deduction of Structure Unit B,Structure elucidation of 5 2D NMR Data:Linkage between Structures Unit A and B,Structure elucidation of 5 NOESY:Relative configuration,UV induc
17、ed cyclization,Ref.:J.Org.Chem.2004,69,4279-4282.,UV induced trans-cis isomerization and cyclization of 4,Structure elucidation of 6 NOESY:Relative configuration,Methylation of 7 and Ozonolysis of 7a.,Absolute configuration,Structures of gnetin F(13)and(-)-ampelopsin D(14).,UV induced trans-cis isom
18、erization and cyclization of 7,HPLC chromatogram of reaction mixture at 100 min,7(680),6(680),8(678),Proposed scheme for the unknown compound,Oligomerization:Dimer to Trimer(Idea),HOW?!,Ref.8:Monomer to Dimer,Chem.Comm.1977,7,208-210.,Ref.9:Dimer to Tetramer,Tetrahedron 1996,52,9991-9998.,Dimer to T
19、rimer(Experimental*),*First example from resveratrol dimer to trimer(Hybrid reaction).,Yield 28%,Yield 28%,Resveratrol,+,Dimer to Trimer(Experimental),Resveratrol,+,+,Yield 26%,Yield 26%,Antioxidant Activity,DPPH(2,2-diphenyl-1-picrylhydrazyl),a stable free radical,has been extensively used to evalu
20、ate free radical scavenging capacities of compounds.,Microplate reader was used to monitor the decrease of absorption at 517nm.,With 96-well plate,antioxidant activities of 32 samples can be determined in 1 hour in triplicate.,High Throughput!,Antioxidant activities of resveratrol dimers,*SC50=26.28
21、 g/ml,SC50=30.38 g/ml,SC50=7.36 g/ml,Hypothesis:Is cyclization an antioxidant activity promoting reaction?,*SC50 is the concentration of sample producing 50%decrease of DPPH absorption.The lower value,the stronger antioxidant activity.,Why cyclized products were synthesized?,UV,Antioxidant activitie
22、s of resveratrol trimers,SC50=118.10g/ml,SC50=87.04g/ml,SC50=25.28g/ml,Further evidence for the hypothesis!Cyclization is an antioxidant activity promoting reaction!,UV,Generation of active oxygen species in the chloroplast(叶绿体)and antioxidative mechanisms,Ref.10:Photooxidative stress in plants.Phys
23、iologia Plantarum 1994,92,696-717,Proposal of a new mechanism of antioxidative defense system in plant,When the plant was exposed to excessive UV irradiation,reactive oxygen species(ROS)was generated massively,which was destructive to plant tissues.In response to this oxidative stress,antioxidative
24、defense system was activated,and compounds with stronger antioxidant activities were synthesized to remove excessive ROS.We hypothesize that generation of cyclized compounds is a respondence to ROS induced by UV irradiation,thus stilbenes were supposed to play a role in the antioxidative defense sys
25、tem of plant.,UV induced trans-cis isomerization and cyclization of resveratrol,HPLC chromatogram of reaction mixture at 8h.,trans-resveratrol(228),cis-resveratrol(228),Unknown compound(226);2%,trans-resveratrol,cis-resveratrol,Unknown compoundProposed structure,UV irradiation on ethyl acetate extra
26、ct,0 min,120 min,Cyclized dimer5,Cyclized trimer8,Biological importance of oligomerization of stilbenes,+,Why trimer were synthesized,though their antioxidant activities were lower?,SC50=26.28 g/ml,SC50=118.10g/ml,SC50=172.1 g/ml,SC50=16.40 g/ml,Ref.11:A new class of phytoalexins from grapevinesExpe
27、rientia 1977,15,151-152.,ResveratrolNon-antifungal,Antifungal,Antifungal,Hypothesis:Is peroxidase catalysing oligomerization an antifungal activity promoting reaction?,Antifungal activities of stilbenes,+,Non-antifungal,Antifungal,Not tested.,*Inhibition rate of growth of Botrytis cinerea(灰葡萄孢菌)at 4
28、00g/ml.,Non-antifungal,Antifungal activities of stilbenes,+,+,Non-antifungal,Antifungal,Not tested.,Non-antifungal,Antifungal activities of stilbenes,+,Non-antifungal,Non-antifungal,Antifungal,Need more evidence to prove the hypothesis that oligomerization promotes antifungal activity.,Inhibition ra
29、te of growth of Botrytis cinerea(灰葡萄孢菌)at 400g/ml.Mol concentration of resveratrol was 3 fold higher than compound 8.,Summary,10 stilbene oligomers were isolated from the EA extract of Parthenocissus laetevirens.Five of them are new compounds.Their structure were elucidated by NMR and MS data.Their
30、biogenetic relationship was proved by photochemical transformation and enzyme catalysing oligomerization.,Their antioxidant activities were assayed.The results led to the hypothesis that UV induced cyclization is an antioxidant activity promoting reaction and consequently stilbenes were implied to p
31、lay a role in the antioxidative defense system of the plant.In addition,the results of antifungal activities reveal that enzyme catalysing oligomerization may be linked to the antifungal defense system of the plant,J.Org.Chem.2008,Resveratrol Hexamer from Vitis chunganeniss,J.Org.Chem.2009,Proposed chunganenol biogenesis(1)from 3 and 5,Driving Force,Acknowledgements,The national natural science foundation of ChinaNCET-06-0520All my students,Welcome to Zhejiang university!,Thanks for your attention!,
