Studies On Chemical Constituents And Anti - Inflammatory Activity

In recent years,more and more research proved that inflammation especially chronic inflammation can induce many diseases,such as cancer,cardiovascular diseases,diabetes,senile dementia,pulmonary heat disease,and autoimmune disease. Inflammatory mediator is synthesized and released by cell or produced by proteases in serum and it play an important role in the inniation and development of inflammation.Phosphodiesterase 4（PDE4）,one of the most important targets in drug research,is mainly distributed in many inflammatory cells,such as mastocyte, macrophages,acidophil granule,and lymphocyte.The inhibitors of PDE4 had been proved effective on asthma,COPD,sensitization dermatitiss,Crohn Disease and multiple sclerasis in clinical trial.In the course of our confinous screening work,we found that Nauclea officinalis Pierre.ex Pitard and Picrasma quassioides（D.Dom） Benn.Showed the significant inhibitory effect on PDE 4.In this paper,the chemical studies of two plants were carried out and some typical compounds of anti-inflammatory effects in vivo and in vitro.By means of different chromatographic methods such as silica gel,Sephadex LH-20,ODS column chromatography,21 compounds including 13 alkaloids and 5 triterpenes were isolated and purified from Nauelea officinalis Pierre.ex Pitard.By physic-chemical data and spectral methods such as IR,ESI-MS,FAB-MS,HR-MS, 1D-NMR,2D-NMR,compared with data in published papers,all these compounds were determined as 2β,3β,19α,23-tetrahydroxyurs-12-en-28-oic acid-28-β-D-glucopyranosyl -（1→2）-β-D-glucopyranoside（1）,quinovic acid（2）,qumovic acid-3-O-α-L-rhamnopyranoside（3）,pyrocincholic acid-3-O-α-L-rhamnopyranosyl-28 -O-β-D-glucopyranoside（4）,pyrocincholic acid-3- O-α-L-rhamnopyranoside（5）, naucleofficine C（6）,pumiloside（7）,naucleofficine D（8）,nauclefidine（9）, naucleamide E（10）,naucleofficine B（11）,naucleofficine E（12）,naucleamides B（13）,strictosamide（14）,angustoline（15）,angustine（16）, 3-（hydroxymethyl）-6,7-dihydroindolo[2,3-a]quinolizin-4（12H）-one（17）,nauclefine （18）,naucleofficine A（19）,daucosterol（20）,β-sitosterol（21）.Among them, compound 1 was a new compound,and compound 4,5 were isolated from this genus for the first time.Eighteen compounds were isolated from Picrasma quassioides（D.Dom） Benn. and determined as 4-methoxy-5-hydroxycanthin-6-one（Ⅰ）,1,2,3,4- tetrahydro-1,3, 4-trioxo-β-carboline（Ⅱ）,canthin-6-one（Ⅲ）,11-hydroxycanthin-6- one（Ⅳ）, 4,5-dimethoxycanthin-6-one（Ⅴ）,N-p-coumaroyltyramine（Ⅵ）,N, N-dimethyltryptamine（Ⅶ）,1-methoxycarbonyl-4-hyclroxyl-β-carboline（Ⅷ）, 1-ethyl-4-methoxy-β-carbolme（Ⅸ）,1-formyl-β-carboline（Ⅹ）,1-methoxycarbonyl -β-carboline（Ⅺ）,1-ethoxycarbonyl-β-carboline（Ⅻ）,3-methylcanthin-2,6-dione （ⅩⅢ）,1-formyl-4-methoxy-β-carboline（ⅩⅣ）,1-ethyl-4,8-dimethoxy-β-carboline（ⅩⅤ）,2-methyl-6-hydroxyl-1,2,3,4-tetrahydro-β-carboline（ⅩⅥ）, 1-methoxy-β-carboline（ⅩⅦ）,5-methoxycanthin-6-one（ⅩⅧ） repectively. Among them,compoundâ…¥,â…¦,â…©â…¥were isolated from this genus for the first time.The inhibitory effects of some compounds from two plants on phosphodiesterase 4 in vitro were tested.Porcine neutrophils were obtained from porcine whole blood and PDE4 was got after the neutrophils had been broken to release.The activity of PDE was decided upon the decreased content of cAMP,which was detected by HPLC method.The positive drug was rolipram.The results showed that alkaloids from Picrasma quassioides（D.Dom） Benn.can markedly inhibit the activity of PDE4.IC₅₀ of 4,5-dimethoxycanthin-6-one,4-methoxy-5-hydroxycanthin-6-one, 3-methylcanthin-2,6-dione was 35.4,30.2 and 27.2μmol·L^-1 separately.In the present study we evaluated the effect of 4-methoxy-5-hydroxycanthin-6 -one,a natural alkaloid isolated from Picrasma quassioides（D.Don） Benn.,on ulcerative colitis induced by dextran sulfate sodium in rats with the positive control drug,sulfasalazine.Given orally for several days,it significantly reduced the severity of colitis and mitigated changes in colon length,colon mucosa myeloperoxidase activity,and level of tumor necrosis factor-αin serum.Its effect was similar to that of sulfasalazine.