Studies On The Chemical Constituents From Cantharis After Biotransformation Of Photosynthetic Bacteria

Cantharis is the dried body of Mylabris phalerata Pallas or Mylabris cichorii Linnaeus(belongs to the family of meloidae),used in the treatment of diseases such as cancer and hepatitis,especially for primary liver cancer significantly.Its secretion cantharidin is an effective component of antitumor active ingredients,but cantharidin on renal injury in great,which to some extent limited its clinical application.The pharmacological experiments showed that the toxicity of cantharis(Mylabris phalerata Pallas)was significantly reduced after photosynthetic bacteria,and the ethyl acetate and n-butanol extraction sites of the cantharis conversion solution were significantly different from those of human hepatoma cell line HepG-2 has an inhibitory effect.In this paper,the active substances of ethyl acetate in cantharis were studied by means of chromatographic tracing,isolation,spectroscopy and fingerprinting in vitro.The content of ethyl acetate in cantharis before and after photosynthetic bacteria was studied.Composition of the similarities and differences,to clarify the cantharis by photosynthetic bacteria metabolic synergistic attenuated material basis.The main research contents are as follows:1.Study on the chemical constituents of ethyl acetate from biotransformation of cantharis by photosynthetic bacteria.In order to investigate the active ingredient of cantharis by photosynthetic bacteria from ethyl acetate extract,human hepatoma cell line was used as a guide to track the active site.The chemical constituents of the ethyl acetate fraction were studied by gel column chromatography and high pressure semi-preparative chromatography.13 compounds were obtained.Their structures were identified by spectral characteristics and reported in the literature.They are N-hydroxyethylcantharimide(1),N-hydroxyethyl exo-4a-methyl-7a-hydroxymethyl-4,7-oxabicyclo[2.2.1]-heptanes-1,3-dicarboximide(2),N-[methylene-4'-(2'-hydroxypyridine)]-cantharimide(3),N-[2'-(3',4'-dihydroxyphenyl)ethanone]-cantharimide(4),cantharimide(5),7a-hydroxymethylcantharim-ide(6),N-acetyltyramine(7),N-Acetyldopamine(8),2-(3',4'-dihydroxyphenyl)-3-acetylamino-6-(N-acetyl-2''-aminoethyl)-1,4-benzodioxane(9),3-hydroxy-3-methylindolin-2-one(10),4-hydroxyisoindolin-1-one(11),2-hydroxyethyl-(4-hydroxy)isoindolin-1-one(12),thymine(13).Among the 13 compounds,the structural types refer to cantharis derivat-ives(1-6),simple phenolic compounds(7-9),simple indole alkaloids(10-12)and bases(13).Compounds 2,3 and 4 are novel compounds,the other eight compounds(except compo unds 5 and 6)were isolated from cantharis for the first time.2.Comparison of the peak shape of HPLC chromatogram of cantharis before and after photosynthetic bacteria biotransformation.Under the same chromatographic conditions,the changes of the chemical composition of cantharis before and after biotransformation were preliminarily elucidated by analyzing the change of HPLC chromatogram before and after metabolism of the compound and cantharis by photosynthetic bacteria.The results showed that the chemical composition of cantharis was changed after the biosynthesis of photosynthetic bacteria.3.Preliminary study on antitumor activity of compounds.The antitumor activity test was performed on human hepatocellular carcinoma cell line HepG-2 by CCK-8 method except for the 12 compounds isolated(except compound 13).The results showed that compounds 8 and 9 had a certain inhibitory trend on HepG-2 cells.