Studies On Chemical Constituents Of Active Fraction For Psoriasis In Datura Metel L.

Flos Datura is the dry flower of Datura metel L.which belongs to the family of Solananeae.It was recorded originally in《Compendium of Materia Medica》and has been recorded in every edition of《Chinese Pharmacopoeia》including the newest edition in 2005.It has the long history to be used as traditional Chinese medicine and utilized widely to cure many diseases such as cough, asthma,convulsion,etc.Due to its strong and wide biological activities.The Drug has been clinical used for the treatment of psoriasis in these years .It showed an excellent curative effect with many advantages.But it had obviously negative effect.Our team have studied the chemical constituents against psoriasis and pharmacological effects in these years.Pharmaceutical research found and confirmed that the chemical constituents extracted with 50% ethanol from Flos Datura was the active fraction for the treatment of psoriasis.In order to better elucidate the medical substances for the treatment of psoriasis,this article deals with the chemical constituents in active fraction for psoriasis.In the course of our studies on chemical constituents in active fraction of treating psoriasis, 8 compounds were isolated with silica. gel, reversed-phase (ODS) column chromatography and HPLC,and the chemical structures of 4 compounds were fully determined by 1D and 2D NMR ,such as ¹H-NMR,¹³C-NMR, DEPT,¹H-¹HCOSY, HSQC and HMBC etc.Combined with ESI-MS, UV,IR and chemical methods.The compounds are 2 megastigmanes compounds and 2 withanolides compounds.The structures of the 4 compound were indentified as: Grasshopperketone[(3S,5R,8R)-3,5-dihydroxy-megastigman-6,7-idene-9-one)],Icariside B₁ [(3S, 5R,8R)-3,5-dihydroxy-megastigman-6,7-idene-9-one-3-O-β-D- glucopyranoside)],withastramonolide[5α,12α,27-trihydroxy-6α, 7α-epoxy-1-oxo-22R-witha-2,24-dienolide],withanoside X [(1α,3β,27-trihydroxy-22R-witha-5,24-dienolide-3-O,27-O-β-D-diglucopyranoside)].These compounds wereseparated from Datura metel L.for the first time.The other compounds's chemical structure are identifying.Our studies further reserched the chemical constituents of active fraction in Flos Datura and the effective substances for the treatment of psoriasis.All these will provide important scientific foundation and material base for further reserch and the development of new drugs.So this article has great value in theory and practice.