A Highly Efficient Synthetic Process Of Hypericin And Its Derivatives

Hypericin of naphthodianthrones has drawn enthusiastic attention because of their high pharmacological activities such as antidepressant antiviral activity,antibacterial activity and anti-inflammatory activity.In addition,their applications in the photodynamic therapy(PDT)as an photosensitizer to induce apoptosis of tumor cell also promote the development of hypericin-containing drug.But high purity of hypericin is expensive and difficult to obtain.The thesis has developed a new chemical process for synthesizing hypericin efficiently via a radical reaction induced by monochromatic light,which includes three steps.1)Emodin anthrone was obtained by reducing emodin in acidic condition.2)The protohypericin was synthesized by dimerization of emodin anthrone in alkaline conditions.3)The protohypericin transformed to hypericin via a radical reacton induced by monochromatic light.Especially,the dimerization of emodin anthrone in Step 2 was assisted with microwave,resulted in the transformation of protohypericin completed in a short reaction time(70 min),lower temperature(in comparison with that reported in literatures),and high yield(up to 96%in isolated yield).Moreover,preperation of hypericin from protohypericin in Step 3 was induced by monochromatic light with 575 nm wavelength,which greatly shortened the reaction time.And with a yield of 96%by using this facile synthetic process.The process established in this thesis is facile,highly efficient,and environmental friendly.It has the potential application to producing hypericin in large scale.Preliminary study of hypericin derivatives synthesized by the established process showed great success.The further application is undergoing in our laboratory.