Deoxycalyciphylline B, a Hepatotoxic Alkaloid from Daphniphyllum calycinum
Daphniphyllum calycinum (DC), a main component of Chinese patent drug Fengliao-Changweikang, is effectively used to cure bowel disease in the clinic. It was recorded that DC possessed slight toxicity, which was caused by the alkaloids existing in its extract. Unfortunately, to date the toxicity level and toxic constituents are still unclear. The present study is designed to illustrate the acute toxicity and induced organ damages of the total alkaloids as well as to determine the toxic constituents. Based on the above studies, not only was the acute toxicity determined but also hepatic toxicity was characterized by increased plasma biomarkers of ALT and AST and liver cell inflammatory infiltrate as well necrosis that was firstly observed. Significantly, deoxycalyciphylline B exhibited exactly the same hepatic toxicity so it was identified as the main toxic constituent in DC. An obvious dose-effect relationship between the toxic compound and induced hepatic injuries was also observed. Moreover, the Chinese patent drug Fengliao-Changweikang contained low levels of the toxic compound, compared with the total alkaloids. Therefore, this Chinese patent drug could be regarded to be safe in this point of view.
Two novel alkaloids with a unique fused hexacyclic skeleton from Daphniphyllum subverticillatum.
Two novel major alkaloids, deoxycalyciphylline B (1) and deoxyisocalyciphylline B (2) with a unique fused hexacyclic skeleton, together with a quite recently reported alkaloid calyciphylline B (3), were isolated from the stem of Daphniphyllum subverticillatum. Their structures were established by spectral methods and chemical evidence, especially 2D NMR techniques. The structure of 1 was further confirmed by a single-crystal X-ray diffraction determination.
Stereochemical studies on esperamicins: Determination of the absolute configuration of hydroxyamino sugar fragment.
Abstract The β-D-gluco-hexopyranose configuration has been assigned for the hydroxyamino sugar fragment of esperamicin A 1 . This determination concluded our study on the absolute configuration of the carbohydrate portion of esperamicins.