C0818, a novel curcumin derivative, interacts with Hsp90 and inhibits Hsp90 ATPase activity

The aims of the present study were to estimate the affinity between 3,5-()-bis(3-methoxy-4-hydroxybenzal)-4-piperidinone hydrochloride (C0818) and heat shock protein 90 (Hsp90) and to investigate the inhibitory effects of this compound on Hsp90 ATPase activity. Fluorescence spectroscopy was used to examine the affinity between varying concentrations of C0818 and Hsp90, N-Hsp90, M-Hsp90 and C-Hsp90. Fluorescence intensities were recorded in the range of 290-510 nm at 293, 303 and 310 K, respectively. A colorimetric assay for inorganic phosphate (based on the formation of a phosphomolybdate complex and the subsequent reaction with malachite green) were used to examine the inhibitory effects of C0818 on Hsp90 ATPase activity. The equilibrium dissociation constantvalue of C0818 was found to be 23.412±0.943 μmol/L. The interaction between C0818 and Hsp90 was driven mainly by electrostatic interactions. C0818 showed the strongest affinity with C-Hsp90. These results conclusively demonstrate the inhibitory activity of C0818 on the activity of Hsp90 ATPase.

Interactions between curcumin derivatives C085 and various constructs of Hsp90 and effects of C085 on Hsp90 ATPase activity / 中国药理学通报

Aim To estimate the affinity between C085 and Hsp90 and the inhibitory effects of C085 on the activity of Hsp90 ATPase. Methods The fluores-cence spectrum experiment was applied to examine the affinity between different C085 concentrations and Hsp90 , NHsp90 , MHsp90 , CHsp90; fluorescence in-tensities were recorded in the range of 290-510 nm at 293 K, 303 K and 310 K, respectively;a colorimetric assay for inorganic phosphate based on the formation of a phosphomolybdate complex and subsequent reaction with malachite green was used to examine the inhibitory effects of C085 on the activity of Hsp90 ATPase. Re-sults The dissociation constant KD value of C085 was (11. 163 ± 0. 316 ) μmol · L-1 . The interaction be-tween C085 and Hsp90 was driven mainly by electro-static interaction. C085 showed strongest affinity with CHsp90. When the concentration of ATP was 1 mmol· L-1 ,the inhibition of Hsp90 ATPase activity of C085 with the IC50 value was 6. 04μmol·L-1 . Conclusions The interaction mechanism between C085 and Hsp90 can be analyzed by fluorescence spectrum. C085 shows strong inhibition ATPase activity of Hsp90 .

Study on Preparation Process of Sodium Copper Porphyrin of Herba Ephedrae and Its Character / 中成药

Objective: To study the comprehensive utilization of Herba Ephedrae resources during the extraction process of ephedrin, that is the extracting of porphyrin compound.Methods: The process conditions for preparing sodium copper porphyrin were optimized by the two preparation processes and twice orthogonal tests. Results: Herba Ephedrae was powdered, steeped and boiled in alcohol, saponified, then extracted with xylene. The ephedrin was extracted from the upper layer of xylene extraction solution and sodium copper porphyrin was obtained from the lower layer by copper substituton, acidulation and alkalization. Conclusion: The optimum preparation process for producing sodium copper porphrin of Herba Ephedrae which is superior to porphyrin in the stability and colour is ascertained.

Extraction of Ephedrine and Prophyrin Copper Sodium of Ephedra / 中成药

Objective: To obtain ephedrine with porphyrin copper sodium from Herba Ephedrae. Methods: Application of ethanol to obtain ephedrine and porphyrin copper sodium from ephedra. The spoinfy reaction of porphyrin will take place, the integral ephedrine will turn into free ephedrine (dissolved in ether), when the liquor of ethanol of ethanol of ephedra are heated with NaOH. Using dimethylponyle to extract, the liquor will into two phases, one's (including sponify porphyrin) is water phase, the other's (including free ephedrine) is ether phase. Results: The yield proportion of ephedrine is 0.72%, and porphyrin copper sodium is 1.8%.Conclusion: It is practicable to extract porphyrin copper sodium with ephedrine from Herba Ephedrae.