First synthesis and characterization for the stereoisomers of Ulipristal acetate
The three stereoisomers, 11α,17α-isomer I, 11α,17β-isomer II and 11β,17β-isomer III are related substances of the selective progesterone receptor modulator Ulipristal acetate. Herein, we presented an efficient and practical synthesis approach to deliver these three stereoisomers for the first time, and also confirmed the structure of the key intermediate 5a by single-crystal X-ray analysis. Our research will be of immense help for organic chemists to study the impurity profile of Ulipristal acetate.
New 11β-aryl-substituted steroids exhibit both progestational and antiprogestational activity
The syntheses of three 11 beta-aryl-19-norpregna-4,9-dien-3-one derivatives with 17-spirolactone and 17 beta-hydroxy-17 alpha-cyanoethyl substitutions are described. The progesterone agonist/antagonist activities of the new compounds are investigated using a recently developed tissue culture system that relies on the progesterone agonist up-regulation of the prostate-specific antigen (PSA) gene in female breast tumor cell lines. Two of the newly synthesized compounds exhibit mixed agonistic/antagonistic progestational activity.
Experimental study on ground vibration of blasting the boulder with tandem shaped charging warhead
Hazardous effects of blasting the boulder with the new breaking-blasting equipment-tandem shaped charging warhead are mainly air shock wave, seismic wave and blast slung shot. Blast-induced ground vibration is one of the inevitable effects and may cause substantial damage to nearby structures. Started from the formation process and mechanism of ground vibration to study the seismic wave, the research attained curve of vibration velocity of monitoring points by TC-4850 and carried out differential and fast Fourier transform analysis of the curve. And the results concluded that blasting vibration with tandem shaped charging warhead mainly comes from prime charge; the attenuation law can be predicted by Sadev’s Formula. Explosion vibration frequency range is 20-150 Hz, while with the increase of distance from the blasting center, blasting vibration intensity attenuates rapidly, vibration duration increases and vibration frequency gradually reduces. Compared with general rock blasting, its attenuation rate of blasting vibration is faster with higher frequency and smaller impact on buildings, but the harm effects should not be ignored for the special application environment.