introduction: pronuclear size, morphology and orientation are known to affect embryo quality and implantation. the present study was aimed at evaluation of the possible relationship between protamine deficiency with pronuclear morphology and also cleavage and embryo quality. material and methods: semen sample of 160 candidate icsi and ivf couples were analyzed for sperm concentration, and motil...

A new method for the ring expansion of cyclic diols is described. Using improved conditions for the ruthenium(0) catalyzed cycloaddition of cyclic 1,2-diols with 1,3-dienes, fused [n.4.0] bicycles (n = 3-6) are formed, which upon exposure to iodosobenzene diacetate engage in oxidative cleavage to form the 9-12 membered rings .

We describe a four-step sequence for the synthesis of complex 2-hydroxy-1-naphthoic acids involving Z-selective olefination of benzaldehyde derivatives with a novel dioxolenone-containing phenyl phosphonate reagent, followed by dioxolenone cleavage with alkaline trifluoroethanol and oxidative cyclization (Mn(OAc)(3)) of the resultant trifluoroethyl beta-keto esters. [reaction: see text]

Light-driven Au(III)-promoted oxidative cleavage of triazole-bearing amine derivatives is utilized for the detection of ionic gold in aqueous media. A bistriazole-bearing boron dipyrromethane (1(BODIPY)) exhibited selective and sensitive fluorescence enhancement by the addition of Au(3+) and subsequent UV irradiation.

[reaction: see text] Oxidative cleavage of olefins by OsO(4)-NaIO(4) sometimes suffers from low yields due to the formation of side products. It is found that the addition of 2,6-lutidine can suppress the side reactions and dramatically improve the yield of this classic reaction.

A rhodium-catalyzed oxidative acylation of benzamides with aryl aldehydes via direct sp(2) C-H bond cleavage is described. In the presence of [Cp*RhCl(2)](2), AgSbF(6), and silver carbonate as an oxidant, N,N-diethyl benzamides can be effectively carbonylated to yield ortho-acyl benzamides.

Background Leptin, as a key hormone in energy homeostasis, plays an important role in reproduction and male fertility. However, its negative or positive effect on sperm quality and assisted reproduction technique is still controversial. The aim of this study was the comparison of seminal leptin concentration in selected couples with male and female factor for intracytoplasmic microinjection (IC...

Protoxylogranatin B, a new protolimonoid identified from the seeds of a Chinese mangrove, Xylocarpus granatum, was proposed as the key biosynthetic intermediate. Its structure was established on the basis of spectroscopic techniques, including 1 H– 1 H COSY, HSQC, HMBC and NOESY spectra. The finding of this compound suggested an oxidative cleavage biogenetic pathway from protolimonoid to limonoid.

Escherichia coli expressing SOS-inducing mutant topoisomerase I was utilized to demonstrate that covalent protein-DNA complex accumulation results in oxidative damage. Hydroxyl radicals were detected following mutant topoisomerase induction. The presence of the Fe(2+) chelator 2,2'-dipyridyl and an iscS mutation affecting Fe-S cluster formation protect against topoisomerase I cleavage complex-m...

We describe here a new metal-free route for the synthesis of 3-nitroindoles by the nitrative cyclization of N-aryl imines with tert-butyl nitrite. The radical transformation allows the assembly of the indole framework through oxidative cleavage of multi C-H bonds, a nitration, cyclization and isomerization cascade.