Anthony Murray

Meiosis-Activating Sterol Promotes the Metaphase I to Metaphase II Transition and Preimplantation Developmental Competence of Mouse Oocytes Maturing in Vitro

Abstract The objective of this study was to determine the effects of a sterol found in ovarian follicular fluid, known as meiosis-activating sterol (FF-MAS), on the maturation of mouse oocytes in vitro. Possible effects of FF-MAS in promoting the metaphase I (MI) to metaphase II (MII) transition (nuclear maturation) and the competence of oocytes to complete preimplantation embryo development to the blastocyst stage (cytoplasmic maturation) were assessed. Cumulus cell-enclosed oocytes that were compromised in their ability to undergo nuclear maturation and subsequent development because of the age or genotype of the female were isolated at the germinal vesicle stage and matured in vitro using media supplemented with 0 to 20 μM FF-MAS. Oocytes that progressed to MII were inseminated in vitro, and the percentages developing to the 2-cell and blastocyst stages were determined. The sterol was omitted from the media used for oocyte insemination or preimplantation development. FF-MAS promoted a significantly higher percentage of oocytes in all groups to progress to MII in vitro. Moreover, FF-MAS treatment of oocytes maturing in vitro dramatically increased the competence of all but one of the groups of oocytes to complete preimplantation development. Therefore, FF-MAS improved mouse oocyte quality by promoting both nuclear and cytoplasmic maturation in vitro.

Conversion of 4-cyanomethyl-pyrazole-3-carboxamides into CB1 antagonists with lowered propensity to pass the blood-brain-barrier.

A series of amides, amidines and amidoximes have been made from the corresponding nitrile compounds, to provide potent antagonists and inverse agonists for the CB1 receptor with considerably lower lipophiliciy, higher polar surface area and improved plasma/brain ratios compared to the centrally acting rimonabant. Extensive investigations of ADME and in vivo pharmacological properties led to selection of the amide series and specifically the 4-(4-fluorophenyl)piperidin-4-ol derivative D4. A clear improvement in the peripheral profile over rimonabant was seen, although some contribution of central effect on the pronounced weight reduction in obese mice cannot be ruled out.

Pyrrolidinone-modified di- and tripeptides: highly diastereoselective preparation and investigation of their stability

Pyrrolidine-2,4-diones have been identified as a novel starting point for the synthesis of peptide analogues. This paper describes a method for the efficient and diastereoselective incorporation of this moiety into peptide chains to furnish di- and tripeptide analogs. The stability of these pyrrolidinone modified di- and tripeptides was found to be markedly improved when compared to that of a natural peptide. In addition, solid phase peptide synthesis employing a pyrrolidinone containing tripeptide is demonstrated.

Synthesis of FF-MAS from lithocholic acid

An effective synthesis of 4,4 dimethyl-cholest-8,14,24-trien-3beta-ol (FF-MAS) from lithocholic acid is described, utilising a double oxidation and regioselective Wittig reaction as key steps.

Short and efficient diastereoselective synthesis of pyrrolidinone-containing dipeptide analogues

The pyrrolidine-2,4-diones have been identified as a convenient starting point for the synthesis of peptide analogues. Herein we describe an optimized two-step reductive amination procedure, which provides a small library of pyrrolidinone-containing dipeptide analogues in high yield and excellent diastereoselectivity.

Meiosis activating sterols derived from diosgenin

Continuing research based on the meiosis activation properties of the endogenous sterol FF-MAS is reported. The synthesis and SAR of 16- and 26-substituted sterols are described, utilising diosgenin as starting material. Selected sterols were tested for their ability to induce oocyte maturation in hypoxanthine arrested mouse oocytes in vitro.

A novel synthesis of 9-cis-retinoic acid and tagretin analogues via the Pauson–Khand or Heck reaction

Abstract The synthesis of a selection of compounds related to 9- cis -retinoic acid and tagretin is outlined. The methodology utilises the Pauson–Khand and Heck reaction as the key steps to prepare the intermediate aryl cyclopentenone regioisomers.