New approaches toward the synthesis of (D-homo) steroid skeletons using Mukaiyama reactions

Temperature-controlled Mukaiyama aldol reaction of cyclododecanone (CDD) with aromatic aldehydes promoted by TMSCl via the (TMS)3Si intermediate generated in situ

A temperature controlled chemo-, regio- and diastereoselective synthesis of enones and Mukaiyama aldol reaction have been developed using sterically hindered CDD with organosilane as a catalyst.

Novel conformationally constrained pyrazole derivatives as potential anti-cancer agents

The synthesis of 17 novel conformationally constrained pyrazole derivatives is reported herein, along with the assessment of their anti-proliferative and anti-angiogenic activities. The evaluation of their inhibitory effect on cell proliferation against HepG2, HeLa, and MCF-7 cells revealed the pyrrolo[2,3-g]indazole 23 as a potent inhibitor of cell growth with IC50 values of 5 μm. Additionally, the inhibition of vascular endothelial growth factor by pyrazoles 20 and 23 (30 % and 35 %, respectively) in HeLa supernatant cells was evidenced. These findings highlight the usefulness of these compounds as potential scaffolds for the design and development of novel anti-cancer agents with pronounced anti-angiogenic activity.

Total synthesis and structure-activity relationship study of the potent cAMP signaling agonist (-)-alotaketal A

A detailed account of the first total synthesis of alotaketal A, a tricyclic spiroketal sesterterpenoid that potently activates the cAMP signaling pathway, is provided. The synthesis employs both intra- and intermolecular reductive allylation of esters for assembling one of the fragments and their coupling. A Hg(OAc)2-mediated allylic mercuration is used to introduce the C22-hydroxyl group. The subtle influence of substituents over the course of the spiroketalization process is revealed. The synthesis confirms the relative and absolute stereochemistry of (-)-alotaketal A and allows verification of alotaketal A's effect over cAMP signaling using reporter-based FRET imaging assays with HEK 293T cells. Our studies also revealed alotaketal A's unique activity in selectively targeting nuclear PKA signaling in living cells.

Design, synthesis and initial biological evaluation of a novel pladienolide analog scaffold

A novel and simplified synthetic scaffold based on pladienolide was designed using a consensus pharmacophore hypothesis. An initial target was synthesized and evaluated to examine the role of the 3-hydroxy group and the methyl groups present at positions 10, 16, 20, 22 in 1, on biological activity. We report the first totally synthetic analog of this macrolide that shows biological activity. Our novel synthetic strategy enables the rapid synthesis of other new analogs of pladienolide in order to develop selective anticancer lead compounds.