Design and synthesis of hetero-steroids via ring-closing metathesis: Biological studies towards in vitro anticancer activity

Light-Driven Two-Step Preparation of 4-Chromanone Fused to Estrone Derivatives

A protocol involving the irradiation of some 3-(2-alkenyl)estrone and 3-(2-alkenyl)-17-norestrone derivatives under a nitrogen atmosphere in organic solvents (both hexane and MeOH) followed by base-mediated intramolecular oxa-Michael cyclization reaction was investigated under steady-state conditions. The solvent effect and nature of the acyl group on the preparative photoreaction were studied and the multiplicity of the excited state was also demonstrated. The ortho-regioisomers were obtained in modest to good yields. Intramolecular based-mediate cyclization reaction of these synthons led to the formation of a set of novel substituted 4-chromanone moieties fused to estrone (and 17-norestrone) in good yields. This two-step sequential procedure involving a photochemical/intramolecular thermal cyclization strategy will be useful for the preparation of wide heterocyclic-fused-steroid compounds.

Microwave-assisted one-pot multicomponent synthesis of steroidal pyrido[2,3-d]pyrimidines and their possible implications in drug development

Protein misfolding can lead to fibrillar and non-fibrillar deposits which are the signs of countless human diseases. A promising strategy for the prevention of such diseases is the inhibition of protein aggregation, and the most crucial step toward effective prevention is the development of small molecules having the potential for protein-aggregation inhibition. In this search, a series of novel steroidal pyrido[2,3-d]pyrimidines have been synthesized employing steroidal ketone, substituted aldehydes, and 2,6-diaminopyrimidin-4(3H)-one through the microwave-assisted one-pot multicomponent methodology. The aggregation inhibition potential of newly synthesized compounds was evaluated on human lysozyme (HLZ). All the synthesized compounds were found to be efficient in the inhibition of protein aggregation in carefully designed in vitro experiments. Moreover, molecular docking studies also determine the binding interactions between all the synthesized compounds and native HLZ through hydrogen bonding. The structures of synthesized compounds were also elucidated using various spectroscopic techniques.