Synthesis and anti-cancer evaluation of steroidal diglycoside–pyrazoline hybrids

Abstract

A new series of steroidal glycoside pyrazoline functional hybrid constructs (SG–pyrazolines 3a–k) synthesized were evaluated for in vitro anti-cancer cytotoxic activity against a panel of human tumor cell lines of lung, breast, CNS, colon and ovarian cancer. These hybrid constructs were also measured at their respective IC₅₀ values on normal cell lines of HMEC and CHO for evaluating the biocompatibility. Several of these new hybrid constructs were found to possess higher growth inhibition activity than the standard cisplatin and support the concept to modulate drug receptor interaction. Regarding the synthesis, firstly a new SG molecule, an extract of Caralluma gracillis, was converted to the chalcones (2a–k) via the condensation of sp³ C–H bonds on methyl keto of the D-ring of SG with appropriate substituted benzaldehydes. The cyclocondensation of SG–chalcones (2a–k) with hydrazine specifically catalyzed by Ag(I) N-heterocyclic carbene (Ag(I)–NHC) in ethanol has produced selectively the SG–pyrazoline hybrids (3a–k).