6β-Acetamido-5α-hydroxy-cholestan-3β-yl acetate

Exploration of Binding Affinities of a 3β,6β-Diacetoxy-5α-cholestan-5-ol with Human Serum Albumin: Insights from Synthesis, Characterization, Crystal Structure, Antioxidant and Molecular Docking

The present study describes the synthesis, characterization, and in vitro molecular interactions of a steroid 3β,6β-diacetoxy-5α-cholestan-5-ol. Through conventional and solid-state methods, a cholestane derivative was successfully synthesized, and a variety of analytical techniques were employed to confirm its identity, including high-resolution mass spectrometry (HRMS), Fourier transforms infrared (FT-IR), nuclear magnetic resonance (NMR), elemental analysis, and X-ray single-crystal diffraction. Optimizing the geometry of the steroid was undertaken using density functional theory (DFT), and the results showed great concordance with the data from the experiments. Fluorescence spectral methods and ultraviolet-vis absorption titration were employed to study the in vitro molecular interaction of the steroid regarding human serum albumin (HSA). The Stern-Volmer, modified Stern-Volmer, and thermodynamic parameters' findings showed that steroids had a significant binding affinity to HSA and were further investigated by molecular docking studies to understand the participation of active amino acids in forming non-bonding interactions with steroids. Fluorescence studies have shown that compound 3 interacts with human serum albumin (HSA) through a static quenching mechanism. The binding affinity of compound 3 for HSA was found to be 3.18 × 104 mol-1, and the Gibbs free energy change (ΔG) for the binding reaction was -9.86 kcal mol-1 at 298 K. This indicates that the binding of compound 3 to HSA is thermodynamically favorable. The thermodynamic parameters as well as the binding score obtained from molecular docking at various Sudlow's sites was -8.2, -8.5, and -8.6 kcal/mol for Sites I, II, and III, respectively, supporting the system's spontaneity. Aside from its structural properties, the steroid demonstrated noteworthy antioxidant activity, as evidenced by its IC50 value of 58.5 μM, which is comparable to that of ascorbic acid. The findings presented here contribute to a better understanding of the pharmacodynamics of steroids.

Bismuth(III) reagents in steroid and terpene chemistry

Steroid and terpene chemistry still have a great impact on medicinal chemistry. Therefore, the development of new reactions or “greener” processes in this field is a contemporaneous issue. In this review, the use of bismuth(III) salts, as “ecofriendly” reagents/catalysts, on new chemical processes involving steroids and terpenes as substrates will be focused. Special attention will be given to some mechanistic considerations concerning selected reactions.

16α,17α-Ep-oxy-5α-hydr-oxy-6β-nitrooxy-20-oxopregnan-3β-yl acetate

The title steroid, C(23)H(33)NO(8), is a pregnane derivative obtained regio-, stereo- and chemoselectively from the ring opening of the corresponding 5α,6α;16α,17α-diepoxide with bis-muth(III) nitrate. There are two symmetry-independent mol-ecules in the asymmetric unit that show no significant differences concerning bond lengths and angles. All rings are trans-fused. The conformations of the six-membered rings are close to chair forms, while the five-membered ring adopts an envelope conformation. The mol-ecules are held together by an extensive O-H⋯O hydrogen-bonding network of chains runnning along the a axis.