Multicomponent synthesis of 4,4-dimethyl sterol analogues and their effect on eukaryotic cells

Design, Synthesis, and Biological Evaluation of Two Series of Novel A-Ring Fused Steroidal Pyrazines as Potential Anticancer Agents

BACKGROUND

Increasingly, different heterocyclic systems have been introduced into the steroid nucleus to significantly enhance the antitumor activities of steroid molecules. However, in this study, few literature precedents describing the pyrazine heterocyclic-condensed modification to an A-ring of steroid monomers were found, although the pyrazine group is thought to be essential for the potent anticancer activity of clinically relevant drugs and natural steroid dimers.

METHODS AND RESULTS

Two series of novel A-ring fused steroidal pyrazines were designed and efficiently synthesized from commercially available progesterone via key α-ketoenol intermediates. Through a cell counting kit-8 cytotoxic assay of 36 derivatives for three tumor cells, 14 compounds displayed significant antiproliferative activity compared to 5-fluorouracil, especially for human prostatic tumor cells (PC-3) in vitro. Further mechanistic studies indicated that the most active compound, 12n (IC₅₀, 0.93 μM; SI, 28.71), could induce the cell apoptosis of PC-3 cells in a dose-dependent manner and cause cell cycle arrest in the G2/M phase. The molecular docking study suggested that compound 12n fitted the active sites of cytochrome P450 17A1 (6CIZ) well.

CONCLUSIONS

12n might serve as a promising lead compound for the development of novel anticancer drugs. This facile ring-closing strategy may provide a novel and promising avenue for the cycloaddition reaction of the steroidal skeleton through α-ketoenol intermediates.

Steroid diversification by multicomponent reactions

Reports on structural diversification of steroids by means of multicomponent reactions (MCRs) have significantly increased over the last decade. This review covers the most relevant strategies dealing with the use of steroidal substrates in MCRs, including the synthesis of steroidal heterocycles and macrocycles as well as the conjugation of steroids to amino acids, peptides and carbohydrates. We demonstrate that steroids are available with almost all types of MCR reactive functionalities, e.g., carbonyl, carboxylic acid, alkyne, amine, isocyanide, boronic acid, etc., and that steroids are suitable starting materials for relevant MCRs such as those based on imine and isocyanide. The focus is mainly posed on proving the amenability of MCRs for the diversity-oriented derivatization of naturally occurring steroids and the construction of complex steroid-based platforms for drug discovery, chemical biology and supramolecular chemistry applications.

Metabolism and Biological Activities of 4-Methyl-Sterols

4,4-Dimethylsterols and 4-methylsterols are sterol biosynthetic intermediates (C4-SBIs) acting as precursors of cholesterol, ergosterol, and phytosterols. Their accumulation caused by genetic lesions or biochemical inhibition causes severe cellular and developmental phenotypes in all organisms. Functional evidence supports their role as meiosis activators or as signaling molecules in mammals or plants. Oxygenated C4-SBIs like 4-carboxysterols act in major biological processes like auxin signaling in plants and immune system development in mammals. It is the purpose of this article to point out important milestones and significant advances in the understanding of the biogenesis and biological activities of C4-SBIs.

The binding properties of metandienone and human serum albumin by comparing with other five similar compounds

Metandienone (MET) is an exogenous anabolic androgenic steroid. The interaction between MET and human serum albumin (HSA) was investigated by molecular modeling and different optical techniques. There was no possibility of energy transfer, and the fluorescence quenching of HSA induced by MET was mainly due to the complex formation. The differences of binding ability between MET and compounds 1-5 were significantly caused by space steric hindrance. The single crystallographic data of two steroids (compounds 4 and 5) were obtained in the methanol at the first time. In addition, the binding ability was slightly affected by -OH, -CH₃ , and -COCH₃ . The results of displacement experiment demonstrated that the MET binding site was mainly located in site 1 of HSA. H-bonding and van der Waals forces were significant in the MET-HSA binding. MET played an insignificant role on the local conformation change in HSA.