Synthesis, antibacterial and antifungal activities of 6,5 fused steroidal oxazoles in cholestane series

Recent advances on synthesis and biological activities of C-17 aza-heterocycle derived steroids

Steroids modification for improving their biological activities is one of the most efficient and fruitful methods to develop novel medicines. Steroids with aza-heterocycles attaching to the C-17 owing various biological activities have received great attentions and some of the compounds are developed successfully as drugs. In this review, the research of the syntheses and biological activities of steroids bearing various aza-heterocycles published in the last 8 years is assembled, and some important structure-activity relationships (SARs) of active compounds are presented. According to the analysis of the literatures and our experiences in this field, the potential of aza-heterocyclic steroids as medicinal drugs is proposed.

A comprehensive review on biological activities of oxazole derivatives

The utility of oxazole as intermediates for the synthesis of new chemical entities in medicinal chemistry have been increased in the past few years. Oxazole is an important heterocyclic nucleus having a wide spectrum of biological activities which drew the attention of researchers round the globe to synthesize various oxazole derivatives and screen them for their various biological activities. The present review article aims to review the work reported on therapeutic potentials of oxazole scaffolds which are valuable for medical applications during new millennium.

Optical properties and fluorescence quenching of carbazole containing (D–π–A) push–pull chromophores by silver nanoparticles: a detailed insight via an experimental and theoretical approach

(4Z)-4-[(9-Ethyl-9H-carbazol-3-yl)methylidene]-2-phenyl-1,3-oxazol-5(4H)-one (ECPO) was prepared by the one-pot multi-component reaction of 9-ethyl-9H-carbazole-3-carbaldehyde, hippuric acid, anhydrous sodium acetate and acetic anhydride under microwave irradiation.

Synthesis and antifungal activity of bile acid-derived oxazoles

Peracetylated bile acids (1a-g) were used as starting materials for the preparation of fourteen new derivatives bearing an oxazole moiety in their side chain (6a-g, 8a-g). The key step for the synthetic path was a Dakin-West reaction followed by a Robinson-Gabriel cyclodehydration. A simpler model oxazole (12) was also synthesized. The antifungal activity of the new compounds (6a-g) as well as their starting bile acids (1a-g) was tested against Candida albicans. Compounds 6e and 6g showed the highest percentages of inhibition (63.84% and 61.40% at 250 μg/mL respectively). Deacetylation of compounds 6a-g, led to compounds 8a-g which showed lower activities than the acetylated derivatives.

Synthesis and characterization of steroidal heterocyclic compounds, DNA condensation and molecular docking studies and their in vitro anticancer and acetylcholinesterase inhibition activities

A facile and efficient approach for the synthesis of steroidal heterocyclic compounds (4–12) has been performed. Furthermore, these newly synthesized compounds were evaluated for their various biological activities.

Surface modified thin film from silk and gelatin for sustained drug release to heal wound

A thin film was prepared from silk and gelatin and the surface was modified. The drug-loaded surface-modified film showed sustained drug release and enhanced wound healing in the rat model.

Synthesis and anti-tumor evaluation of B-ring substituted steroidal pyrazoline derivatives

The synthesis and anti-tumor activity screening of new steroidal derivatives (4-18) containing pharmacologically attractive pyrazoline moieties are performed. During in vitro anticancer evaluation, the newly synthesized compounds displayed moderate to good cytotoxicity on cervical and leukemia cancer cell lines. In addition these compounds were found to be nontoxic to normal cell (PBMCs) (IC50>50 μM). The structure-activity relationship is also discussed. The most effective anticancer compound 9 was found to be active with IC50 value of 10.6 μM. It demonstrated significant antiproliferative influence on Jurkat cell lines. The morphological changes and growth characteristics of HeLa cells treated with compound 4 were analyzed by means of SEM.

Antifungal activity of 2α,3β-functionalized steroids stereoselectively increases with the addition of oligosaccharides

Invasive fungal infections pose a significant problem to the immune-compromised. Moreover, increased resistance to common antifungals requires development of novel compounds that can be used to treat invasive fungal infections. Naturally occurring steroidal glycosides have been shown to possess a range of functional antimicrobial properties, but synthetic methodology for their development hinders thorough exploration of this class of molecules and the structural components required for broad spectrum antifungal activity. In this report, we outline a novel approach to the synthesis of glycoside-linked functionalized 2α,3β-cholestane and spirostane molecules and present data from in vitro screenings of the antifungal activities against human fungal pathogens and as well as mammalian cell toxicity of these derivatives.

N,N'-Bis(3β-acet-oxy-5α-cholest-6-yl-idene)hydrazine

The asymmetric unit of the title compound, C₅₈H₉₆N₂O₄, contains two crystallographically independent mol­ecules. All cyclohexane rings are in chair conformations, while the furan ring is in an envelope conformation in one mol­ecule and a twist conformation in the other. Two acetaldehyde and one isobutane groups are disordered over two orientations with refined site occupancies of 0.940 (4):0.060 (4) and 0.791 (7):0.209 (7), respectively. In the crystal, mol­ecules are stacked along the a axis through van der Waals inter­actions.

Novel and efficient synthesis and antifungal evaluation of 2,3-functionalized cholestane and androstane derivatives

Synthetic modifications of cholesterol and other traditional steroid molecules have become a promising area for the exploration and development of novel antifungal agents, especially with respect to the development of fatty-acid esters of steroids. In addition, 2,3-functionalized steroids are also compounds with potentially interesting biological properties and proper functionalization of 2,3-steroids can lead to the development of efficient syntheses of building blocks for novel fatty-acid esters of steroids. In this Letter, we outline a novel and efficient approach to the synthesis of 2,3-functionalized cholestane and androstane derivatives and present their promising preliminary antifungal activities against a number of fungal species.