Synthesis, Biological Activity, and Three-Dimensional Quantitative Structure−Activity Relationship Model for a Series of Benzo[c]quinolizin-3-ones, Nonsteroidal Inhibitors of Human Steroid 5α-Reductase 1

Small-molecule agents for treating skin diseases

Skin diseases are a class of common and frequently occurring diseases that significantly impact daily lives. Currently, the limited effective therapeutic drugs are far from meeting the clinical needs; most drugs typically only provide symptomatic relief rather than a cure. Developing small-molecule drugs with improved efficacy holds paramount importance for treating skin diseases. This review aimed to systematically introduce the pathogenesis of common skin diseases in daily life, list related drugs applied in the clinic, and summarize the clinical research status of candidate drugs and the latest research progress of candidate compounds in the drug discovery stage. Also, it statistically analyzed the number of publications and global attention trends for the involved skin diseases. This review might provide practical information for researchers engaged in dermatological drugs and further increase research attention to this disease area.

Pd-catalyzed steroid reactions

We review the most important achievements of the last decade in the field of steroid synthesis in the presence of palladium catalysts. Various palladium-catalyzed cross-coupling reactions, including Heck, Suzuki, Stille, Sonogashira, Negishi and others, are exemplified with steroid transformations.

Synthesis of New DPP-4 Inhibitors Based on a Novel Tricyclic Scaffold

A novel molecular scaffold has been synthesized, and its synthesis and incorporation into new analogues of biologically active molecules will be discussed. A comparison of the inhibitory activity of these compounds to the known type-2 diabetes compound (sitagliptin) against dipeptidyl peptidase-4 (DPP-4) will be shown.

Preparation and structural analysis of (±)-cis-ethyl 2-sulfanylidenedecahydro-1,6-naphthyridine-6-carboxylate and (±)-trans-ethyl 2-oxooctahydro-1H-pyrrolo[3,2-c]pyridine-5-carboxylate

Bicycle ring closure on a mixture of (4aS,8aR)- and (4aR,8aS)-ethyl 2-oxodecahydro-1,6-naphthyridine-6-carboxylate, followed by conversion of the separatedcisandtransisomers to the corresponding thioamide derivatives, gave (4aSR,8aRS)-ethyl 2-sulfanylidenedecahydro-1,6-naphthyridine-6-carboxylate, C11H18N2O2S. Structural analysis of this thioamide revealed a structure with two crystallographically independent conformers per asymmetric unit (Z′ = 2). The reciprocal bicycle ring closure on (3aRS,7aRS)-ethyl 2-oxooctahydro-1H-pyrrolo[3,2-c]pyridine-5-carboxylate, C10H16N2O3, was also accomplished in good overall yield. Here the five-membered ring is disordered over two positions, so that both enantiomers are represented in the asymmetric unit. The compounds act as key intermediates towards the synthesis of potential new polycyclic medicinal chemical structures.

Enantioselective annulations for dihydroquinolones by in situ generation of azolium enolates

A convergent, catalytic asymmetric formal [4 + 2] annulation for the synthesis of dihydroquinolones has been developed. Carboxylic acids can be employed as precursors to NHC enolates through an in situ activation strategy. Simultaneous generation of a reactive aza-o-quinone methide under the basic conditions employed for NHC generation leads to a dual activation approach.

Molecular modeling of some 1H-benzimidazole derivatives with biological activity against Entamoeba histolytica: a comparative molecular field analysis study

Comparative molecular field analysis (CoMFA) was performed on a set of 1H-benzimidazole derivatives. Molecular modeling and 3D-QSAR were employed to determine the tautomeric form that would probably fit a target receptor in Entamoeba histolytica. CoMFA results suggest that the antiamoebic activity is favored with steric bulk at position 5 of the benzimidazole ring and low electron density on the group at position 2. To the best of our knowledge this is the first 3D-QSAR study performed for benzimidazoles as antiamoebic agents. The CoMFA models derived will be very valuable to design new and more potent compounds against E. histolytica.

5alpha-Reductase activity in Lycopersicon esculentum: cloning and functional characterization of LeDET2 and evidence of the presence of two isoenzymes

The full-length cDNA (LeDET2) encoding a 257 amino acid protein homolog of Arabidopsis DET2 (AtDET2) was isolated in tomato (Lycopersicon esculentum). LeDET2 has 76% similarity with AtDET2 and structural characteristics conserved among plant and mammalian steroid 5alpha-reductases (5alphaRs). LeDET2 is ubiquitously expressed in tomato tissues with higher levels in leaf than in stem, root, seed and callus. When expressed in mammalian cells (COS-7), recombinant LeDET2 was active on substrates typical of mammalian 5alphaRs (progesterone, testosterone, androstenedione), but reduced at very low levels campestenone, the substrate described for AtDET2. Similar results were obtained with the expression in COS-7 of recombinant AtDET2 that showed 5alphaR activity for progesterone and not for campestenone. Recombinant LeDET2 was inhibited by several inhibitors of the human 5alphaRs and the application of an active inhibitor to tomato seedlings induced dwarfism and morphological changes similar to BR-deficient mutants. In tomato tissues, campestenone was 5alpha-reduced in leaf, stem and root homogenates, like progesterone and testosterone, while androstenedione was converted to testosterone, evidencing for the first time a 17beta-hydroxysteroid dehydrogenase activity in plants. Moreover, two separate 5alphaR activities with different kinetic characteristic and response to inhibitors were characterized in tomato tissues. The presence of two 5alphaR isoenzymes was demonstrated also in Arabidopsis using the det2-1 mutant, in which a residual 5alphaR activity for campestenone and progesterone was evidenced and characterized. Therefore, the existence of two isoenzymes of 5alphaR is probably characteristic of the whole plant kingdom highlighting the similarities between the animal and plant steroid biosynthetic pathways.