Asymmetric organocatalyzed synthesis of coumarin derivatives

Comprehensive Phytochemical Profiling, Biological Activities, and Molecular Docking Studies of Pleurospermum candollei: An Insight into Potential for Natural Products Development

The purpose of this study was to find the biological propensities of the vegetable plant Pleurospermum candollei by investigating its phytochemical profile and biological activities. Phytochemical analysis was done by spectroscopic methods to investigate the amount of total polyphenols, and biological evaluation was done by the different antioxidant, enzyme inhibitory (tyrosinase, α-amylase, and α-glucosidase), thrombolytic, and antibacterial activities. The highest amount of total phenolic and flavonoid contents was observed in methanolic extract (240.69 ± 2.94 mg GAE/g and 167.59 ± 3.47 mg QE/g); the fractions showed comparatively less quantity (57.02 ± 1.31 to 144.02 ± 2.11 mg GAE/g, and 48.21 ± 0.75 to 96.58 ± 2.30 mg QE/g). The effect of these bioactive contents was also related to biological activities. GCMS analysis led to the identification of bioactive compounds with different biological effects from methanolic extract (antioxidant; 55.07%, antimicrobial; 56.41%), while the identified compounds from the n-hexane fraction with antioxidant properties constituted 67.86%, and those with antimicrobial effects constituted 82.95%; however, the synergetic effect of polyphenols may also have contributed to the highest value of biological activities of methanolic extract. Molecular docking was also performed to understand the relationship of identified secondary metabolites with enzyme-inhibitory activities. The thrombolytic activity was also significant (40.18 ± 1.80 to 57.15 ± 1.10 % clot lysis) in comparison with streptokinase (78.5 ± 1.53 to 82.34 ± 1.25% clot lysis). Methanolic extract also showed good activity against Gram-positive strains of bacteria, and the highest activity was observed against Bacillus subtilis. The findings of this study will improve our knowledge of phytochemistry, and biological activities of P. candollei, which seems to be a ray of hope to design formulations of natural products for the improvement of health and prevention of chronic diseases; however, further research may address the development of novel drugs for use in pharmaceuticals.

Copper-Catalyzed Synthesis of Coumarins. A Mini-Review

Coumarin (2H-chromen-2-one) derivatives have important uses in medicinal and synthetic chemistry, for example, as fluorescent probes. These properties have prompted chemists to develop efficient synthetic methods to synthesize the coumarin core and/or to functionalize it. In this context, many metal-catalyzed syntheses of coumarins have been introduced; among them, copper-catalyzed reactions appear to be very promising owing to the non-toxicity and cheapness of copper complexes. In this mini-review, the results in this field are summarized. We hope to stimulate other applications of these complexes in the preparation of coumarin derivatives.

Advances on Greener Asymmetric Synthesis of Antiviral Drugs via Organocatalysis

Viral infections cause many severe human diseases, being responsible for remarkably high mortality rates. In this sense, both the academy and the pharmaceutical industry are continuously searching for new compounds with antiviral activity, and in addition, face the challenge of developing greener and more efficient methods to synthesize these compounds. This becomes even more important with drugs possessing stereogenic centers as highly enantioselective processes are required. In this minireview, the advances achieved to improve synthetic routes efficiency and sustainability of important commercially antiviral chiral drugs are discussed, highlighting the use of organocatalytic methods.