Synthesis, ABTS-Radical Scavenging Activity, and Antiproliferative and Molecular Docking Studies of Novel Pyrrolo[1,2-a]quinoline Derivatives

Biological properties of pyrroloquinoline and pyrroloisoquinoline derivatives

In this review, we summarize pyrroloquinoline and pyrroloisoquinoline derivatives (PQs and PIQs) that act on a broad spectrum of biological targets and are used as bacteriostatic, antiviral, plasmodial, anticancer, antidiabetic and anticoagulant agents. Many of these compounds play important roles in the study of DNA and its interactions, the regulation of the cell cycle and programmed cell death. This review involves twenty-five types of skeletally analogical compounds bearing pyrrole and (iso)quinoline scaffolds with different mutual annelations.

Synthesis and antioxidant activities of berberine 9-O-benzoic acid derivatives

Although berberine (BBR) shows antioxidant activity, its activity is limited. We synthesized 9-O-benzoic acid berberine derivatives, and their antioxidant activities were screened via ABTS, DPPH, HOSC and FRAP assays. The para-position was modified with halogen elements on the benzoic acid ring, which led to an enhanced antioxidant activity and the substituent on the ortho-position was found to be better than the meta-position. Compounds 8p, 8c, 8d, 8i, 8j, 8l, and especially 8p showed significantly higher antioxidant activities, which could be attributed to the electronic donating groups. All the berberine derivatives possessed proper lipophilicities. In conclusion, compound 8p is a promising antioxidant candidate with remarkable elevated antioxidant activity and moderate lipophilicity.

Although berberine (BBR) shows antioxidant activity, its activity is limited.

Natural Product-Derived Chiral Pyrrolidine-2,5-diones, Their Molecular Structures and Conversion to Pharmacologically Important Skeletons

The versatility of the natural products (2S,3S)- and (2S,3R)-3-hydroxy-5-oxotetrahydrofuran-2,3-dicarboxylic acids (1 and 2), isolated in large amounts from tropical plant sources, has been demonstrated by the construction of 3-substituted and 3,4-disubstituted chiral pyrrolidine-2,5-diones. The absolute configurations of chiral pyrrolidine-2,5-diones have been ascertained using chiroptical spectroscopic methods and/or single-crystal XRD data. A combination of different reaction strategies delivering a diverse matrix of fused heterocyclic ring systems is presented. The pyrrolo[2,1-a]isoquinoline alkaloid (+)-crispine A possesses a wide range of pharmacological activities including antidepressant, antiplatelet, antileukemic, and anticancer activities. The analogues of indolizino[8,7-b]indole alkaloids (+)- and (-)-harmicine show strong antileishmanial, antinociceptive, PDE5-inhibitory, antimalarial, and antiviral activities. The bicyclic furo[2,3-b]pyrrolo skeleton is present in many natural products. Thus, the uniqueness of relatively cheap, naturally occurring chiral 2-hydroxycitric acid lactones as chirons has been demonstrated by the construction of some important molecular skeletons that are otherwise difficult to synthesize.