Synthesis and Biological Evaluation of Carbazole Aminoalcohols as Antitumor Agents

Structure activity relationship (SAR) and anticancer activity of pyrrolidine derivatives: Recent developments and future prospects (A review)

Pyrrolidine molecules are a significant class of synthetic and natural plant metabolites, which show the diversity of pharmacological activities. An extensive variety of synthetic pyrrolidine compounds with numerous derivatization like spirooxindole, thiazole, metal complexes, coumarin, etc have revealed significant anticancer activity. Pyrrolidine molecules are found not only as potential anticancer candidates but also retain the lowest side effects. Depending upon the diverse substitution patterns of the derivatives, these molecules have demonstrated an incredible ability to regulate the various targets to give excellent anti-proliferative activities. Taking these into consideration, efforts have been taken by the scientific fraternity to design and develop a potent anticancer scaffold with negligible side effects. In the present review, we cover the latest advancements in the synthesis of pyrrolidine molecules which have promising anticancer activity toward numerous cancer cell lines. Additionally, it also highlights the effectiveness of derivatives via elucidation of Structural-Activity-Relationship (SAR) which is discussed in detail.

Visible Light-Mediated Enantioselective Addition of α-Aminoalkyl Radicals to Ketones Catalyzed by Chiral Oxazaborolidinium Ion

The development of a visible light-mediated synthetic method for chiral 1,2-amino tertiary alcohols is described. In the presence of a chiral oxazaborolidinium ion catalyst and photosensitizer, the enantioselective addition of an α-aminoalkyl radical to aryl methyl ketones under visible light provides chiral 1,2-amino tertiary alcohol derivatives in high yields (up to 88%) with excellent enantioselectivities (up to 98% ee). With mechanistic studies such as radical trapping analysis, radical clock analysis, and the measurement of quantum yield, a plausible catalytic cycle is proposed.

Identification of an orally active carbazole aminoalcohol derivative with broad-spectrum anti-animal trypanosomiasis activity

Animal trypanosomiasis, caused by the members of subgenus Trypanozoon (Trypanosoma brucei brucei, T. evansi and T. equiperdum), has reduced animal productivity leading to significant negative economic impacts in endemic regions. Due to limited drug discovery and the emergence of drug-resistance over many recent decades, novel and effective compounds against animal trypanosomiasis are urgently required. This study was conducted to evaluate the antitrypanosomal potential of a batch of carbazole aminoalcohol derivatives. Among them, we found that the most effective compound was H1402, which exhibited potent trypanocidal efficacy against the bloodstream-form of T. b. brucei (EC₅₀ = 0.73 ± 0.05 µM) and presented low cytotoxicity against two mammalian cell lines with CC₅₀ > 30 µM. Using a murine model of acute infection, oral administration with H1402 demonstrated a complete clearance of T. b. brucei and all the infected mice were cured when they were treated twice daily for 5 days at a dose of 100 mg/kg. Furthermore, parasites were not detected in mice infected with T. evansi and T. equiperdum (the causative agents of surra and dourine, respectively, in animals) within 30 days following the same regimen with H1402. In addition, H1402 caused severe morphological and ultrastructural destruction to trypanosomes, as well as causing phosphatidylserine externalization, which are suggested to be the most likely cause of cell death. Overall, the present data demonstrated that H1402 could be promising as a rapid, safe and orally active lead compound for the development of new chemotherapeutics for animal trypanosomiasis.

Antibiotic activities of propanolamine containing 1,4-benzoxazin-3-ones against phytopathogenic bacteria

Various 1,4-benzoxazin-3-one derivatives containing propanolamine groups have been shown to exhibit good antibacterial activity against Pseudomonas syringae pv actinidiae (Psa), X. axonopodis pv citri (Xac) and Xanthomonas oryzae pv oryzae (Xoo). 1,4-benzoxazin-3-one 4n showed the best inhibitory effects against Psa, Xac and Xoo, exhibiting in vitro EC₅₀ values of 4.95, 4.71 and 8.50 μg mL⁻¹, respectively. These potencies were superior to the corresponding EC₅₀ values of the commercial antibiotics bismerthiazol (BT, 89.10, and 116.90 μg mL⁻¹) and thiodiazole copper (TC, 127.30, 82.73 and 87.50 μg mL⁻¹). Treatment on the bacterial leaf blight of rice revealed that compound 4n displayed better curative (51%) and protective (48%) activities for reducing rice BLB than either BT (41%, 39%) or TC (43%, 41%). Scanning electron microscopy (SEM) imaging of Xoo that had been treated with 1,4-benzoxazin-3-one 4n (50–100 μg mL⁻¹) revealed that the bacterial cells had experienced extensive cell wall damage, which is the likely cause of its antimicrobial activity and bacterial death.

Various 1,4-benzoxazin-3-one derivatives containing propanolamine groups have been shown to exhibit good antibacterial activity against Pseudomonas syringae pv actinidiae (Psa), X. axonopodis pv citri (Xac) and Xanthomonas oryzae pv oryzae (Xoo).