Background and purpose: The preponderance of microbial infections remains a global challenge. In the present study, synthesis of novel cysteine-based antimicrobial agents and their biological evaluation is reported. Experimental approach: The reaction of p -toluenesulphonyl chloride with cysteine afforded 2-{[(4-methylphenyl)sulphonyl]amino}-3-sulphanylpropanoic acid (3) which was acetylated based on Lumiere-Barbier method using acetic anhydride. The ammonolysis of the acetylated compound (4) gave the carboxamide derivative ( 5 ) which reacted with aniline, aminopyridine and diaminopyrimidine via nickel catalyzed Buchwald-Hartwig amidation reaction to afford compounds 6a, 6b, and 6c , respectively. The compounds were characterized using FTIR, 1 H-NMR, 13 C-NMR, and elemental analysis. The in vitro antimicrobial activities were determined. Their physicochemical properties were generated in silico and the molecular docking studied bacterial and fungal infections. Findings/Results: Compounds 4, 6b, and 6c exhibited excellent in vitro antibacterial activities while compound 4 had the best antifungal activities. From the in silico antimicrobial results, compound 3 had a better binding affinity (-10.95 kcal/mol) than penicillin (-10.89 kcal/mol) while compounds 3 and 4 had binding affinities (-10.07 and -10.62kcal/mol) comparable to ketoconazole (-10.85 kcal/mol). Conclusion and implication: All the synthesized compounds exhibited significant antibacterial and antifungal activities and were confirmed to be potential antimicrobial agents.

The experiment was conducted to ascertain the level of genetic diversity in sweet potato accessions using microsatellites. Thirty sweet potato accessions obtained from the International Potato Center (CIP), Kumasi, Ghana, Mozambique, and local germplasm of the National Root Crops Research Institute (NRCRI), Umudike, Abia State, Nigeria, as well as sweet potato vines from local farmers' fields in Jos, Plateau State, and Bauchi State, Nigeria, were analyzed for genetic diversity using five microsatellite markers. The results showed that the polymorphic SSR loci revealed diverse relationship among the sweet potato cultivars, which was grouped into four major clusters by unweighted pair group method analysis (UPGMA) method. Cluster analysis showed a Jaccard co-efficient ranging from 0.0 to 3.0 indicating high genetic diversity. The primers detected a total of 18 alleles and the number of alleles per locus was 4 for IBR-19, IBR-286, IBR-297 and 3 for IBR-16 and IBR-242 with an average of 3.67 alleles per locus. The polymorphic information content (PIC) of the markers varied from 0.35 to 0.72 with an average of 0.497. Marker IBR-19 revealed the highest PIC of 0.72, while marker IBR-297 had the lowest PIC of 0.35. Observed heterozygosity ranged from 0.32 to 0.89 with a mean of 0.675 across the five SSR loci. The results from the Analysis of molecular variance (AMOVA) which was used to quantify the diversity level and genetic relationship among the thirty sweet potato accessions indicated that a high diversity was mostly distributed within the populations for sweet potato accessions (75.12%) and (15.67%) among the populations.