Synthesis, evaluation and molecular docking studies of amino acid derived N-glycoconjugates as antibacterial agents

Synthesis, Characterization, and Antibacterial Activity of Biocompatible Aluminium Complexes with N-(2-Hydroxy-5-methyl benzyl)phenylalanine

New antibacterial ligand H3hmbpa-5 (N-(2-hydroxy-5-methyl benzyl)phenylalanine) and its aluminium complexes Al(OPri)(Hhmbpa-5), Al(H2hmbpa-5)(Hhmbpa-5), and Al(H2hmbpa-5)3 were synthesized in excellent yield in a stoichiometric ratio of 1 : 1, 1 : 2, and 1 : 3 (Al(OPri)3 : ligand), based on an idea of biological activity of the phenylalanine and its substituted N-aryl derivatives and Al (III) derivatives. The complexes were characterized by FT-IR, 1H, 13C NMR, UV-visible, and elemental analysis. An inhibition zone test was used for the evaluation of the antibacterial test. The results show that the ligand and aluminium complexes have superior antibacterial activity against Pseudomonas aeruginosa (MTCC-424), Streptococcus aureus (MTCC-103), Klebsiella pneumoniae (MTCC-3389), and Klebsiella pneumoniae (MTCC-109).

Stereoselective synthesis of glycosyl azides from anomeric hydroxides via protecting group manipulations

Herein, we report the direct conversion of anomeric hydroxides to glycosyl azides in one step using diphenylphosphoryl azide. Protecting group manipulations on the hexose sugars have enabled the stereoselective synthesis of either the α-glycosyl azides or the β-anomeric azides in moderate to very good yields. The reaction has also been successfully used to enable the synthesis of β-2-deoxy-2-aminoglucosyl azides.

Amino acids/peptides conjugated heterocycles: A tool for the recent development of novel therapeutic agents

Amino acids/peptide conjugated heterocycles represent an important class of therapeutical agents. Biologically active heterocycles are conjugated with amino acids or peptides to increase the drug resistance. Furthermore, the amino acid/peptide based drugs have low toxicity, ample bioavailability and permeability, modest potency and good metabolic and pharmacokinetic properties. Synthetic amino acid/peptides based heterocyclic conjugates constitute a promising choice for the development of new, less toxic and safer conventional pharmaceutical drugs in the near future. In this review, we discuss and highlight the recent findings of the structural features that encourage biological applications of amino acid/peptides based conjugates.

Synthesis and molecular docking studies of xanthone attached amino acids as potential antimicrobial and anti-inflammatory agents

A series of novel xanthone conjugated amino acids were synthesised and characterised by analytical and spectroscopic methods. All the synthesized analogues (2-23) were screened for their in vitro antimicrobial and anti-inflammatory activities. Compounds 7, 8, 9, 12, 18, 19, 20, 21 and 23 showed excellent antimicrobial activities compared to antibacterial and antifungal reference drugs gentamicin and bavistin, respectively. Compounds 7-12 and 18-23 showed good anti-inflammatory activity compared to a standard drug, indomethacin. The preliminary structure-activity relationship revealed that tryptophan, tyrosine, phenylalanine, proline and cysteine conjugated compounds showed excellent antimicrobial and anti-inflammatory activities. This may be explained by the contribution of aromaticity and hydrophobicity of amino acids. Molecular docking studies were performed for all the synthesised compounds, among which compounds 20, 21 and 23 showed the highest docking scores for antimicrobial activity while compounds 9, 20 and 22 showed the highest docking scores for anti-inflammatory activity. Different amino acids conjugated xanthone derivatives were synthesized and evaluated for their in vitro biological activities. The conjugation was found to play a major role in improving the biological activities of those compounds.