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 (<b>2-23</b>) were screened for their <i>in vitro</i> antimicrobial and anti-inflammatory activities. Compounds <b>7</b>, <b>8</b>, <b>9</b>, <b>12</b>, <b>18</b>, <b>19</b>, <b>20</b>, <b>21</b> and <b>23</b> showed excellent antimicrobial activities compared to antibacterial and antifungal reference drugs gentamicin and bavistin, respectively. Compounds <b>7-12</b> and <b>18-23</b> 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 <b>20</b>, <b>21</b> and <b>23</b> showed the highest docking scores for antimicrobial activity while compounds <b>9</b>, <b>20</b> and <b>22</b> showed the highest docking scores for anti-inflammatory activity. Different amino acids conjugated xanthone derivatives were synthesized and evaluated for their <i>in vitro</i> biological activities. The conjugation was found to play a major role in improving the biological activities of those compounds.