In the present study bioactive methanolic extract along with
chloroform and
hexane extracts obtained from shade dried leaves of the Himalayan aromatic medicinal plant Nepeta leucophylla Benth. Were screened for the presence of
triterpenoids, especially
oleanolic acid (OA). Total three compounds
oleanolic acid,
squalene and linoleic methyl
ester were isolated from
methanol extract. The percentage yield of OA was 0.11%. Out of these three, OA is more bioactive and was further subjected to derivatization using greener Ultrasonication method. Total three derivatives (3-Acetyl
oleanolic acid, 3-Phthaloyl
oleanolic acid and 3-Oxo
oleanolic acid) were synthesized with 91.16%, 93.98%, and 83.6% respectively. Further, the
antioxidant potential of OA and its derivatives were evaluated using DPPH assay which suggested that the 3-Phthaloyl
oleanolic acid exhibits highest
antioxidant potential with 40.83 ± 1.14% inhibition. OA and its derivatives were screened in-silico antibacterial potential against three bacterial pathogens (E-coli, M.
tuberculosis and S. aureus) and
antiviral potential against Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2), Human immunodeficiency virus (HIV) and H1N1 influenza virus. The in-silico results suggested that 3-phthaloyl
oleanolic acid showed best H-bonding with FtsA (Staphylococcus aureus), enoyl acyl
reductase (E. coli) and
arabinosyl transferase (Mycobactrium
tuberculosis). 3-Phthaloyl
oleanolic acid also showed best H-Bond interactions with the target
proteins hemagglutinin (H1N1) and
reverse transcriptase (HIV), whereas,
oleanolic acid exhibited the best interactions with
RNA dependent RNA polymerase (SARS-CoV-2) and thus could be considered for further in vitro studies.