ISOLATION AND IN SILICO ANTIVIRAL POTENTIAL OF CARYOPHYLLENE AND EUCALYPTOL AGAINST SARS-COV-2 AS ANTI-COVID-19 DRUG CANDIDATE

• Main Author: Setiawansyah, Arif
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/66234
• Institution: Institut Teknologi Bandung

Background and purpose: COVID-19 is a respiratory disease caused by infection of SARS-COV-2. Even though the COVID-19 vaccines are available, vaccinated individuals are still infected by the SARS-CoV-2. Additionally, the current therapy for COVID-19 uses nucleoside analog and protease inhibitor that is generally used in HIV treatment. However, as the use increases, these drugs provide serious side effects. Therefore, discovering new anti-COVID-19 that is more effective with minimum side effects needs to be undertaken. Caryophyllene and eucalyptol are natural product compounds that have been studied and reported to provide broad pharmacological activity. This research is an effort to isolate and evaluate the anti- COVID-19 potential of caryophyllene and eucalyptol by understanding the molecular interactions with various proteins that play a role in the SARS-CoV-2 infection cycle. Methods: Caryophyllene isolation was carried out using silver nitrate-impregnated silica gel column chromatography with the n-hexane-ethyl acetate (8:2) as the mobile phase. The isolation of eucalyptol was done using two steps of intermittent column chromatography using n-hexane-ethyl acetate (8:2) as the first mobile phase system and n-hexane-ethyl acetate (9.5:0.5) as the second mobile phase system. The evaluation of the anti-COVID-19 potential of caryophyllene and eucalyptol was implemented using a molecular docking study against ACE-2, TMPRSS2, SARS-CoV-2 Mpro, SARS-CoV-2 Plpro, dan SARS- CoV-2 macrodomain. The molecular docking study was done using Autodock 4.2, assisted by Autodock Tools. The protein preparation and result visualization were carried out using Biovia Discovery Studio. Results: Isolation of caryophyllene using column chromatography with n-hexane-acetone (7:3) as the mobile phase provides caryophyllene with a purity of 79%. Purification of caryophyllene using silver nitrate-impregnated silica gel column chromatography can separate the isomer (humulene and caryophyllene oxide) and gives caryophyllene a purity of 98%. On the other hand, the isolation of eucalyptol using two steps of intermittent column chromatography provide eucalyptol with a purity of 94%. The molecular docking study revealed that caryophyllene possesses an excellent affinity to SARS- CoV-2 papain-like protease with a free binding energy and inhibition constant of - 7.22 kcal/mol and 5.07 µM, respectively. Meanwhile, eucalyptol has a poor affinity for target proteins. Conclusion: Caryophyllene can be separated and purified from its isomers using the silver nitrate-impregnated silica gel column chromatography technique obtaining high purity of caryophyllene. The isolation of eucalyptol using two steps of intermittent column chromatography provides high purity of eucalyptol. Caryophyllene is potentially developed as SARS-CoV-2 papain-like protease inhibitor according to the prediction of molecular interaction by molecular docking study.