Isolation and identification of compounds from Neo-uvaria foetida with the aid of LC-MS/MS based molecular networking and evaluation of their activity against HCoV-229E and SARS-CoV- / S.Yaallini Sukumaran

S.Yaallini , Sukumaran (2024) Isolation and identification of compounds from Neo-uvaria foetida with the aid of LC-MS/MS based molecular networking and evaluation of their activity against HCoV-229E and SARS-CoV- / S.Yaallini Sukumaran. Masters thesis, Universiti Malaya.

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Abstract

A preliminary survey of the ethyl acetate (EtOAc) bark extract of the Malaysian Annonaceaous species, Neo-uvaria foetida exhibited significant antiviral inhibitory activity against the HCoV-229E test (coronavirus model) with an IC50 value of 3.82 μg/mL. Due to the limited studies available on the phytochemical composition of N. foetida, an intensive LC-MS/MS-based dereplication technique coupled with molecular networking (MN) was employed to accelerate the research workflow in identifying known and new active compounds from the EtOAc bark extract. From the MN analysis, a total of 26 known compounds under the classification of labdane diterpenoids, abietane diterpenoid, kaurene diterpenoid, sesquiterpenoids, fatty acids, oxoaporphine alkaloids, amino acid derivatives, amides, carboline alkaloid, cyclic tetrapeptide, styryl-lactones and flavonoids. In addition, 11 compounds were isolated in which seven were known compounds; 17-O-acetylacuminolide 1, acuminolide 2, spiroacuminolide 3, pinocembrin 4, stigmasterol 3-stearate 5 and stigmasterol 3-O-ß-D-glucoside 6 and five new compounds; 8-epi-acuminolide 7, foetidalabdane A 8, 16-foetinorlabdoic acid 9, foetidalactone A 10 and foetidalactone B 11. All the compounds afforded were structurally characterize using various spectroscopic techniques; 1D-NMR (1H-NMR, 13C-NMR, DEPT), 2D-NMR (COSY, HMBC, HSQC, NOESY), FTIR, UV, and LC-MS. HCoV-229E inhibitory evaluation was conducted against all the isolated compounds in which 17-O-acetylacuminolide 1 (2.25 μM), foetidalabdane A 10 (2.16 μM), and foetidalabdane B 11 (2.51 μM) showed the most potent anti-HCoV-229E activity. All the new compounds along with the considerably active ones (1, 2, 3, 7, 8, 9, 10 and 11) were tested for SARS-CoV-2 antiviral assay, in which 8-epi-acuminolide 7 and foetidalabdane A 8 showed moderate inhibitory activity at IC50 values at 63.28 μM and 93.45 Μm respectively. Targeted isolation was performed via MN dereplication technique, resulting in the identification of taxonomically related new compounds which were non-toxic and exhibited antiviral inhibitory activity against the coronaviruses.

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