Page 108 - Pharma News Letter - Vol2 Issue 1

Chapter V

Tetraenone A: A New Β-Ionone Derivative From Tetraena
Aegyptia

Metabolites. 2023; 13(12): 1202.
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Ahmed Ashour, Asmaa E. Sherif, Selwan M El-Sayed, Ji-Young Kim, Dae Sik
Jang, Abtin Anvari, Abdelbasset A. Farahat, Sabrin R. M. Ibrahim, Gamal A.
Mohamed, Bayan E. Ainousah, Raghad F. Aljohani, Razan R. Al-Hejaili, Rahaf

H. Khoja, Ahmed H. E. Hassan, Ahmed A. Zaki

Abstract

In this study, the chemical investigation of Tetraena aegyptia (Zygophyllaceae) led to the
identification of a new megastigmene derivative, tetraenone A ((2S, 5R, 6R, 7E)-2-hydroxy-
5,6-dihydro-β-ionone) (1), along with (3S, 5R, 6S, 7E)-3-hydroxy-5,6-epoxy-5,6-dihydro-β-
ionone- (2), 3,4-dihydroxy-cinnamyl alcohol-4-glucoside (3), 3β,19α-dihydroxy-ursan-28-oic
acid (4), quinovic acid (5), p-coumaric acid (6), and ferulic acid (7), for the first time. The
chemical structures of 1–7 were confirmed by analysis of their 1D and 2D NMR and HRESIMS
spectra and by their comparison with the relevant literature. The absolute configurations of 1
and 2 were assigned based on NOESY interactions and ECD spectra. Conformational analysis
showed that 1 existed exclusively in one of the two theoretically possible chair conformers with
a predominant s-trans configuration for the 3-oxobut-1-en-1-yl group with the ring, while the
half-chair conformer had a pseudo-axial hydroxy group that was predominant over the other
half-chair conformation. Boat conformations were not among the most stable conformations,
and the s-trans isomerism was in favor of s-cis configuration. In silico investigation revealed
that 1 and 2 had more favorable binding interactions with Mpro rather than with TMPRSS2.
Accordingly, molecular dynamic simulations were performed on the complexes of compounds
1 and 2 with Mpro to explore the stability of their interaction with the target protein structure.
Compounds 1 and 2 might offer a possible starting point for developing covalent inhibitors of
Mpro of SARS-CoV-2

Reference:

https://doi.org/10.3390/metabo13121202

108 Faculty of Pharmacy Newsletter