Triterpenoids from the leaves of Camellia chrysantha growing in Quang Ninh (Vietnam) and their activities on main protease (Mpro) and ACE2

Abstract Camellia chrysantha (Hu) Tuyama (Theaceae) is used as a high‐class herbal tea called “yellow camellia”, “golden camellia”, “camellia queen”. Phytochemical investigation of the leaves of C. chrysantha led to the isolation of four triterpenoids β‐amyrin hexanoate ( 1 ), friedelin ( 2 ), friedelanol ( 3 ), β‐amyrin ( 4 ) together with one steroid chondrillasterol ( 5 ). Their chemical structures were established based on analysis of their spectroscopic data including 1D, 2D‐NMR, MS data and comparing with literatures. It is the first time β ‐amyrin hexanoate and chondrillasterol were isolated from the genus Camellia , and similarly for friedelin, friedelanol and β‐amyrin from C. chrysatha . Beta‐amyrin hexanoate which presents a high amount in the leave of C. chrysantha , exhibited the enzyme inhibitory activity against 3CL pro /M pro but non‐toxicity toward normal Vero cells.