Terpenoids with anti-influenza activity from the leaves of Euphorbia leucocephala.

Two rearranged terpenoids with a rare 3,4,5-trimethyl-cyclohexa-2,5-dien-1-one moiety, namely leucocephins A (1) and B (2), and a megastigmane, namely leucocephin C (3), as well as three known compounds, hollongdione (4), 3-acetoxy-lup-12,20(29)-diene (5), and ß-amyrin acetate (6) were isolated from the leaves of Euphorbia leucocephala. Their structures and absolute configurations were determined by spectroscopic methods and comparing with literature data. Compounds 4-6 exhibited potent anti-influenza A virus activity comparable to the positive control, betulinic acid.

Polyoxygenated Terpenoids and Polyketides from the Roots of Flueggea virosa and Their Inhibitory Effect against SARS-CoV-2-Induced Inflammation.

Six new polyoxygenated terpenoids, podovirosanes A-F (1-6), and two known polyketides (7 and 8) were isolated from the roots of F. virosa. Their structures, along with absolute configurations, were deduced using spectroscopic analysis as well as computational calculations, including TDDFT calculation of ECD spectra and GIAO NMR calculations combined with DP4+ probability analysis. Compounds 2, 3, 5, and 8 were found to reduce the phosphorylation levels of NF-κB p65 in SARS-CoV-2 pseudovirus-stimulated PMA-differentiated THP-1 cells.