14-Noreudesmanes and a phenylpropane heterodimer from sea buckthorn berry inhibit Herpes simplex type 2 virus replication

Abstract Two new 14-noreudesmane sesquiterpenes, one new phenylpropane heterodimer, caulilexin C, and uvaol were isolated from the 70% MeOH extract of the fruit peel of Elaeagnus rhamnoides . The structures of the compounds were elucidated by HRESIMS and advanced NMR methods. The absolute configuration of ( R )-6,9-dihydroxy-1-oxo-14-noreudesm-5,7,9-triene was determined by the TDDFT-ECD method. The new compounds, together with structurally similar naphthalenes (musizin, musizin-8- O -glucoside, torachrysone-8- O -glucoside) and 1,4-naphthoquinone (2-methylstipandrone), isolated previously from Rumex aquaticus , were investigated for their antiviral activity against Herpes simplex virus type 2 (HSV-2) using two different methods. Applying the traditional virus yield reduction test, ( R )-6,9-dihydroxy-1-oxo-14-noreudesm-5,7,9-triene, 1-[3-methoxy-4-(2-methoxy-4-(1 E )-propenyl-phenoxy)-phenyl]-propane-1,2-diol, and musizin caused a 2.00 log 10 , 3.49 log 10 , and 2.33 log 10 reduction of HSV-2 yield, respectively, at a concentration of 12.5 μM. 2-Hydroxy-1-methoxy-6,9-dioxo-14-noreudesm-1,3,5(10),7-tetraene exhibited an antiviral effect at concentration of 50 μM only. Similar results were obtained when the qPCR method was used to test the antiviral activity of the compounds.