Two new iridoid glycosides (1 and 2), together with the known compounds barlerin (3) and verbascoside (4), were isolated from Barleria prionitis. The new iridoid glycosides were determined to be 6-O-trans-p-coumaroyl-8-O-acetylshanzhiside methyl ester (1) and its cis isomer (2) by using spectroscopic, especially 2D NMR, data. A 3:1 mixture of 1 and 2 was shown to have potent in vitro activity against respiratory syncytial virus (EC50 2.46 microgram/mL, IC50 42.2 microgram/mL).

Three new phenylpropanoid glycosides, named luteoside A (3), luteoside B (4), and luteoside C (5), were isolated together with the known compounds verbascoside (1) and isoverbascoside (2) from the roots of the medicinal plant Markhamia lutea. The structures of the new compounds were determined to be 1-O-(3, 4-dihydroxyphenyl)ethyl beta-D-apiofuranosyl(1-->2)-alpha-l-rhamnopyranosyl(1-->3)-4-O- caffeo yl-6-acetyl-beta-d-glucopyranoside, 1-O-(3,4-dihydroxyphenyl)ethyl beta-d-apiofuranosyl(1-->2)-alpha-l-rhamnopyranosyl(1-->3)-6-O- caffeo yl-beta-d-glucopyranoside, and 1-O-(3,4-dihydroxyphenyl)ethyl beta-D-apiofuranosyl(1-->2)-alpha-l-rhamnopyranosyl(1-->3)-6-O- ferulo yl-beta-d-glucopyranoside, respectively, on the basis of chemical and spectroscopic data. All five phenylpropanoid glycosides exhibited potent in vitro activity against respiratory syncytial virus.

Two new lignans, rhinacanthin E (1) and rhinacanthin F (2), were isolated from the aerial parts of the plant Rhinacanthus nasutus. Their structures were established by detailed spectroscopic analysis. These compounds show significant antiviral activity against influenza virus type A.