ABSTRACT
<p><b>OBJECTIVE</b>To study the antiviral constituents in the stems and leaves of Pithecellibium clypearia.</p><p><b>METHOD</b>The constituents of P. clypearia were systematically separated with various chromatographic techniques in combination with antiviral activity monitoring. Their structures were elucidated by physical and chemical properties and spectral data.</p><p><b>RESULT</b>Six compounds were isolated from P. clypearia and were identified as: tricetiflavan (5, 7, 3', 4', 5'-pentahydroxylflavan) (1), myricitrin (myricetin-3-O-alpha-L-rhamnopyranoside) (2), quercitrin (quercetin-3-O-alpha-L-rhamnopyranoside) (3), quereetin (4), methyl gallate (5) and gallic acid (6).</p><p><b>CONCLUSION</b>Compound 1 approximately 5 were obtained from this plant for the first time. Compound 4 was found to show an obvious anti-respiratory syncytial virus (RSV) activity.</p>