Structural elucidation and virucidal properties of resveratrol octamers isolated from Vatica albiramis.

Two highly condensed resveratrol octamers, vateriaphenol A and a newly discovered analogue, vaticanol Q, were isolated from the stem of Vatica albiramis. Vaticanol Q represents the first naturally occurring resveratrol octamer bearing a rare ortho-quinone moiety, as unambiguously established through comprehensive spectroscopic analyses, including low-temperature NMR and circular dichroism. The absolute configuration of vaticanol Q was deduced based on biosynthetic considerations and chiroptical data, further supported by micro-electron diffraction and synchrotron X-ray crystallography of its biosynthetic precursor, (-)-hopeaphenol. Vateriaphenol A exhibited potent virucidal activities against feline calicivirus, influenza A virus, and mumps virus, highlighting the potential of highly condensed stilbenoids as promising antiviral leads.