New oligomeric neolignans from the leaves of Magnolia officinalis var. biloba

Six new oligomeric neolignans including two trimeric neolignans (1 and 2) and four dimeric neolignans (3-6) were isolated from the leaves of Magnolia officinalis var. biloba. Their structures were determined based on HR-ESIMS and NMR data, as well as electronic circular dichroism (ECD) calculations. Compound 1 is formed from two obovatol moieties directly linked to an aromatic ring of the remaining obovatol moiety, which is an unprecedented type...