Squadinorlignoside: A Novel 7,9′‐Dinorlignan from the Stems of Annona squamosa

Two new polar lignans, i.e., squadinorlignoside (= 4‐[(1E)‐1‐(hydroxymethyl)‐3‐(4‐hydroxyphenyl)prop‐1‐en‐1‐yl]phenyl β‐D‐glucopyranoside; 1) and (6R,7R,8S)‐7a‐[(β‐D‐glucopyranosyl)oxy]‐1‐methoxyisolariciresinol (2) were isolated from the stems of Annona squamosa, together with eight known lignans and five known neolignans (compounds 3–15; Fig. 1). All of these constituents are reported for the first time from the genus Annona. The structures, absolute configurations, and selected conformational aspects of the new compounds were elucidated spectroscopically. Compound 1 is the first example of a 7,9′‐dinorlignan natural product.