Mexicanolide limonoids from the Madagascan Meliaceae Quivisia papinae

The seeds of Quivisia papinae have yielded five mexicanolide group limonoids, together with two known mexicanolide limonoids and two known triterpenoids. Quivisianolide A 9 possesses a hitherto unreported 9α,11α-epoxide ring, quivisianolide B 10 the corresponding Δ9(11) double bond, and quivisianone 11 is a 17-keto seco-ring D compound.