Logeracemin A, an Anti-HIV Daphniphyllum Alkaloid Dimer with a New Carbon Skeleton from Daphniphyllum longeracemosum

Logeracemin
A (1), the first Daphniphyllum alkaloid dimer featuring an unprecedented carbon skeleton with a
unique conjugated trispiro­[4,5] decane backbone, was isolated from Daphniphyllum longeracemosum. Its structure and absolute
configuration were established on the basis of spectroscopic data
and X-ray crystallography. Logeracemin A showed significant anti-HIV
activity with an EC50 of 4.5 ± 0.1 μM and a
selectivity index of 6.2. The structure–activity relationship
of the tested compounds was briefly discussed.