The structure of codaphniphylline

The chemistry of Daphniphyllum alkaloids

The triterpenoids Daphniphyllum alkaloids share the unique fused hexacyclic ring framework are isolated from the genus Daphniphyllum. These natural products possess comprehensive biological activities and exhibit excellent potential medicinal appliment. This review covers the reported isolation studies and biological activities of Daphniphyllum alkaloids spanning the period from 1966 to the beginning of 2020, In the meantime, the total synthesis of Daphniphyllum alkaloids will be emphatically summarized for supplement over this review series.

Alkaloids from the leaves of Daphniphyllum subverticillatum

Four new alkaloids, 17-hydroxydaphnigraciline (1), subdaphnidine A (2), daphnezomine L methyl ester (3), and 11-hydroxycodaphniphylline (4), along with 24 known analogues, were isolated from the leaves of Daphniphyllum subverticillatum. The structures of 1-4 were elucidated on the basis of spectroscopic methods and from chemical evidence. Daphnilongeridine (5) showed cytotoxicity against several tumor cell lines at IC(50) values in the range 2.4-9.7 microM and against the HMEC human microvascular endothelial cell line with an IC(50) of 2.7 microM.

Alkaloids from the twigs of Daphniphyllum calycinum

Twelve new alkaloids, caldaphnidines G-R (1-12), along with 24 known ones, were isolated from the twigs of Daphniphyllum calycinum. Their structures were elucidated by spectroscopic methods, especially two-dimensional NMR techniques.

Macropodumines A–C: Novel Pentacyclic Alkaloids with an Unusual Skeleton or Zwitterion Moiety fromDaphniphyllum macropodum Miq

Three novel alkaloids, macropodumines A-C (1-3), were isolated from the stem of Daphniphyllum macropodum Miq. Interestingly, the structure of macropodumine A (1) was characterized as having a fused pentacyclic system including an unusual eleven-membered macrolactone ring, whereas macropodumine B (2) contains a rare cyclopentadienyl carbanion, which is stabilized as a zwitterion by an internal iminium cation. The structures of these new metabolites were established on the basis of their detailed spectroscopic analysis. In particular, the unique structure of zwitterion 2 was further confirmed by using single-crystal X-ray diffraction analysis.