Episesartemin A

Phytochemistry. 2017 Mar;135:181-190.

Sensory active piperine analogues from Macropiper excelsum and their effects on intestinal nutrient uptake in Caco-2 cells.[Pubmed: 28065397]

The phytochemical profile of Macropiper excelsum (G.Forst.) Miq. subsp. excelsum (Piperaceae), a shrub which is widespread in New Zealand, was investigated by LC-MS-guided isolation and characterization via HR-ESI-TOF-MS and NMR spectroscopy.
METHODS AND RESULTS:
The isolated compounds were sensorily evaluated to identify their contribution to the overall taste of the crude extract with sweet, bitter, herbal and trigeminal impressions. Besides the known non-volatile Macropiper compounds, the lignans (+)-diayangambin and (+)-excelsin, four further excelsin isomers, (+)-diasesartemin, (+)-sesartemin, (+)-Episesartemin A and episesartemin B were newly characterized. Moreover, piperine and a number of piperine analogues as well as trans-pellitorine and two homologues, kalecide and (2E,4E)-tetradecadienoic acid N-isobutyl amide were identified in M. excelsum, some of them for the first time.

Tetrahedron, 1980, 36(24):3551-3558.

New unsymmetrically substituted tetrahydrofurofuran lignans from artemisia absinthium: Assignment of the relative stereochemistry by lanthanide induced chemical shifts.[Reference: WebLink]

The isolation of thirteen tetrahydrofurofuran lignans from the roots of A. absinthium and six closely related species is reported.
METHODS AND RESULTS:
A new group of four lignans, all stereoisomers of 1- [(3,4-methylenedioxy-5-methoxy) phenyl]-4-(3,4,5-trimethoxyphenyl)-tetrahydro-1H,3H-furo[3,4-c]furan, was found. The compounds, named sesartemin, Episesartemin A, episesartemin B, and diasesartemin, were characterized by 1H NMR (including lanthanide induced shifts), UV, IR and MS.
CONCLUSIONS:
A fifth new lignan of the sesamin type (the eq/eq isomer of fargesin) could be identified as a minor constituent. The relative configurations of two further products (fargesin and epiashantin) could be confirmed by the lanthanide induced shift technique.