5-Methoxypropacin, a novel coumarinolignoid from Protium unifoliolatum

Abstract

The novel coumarinolignoid 5-methoxypropacin (1) was isolated from the ethereal extract of the wood of the Amazonian species Protium unifoliolatum. Its structure was elucidated by spectroscopic methods as IR, 1D and 2D ¹H, ¹³C-NMR and mass spectrometry. The regioisomer and the position of coumarin and arylpropanoid coupling were determined by long-distance C–H correlation (HMBC) and NOE experiments. Scopoletin and β-sitosterol were also isolated and identified by the same physical methods.

Keywords:

• Protium unifoliolatum
• Burseraceae
• Coumarolignoid
• 5-Methoxypropacin