Crystal structure of bergapten: a photomutagenic and photobiologically active furanocoumarin

Abstract

The title compound, C12H8O4, is a furanocoumarin [systematic name: 4-methoxy-7H-furo[3,2-g]chromen-7-one], which was isolated from the Indian herb T. stictocarpum. The molecule is almost planar with an r.m.s. deviation of 0.024 Å for the hetero atoms of the fused-ring system. In the crystal, molecules are linked by C—H...O hydrogen bonds, forming a three-dimensional framework. There are offset π–π interactions present involving the coumarin moieties stacking along the a-axis direction [shortest inter-centroid distance = 3.717 (3) Å].

Keywords

• crystal structure
• bergapten
• T. stictocarpum
• psoralen
• furanocoumarin
• photobiological activity
• C—H...O hydrogen bonds
• π–π interactions