Isolation, characterization, crystal structure, free radical scavenging- and computational studies of 9-[-4(propan-2-yl)pheny]-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione from Garcinia kola seeds

摘要

A new crystallographic form of a pure xanthenedione derivative (11'), C22H24O3, was isolated from the hexane extract of the seeds of Garcinia kola. The structure of the compound was determined on the basis of FTIR and NMR spectroscopy and confirmed by single-crystal X-ray diffraction analysis. The compound crystallized as C22H24O3 H2O H3O+ Cl-, as the result of the extraction process, adopts monoclinic, space group P21/n (no. 14) and is stabilized by OW-H center dot center dot center dot OW, OW-H center dot center dot center dot Cl, C-H center dot center dot center dot OW, C-H center dot center dot center dot Cl intramolecular hydrogen bonds and weak OW-H center dot center dot center dot O, C-H center dot center dot center dot O, intermolecular interactions forming a 3-D supramolecular structure. The molecular property of the pure xanthene derivative, C22H24O3, has also been investigated using the density functional theory (DFT) method. The calculated IR, H-1 and C-13 data were found to be in good agreement with experimental values. The compound C22H24O3 showed weak DPPH radical scavenging activity with IC50 value of 2.37 +/- 0.08 mg/ml. (C) 2017 Elsevier B.V. All rights reserved.