13C NMR spectra of some coumarins of Haplophyllum obtusifolium

Coumaris ofHaplophyllum obtusifolium Ledeb. — obtusinin, capensin, and fraxetin 7-O--D-glucopyranoside — have been investigated by¹³C NMR spectroscopy. Several distinctive features of their NMR spectra have been observed. A complete assignment of the¹³C NMR spectra of these coumarins has been made and their structures have been confirmed.Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 796–799, November–December, 1987.