Total assignment of the ¹H and ¹³C NMR spectra of piperovatine

Abstract

Total and unambiguous assignment of the1H NMR spectrum of piperovatine [6‒(4‒methoxyphenyl)‒N‒(2‒methylpropyl)‒2,4‒hexadienamide] was carried out using conventional 1D NMR methods and spectral spin–spin simulation. Based on these data, the complete assignment of the13C NMR chemical shift values was made by a13C/1H chemical shift correlation diagram and conventional considerations for the quaternary carbon atom.

1H and 13C NMR assignments of dihydropipataline, the main of four long‐chain 1‐(3,4‐methylenedioxyphenyl)‐alkanes from Piper darienence D.C.

“…These phytochemical investigations led to the isolation of a number of physiologically active compounds [1]. In a previous paper we reported the isolation of piperovatine from the ethanolic extract of the roots of Piper darienence D.C. [2]. We now report the isolation, from the petroleum ether extract, and the structure determination of the four new natural products: dihydrojuvadecene (1) [1-(3,4methylenedioxyphenyl)-decane], 1-(3,4-methylenedioxyphenyl)-undecane (2), dihydropipataline (3) [1-(3,4-methylenedioxyphenyl)-dodecane] and 1-(3,4-methylenedioxyphenyl)-tetradecane (4).…”

“…In a previous paper we reported the isolation of piperovatine from the ethanolic extract of the roots of Piper darienence D.C. [2]. We now report the isolation, from the petroleum ether extract, and the structure determination of the four new natural products: dihydrojuvadecene (1) [1-(3,4methylenedioxyphenyl)-decane], 1-(3,4-methylenedioxyphenyl)-undecane (2), dihydropipataline (3) [1-(3,4-methylenedioxyphenyl)-dodecane] and 1-(3,4-methylenedioxyphenyl)-tetradecane (4). Although compounds 1-3 have been obtained by catalytic hydrogenation of the unsaturated natural products with C 10 (juvadecene) [3], C 11 [4] and C 12 (pipataline) [5] alkenyl side chains, this is the first time that the saturated compounds are isolated from nature.…”