Carbon‐13 NMR spectra of Piper alkamides and related compounds

Abstract

13C NMR spectra of Piper alkamides and related compounds have been completely assigned on the basis of splitting patterns in the coupled spectra, application of additivity relationships and internal comparison of chemical shifts.

New Insecticidal Amides from Petroleum Ether Extract of Dried Piper nigrum L. Whole Fruits

“…[1][2][3][4][5] In search of plant-based potent insecticides, [6][7][8][9][10] current investigations on the petroleum ether extract of the dried whole fruits of P. nigrum have resulted in the isolation of two new, seven hitherto unreported from this plant and eleven known compounds. Compounds isolated from petroleum ether extract included stigmastanol (3), 11) bsitosterol (4) 12) stigmasterol (5), 12) stigmastanol 3-O-b-D-glucopyranoside (6), 11,13) b-sitosterol 3-O-b-D-glucopyranoside (7), [13][14][15][16] [(2E,4E)-octadienoyl]-N-isobutylamide (8), 17) sarmentine (9), 18) [(2E,4E)-dodecadienoyl]-N-isobutylamide (10), 19) [(2E,4E)-dodecadienoyl]pyrrolidine (11) [4], hexadecanoic ethyl ester (12), 20) octadecanoic acid (13), 21) pellitorine (14) [18], hexadecanoylpyrrolidine (15), 22) [(2E)-octadecanoyl]pyrrolidine (16), 22) 1-[(2E,4E,12Z)-octadecatrienoyl]-N-isobutylamide (17), 23) piptaline (18), 24) 1-[7-(3,4-methylenedioxyphenyl)-(2E,4E)-heptadienoyl]-N-isobutylamide (19), 25) 1-(3,4-methylenedioxyphenyl)-(1E)-tetradecene (20), 18) using different chromatographic techniques. The toxicities of 8-11, 14-17 and 19 were determined against fourth instar larvae of Aedes aegypti by WHO method 26) and were found ...…”

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

“…In this work we also describe the 1 H and 13 C NMR assignments of the main compound 3 based on 1D and 2D NMR techniques together with spectral 13 C NMR simulation and ab initio DFT-GIAO (gauge including atomic orbitals [7]) NMR calculations at the BPW91/6-311G(d,p) and B3LYP/6-311++G(2d,p) levels on an ab initio DFT optimized molecular geometry. Although the 13 C NMR spectral study of 3 has been described [8], the signal assignment was based only on additivity relationships.…”