Table 2.

Chemical shifts of P-coumaric acid in H¹ NMR spectra, δ (ppm).

Proton number	Chemical shift (δ ppm)
	Theoretical [29, 30]	Experimental (isolated compound)
1	12.13	—
2	8.10	7.341
3	6.97	6.689
4	3.56	3.219
5	7.06	6.725
6	7.65	7.364
7	6.44	6.199
8	8.15	7.521