Vibrational Spectroscopy-Based Chemometrics Analysis of Clinacanthus nutans Extracts after Postharvest Processing and Extract Effects on Cardiac C-Kit Cells

Table 2

List of functional group differences reported in C. nutans aqueous and ethanol extracts along with their tentative identification from parameter 1.

Test sample wavenumber (cm^−1)	Reference wavenumber (cm^−1)	Functional group assignment	Tentative identification
Aqueous extract
3229	3570–3200	O-H, H-bonded, hydroxy group	Polyhydroxy compound
2928	2935–2915	as CH2	Lipids, protein
1604	1615–1580	C=C-C, aromatic ring	Aromatic compound
1514	1555–1485	NO2, nitrogen-oxy group	Aromatic nitro compound
1402	1410–1310	O-H, alcoholic group	Phenol or tertiary alcohol
1045	∼1050	C-O, alcoholic group	Primary alcohol
934, 903, 871	995–850	P-O-C	Aromatic phosphates
836	840–815	Nitrate ions	Nitrate compound
777	800–700	C-Cl	Aliphatic chloro compound
651	660–630	CH3-S	Thioethers
Absolute ethanol extract
3273	3570–3200	O-H, H-bonded, hydroxy group	Polyhydroxy compound
2921	2935–2915	asymmetric CH2	Lipids, protein
2852	2865–2845	symmetric CH2	Lipids, protein
1726	1740–1725	C=O, carbonyl group	Aldehyde compound
1625	1680–1620	C=C	Alkenyl
1403, 1370	1410–1310	O-H, alcoholic group	Phenol or tertiary alcohol
1246	1270–1230	ф-O-H, aryl-O stretch	Aromatic ethers
1050	∼1050	C-O, alcoholic group	Primary alcohol
932, 902, 851	995–850	P-O-C	Aromatic phosphates
837	840–815	Nitrate ions	Nitrate compound
777	800–700	C-Cl	Aliphatic chloro compound

note:  = stretching;  = bending.