Nutraceutical Potential of Five Mexican Brown Seaweeds

Table 5

Signals assigned in the ATR/FT-IR second-derivative spectrum of the hydroethanolic extracts from different brown seaweeds and fucoidan, laminarin, and alginate standards.

	Functional groups
Seaweed/absorption frequency (cm^−1)	O-H stretching vibrations; N-H stretching vibrations (3371–3700 cm^−1)^1,4,6	C-H stretching vibrations; N-H stretching vibrations (2941–2944 cm^−1)^1,2,4,7	Carbonyl group stretching (1616–1732 cm^−1)^1,5	Asymmetrical bending vibration of CH3 and OH bending (1369–1420 cm^−1)^1,3,4,7	Stretching vibrations of sulfoxides (S=O)-CN stretching (1034–1075 cm^−1)^1,2,4	Sulfate groups at the axial C4 position of; C-O-S symmetrical stretching vibrations (822–849 cm^−1)^1,5
Silvetia compressa	3317.11		1603.2	1416.68	1040.32	893.22/828.88
Cystoseira osmundacea	3324.58	2924.93	1627.84	1416.73	1083.6/1041.00	893.38/824.84
Ecklona arborea	3326.23	2892.87	1635.92		1070/1039.85	893.34
Pterygophora californica	3317.17/3695.33		1617.10		1039.84	892.57
Egregia menziessi	3239.7/3662.76	2988.65/2972.72/2901.72		1406.59/1394.17	1075.94/1066.32; 1056.99/1028.03	892.97/879.27/869.42
Fucoidan	3413.56	2989.01/2935.16/	1634.58		1079.42	827.51
Laminarin	3318.46/3710.74	2924.67			1071.75	892.62/838.90
Sodium alginate				1403.89	1085	877.79

¹Lim et al. [73]; ²Park et al. [74]; ³Yee et al. [75]; ⁴Kannan [76]; ⁵Shekhar et al. [77]; ⁶Guo and Zhang [78]; ⁷D’Souza et al. [79].