Monocyclic phenolic acids; hydroxy- and polyhydroxybenzoic acids: occurrence and recent bioactivity studies

Abstract

Among the wide diversity of naturally occurring phenolic acids, at least 30 hydroxy- and polyhydroxybenzoic acids have been reported in the last 10 years to have biological activities. The chemical structures, natural occurrence throughout the plant, algal, bacterial, fungal and animal kingdoms, and recently described bioactivities of these phenolic and polyphenolic acids are reviewed to illustrate their wide distribution, biological and ecological importance, and potential as new leads for the development of pharmaceutical and agricultural products to improve human health and nutrition.

Figure 1

Flavonoids and phenolic acids.

Figure 2

3-Hydroxybenzoic acid (1) and 4-Hydroxybenzoic acid (2).

Figure 3

Pyrocatechuic acid (3), Gentisic acid (4), and α-Resorcylic acid (5).

Figure 4

Salicylic acid (6), 6-Methylsalicylic acid (7), β-Resorcylic acid (8), and Orsellinic acid (9).

Figure 5

Protocatechuic acid (10), Vanillic acid (11), and Isovanillic acid (12).

Figure 6

Gallic acid (13), Syringic acid (14), and Digallic acid (15).

Figure 7

Lunularic acid (16) and Hydrangeic acid (17).

Figure 8

Pinosylvic acid (18), 4-O-Methylpinosylvic acid (19), and Gaylussacin (20).

Figure 9

Anacardic acid (21) and Ginkgolic acid (22).

Figure 10

Turgorin A (23).

Figure 11

Merulinic acid A (24).

Figure 12

Platencin (25) and Platensimycin (26).

Figure 13

Lasalocid (27).

Figure 14

Canabidiolic acid (28).

Figure 15

Cajaninstilbene acid (29) and Isocajaninstilbene acid (30).