√ Anti-Cancer: Protocatechuic acid is used as a raw material to synthesize the anticancer drug Erlotinib through various reactions such as etherification and nitration.

√ Antibacterial: Protocatechuic acid has inhibitory effects on various bacteria, including Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus agalactiae, Haemophilus influenzae, Pseudomonas aeruginosa, Escherichia coli, and Proteus vulgaris. In mice, it reduces the mortality rate caused by Staphylococcus aureus infection by 30%.

√ Expectorant and Bronchodilator: Protocatechuic acid has shown significant bronchodilatory effects in a guinea pig histamine aerosol-induced asthma test. It is clinically used to treat chronic bronchitis. In mice administered 4.68 mg of Protocatechuic acid by gastric lavage, it exhibits expectorant effects.

√ Detoxification: Protocatechuic acid has a protective effect against cobra venom poisoning in mice. It also has a significant inhibitory effect on "formalin-induced foot swelling" in mice, which is stronger than salicylic acid and close to acetylsalicylic acid.

√Adding Protocatechuic acid to animal feed formulas enhances the antioxidant and anti-inflammatory abilities of weaning piglets, alleviating oxidative damage caused by weaning and effectively reducing inflammatory responses and improving anemia, thus lowering piglet mortality. Protocatechuic acid can substitute antibiotics to alleviate stress-induced ailments in weaning piglets.

√The use of a feed additive containing 0.75-3% Protocatechuic acid improves boar's spermatogenic ability, enhances sperm quality, and extends their reproductive lifespan.

√When used in the feed of crucian carp, in conjunction with Puerarin and combined with vitamins, minerals, and heat-resistant probiotics, Protocatechuic acid improves lipid metabolism and has a significant anti-inflammatory and detoxifying effect on hepatitis and enteritis, reinforcing the overall immune system and metabolic balance of crucian carp. This results in higher weight gain, thicker dorsal muscle, and better coloration.

√Properly dosed Protocatechuic acid in feed significantly improves the growth performance and meat quality of yellow feather broilers, enhances antioxidant capacity, improves intestinal immune function, and tightens the gut connection. It can also promote gut health by improving the gut microbiome structure, leading to better post-molt layer performance and egg quality.

√The use of Protocatechuic acid in feed additives for ducks increases their weight by 20-25%, and the nutritional content becomes richer.

√ Alternative to Bisphenol A (BPA) in New Materials: Protocatechuic acid contains hydroxyl and carboxyl functional groups that can introduce flexible segments, leading to a higher cross-linking density, improved heat stability, impact resistance, and greater elongation at break in materials, making it suitable for aerospace applications. Protocatechuic acid-modified acrylic ester resins outperform poly (methyl methacrylate) (PMMA) materials based on bisphenol A in terms of performance.

√ As a Key Ingredient for Synthesizing Vanillin (also known as Vanilla Aldehyde, with the chemical name 3-methoxy-4-hydroxybenzaldehyde): Protocatechuic acid is a primary component used in the synthesis of vanillin, a popular flavor compound used in various food and fragrance products.