Protocatechualdehyde

Description

3,4-Dihydroxybenzaldehyde has been recognized as one of the antifungal compound extracted from the outer skin of green Cavendish bananas. Protocatechualdehyde is extracted from roots of the common traditional Chinese medicine Salvia miltiorrhiza Bge, which was harvested in autumn for better quality. Now, the existence of protocatechualdehyde has been found in variety of herbs, for example, in the leaf of Stenoloma Chusanum (L.) Ching and Ilex chinensis Sims.

Chemical properties

Pale beige acicular crystal (in water or methylbenzene) or off-white powder, crystal twin shape. Solubility: easily soluble in ethanol, acetone, ethyl acetate, ethyl ether, and hot water; soluble in cold water; insoluble in benzene and chloroform. Specific optical rotation: easily oxidized to benzoquinone and changes color, and it is instable in water. protocatechualdehyde can be found in barley, grapevine, green Cavendish, and root of herb S. miltiorrhiza.

History

In the 1940s, the research was conducted overseas to obtain protocatechualdehyde form herbs. In 1972, the chemical group of Chinese herbal medicine in Nanjing College of Pharmacy systematically studied chemical composition in purple flower holly leaf and separated six monomers including protocatechualdehyde. Then they compared the effect of protocatechualdehyde, Salvia miltiorrhiza injection and hairy holly root injection, in which protocatechualdehyde is the most effective in increasing coronary sinus flow. Further experiments examined that protocatechualdehyde can increase coronary flow and improve coronary circulation, so it was called after perhexiline. Further clinical observation indicated that protocatechualdehyde has effect on coronary heart disease. The graduates of Nanjing College of Pharmacy in 1975 extracted, separated, isolated, and identified protocatechualdehyde in Salviamiltiorrhiza during the internship in Nanjing Municipal Hospital and studied its distribution, excretion, and toxicity in animals for clinical rational drug usage

The Uses of Protocatechualdehyde

3,4-Dihydroxybenzaldehyde is used in as an apoptosis inducer of human leukemia cells. It may be used for the surface modification of nanocrystalline TiO2 particles. Electrodeposited layer of 3,4-dihydroxybenzaldehyde may be used as effective redox mediator during oxidation of NADH at graphene. It may be used in the preparation of new diSchiff base ligands, which forms di-, tri- and tetranuclear Co(II) and Cu(II) complexes.

Definition

ChEBI: 3,4-dihydroxybenzaldehyde is a dihydroxybenzaldehyde.

Clinical Use

Perhexiline injection containing protocatechualdehyde 100? mg/2? mL by intravenous infusion or intramuscular injection was used to treat coronary heart disease, chest tightness, angina, and myocardial infarction.
Injection treats ischemic stroke and improves both symptoms and signs of patients. Treating chronic hepatitis and early cirrhosis: relieving the symptoms, promoting the recovery of liver function, and hepatosplenomegaly. It can significantly improve the blood rheology index for patients with acute exacerbation of chronic pulmonary heart disease. Treatment of peptic ulcer: a certain effect.
Others: it has effect on many diseases like viral myocarditis, embolism of central retinal artery, thromboangiitis obliterans, scleredema neonatorum, scleroderma, psoriasis, nerve deafness, and toxemia of pregnancy.

Enzyme inhibitor

This aldehyde (FW = 138.12 g/mol), also known as 3,4- dihydroxybenzaldehyde and 4-formylcatechol, is soluble in water (5 g/100 mL at 20°C) and has a pKa value of 7.55 at 25°C. Protocatechualdehyde induces apoptosis in cytotoxic T cells. Target(s): aldehyde oxidase; aldose reductase; b-carotene 15,15’-monooxygenase; mandelonitrile lyase; protocatechuate 3,4-dioxygenase; protocatechuate 4,5- dioxygenase; tyrosinase, weakly inhibited, IC50 = 620 μM; and xanthine oxidase.

Purification Methods

Crystallise the aldehyde from water or toluene and dry it in a vacuum desiccator over KOH pellets or shredded wax respectively. [Beilstein 8 IV 1762.]