protocatechuic acid

A summary of the most common chemical descriptors (InChI Key and SMILES codes) for protocatechuic acid are summarized together with 3D and 2D structures and relevant physico-chemical properties.

What is protocatechuic acid?

The molecule protocatechuic acid presents a molecular formula of C7H6O4 and its IUPAC name is 3,4-bis(oxidanyl)benzoic acid.

3D structure

Cartesian coordinates

Geometry of protocatechuic acid in x, y and z coordinates (Å units) to copy/paste elsewhere. Generated with Open Babel software.

2D drawing


protocatechuic acid YQUVCSBJEUQKSH-UHFFFAOYSA-N chemical compound 2D structure molecule svg
protocatechuic acid


Molecule descriptors

IUPAC nameprotocatechuic acid
InChI codeInChI=1S/C7H6O4/c8-5-2-1-4(7(10)11)3-6(5)9/h1-3,8-9H,(H,10,11)

Physico-Chemical properties

IUPAC name3,4-bis(oxidanyl)benzoic acid
Molecular formulaC7H6O4
Molecular weight154.12
Melting point (ºC)
Boiling point (ºC)
Density (g/cm3)
Molar refractivity
Topological polar surface area77.8

LogP and topological polar surface area (TPSA) values were estimated using Open Babel software.

The n-octanol/water partition coeficient (Kow) data is applied in toxicology and drug research. Kow values are used, to guess the environmental fate of persistent organic pollutants. High partition coefficients values, tend to accumulate in the fatty tissue of organisms. Molecules with a log(Kow) (or LogP) greater than 5 are considered to bioaccumulate.

TPSA values are the sum of the surface area over all polar atoms or molecules, mainly oxygen and nitrogen, also including hydrogen atoms.

In medicinal chemistry, TPSA is used to assess the ability of a drug to permeabilise cells.

For molecules to penetrate the blood-brain barrier (and act on receptors in the central nervous system), TPSA values below 90 Å2 are required. Thus, molecules with a polar surface area greater than 140 Å2 tend to be poorly permeable to cell membranes.