title: 3-Eth-oxy-carbonyl-2-hy-droxy-6-meth-oxy-4-methyl-benzoic acid.
abstract: The title compound, C(12)H(14)O(6), a substituted isophthalic acid monoester which was isolated from the lichen Thamnolia vermicularis var. subuliformis, displays intra-molecular carbox-yl-meth-oxy O-H⋯O and hy-droxy-carboxyl O-H⋯O hydrogen-bonding inter-actions. The terminal methyl group of the ethyl ester is disordered over two sets of sites with occupancies of 0.599 (19) and 0.401 (19).
authors.forename: Yun-Xia
authors.initials: YX
authors.lastname: Deng
authors.forename: Tao
authors.initials: T
authors.lastname: Guo
authors.forename: Hui
authors.initials: H
authors.lastname: Xie
authors.forename: Sheng-Li
authors.initials: SL
authors.lastname: Pan