1 Hainan Provincial Key Laboratory of Tropical Pharmaceutical Herb Chemistry, College of Chemistry & Chemical Engineering, Hainan Normal University, Haikou 571158, People's Republic of China.
In the title compound, C(11)H(14)O(4), isolated from the stems of Trigonostemon xyphophylloides, an intra-molecular O-H⋯O hydrogen bond helps to establish an essentially planar conformation for the mol-ecule (r.m.s. deviation = 0.044 Å).