Six different metal-ion complexes of D-glucobenzothiazoline were synthesized and characterized by analytical and spectral techniques. Formation of different types of species (ML and ML₂) were observed with Cu²⁺, Ag⁺, Cd²⁺, Hg²⁺, and Zn²⁺ ions. Existence of an anomeric mixture in the case of the Cu²⁺ complex is identified from the EPR spectra, and the results were further supported by the simulated spectra. The structures were proposed based on different studies.