Organodigermanium Compounds: Structures and Properties

A series of substituted bis(triazole) derivatives of organodigermanes (1–3) containing reactive phenolic and sugar functional groups, [1,4-C2HN3(R)GePh2–]2 (R = β-(d)-glucopyranoso-C5H5O(OAc)3CH2OAc (1); R = CH2–1,2,3,5-(HO)C6H2(t-Bu)2 (2); and R = CH2–1,2,3,5-(HO)C6H2(CHO)(t-Bu) (3)), was synthesized by the copper-catalyzed azide–alkyne cycloaddition (CuAAC) reaction. The structural features (1, XRD analysis) and optical properties (1–3, absorbance, and emission) of these digermanium heterocyclic compounds were studied. The antioxidant (DPPH test), lipoxygenase inhibitory (inhibition of LOX 1-B), and antiproliferative activities (MTT test; HCT-116, MCF-7, A-549 cancer cell lines) of differently substituted 1–6 (R = p-BrC6H4CH2 (4); R = CH2COOEt (5); R = CH2CH2O-p-C6H4CHO (6)) were investigated, indicating their promising antioxidant (for 2 EC50 103 ± 4 μM) and lipoxygenase inhibition activity (for 4 IC50 29 ± 2 μM), moderate antiproliferative activities (for 5 IC50 55–71 μM), and low toxic properties (WI-38, IC50 > 36 μM). Comparison of the biological activity of the leader digermanes 2, 4, and 5 with related organic triazoles 1,4-C2HN3(R) (2a, 4a, 5a) and monogermanes 1,4-C2HN3(R)GePh3 (2b, 4b, and 5b) indicates the influence of the Ge–Ge fragment.