Isolation and characterization of a novel flavanone glycoside from an endemic plant Haplanthodes neilgherryensis

The chemical characterization study of an endemic plant, Haplanthodes neilgherryensisis (Wight) R.B. Majumdar from Western Ghats of India, resulted in to the isolation of a new flavanone glycoside, 5-hydroxy-7-methoxy-8-O-β-D-glucopyranosyl-2S-flavanone (1), along with 3 known flavonoids, 7-O-methyl dihydrowogonin (2), 7-O-methyl wogonin (3), andrographidine C (4). The structure of 1 was elucidated by using 1 D and 2 D NMR and HRMS experimental data, while for the known compounds, ¹H NMR and mass spectrometry data were compared with the reported literature. Compound 1 was tested in vitro to check the improvement in uptake of glucose by the L6 rat skeletal muscle tissues and the observed EC₅₀ value was 5.8 µM, while rosiglitazone showed EC₅₀ of 2.7 µM.