The phytochemical investigation of the twig and root extracts of Erythrina subumbrans (Hassk.) Merr. (Fabaceae) resulted in the isolation and identification of a new pterocarpan, erythrinocarpan (1), along with 27 known compounds (2-28). All isolated compounds were evaluated for their antidiabetic, antimicrobial, and antiinflammatory properties. Compounds 3, 8, 9, and 22 had α-glucosidase inhibitory activity with IC 50 values of 13.4 AE 0.05, 24.5 AE 0.13, 29.0 AE 0.05, and 12.8 AE 0.14 μM, respectively, while compound 2 inhibited α-amylase activity with an IC 50 value of 67.6 AE 1.12 μM. Compounds 22 and 24 inhibited glycation activity with the IC 50 values of 36.9 AE 0.62 and 40.5 AE 0.37 μM, respectively. From cell-based assays, compound 27 showed the highest ability to induce glucose consumption (IC 50 29.1 AE 0.86 μM) and glucose uptake (2.8-fold), and to inhibit nitric oxide (NO) production (IC 50 52.5 AE 0.56 μM) without cell toxicity. Furthermore, compound 9 showed antimicrobial activities against Gram-positive bacteria and fungi with MIC values ranging from 2-4 μg/mL.