Seven new trialkyl-substituted benzene derivatives named benwamycins A-G (-), together with three known congeners, -, were isolated from culture broth of the soil-derived sp. KIB-H1471. Their structures were elucidated by using 1D and 2D NMR analyses in combination with HRESIMS data. The absolute configurations of - were determined by chemical conversion and comparison of circular dichroism spectra and confirmed for by single-crystal X-ray crystallography. Compounds and have a unique γ-pyrone-like ring on one side chain. Compounds and inhibited human T cell proliferation with IC values of 14.3 and 12.5 μM, respectively, without obvious cytotoxicity for naïve human T cells. Compounds and could weakly enhance insulin-stimulated glucose uptake.