Chemical constituents of Spach aerial parts and their antimicrobial, antioxidant and antityrosinase activities.

A previously undescribed triterpenoid saponin, 3--[-l-rhamnopyranosyl-(1→2)-{-d-glucopyranosyl-(1→6)-}-d-galactopyranosyl-(1→2)--d-glucuronopyranosyl]-sophoradiol (), in addition to twenty-nine known constituents (-) were isolated from the aerial parts of Spach. Structures elucidation was performed by comprehensive 1D- and 2D-NMR analyses and HRESIMS. The extracts, fractions and isolated compounds were evaluated for their antibacterial, antioxidant and tyrosinase inhibitory activities. The experimental findings indicated that genistin (), isosalipurpol (), and koaburaside () have moderate to low antibacterial activity against , , and bacteria with MICs ranging from 31.2 to 125 μg/mL. Compounds and exhibited a good antiradical activity potential (IC 11.8 and 11.1 μg/mL, respectively). Only compounds , and exhibited low inhibitory effect against mushroom tyrosinase (IC from 90.2 to 225.6 μg/mL).