A new labdane diterpene, along with 10 known sterols and flavonoids, was isolated from the hydroalcoholic extract of the leaves of Saraca indica. The chemical structure of the new compound was identified as 6,9-epoxy marrubiinic acid on the basis of spectroscopic analyses including two-dimensional NMR. The antimicrobial potential of the new compound was evaluated against Gram-positive and Gram-negative bacteria as well as fungi. It showed a significant antifungal activity against Geotrichum candidum with MIC 0.48 mg/mL. It also showed potential cytotoxicity against human cancer cell lines with IC 50 ranging from 1.07 to 1.29 mg/well.