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The title compound, C20H26O4, was extracted from Leucas Urticifolia, a wild Lamiaceae herb distributed in the Punjab, Baluchistan, Sindh and the Rajputana desert of Pakistan. The plant is utilized for various medicinal applications by the local community. The title compound is based on the pimarane-diterpene skeleton. The molecule exhibits an epoxy ring fused to momilactone-A, leading to a pentacyclic molecular structure. The absolute configuration was assigned by comparison with the crystal structure of momilactone, but needs further verification. The crystal structure is governed by four intermolecular hydrogen-bond interactions of the C-H center dot center dot center dot O type.