Crystal structure, Hirshfeld surface analysis and electrostatic potential study of naturally occurring cassane-type diterpenoid Pulcherrimin C monohydrate at 100 K.

The title cassane-type diterpenoid known as pulcherrimin C, C₃₄H₃₆O₈·H₂O, systematic name 5,6-bis-(benzo-yloxy)-4a-hy-droxy-4,7,11b-trimethyl-1,2,3,4,4a,5,6,6a,7,11,11a,11b-dodeca-hydro-phenanthro[3,2-b]furan-4-carb-oxy-lic acid monohydrate, was isolated as a monohydrate from the medicinally important plant Caesalpinia pulcherrima, found in the tropical regions of south and south-east Asia. The mol-ecule is composed of three trans-fused six-membered rings having chair, chair and half-chair conformations, and a five-membered planar furan ring. In the crystal, O-H⋯O hydrogen bonds link mol-ecules into chains parallel to the b axis. Weak C-H⋯π inter-actions are also observed. Hirshfeld surface analysis indicates that the contribution of O⋯H inter-actions towards the total generated Hirshfeld surface is 21.5%.