(E)-4-Fluoro-2-[(4-hy­droxy­pheneth­yl)imino­meth­yl]phenol

The title compound, C₁₅H₁₄FNO₂, has an E conformation about the C=N bond, which facilitates the formation of an intra­molecular O—H...N hydrogen bond. The F atom is disordered over two adjacent sites in a 0.65 (7):0.35 (7) ratio. The dihedral angle between the benzene ring planes is 14.2 (2)°. In the crystal, mol­ecules are linked by O—H...O hydrogen bonds, forming C(14) [010] chains.

17βH-Periplogenin, a cardiac aglycone from the root bark of Periploca sepium Bunge

The title compound {systematic name: 4-[(3S,5S,8R,9S,10R,13R,14S,17S)-3,5,14-trihy­droxy-10,13-dimethyl­hexa­deca­hydro-1H-cyclo­penta­[a]phenanthren-17-yl]furan-2(5H)-one}, C₂₃H₃₄O₅, was isolated from the roots of Periploca sepium Bunge, a famous Chinese traditional herbal medicine. The three six-membered rings adopt chair conformations, the cyclo­pentane ring displays an approximate envelope conformation (with the C atom bearing the methyl substituent at the flap) and the five-membered lactone ring adopts an essentially planar [maximum deviation of 0.004 (8) Å] conformation. In the crystal, mol­ecules are linked into helical chains along [010] by O—H...O hydrogen bonds and weak C—H...O inter­actions. Two intra­molecular O—H...O hydrogen bonds are also present.