Zwitterionic 4-piperidinecarboxylic acid monohydrate.

The title compound, 4-piperidiniocarboxylate (isonipecotic acid), crystallizes as a zwitterion and incorporates one water molecule, i.e. C(6)H(11)NO(2).H(2)O. The piperidine ring adopts a chair conformation and the alpha-carboxylate group is oriented in the equatorial position. The combination of the interactions between the alpha-amino and alpha-carboxylate groups and the water molecules builds a three-dimensional assembly of hydrogen bonds.

3alpha-Hydroxytirucalla-7,24-dien-21-oic acid: a triterpene from Protium crenatum Sandwith.

The crystal structure of the title compound, C30H48O3, a triterpene extracted from the resin of Protium crenatum Sandwith, is reported. The aliphatic acidic side chain is attached to the tirucallene four-ring system on its alpha-face and is extended by 7.248 (5) A in the 'left-hand' orientation.