1H and 13C NMR assignments of dihydropipataline, the main of four long-chain 1-(3,4-methylenedioxyphenyl)-alkanes from Piper darienence D.C. - Meléndez-Rodríguez, Myriam; Rendón, Willy; Chávez, Galia; Martínez-Guajardo, Gerardo; Joseph-Nathan, Pedro (Spectroscopy, 2000)