MARTINELLINE AND MARTINELLIC ACID, NOVEL G-PROTEIN LINKED RECEPTOR ANTAGONISTS FROM THE TROPICAL PLANT MARTINELLA-IQUITOSENSIS (BIGNONIACEAE)

Two novel pyrroloquinoline alkaloids, martinelline (1) and martinellic acid (2), were isolated from an organic extract of Martinella iquitos ensis roots. The ethnobotanical use of the two Martinella species as a n eye medication in South America may be explained in part by the pres ence of 1 and to a lesser extent 2; this study relates the bradykinin (BK) B-1 and B-2 receptor antagonist activity of 1 and 2 as well as th e affinity of 1 for histaminergic, alpha(1)-adrenergic, and muscarinic receptors. 1 and 2 represent the only naturally occurring nonpeptide BK antagonists reported to date. The antibiotic potential, cytotoxicit y, and lytic activity were also evaluated for these compounds.