Pilocarpus spp.: a survey of its chemical constituents and biological activities

Abstract

Pilocarpus species have been exploited as the only source of the imidazole alkaloid pilocarpine (used in glaucoma treatment), since its isolation up to the present. Almost all Pilocarpus species are native from Brazil. Because of the medicinal importance of pilocarpine, several of them are in the path of extinction. Other secondary metabolites, such as coumarins, flavonoids and terpenes, were described for Pilocarpus species. In this review the secondary metabolites, other than pilocarpine, isolated from Pilocarpus species and their biological activities were compiled. Although the variety of structures and the importance of the biological activities described in literature for Pilocarpus species this is an unexploited field of research in Natural Products and Pharmacology.

Screening species of Pilocarpus (Rutaceae) as sources of pilocarpine and other imidazole alkaloids

“…Several epimers and isomers have been reported (Tedeschi et al 1974;Voigtländer et al 1978) with the same molecular formula. Of these isomers; pilosine has been reported in P. microphyllus and pilosine, isopilosine, epiisopilosine and epiisopiloturine in P. jaborandi (Santos and Moreno 2004). This is nearly the opposite of the present results, as P. jaborandi did not present any of these alkaloids.…”

“…Pilocarpidine was observed in P. jaborandi (Santos and Moreno 2004) and its structure and synthesis have been described (Cordell 1981). In the present study, alkaloid 3 (m/z 195) with high resolution mass and fragmentation compatible with pilocarpidine, was only observed in the P. jaborandi sample.…”

“…Different species present varied alkaloid profiles: pilocarpine is reported in six species, whereas seven other imidazole alkaloids are reported in only three species (Santos and Moreno 2004). Of these, only epiisopilosine has been screened for pharmacological and toxicological activity.…”

“…However, its DL 50 is twice that of pilocarpine, indicating that it is less toxic (Lucio et al 2002). Other, non-imidazole, alkaloids have also been found in this genus and show hallucinogenic and antifungal activity (Santos and Moreno 2004).…”

“…Other studies between 1959 and 1996 were performed on single species using classical isolation and identification techniques (Santos and Moreno 2004). No comparative studies of the imidazole alkaloids found in different Pilocarpus species using modern chromatographic techniques have been reported.…”