Phytochemical profile of Psychotria carthagenensis obtained by analysis using UHPLC-MS and GC-MS.

There are about 1600 species of the genus Psychotria (Rubiaceae), which occur in many regions of the planet. The species Psychotria carthagenensis is used commonly for vomiting, fever, diarrhea, and spasms; also as an analgesic, sedative and a tonic1. Species of this genus present several alkaloids as metabolites, mainly quinolinic, indoles and poly-indoles derivates and monoterpene indoles2. Samples of stems of P. carthagenensis, collected at the locality of Brejo Novo, Jequié – Bahia, were used for botanical identification (HUESB 12351) and extracted by maceration with ethanol. The crude ethanol extract was subjected to acid-base partition3, producing one extract soluble in hydromethanolic solution (HMC) and another in hexane (EHC). The analysis by thin layer chromatography of HMC extract indicated the presence of alkaloids by the production of orange spots after being stained with Dragendorff’s reagent. Therefore, the HMC extract was submitted to analysis by Ultra-High-Performance Liquid Chromatography coupled with Mass Spectrometry (UHPLC-MS) using ionization source per electrospray in positive mode. The analysis of HMC by UHPLC-MS allowed to identify, through fragmentation patterns from different data bases (UNPD-ISDB, MassBank and in house library), the constituents: bisphenol A (TR 1.0 min.), agarobiose (TR 2.0 min.), pyrimethamine (TR 4.7 min.), safranin (TR 11.3 min.) and the alkaloids chanoclavine-I (TR 9.1 min.), glomerulatine B (TR 11.9 min.) and ircinal B (TR 13.0 min). The glomerulatine B was previously isolated from Psychotria glomerulata4 and there is no other studies about the occurrence of the other alkaloid identified here in other species of Psychotria. The EHC extract was fractionated by liquid chromatography on a normal phase column and, fractions F-13 and F-20 (yellowish and oily) were analyzed by gas chromatography coupled to mass spectrometry (GC-MS). The GC-MS analysis of EHC F-13 and F-20 allowed the identification, through NIST Mass Spectral Library (NIST 11), of three phytosterols, six fatty esters, and α-tocopherol. Although there are reports of alkaloid detection by CG-MS such as of the N,N-dimethyltryptamine, N-momethyltryptamine and methyl-1,2,3,4-tetrahydro--carboline5 and the determination of concentration of phenolic, flavonoid, condensed tannin and flavonol in this species2, we could not find reports about the occurrence of other compounds. The identification of P. carthagenensis substances by GC-MS and UHPLC-MS help to characterize the chemical profile of the species and the isolation of HMC alkaloids is still in progress.
References:
1. Matsuura, H. N.; Porto, D. D.; Fett-Neto, A. G. Bioactive alkaloids from South American Psychotria and related Rubiaceae. Natural Products, 2013. Doi:10.1007/978-3-642-22144-6_101
2. Formagio, A. S. N.; Volobuff, C. R. F.; Santiago, M.; Cardoso, C. A. L.; Vieira, M. C.; Pereira, Z. V. Evaluation of antioxidant activity, total flavonoids, tannins and phenolic compounds in Psychotria leaf extracts. Antioxidants, 3, 745-757, 2014. doi:10.3390/antiox3040745
3. Lima, L. B. Triagem da atividade antioxidante e antiacetilcolinesterásica de extratos naturais: seleção e estudo químico biomonitorado de Streptomyces sp. e de Psychotria carthagenensis. Masters dissertation. USP, Ribeirão Preto - SP, 2011.
4. Solís, P. N.; Ravelo, A. G.; Palenzuela, J. A.; Gupta, M. P.; González, A.; Phillipson, J. D. Quinoline alkaloids from Psychotria glomerulata. Phytochemistry, v. 44, 5, 963-969, 1997.
5. Holmstedt, B.; Lindgren, J. E.; Rivier, L.; Do Valle, J. R. Ayahuasca, caapi or yage - hallucinogenic drink of Amazonian Basin Indians [Brazil]. Ciência e Cultura, 31(10), 1120-4, 1979.