Guaianolide Sesquiterpene Lactones and Aporphine Alkaloids from the Stem Bark of Guatteria friesiana

Emmanoel V. Costa,a,* Liviane N. Soares,a Maria L. B. Pinheiro,a Beatriz H. L. N. S. Maia,b Francisco A. Marques,b Andersson Barison,b Jackson R. G. S. Almeida,c Iran L. Sousa,d Renan S. Galaverna,d Gabriel Heerdt,d Nelson H. Morgon,d Leonard D. R. Acho,e Emerson S. Lima,e Felipe M. A. da Silva,a Hector H. F. Koolenf
aDepartment of Chemistry, Federal University of Amazonas - UFAM, 69080-900 Manaus, AM, Brazil. bDepartment of Chemistry, Federal University of Paraná - UFPR, 80060-000 Curitiba, PR, Brazil. cCenter for Study and Research of Medicinal Plants, Federal University of Vale do São Francisco - UNIVASF, 56304-205 Petrolina, PE, Brazil. dInstitute of Chemistry, University of Campinas - UNICAMP, 13083-970 Campinas, SP, Brazil. eFaculty of Pharmacy, Federal University of Amazonas - UFAM, 69077-000 Manaus, AM, Brazil. fMetabolomics and Mass Spectrometry Research Group, Amazonas State University - UEA, 690065-130 Manaus, AM, Brazil. *[email protected]
Keywords: Guatteria friesiana; Guaianolide sesquiterpene lactones; Aporphine alkaloids; Absolute stereochemistry; Anti-glycation activity.

Guatteria friesiana (W.A. Rodrigues) Erkens & Maas (synonym: Guatteriopsis friesiana) is a small tree (3-10 m) distributed exclusively through the Brazilian Amazon region. Previous phytochemical investigations with this species described terpenoids (in essential oils) and a rich alkaloid content [1-5]. In our continuing search for bioactive compounds derived from endemic Amazon plants, the stem bark from G. friesiana were re-investigated. The hexane extract yielded three undescribed guaianolide sesquiterpenes named guatterfriesols A-C (1-3), along with a mixture of -sitosterol (4) and stigmasterol (5) while the methanol extract gave four new aporphine alkaloids derivatives named (R)-dihydroguatteriscine (6), guatterfriesidine (7), iso-9-methoxyguatterfriesine (8), and hydroxyguatteriopsiscine (9). All data for the guaianolide sesquiterpenes and aporphine alkaloids derivatives are being described for the first time in the literature. This is the first report of guaianolides in the Annonaceae family. These compounds were isolated by conventional chromatographyc techniques and their structural elucidation was performed by spectroscopic methods and MS spectrometry. The absolute stereochemistry was assigned by NOE NMR experiments, ECD spectroscopy and theoretical calculations. All isolated compounds were submitted to an anti-glycation activity assay. Among the isolated compounds, the alkaloid guatterfriesidine (7) showed a potent anti-glycation activity by inhibiting the formation of advanced glycation end-products (AGEs) by prevention of oxidation in both, BSA/methyglyoxal and BSA/fructose systems.

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[2] COSTA, E.V., et al. Phytochemistry 69, 1895-1899, 2008.
[3] COSTA, E.V., et al. J. Braz. Chem. Soc. 24, 788-796, 2013.
[4] COSTA, E.V., et al. J. Nat. Prod. 72, 1516-1519, 2009.
[5] COSTA, E.V., et al. J. Nat. Prod. 79, 1524-1531, 2016.