Prospecção química e farmacológica dos extratos de Cordia glazioviana Taub. e Cordia oncocalyx Taub.

Abstract

In this work, the chemical investigation of the ethanol extracts of the stems of Cordia glazioviana Taub. and Cordia oncocalyx Taub. (Boraginaceae), typical trees of the northeastern of Brazil, are described. From C. glazioviana were isolated four sesquiterpenes [10,12-dihydroxybisabolol (1), hamanasal A (2), 1β,6β-dihydroxy-7-epi-eudesm-3-ene (3), and 1β,6β-dihydroxy-7-epi-eudesm-4(15)-ene (4)], one phenolic meroterpene [didehydroconicol (5)], five hydroquinones [rel-1,4-dihydroxy-5α-formyl-8aβ-methyl-5,6,7,8,8a,9,10,10a-octahydro-10-anthracenone (6), 12,16-diepoxy-1,4-dihydroxy-globiferin (7), (2E)-3’,8’-dihydroxy-3’-7’-dimethylnona-1’,6’-dienyl-1,4-benzene diol (8), cordiaquinol D (9) and rel-1,4-dihydroxy-8α,11α;9α,11α-diepoxy-2-methoxy-8aβ-methyl-5,6,7,8,8a,9,10,10a-octahydro-10-antracenone (20)] and two quinones (2-methoxy-7-methyl-(6→4’)-1’-hydroxy-dihydropyran-l,4-naphthalenedione (10) and oncocalyxone A (15)]. Compounds 6, 7, 8, 9 and 10 are described for the first time. From C. oncocalyx were isolated seven quinones [rel-10β,11β-epoxy-11β-ethoxy-8α-hydroxy-2-methoxy-8aβ-methyl-5α,6,7,8,8a,9,10aβ-octahydro-1,4-anthracendione (11), rel-10β,11β-epoxy-2,11β-dimethoxy-8α-hydroxy-8aβ-methyl-5α,6,7,8, 8a,9,10,10aβ-octahydro-1,4-anthracendione (12), 11α-Oncocalyxone D (13), rel-10β,11β-epoxy-8α,5-dihydroxy-2-methoxy-8aβ-methyl-5,6,7,8,8a,9,10,10aβ-octahydro-1,4-anthracendione (14), oncocalyxone A (15), 6-formyl-2-methoxy-9-methyl-1,4-phenanthrendione (16) and oncocalyxone B (22)] and five hydroquinones [rel-1,4,8α-trihydroxy-5-furanyl-2-methoxy-8aβ-methyl-6,7,8,8a,9,10-hexahydro-10-anthracenone (17), rel-10α,11α-epoxy-8α,11β-dihydroxy-8aβ-methyl-5β,6,7,8,8a,9,10,10aβ-octahydro-1,4-anthracenediol (18), rel-9α,11α-epoxy-1,4,8α-trihydroxy-2-methoxy-8aβ-methyl-5,6,7,8,8a, 9,10,10aβ-octahydro-10-anthracenone (19), rel-8α,11α;9α,11α-diepoxy-1,4-dihydroxy-2-methoxy-8aβ-methyl-5,6,7,8,8a,9,10-10aβ-octahydro-10-anthracenone (20) and rel-1,4,8α-trihydroxy-5-carboxyethyl-2-methoxy-8aβ-methyl-6,7,8,8a,9,10-hexahydro-10-anthracenone (21)]. Compounds 11, 12, 14, 17 and 21 are new. The structures of all isolated compounds were elucidated using spectroscopic methods (IR, 1H and 13C NMR, and HRESIMS), and comparison with data available in the literature. All isolated compounds from C. oncocalyx were screened on the neurogenic inhibition and respective receptors. Seven of them were active (11, 14, 15, 16, 17, 19 and 22), being particularly reverted by promethazine and yohimbin. The isolated compounds of C. glazioviana were tested against the colon adenocarcinoma cancer cell line, from which cordiaquinol D (9) was strongly active, with IC50 0.8.