1H and 13C NMR assignments of new methoxylated furanoflavonoids from Lonchocarpus araripensis.

Departamento de Química Orgânica e Inorgânica, Centro de Ciências, Universidade Federal do Ceará, CP 12.200, 60021-970 Fortaleza, CE, Brazil.
Magnetic Resonance in Chemistry (Impact Factor: 1.53). 10/2008; 47(2):165-8. DOI:10.1002/mrc.2352
Source: PubMed

ABSTRACT Two new polymethoxylated flavonoids, 2',5',6'-trimethoxy-[2'',3'' : 3',4']furano dihydrochalcone and 2,4',4,5-tetramethoxy-[2'',3'' : 6,7]-furanodihydroaurone, were isolated from the root barks of Lonchocarpus araripensis, along with the known compounds 3,4,5,6-tetramethoxy-[2'',3'' : 7,8]-furanoflavan, 3,6-dimethoxy-1'',1''-dimethylcromene-[2'',3'' : 7,8]-flavone, 3',4'-methylenodioxy-5,6-dimethoxy-[2'',3'' : 7,8]-furanoflavone, 3,5,6-trimethoxy-[2'',3'' : 7,8]-furanoflavanone, 3,5,6-trimethoxy-[2'',3'' : 7,8]-furanoflavone, and 6alpha-hydroxy-medicarpin. The complete (1)H and (13)C NMR assignments of the new furan flavonoids were performed using 1D and 2D pulse sequences, including COSY, HSQC, and HMBC experiments, and comparison with spectral data for analog compounds from the literature, particularly for the new furanodihydroaurone because of several inconsistencies on the carbonyl chemical shifts from the literature.

0 0
  • [show abstract] [hide abstract]
    ABSTRACT: Leaves, stem bark and root of Lonchocarpus xuul and Lonchocarpus yucatanensis were studied separately. A chalcone, 2',4-dimethoxy-6'-hydroxylonchocarpin (), and the flavones 5,4'-dihydroxy-3'-methoxy-(6:7)-2,2-dimethylpyranoflavone (2) and 5,4'-dimethoxy-(6:7)-2,2-dimethylpyrano-flavone (3), together with the known carpachromene (4), were isolated from the leaves of both species. Similarly, the previously reported flavans xuulanin (5) and 3beta-methoxyxuulanin (6), together with the novel 3beta,4beta,5-trimethoxy-4'-hydroxy-(6:7)-2,2-dimethylpyranoflavan (7), 3-hydroxy-4,5-dimethoxy-(6:7)-2,2-dimethyl-pyranoflavan (8), and 3,4-dihydroxy-5-methoxy-(6:7)-2,2-dimethylpyranoflavan (10), were isolated from the stem bark and root of both species. Finally, the known 2',4'-dihydroxy-3'-(3-methylbut-2-enyl) chalcone (13) was obtained from the root of L. xuul only. The structures of the various metabolites were established by interpretation of their spectroscopic data.
    Phytochemistry 08/2002; 60(5):533-40. · 3.05 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Two new aurones, 4'-chloro-2-hydroxyaurone (1) and 4'-chloroaurone (2) were isolated from Spatoglossum variabile. The structures of these compounds were elucidated by modern spectroscopic techniques.
    CHEMICAL & PHARMACEUTICAL BULLETIN 02/2001; 49(1):105-7. · 1.56 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: Two 2-hydroxy-2-benzylcoumaranone glycosides, 2,4, 6-trihydroxy-2-[(4'-hydroxyphenyl) methyl]-3(2H)-benzofuranone-4-yl-beta-D-glucopyranoside (maesopsin 4-O-glucoside) (1) and 2,4,6-trihydroxy-2-[(4'-hydroxyphenyl) methyl]-3(2H)-benzofuranone-4-yl-beta-D-glucopyranosido-4'-y l-alpha-L -rhamnopyranoside (maesopsin 4-O-glucosido 4'-O-rhamnoside) (2), two neolignan glycosides, 2R-(E)-2, 3-dihydro-2-(4'-hydroxy-3'-methoxylphenyl)-5-(3"-hydroxy-1"-pro pen yl) -7-methoxy-3-benzofuranmethanol-4'-yl-beta-D-glucopyranosyl-(1-->3 )-[ beta-D-glucopyranosyl-(l-->2)]-beta-d-glucopyranoside (3) and (threo) 1-(4'-hydroxy-3'-methoxy)-2-(4"-hydroxymethyl-2", 6"-dimethoxyphenoxy)-propane-1,3-diol-4'-yl-beta-d-glucopynosid e (4), and a phenylpropanoid glycoside, 3-methoxy-5-(2'-propenyl)-1, 2-benzenediol-1-yl-beta-D-apiofuranosyl-(1-->6)-beta-D- glucopyransodie (5) were isolated from the bark of Hovenia trichocarea. Compounds 1-5 were named hovetricosides C-G, respectively, and their structures were established by extensive NMR experiments and chemical methods. Also obtained in this investigation were the known compounds acanthoside B, kelampayoside A, shashenoside I, and 3,4, 5-trimethoxyphenol-1-O-beta-D-xylopyranosyl-(1-->6)-beta-D- glucopyranoside.
    Journal of Natural Products 06/1998; 61(6):786-90. · 3.29 Impact Factor