Polyphenolic glycosides from african proteaceae

Journal of Natural Products

Volumn 62, Issue 11, 1999, Pages 1526-1531

  Verotta, L ^a   Orsini, F ^a   Pelizzoni, F ^a   Torri, G ^b   Rogers, C B ^c  

^a UNIVERSITY OF MILAN   (Italy)

^b Istituto di Ricerche Chimiche e Biochimiche G Ronzoni   (Italy)

^c UNIVERSITY OF KWAZULU NATAL   (South Africa)

Author keywords

[No Author keywords available]

Indexed keywords

GLUCOPYRANOSIDE; GLYCOSIDE; POLYPHENOL DERIVATIVE;

ARTICLE; CARBON NUCLEAR MAGNETIC RESONANCE; CHEMICAL ANALYSIS; CHEMICAL COMPOSITION; DRUG STRUCTURE; NONHUMAN; PHYTOCHEMISTRY; PROTON NUCLEAR MAGNETIC RESONANCE;

EID: 0032729712     PISSN: 01633864     EISSN: None     Source Type: Journal    
DOI: 10.1021/np9902237     Document Type: Article

References (13)

1. Watt, J. M.; Breyer-Brandwijk, M. G. Medicinal and Poisonous Plants of Eastern and Southern Africa, S. Livingstone: Edinburgh, p 1962; pp 872-875.
2. Perold, G. W.; Beylis, P.; Howard, A. S. J. Chem. Soc., Perkin Trans I 1973, 638-643.
3. Perold, W. G.; Beylis, P.; Howard, A.-S. J. Chem. Soc., Perkin Trans I 1973, 643-649.
4. Perold, G. W.; Rosenberg, M. E. K.; Howard, A. S.; Huddle, P. A. J. Chem. Soc., Perkin Trans 1 1979, 239-243.
5. Pelizzoni, F.; Verotta, L.; Rogers, C. B.; Colombo, R.; Pedrotti, B.; Balconi, G.; Erba, E.; D'Incalci, M. Nat. Prod. Lett. 1993, 1, 273-280.
6. Orsini, F.; Pelizzoni, F.; Verotta, L.; Aburjai, T.; Rogers, B. C. J. Nat. Prod. 1997, 60, 1082-1087.
7. Cristoni, A. (Indena SpA, Milano-Italy) personal communication.
8. Liguori, A.; Procopio, A. J. Chem. Soc., Perkin Trans. 1 1993 1783-1786.
9. Transesterification with ethyl benzoate in the presence of alumina (Rana, S. S.; Barlow, J. J.; Matta, K. L. Tetrahedron Lett. 1981, 22, 5007-5010), a useful procedure recommended for the regioselective acetylation of primary hydroxy groups, did not afford the desired compound.
10. Kane, D.; Walker, S.; Cheng, Y.; Van Engen, D. J. Am. Chem. Soc. 1989, 111, 6881-6882.
11. 6 This approach, however, can be highly convenient for the preparation of less polar monomethyl derivatives, useful for the evaluation of the influence of the free hydroxyl groups on the biological activity.
12. Direct benzylation of 1,2,4-trihydroxybenzene with benzyl bromide in dimethylformamide afforded 2,4-dibenzyloxyphenol in 5% yield, accompanied by the tribenzyl derivative (5%), by other monobenzyl (35%) and dibenzyl derivatives (7%), with a 52% total recovery.
13. The synthesis of 2,4-dibenzyloxyphenol is reported in the Supporting Information.