Chemical Investigation of Opuntia tuna Mill growing in Egypt

The fruit of the genus Opuntia is of great economic value as it is used to some extent as forage. It is also cultivated for its edible fruits. Opuntia tuna is wildly growing in Egypt and is also cultivated for its edible properties [1]. Opuntia tuna was subjected to chemical investigation in this work for the first time. We report here on the flavonoids of the flowers and the mucilage and the betalaines of the fruits. Isolation and purification processes were carried out by applying successive chromatographic techniques (column chromatography, TLC, PPC and HPLC). Identification of the isolated compounds was carried out by spectroscopic analysis (UV, MS, ¹H-NMR and ¹³C-NMR). Quantitation of betalaines was established by TLC densitometry. The isolated flavonoids were identified as isorhamnetin, isorhamnetin-3-O-glucoside and isorhamnetin-3-O-rhamnoglucoside [2]. The mucilage study revealed the presence of L-rhamnose, L-arabinose, D-galactose, fructose D-glucuronic acid and D-galacturonic acid [3]. Indicathanthin, betanin and isobetanin were identified [4].

References: [1] Watt, J. M. and Breyer Brandwijk, M. G. (1962) “ The Medicinal and Poisonous Plants of Southern and Eastern Africa“ 2^nd ed., E. and S l-evinston Ltd., Edinburgh, U.K. [2] Abdel Shafeek, K. A., et al. (2000) J. Nat. Prod., 63: 845–847. [3] Nazif, N. N. (2001) Bull. Fac. Pharm., Cairo Univ., Vol. 39, No. 1. [4] Forni, E., et al. (1992) J. Chromatogr. 593: 177–83.