Preliminary assessment of the chemical stability of dried extract from Guazuma ulmifolia Lam. (Sterculiaceae)

Guazuma ulmifolia Lam. (Sterculiaceae), popularly known as „Mutamba“, is a tropical-American plant found from Mexico to southern South America. In the popular medicine of several Latin-American countries, it is used for the treatment of burns, diarrhea, inflammations and alopecia. Polysaccharides, epicatechin (EP) and procyanidin oligomers, such as procyanidins B2 (PB2) and B5, three trimers [procyanidin C1; epicatechin-(4β→6)-epicatechin-(4β→8)-epicatechin; epicatechin-(4β→8)-epicatechin-(4β→6)-epicatechin] and one tetramer have been isolated and identified from its extract [1]. The anti-diabetic properties [2], hypotensive and vasorelaxant activity [3], anti-ulcer [4], anti-bacterial activities [5], and antiviral activity [6] from the bark, aerial parts, fruits, crude extract and fractions were attributed to the presence of proanthocyanidins. The preliminary stability of the dried extracts from bark of G. ulmifolia containing or not colloidal silicon dioxide (CSD) was evaluated. The physical-chemical properties and compatibility of CSD in the extract were evaluated for 21 days of storage under stress conditions of temperature (45±2°C) and humidity (75±5%). Thermal analysis (TG) was supplemented using a selective high-performance liquid chromatography (HPLC) for determination of stability of the characteristic constituents (chemical markers), namely PB2 and EP. The results showed that PB2 is an appropriate compound to use as chemical marker in control quality of dried extracts of G. ulmifolia. The stress study showed that there was no significant difference between the two extracts. On the other hand, considering the TG data and the high temperatures involved, the results suggest that CSD would increase the stability of dried extracts of G. ulmifolia.

Acknowledgements: CNPq, CAPES.

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[5] Camporese, A. et al. (2003)J. Ethnopharmacol. 87:103–107.

[6] Felipe, A.M.M. et al. (2006) Biol. Pharm. Bull. 29:1092–1095.