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| Author(s): |
Caroline Cristina Fernandes da Silva
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB) |
| Defense date: | 2013-02-06 |
| Examining board members: |
Maria Luiza Faria Salatino;
Cláudia Maria Furlan;
Lucimar Barbosa da Motta;
Erica Weinstein Teixeira
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| Advisor: | Maria Luiza Faria Salatino |
| Abstract | |
Propolis is a complex mixture of substances with resinous aspect, prepared mostly by Apis mellifera honeybees. It has a diverse chemical composition, according to the flora around the hive. The aims of this work are to chemically characterize four samples of propolis from different regions of Brazil (MG, CE, SC and PR states) and to isolate and test the antioxidant (DPPH and β-carotene methods) and anti-HIV (inhibitory activity of HIV-1 reverse transcriptase) activities of the compounds present on those samples. The volatile fraction sample of green propolis from Viçosa (MG) was extracted and analyzed by GC-MS. We verified the presence of mono-and sesquiterpenes and phenolic acids. Among them ledene, muuroladiene, β-copaene, aloaromadendrene and nerolidol were detected for the first time in the volatile fraction of Brazilian green propolis. One of its major constituents, the allyl ester of 3-prenylcinnamic acid was isolated and tested for biological activities. It was shown to have high antioxidant activity by the β-carotene method, but showed no activity regarding the other tests. It is suggested that the lack of activity is linked to the absence of free phenolic hydroxyl on the compound. The samples from CE, PR and SC states were analyzed by various chromatographic, including HPLC-MS-MS, and colorimetric techniques. The sample from CE, with unknown resin source, contains flavonoids (eg, naringenin and isorhamnetin) and phenolic acids (e.g. ρ-coumaric acid and caffeic). Its chemical composition is different from a previously described sample from the same state. The flavonoids galangin and pinocembrin, typical from European propolis, were detected in the sample from SC, which suggests that its botanical source is Populus deltoide. The sample from PR does not have these flavonoids; instead it possesses prenylated phenolic acids. Its composition is different from samples previously described, suggesting that the sample corresponds to a new type of propolis from southern Brazil. The three propolis samples were subjected to bioguided isolation of their constituents. Nineteen substances were obtained, nine of them with high antioxidant activity, one with anti-HIV action, and three with moderate anti-HIV activity. It is suggested that the antioxidant activity of these propolis is conferred by their major constituents, such as p-coumaric acid, present in all three samples, quercetin, isorhaminetin and 7,4\',5\'-trimethylmyricetin-5,3\'-dihydroxy-3-O-caffeoyl glucoside in propolis from CE; a mixture of dihydrocaffeoylquinic and dimethoxycinnamoyl-dihydrocaffeoylquinic acids in propolis from PR; and caffeic acid, pinocembrin and a unknown compound named 16, in propolis from SC. Compounds with anti-HIV activity were isolated from propolis from CE (naringenin, quercetin and isorhaminetin) and PR (4-acetyl-5-carboxy-coumaric acid), indicating that these types of propolis have high potential in the search for active compounds (AU) | |
| FAPESP's process: | 08/05919-4 - Chemical characterization of four Brazilian propolis samples: isolation of compounds and test of antioxidant and anti-HIV activities |
| Grantee: | Caroline Cristina Fernandes da Silva |
| Support Opportunities: | Scholarships in Brazil - Doctorate |