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Lipophilic profile of the edible halophyte Salicornia ramosissima

Publication . Isca, Vera M. S.; Seca, Ana M. L.; Pinto, Diana C. G. A.; Silva, Helena; Silva, Artur M. S.

Salicornia ramosissima J. Woods is considered, in the Iberian Peninsula and France, a gourmet product. Nevertheless, is one of the less studied Salicornia species. In this work, GC-MS was employed to, for the first time; fully characterise the lipophilic profile of S. ramosissima and to assess the effect of natural and extra irrigation in that profile. The obtained data showed esterified and free fatty acids, fatty alcohol, sterols, alkanes and aromatic acid derivatives, being palmitic acid, tetracosanol and octacosanol the most abundant compounds. The extra irrigation increases significantly (P < 0.001) the content of esterified lipophilic compounds. Stigmastanol, 24-ethyl-δ(22)-coprostenol, several secondary fatty alcohols and dicarboxylic acids were identified for the first time in Salicornia genus. Several of the detected compounds are known to have health benefits and our results suggest that S. ramosissima should be considered as an important dietary source of lipophilic phytochemicals.

2014-06Journal article

Open access

Antioxidant and anticholinesterasic activities of Morella faya (Aiton) Wilbur extracts

Publication . Silva, Bruno J. C.; Seca, Ana M. L.; Moreno-Rodriguez, L.; Barreto, Maria do Carmo

Morella faya (Aiton) Wilbur (Myricaceae), formerly Myrica faya, is a shrub or small tree native to Macaronesia, Spain and Portugal and invasive in Hawai'i [1]. In the present study, bioactivities of extracts from leaves and bark collected in S. Miguel, Azores, were determined. Extracts were prepared by sequentially extracting the dry material with dichloromethane and acetone at room temperature. The antioxidant activity of the extracts was determined by the DPPH radical scavenging and FeCl3 reduction assays, total phenolics by the Folin-Ciocalteau method and in vitro anticholinesterasic (anti-AChE) activity by a modification of the Ellman method [2]. The dichloromethane extracts did not present any of these activities between 4.9 and 1250 µg/mL. Both acetone extracts presented a high antioxidant activity. For the DPPH scavenging activity, EC50= 17.7 ± 0.13 and 16.9 ± 0.36 µg/mL for leaves and bark, respectively and 4.5 ± 1.1 µg/mL for quercetin (positive control). In the FeCl3reduction assay, EC50 values were 3.8 ± 0.40 and 3.9 ± 0.16 µg/mL for leaves and bark respectively, and 0.995 ± 0.06 µg/mL for gallic acid (positive control). The acetone extracts also showed anti-AChE activity, stronger for the bark, with IC50= 82.9 ± 6.16 µg/mL and weaker for the leaves, with IC50= 333.0 ± 27.3 µg/mL, which are interesting values for whole extracts. Anti-AChE activity was inversely proportional to the amount of phenolic compounds, 639.3 ± 17.8 mg GAE/g of leaf extract and 95.3 ± 6.55 mg GAE/g of bark extract, therefore the compounds responsible for this effect do not belong to this group. The antioxidant activity cannot be explained by the amount of these compounds alone, since it was quite similar for both acetone extracts and did not therefore reflect the differences in polyphenol content.

2014Journal article

Open access

Xanthenedione derivatives, new promising acetylcholinesterase inhibitor agents

Publication . Seca, Ana M. L.; Leal, Stephanie B.; Pinto, Diana C. G. A.; Barreto, Maria do Carmo; Silva, Artur M. S.

Acetylcholinesterase inhibitors (AChEIs) are employed in medicine mostly for correcting the effects of insufficient levels of acetylcholine [1]. Xanthones are a class of secondary metabolites associated with important pharmacological properties, being some of its derivatives AChEIs [2]. Xanthenedione derivatives are not widely spread in nature but their synthesis and bioactivities evaluation is still a hot topic. Following our interest in the synthesis of biologically active compounds, several xanthene-1,9(2H)-diones (2a-2f) were synthesized by simple and efficient methodologies from (E,E)-3-cinnamoyl-5-hydroxy-2-styrylchromones (Scheme 1) [3] and their acetylcholinesterase activity evaluated by a modification of the Ellman's method [4]. The results (Table 1) showed that variations in the substitution and hydroxylation pattern seem to be important for their activity, being the xanthenedione bearing a catechol unit the most potent AChEI, even more active than galantamine, an AChEI alkaloid used clinically in early stages of Alzheimer's disease. SAR studies showed that the presence of hydroxyl 3-aryl and 4-benzylidene moieties is essential for the activity. Furthermore xanthenedione 2c showed a combination of partially competitive and non-competitive inhibition, while xanthenedione 2e shows an almost pure competitive type inhibition. The most active xanthenediones 2e and 2c present zero violations of Lipinski's 'rule of five' and xanthenedione 2c combine higher AChE activity with good oral bioavailability properties (TPSA < 140 Å2). The results suggest that they may be excellent templates for drugs to be used in the prevention and treatment of neurodegenerative diseases.

2014Journal article

Open access

The genus Inula and their metabolites : From ethnopharmacological to medicinal uses

Publication . Seca, Ana M. L.; Grigore, Alice; Pinto, Diana C. G. A.; Silva, Artur M. S.

ETHNOPHARMACOLOGICAL RELEVANCE: The genus Inula comprises more than one hundred species widespread in temperate regions of Europe and Asia. Uses of this genus as herbal medicines have been first recorded by the Greek and Roman ancient physicians. In the Chinese Pharmacopoeia, from the 20 Inula spp. distributed in China, three are used as Traditional Chinese medicines, named Tumuxiang, Xuanfuhua and Jinfeicao. These medicines are used as expectorants, antitussives, diaphoretics, antiemetics, and bactericides. Moreover, Inula helenium L. which is mentioned in Minoan, Mycenaean, Egyptian/Assyrian pharmacotherapy and Chilandar Medical Codex, is good to treat neoplasm, wound, freckles and dandruff. Many other Inula spp. are used in Ayurvedic and Tibetan traditional medicinal systems for the treatment of diseases such as bronchitis, diabetes, fever, hypertension and several types of inflammation. This review is a critical evaluation of the published data on the more relevant ethnopharmacological and medicinal uses of Inula spp. and on their metabolites biological activities. This study allows the identification of the ethnopharmacological knowledge of this genus and will provide insight into the emerging pharmacological applications of Inula spp. facilitating the prioritirization of future investigations. The corroboration of the ethnopharmacological applications described in the literature with proved biological activities of Inula spp. secondary metabolites will also be explored.

2014-06Journal article

Open access

The edible Fucus spiralis life-cycle : GC-MS profile analysis

Publication . Seca, Ana M. L.; Aguiar, Nuno F. B.; Gouveia, Vera L. M.; Silva, Artur M. S.; Pinto, Diana C. G. A.

Fucus spiralis Linnaeus, known in Azores as "Fava-do-mar'' is an edible brown macroalga (Ochrophyta (Phaeophyceae)) which can be found on rocks at upper intertidal leveis, where it forms a patchy zone. It is the only member of the genus Fucus that can be found in Azores and its receptacles are eaten as a local delicacy. Nutritionally, it is very rich in fiber (crude content 63.9% dw) contains important minerais Na, K, Mg, Ca and low content in lipids (5.2%). This edible seaweed is also rich in secondary metabolites, such as phlorotannins, sterols and fatty acids, which are associated with several biological activities. From the human health point ofview, all the above mentioned constituents are of extreme importance and show the potential of F. spiralis as a nutraceutical product. […].

2016-01Conference object

Open access