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Dive into the research topics where A. Teresa Caldeira is active.

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Featured researches published by A. Teresa Caldeira.


Bioresource Technology | 2011

An artificial intelligence approach to Bacillus amyloliquefaciens CCMI 1051 cultures: application to the production of anti-fungal compounds.

A. Teresa Caldeira; José M. Arteiro; José C. Roseiro; José Neves; Henrique Vicente

The combined effect of incubation time (IT) and aspartic acid concentration (AA) on the predicted biomass concentration (BC), Bacillus sporulation (BS) and anti-fungal activity of compounds (AFA) produced by Bacillus amyloliquefaciens CCMI 1051, was studied using Artificial Neural Networks (ANNs). The values predicted by ANN were in good agreement with experimental results, and were better than those obtained when using Response Surface Methodology. The database used to train and validate ANNs contains experimental data of B. amyloliquefaciens cultures (AFA, BS and BC) with different incubation times (1-9 days) using aspartic acid (3-42 mM) as nitrogen source. After the training and validation stages, the 2-7-6-3 neural network results showed that maximum AFA can be achieved with 19.5 mM AA on day 9; however, maximum AFA can also be obtained with an incubation time as short as 6 days with 36.6 mM AA. Furthermore, the model results showed two distinct behaviors for AFA, depending on IT.


Agroforestry Systems | 2013

Modelling molecular and inorganic data of Amanita ponderosa mushrooms using artificial neural networks

Cátia Salvador; M. Rosário Martins; Henrique Vicente; José Neves; José M. Arteiro; A. Teresa Caldeira

Wild edible mushrooms Amanita ponderosa Malençon and Heim are very appreciated in gastronomy, with high export potential. This species grows in some microclimates, namely in the southwest of the Iberian Peninsula. The results obtained demonstrate that A. ponderosa mushrooms showed different inorganic composition according to their habitat and the molecular data, obtained by M13-PCR, allowed to distinguish the mushrooms at species level and to differentiate the A. ponderosa strains according to their location. Taking into account, on the one hand, that the characterisation of different strains is essential in further commercialisation and certification process and, on the other hand, the molecular studies are quite time consuming and an expensive process, the development of formal models to predict the molecular profile based on inorganic composition comes to be something essential. In the present work, Artificial Neural Networks (ANNs) were used to solve this problem. The ANN selected to predict molecular profile based on inorganic composition has a 6-7-14 topology. A good match between the observed and predicted values was observed. The present findings are wide potential application and both health and economical benefits arise from this study.


Annals of Microbiology | 2009

MSP-PCR and RAPD molecular biomarkers to characterizeAmanita ponderosa mushrooms

A. Teresa Caldeira; Cátia Salvador; Fátima Pinto; José M. Arteiro; M. Rosário Martins

Amanita ponderosa is a specie of wild edible mushrooms growing spontaneously in some Mediterranean microclimates, namely in Alentejo and Andaluzia, in the Iberian Peninsula. The nutritional values of these fungi make them highly exportable. Due to the wide diversity of mushrooms in nature, it is essential to differentiate and to identify the various edible species. RAPD markers have been used as a valuable tool to distinguish the different genotypes, although this method has not yet been used toAmanita ponderosa. Two methods were used to establish different genetic fingerprinting patterns of edible mushrooms. Samples ofAmanita ponderosa were collected in six different regions of the southwest of the Iberian Peninsula and compared by RAPD-PCR and MSP-PCR. Additionally, to compare molecular profiles with others genera of edible mushrooms, three species of Basidiomycetes (Pleurotus ostreatus, Lactarius deliciosus andCoriolus versicolor) and an Ascomycete were used. Results showed that some molecular markers discriminate among an Ascomycete from Basidiomycetes (Amanita ponderosa, Pleurotus ostreatus, Lactarius deliciosus andCoriolus versicolor) and discriminate among the different genera within basidiomycetes, as it is expected. Moreover, OPF-6, OPG-2, OPG3 and M13 primes allowed to unravel a level of genetic polymorphism withinAmanita ponderosa mushrooms collected from different geographic origin.


Bioorganic Chemistry | 2016

New cholinesterase inhibitors for Alzheimer's disease: Structure Activity Studies (SARs) and molecular docking of isoquinolone and azepanone derivatives.

Patrícia Bacalhau; Amor A. San Juan; Carolina S. Marques; Daniela Peixoto; Albertino Goth; Cátia Guarda; Mara Silva; Sílvia Arantes; A. Teresa Caldeira; Rosário Martins; Anthony J. Burke

A library of isoquinolinone and azepanone derivatives were screened for both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activity. The strategy adopted included (a) in vitro biological assays, against eel AChE (EeAChE) and equine serum BuChE (EqBuChE) in order to determine the compounds IC50 and their dose-response activity, consolidated by (b) molecular docking studies to evaluate the docking poses and interatomic interactions in the case of the hit compounds, validated by STD-NMR studies. Compound (1f) was identified as one of these hits with an IC50 of 89.5μM for EeAChE and 153.8μM for EqBuChE, (2a) was identified as a second hit with an IC50 of 108.4μM (EeAChE) and 277.8μM (EqBuChE). In order to gain insights into the binding mode and principle active site interactions of these molecules, (R)-(1f) along with 3 other analogues (also as the R-enantiomer) were docked into both RhAChE and hBuChE models. Galantamine was used as the benchmark. The docking study was validated by performing an STD-NMR study of (1f) with EeAChE using galantamine as the benchmark.


Brazilian Journal of Microbiology | 2013

Molecular approach to characterize ectomycorrhizae fungi from Mediterranean pine stands in Portugal.

Carla Ragonezi; A. Teresa Caldeira; M. Rosário Martins; Cátia Salvador; Celeste Santos-Silva; Elsa Ganhão; Krystyna Klimaszewska; Amely Zavattieri

Stone pine (Pinus pinea L.), like other conifers, forms ectomycorrhizas (ECM), which have beneficial impact on plant growth in natural environments and forest ecosystems. An in vitro co-culture of stone pine microshoots with pure mycelia of isolated ECM sporocarps was used to overcome the root growth cessation not only in vitro but also to improve root development during acclimation phase. Pisolithus arhizus (Scop.) Rauschert and Lactarius deliciosus (L. ex Fr.) S.F. Gray fungi, were collected, pure cultured and used in in vitro co-culture with stone pine microshoots. Samples of P. arhizus and L. deliciosus for the in vitro co-cultures were collected from the pine stands southwest Portugal. The in situ characterization was based on their morphotypes. To confirm the identity of the collected material, ITS amplification was applied using the pure cultures derived from the sporocarps. Additionally, a molecular profile using PCR based genomic fingerprinting comparison was executed with other genera of Basidiomycetes and Ascomycetes. Our results showed the effectiveness of the techniques used to amplify DNA polymorphic sequences, which enhances the characterization of the genetic profile of ECM fungi and also provides an option to verify the fungus identity at any stage of plant mycorrhization.


Bioorganic Chemistry | 2016

Insights into (S)-rivastigmine inhibition of butyrylcholinesterase (BuChE): Molecular docking and saturation transfer difference NMR (STD-NMR)

Patrícia Bacalhau; Amor A. San Juan; Albertino Goth; A. Teresa Caldeira; Rosário Martins; Anthony J. Burke

Rivastigmine is a very important drug prescribed for the treatment of Alzheimers disease (AD) symptoms. It is a dual inhibitor, in that it inhibits both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). For our screening program on the discovery of new rivastigmine analogue hits for human butyrylcholinesterase (hBuChE) inhibition, we investigated the interaction of this inhibitor with BuChE using the complimentary approach of the biophysical method, saturation transfer difference (STD)-NMR and molecular docking. This allowed us to obtain essential information on the key binding interactions between the inhibitor and the enzyme to be used for screening of hit compounds. The main conclusions obtained from this integrated study was that the most dominant interactions were (a) H-bonding between the carbamate carbonyl of the inhibitor and the NH group of the imidazole unit of H434, (b) stacking of the aromatic unit of the inhibitor and the W82 aromatic unit in the choline binding pocket via π-π interactions and (c) possible CH/π interactions between the benzylic methyl group and the N-methyl groups of the inhibitor and W82 of the enzyme.


Annals of Microbiology | 2014

Molecular evaluation of some Amanita ponderosa and the fungal strains living in association with these mushrooms in the southwestern Iberian Peninsula

Cátia Salvador; M. Rosário Martins; José M. Arteiro; A. Teresa Caldeira

Amanita ponderosa are wild edible mushrooms that grow only in some microclimates, particularly those in the southwestern part of the Iberian Peninsula. Due to the vast diversity of mushrooms in nature, as well as nutrient variability, which is highly dependent on soil type and environmental conditions, it is essential to be able to characterize fungal microbiota that lives in association with mushrooms and to differentiate A. ponderosa strains of different regions for certification purposes. In this study, we characterized the genetic profile of A. ponderosa mushrooms and the fungal strains that live in association with them in their natural habitat and compared the fingerprinting profiles obtained by M13-PCR amplification of the genomic DNA. We found that the predominant fungal isolates living in association with A. ponderosa were Aspergillus spp., Penicillium spp. and Mucor spp. M13-PCR molecular analysis showed that different fungal isolates had different genetic profiles. This approach allowed us to differentiate the different fungi strains isolated from fruiting bodies of A. ponderosa both rapidly and in a reproducible manner and to group them according to genus. Our fingerprinting analyses also distinguished different A. ponderosa mushrooms collected from different regions. Consequently, we conclude that this method is a very discriminatory approach for differentiating both A. ponderosa from different sites and the fungal microbiota that lives in association with these mushrooms.


Natural Product Research | 2017

Antioxidant activity and cholinesterase inhibition studies of four flavouring herbs from Alentejo

Sílvia Arantes; Andreia Piçarra; Fátima Candeias; Dora Martins Teixeira; A. Teresa Caldeira; M. Rosário Martins

Abstract Essential oils (EOs) and aqueous extracts of aerial parts of four aromatic species, Calamintha nepeta, Foeniculum vulgare, Mentha spicata and Thymus mastichina, from southwest of Portugal were characterised chemically and analysed in order to evaluate their antioxidant potential and cholinesterase inhibitory activities. The main components of EOs were oxygenated monoterpenes, and aqueous extracts were rich in phenol and flavonoid compounds. EOs and aqueous extracts presented a high antioxidant potential, with ability to protect the lipid substrate, free radical scavenging and iron reducing power. Furthermore, EOs and extracts showed AChE and BChE inhibitory activities higher than rivastigmine, the standard drug. Results suggested the potential use of EOs and aqueous extracts of these flavouring herbs as nutraceutical or pharmaceutical preparations to minimise the oxidative stress and the progression of degenerative diseases.


International Journal of Analytical Chemistry | 2018

A Data Mining Approach to Improve Inorganic Characterization of Amanita ponderosa Mushrooms

Cátia Salvador; M. Rosário Martins; Henrique Vicente; A. Teresa Caldeira

Amanita ponderosa are wild edible mushrooms that grow in some microclimates of Iberian Peninsula. Gastronomically this species is very relevant, due to not only the traditional consumption by the rural populations but also its commercial value in gourmet markets. Mineral characterisation of edible mushrooms is extremely important for certification and commercialization processes. In this study, we evaluate the inorganic composition of Amanita ponderosa fruiting bodies (Ca, K, Mg, Na, P, Ag, Al, Ba, Cd, Cr, Cu, Fe, Mn, Pb, and Zn) and their respective soil substrates from 24 different sampling sites of the southwest Iberian Peninsula (e.g., Alentejo, Andalusia, and Extremadura). Mineral composition revealed high content in macroelements, namely, potassium, phosphorus, and magnesium. Mushrooms showed presence of important trace elements and low contents of heavy metals within the limits of RDI. Bioconcentration was observed for some macro- and microelements, such as K, Cu, Zn, Mg, P, Ag, and Cd. A. ponderosa fruiting bodies showed different inorganic profiles according to their location and results pointed out that it is possible to generate an explanatory model of segmentation, performed with data based on the inorganic composition of mushrooms and soil mineral content, showing the possibility of relating these two types of data.


Canadian Journal of Forest Research | 2013

Prediction of bioactive compound activity against wood contaminant fungi using artificial neural networks

Henrique Vicente; José C. Roseiro; José M. Arteiro; José Neves; A. Teresa Caldeira

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