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Research Project
Associated Laboratory for Green Chemistry - Clean Technologies and Processes
Funder
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Publications
Transition Metal‐Catalyzed Transformations of Chalcones
Publication . Santos, Clementina M.M.; Silva, Artur
Chalcones are a class of naturally occurring flavonoid compounds associated to a
variety of biological and pharmacological properties. Several reviews have been published
describing the synthesis and biological properties of a vast array of analogues. However, overviews
on the reactivity of chalcones has only been explored in a few accounts. To fill this gap, a
systematic survey on the most recent developments in the transition metal-catalyzed transformation
of chalcones was performed. The chemistry of copper, palladium, zinc, iron,
manganese, nickel, ruthenium, cobalt, rhodium, iridium, silver, indium, gold, titanium,
platinum, among others, as versatile catalysts will be highlighted, covering the literature from
year 2000 to 2023, in more than 380 publications.
Effects of Summer Water Deficit Stress on Olive Fruits and Oil Quality
Publication . Araújo, Márcia; Rodrigues, Nuno; Santos, Conceição; Pinto, Diana; Pereira, J.A.; Silva, Artur; Dias, Maria Celeste
The Mediterranean basin is the leading worldwide region for olive production. Extreme
weather is increasingly frequent in this region, and how these climate extremes will affect olive
products and quality remains unknown. We aim to study the effects of the water deficit stress, which
occurred in the summer of 2017, on olive fruit and oil quality from a 30-year-old orchard. Fruits from
olive trees standing on (i) one hydrated and (ii) one dry area of an orchard at the north of Portugal
were harvested. Fruits’ water content, oil yield and quality, fruit carbohydrates, and fruit and oil
phenolic metabolite profiles were analyzed. Fruits from the dry area presented low water availability
and increased carbohydrates, oleuropein, oleoside, and elenolic acid glucoside abundance. Oil yield
was lower in the dry area, but the abundance of oleacein increased, together with traits of some
sensory sensations. Climate stress events can reduce oil yield but stimulate the accumulation of
bioactive compounds that improve oil quality and nutritional value.
Influence of interannual climate conditions on the composition of olive oil from centenarian olive trees
Publication . Bortuluzzi, Letícia Cabrera Parra; Casal, Susana; Cruz, Rebeca; Peres, António M.; Baptista, Paula; Rodrigues, Nuno
In recent years, occurrences of heat waves and drought have become increasingly frequent,
highlighting the undeniable impact of climate change. The rise in temperatures and decline in
rainfall have had severe repercussions on olive trees’ behavior and olive oil production. This study
aims to evaluate the effects of two-year climate variations on olive oils from centenarian olive trees
situated in the Côa Valley region of Northern Portugal. A selection of 25 centenarian plants was
made, and the climate influence on fatty acid content, tocopherols, individual phenols, oxidative
stability, and antioxidant activity was assessed over two consecutive years. During the second year
of the study, a significant variation (p-value < 0.05) in the proportion of palmitic acid was observed,
which increased from 12.9% to 13.6%. Conversely, stearic and arachidic acids exhibited a decrease
from 2.7% to 2.3% and from 0.37% to 0.35%, respectively. Analysis of the oils revealed a noteworthy
difference (p-value < 0.05) in the concentration of -tocopherol. The concentration of oils derived
from hydroxytyrosol and tyrosol significantly decreases (p-value < 0.005) during the second year.
Additionally, significant differences (p-value < 0.005) were observed in the total phenol content and
the percentage of ABTS inhibition, both of which decreased in the second year. These findings
reinforce the notion that climatic conditions play a key role in shaping the composition of olive oils.
Detailed Phytochemical Composition, Cyto-/Hepatotoxicity, and Antioxidant/Anti-Inflammatory Profile of Moroccan Spices: A Study on Coriander, Caraway, and Mystical Cumin
Publication . Bouzaid, Hiba; Espírito Santo, Liliana; Ferreira, Diana M.; Machado, Susana; Costa, Anabela S.G.; Dias, Maria Inês; Calhelha, Ricardo C.; Barros, Lillian; Chater, Oumaima; Rodi, Youssef Kandri; Errachidi, Faouzi; Chahdi, Fouad Ouazzani; Oliveira, Beatriz; Alves, Rita C.
Coriander, caraway, and mystical cumin are famous for their aromatic properties and
widely used in Moroccan cuisine. The nutritional/phytochemical composition of their seeds (used
for food flavoring and preservation) were compared. Their antioxidant, anti-inflammatory, cytotoxic
and hepatotoxic effects were also explored. The fat content was similar among the samples (13%),
with monounsaturated fatty acids being predominant. The coriander and mystical cumin seeds
were extremely rich in C18:1n9c (81 and 85%, respectively) while, in the caraway, C18:1n12 (25%)
was found together with C18:1n9c (32%). The caraway seeds also presented a higher proportion
of C18:2n6c (34%) than the other seeds (13 and 8%, correspondingly). γ-Tocotrienol was the major
vitamin E form in all the samples. The caraway seeds contained double the amount of protein
(~18%) compared to the other seeds (~8%) but, qualitatively, the amino acid profiles among all
seeds were similar. The seeds were also rich in dietary fiber (40–53%); however, differences were
found in their fiber profiles. Caraway showed the highest antioxidant profile and anti-inflammatory
activity and an LC-DAD-ESI/MSn analysis revealed great differences in the phenolic profiles of the
samples. Cytotoxicity (NCI-H460, AGS, MCF-7, and CaCo2) and hepatotoxicity (RAW264.7) were
not observed. In sum, besides their flavoring/preservation properties, these seeds are also relevant
source of bioactive compounds with health-promoting activities.
Localized cancer photodynamic therapy approach based on core–shell electrospun nanofibers
Publication . Costa, Sofia M.; Lourenço, Leandro M.O.; Calhelha, Ricardo C.; Calejo, Isabel; Barrias, Cristina C.; Fangueiro, Raul; Ferreira, Diana P.
Photodynamic therapy (PDT) has been considered a promising treatment for several types of cancer,
including cervical cancer. Localized drug delivery systems (DDSs) based on nanofibers produced by
electrospinning have emerged as a powerful platform to carry and deliver photosensitizers (PSs) onto or
adjacent to the tumor site, thereby promoting higher therapeutic efficacy and reducing the side effects
to healthy tissues associated with systemic administration. In this work, core–shell electrospun nanofibers
were produced using biodegradable polymers, such as poly(vinyl alcohol) (PVA) and gelatin (Gel),
to act as a localized DDS for the treatment of cervical cancer using PDT. The synthesized porphyrin
(Por) was able to generate singlet oxygen (FD = 0.62) and displayed higher phototoxicity against
tumor cells compared with healthy cells. The developed PVA–Gel membranes were fully characterized,
revealing defect-free nanofibers with a core–shell structure. Different Por concentrations were added to
the fibers’ core, and their presence and uniform distribution within the nanofibers were confirmed. The
Por release profile from nanofibers showed an initial fast release stage, followed by continuous release
for at least 9 days. The PVA–Gel + Por core–shell nanofibers exhibited a higher inhibition of cancer cell
proliferation under light irradiation when compared to dark and a higher phototoxic effect against tumor
cells compared with non-tumor cells. Overall, this study demonstrates the great potential of core–shell
nanofibers to be used as localized DDSs of PSs for the treatment of cervical cancer.
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Funding agency
Fundação para a Ciência e a Tecnologia
Funding programme
6817 - DCRRNI ID
Funding Award Number
UIDP/50006/2020