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- Cistus ladanifer (Cistaceae) : a natural resource in Mediterranean-type ecosystemsPublication . Frazão, David F.; Raimundo, Joana; Domingues, Joana Lopes; Quintela-Sabarís, Celestino; Gonçalves, José Carlos; Delgado, F.M.G.Cistus ladanifer has a well-defined taxonomic identity. 2,2,6-trimethylcyclohexanone may be an authenticity and taxonomic marker. Its traits and applications make it a possible economic resource fitted for Mediterranean areas. Cistus ladanifer is a dominant shrub species endemic to the western Mediterranean region. Due to its dominant nature and its potential ecological, aromatic or pharmacological applications, C. ladanifer has been the object of numerous studies. In this review current knowledge on different aspects of this species is summarized, from its taxonomy to its chemical characterisation or its competitive traits. There are no doubts about the taxonomic entity of C. ladanifer, although the recognition of infraspecific taxa deserves more attention. Given that the fragrant exudate of C. ladanifer holds a very specific composition, one species specific carotenoid, 2,2,6-trimethylcyclohexanone, derivative is proposed as an authenticity marker for uses of C. ladanifer in pharmacological or aromatic industries. Evidence is also gathered on the extreme adaptation of C. ladanifer to stressful conditions in the Mediterranean region, such as the ability to survive in low hydric and high solar exposition conditions, presistence in poor and contaminated soils, and growth inhibition of several other plants through the release of allelochemicals. Thus, the finding of potential applications for this plant may contribute to enhance the economic dimension of derelict lands, such as mine tailings or poor agricultural Mediterranean areas.
- Rockrose land management : contribution of periodic harvesting to increase value and to control Cistus ladanifer L. shrublandsPublication . Frazão, David F.; Gonçalves, José Carlos; Silva, Amélia M.; Delgado, F.M.G.: Cistus ladanifer L. (Cistaceae) occupies extensive areas as a dominant species (shrublands) or is associated to other major forest typologies in the Iberian Peninsula. Cistus ladanifer shrublands are mostly present in oligotrophic lands with little valorisation and management and as they develop over the years (up to 20-years-old) they promote the ignition and perpetuation of fire. To contribute to the proper management and valorisation of such systems, a 5-year-old dense shrubland was evaluated for its labdanum resin, seeds, and biomass productivity using different non-destructive harvest periodicities (annual and biennial) and seasons (early, mid-, and late summer), in a two-year case-study. Annual harvest modality maximized labdanum resin productivity (reaching 230 ± 50 kg·ha−1 ·2 years−1 at late summer) and photosynthetic biomass productivity. In contrast, a biennial harvest yielded significant amounts of more diversified products. It maximized seeds productivity (reaching 75 ± 41 kg·ha−1 ·2 years−1 independently of the summer season) and lignified biomass. However, it also reached a labdanum resin productivity of 134 ± 20 kg·ha−1 ·2 yearrs−1 at late summer and a photosynthetic biomass productivity around two times lower than the annual harvest. In this study, we propose two modalities of periodic harvest to be considered as proper long cycle management practices of rockrose lands. It intends to minimize fire risks, break the vegetation auto-succession mechanism, and increase profit from nonproductive lands based on three direct outputs with a myriad of applications and valorisation pathways.
- Physicochemical and sensorial characterization of honey spiritsPublication . Anjos, O.; Frazão, David F.; Caldeira, IldaDistilled spirits are usually made from fermented sugar-based materials, such as wines or fermented fruits, but other products can be used, namely berries or honey. In this work, an evaluation of honey spirits is done based on its physicochemical and sensory characteristics. Fourteen honey spirit samples of different brands of honey spirit were purchased at the market and from artisan Portuguese producers. Several analytical determinations, namely alcoholic strength, dry matter, density, total acidity, chromatic characteristics, methanol, acetaldehyde, ethyl acetate and higher alcohols were done to characterize all samples. The results pointed out several differences in physicochemical composition of samples. In general, these drinks are characterized by an alcohol strength between 37.4% and 53.0% and a low methanol content, quite null for most samples. Samples with higher ethanol content corresponded to the artisanal samples. Significant differences (p < 0.05) were also observed in the volatile composition and chromatic characteristics suggesting different production technologies. A first list of sensory attributes was obtained for this beverage. Therefore, further research must be done in order to characterize this spirit drink, which has gained market value.
- Labdanum resin from Cistus ladanifer L.: a natural and sustainable ingredient for skin care cosmetics with relevant cosmeceutical bioactivitiesPublication . Frazão, David F.; Gomes, Carlos Martins; Steck, Jan L.; Keller, Judith; Delgado, F.M.G.; Gonçalves, José Carlos; Bunzel, MirkoLabdanum resin from Cistus ladanifer L. (Cistaceae) is an abundant natural resource in the Iberian Peninsula worth being explored in a sustainable manner. It is already used in the cosmetic industry; mainly by the fragrances/perfumery sector. However, given the highest market share and traditional uses, labdanum resin also has the potential to be used and valued as a cosmetic ingredient for skincare. Aiming to evaluate this potential, labdanum methanolic absolute and fractions purified by column chromatography were characterized by UPLC-DAD-ESI-MS and then evaluated for UVprotection, antioxidant, anti-elastase, anti-inflammatory, and antimicrobial activities. Labdanum absolute represented ~70% of the resin; diterpenoid and flavonoid fractions represented ~75% and 15% of the absolute, respectively. Labdane-type diterpenoids and methylated flavonoids were the main compounds in labdanum absolute and in diterpenoid and flavonoid fractions, respectively. Labdanum absolute showed a spectrophotometric sun protection factor (SPF) near 5, which is mainly due to flavonoids, as the flavonoids’ SPF was 13. Low antioxidant activity was observed, with ABTS radical scavenging being the most significant (0.142 ± 0.017, 0.379 ± 0.039 and 0.010 ± 0.003 mgTE/mgExt, for the absolute and flavonoid and terpene fractions, respectively). Anti-aging and anti-inflammatory activity are reported here for the first time, by the inhibition of elastase activity (22% and 13%, by absolute and flavonoid extract at 1 mg/mL), and by the inhibition of nitric oxide production in LPS-induced RAW 264.7 cells (84% to 98%, at 15 µg/mL extracts, flavonoid fraction the most active), respectively. Antimicrobial activity, against relevant skin and cosmetic product microorganisms, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, and Escherichia coli, revealed that only S. aureus was susceptible to labdanum absolute (MIC: 1.2 mg/mL) and its fractions (MIC: <0.3 mg/mL). In conclusion, labdanum resin showed potential to be used in sunscreen cosmetics, anti-inflammatory skincare cosmeceuticals or medicines but has low potential as a cosmetic product preservative given the low antioxidant and low-spectrum antimicrobial activities.
- Cistus ladanifer L. tissue culture from leaf and stem explants.Publication . Frazão, David F.; Barroca, Celina; Silva, Amélia M.; Delgado, F.M.G.; Gonçalves, José CarlosCistus ladanifer L. exudes a phenolic and terpenoid resin with interesting bioactive and aromatic properties. Despite its high abundance in the wild, this plant can be cultivated to advantage on oligotrophic and trace-elements contaminated soils. Plant tissue culture may be used to produce specific metabolites or for clonal propagation of specific genotypes for plantation. From a biotechnological perspective this is the second study that has attempted in vitro propagation of C. ladanifer from adult plant material. Its goal was to evaluate the potential of leaf and internodal stem explants from C. ladanifer for in vitro tissue culture. Three plant growth regulators were tested: 2,4-Dichlorophenoxyacetic acid (2,4-D), 6-Benzylaminopurine (BAP), and 1-Naphthaleneacetic acid (NAA). From both explants, shoots were regenerated under the influence of BAP (38%) and two types of compact calli were induced: dark green calli were induced under the influence of BAP (above 70%) and light green calli were induced under the influence of 2,4-D with or without BAP (100%). Light green calli grew between 558 and 708% during subsequent subcultures and showed rhizogenic capacity when the amounts of BAP were lower than of 2.4-D, but they showed low potential for shoot organogenesis. Dark green calli were associated with shoot organogenesis. The suitability of the two calli lines to produce metabolites and their transposition to liquid cultures is worth further study in comparison to organ in vitro cultures.
- Cistus ladanifer seeds: from ancient snack to novel and sustainable food ingredientPublication . Frazão, David F.; Paulo, Luísa; Peres, Maria de Fátima; Resende, Mafalda; Espírito Santo, Christophe; Barroca, Celina; Rodrigues, A.M.; Delgado, F.M.G.Cistus ladanifer is a persistent, abundant and widespread underexplored resource in the Iberian Peninsula. The seeds have been used as food for centuries, although their nutritional value and potential as food ingredients have not been exploited until now. In this study seeds from natural shrubland were collected three times during summer for two consecutive years. Analytical evaluation of the macronutrient content, fatty acids, and mineral composition was performed. Regarding the macronutrients, seeds showed a carbohydrate content of 46.1 ± 1.6%, a fibre content of 20.9 ± 1.4%, a protein content of 16.2 ± 0.4%, a lipid content of 13.0 ± 1.1%, and an ash content of 3.87 ± 0.16%. The fatty acids were found to be mostly unsaturated (74.05 ± 0.59%). Potassium was the most abundant mineral (975 ± 53 mg/100 g) followed by phosphorous, magnesium and calcium. In conclusion, several nutrient-related label claims may be used for C. ladanifer seeds as food ingredient. Compared to common cereals, nuts and seeds, C. ladanifer seeds are close to flax and chia seeds in relation to nutritional composition, and to pine nuts in relation to mineral composition.
- Morphological and physiological effects of two different light sources on in vitro multiplication of chestnut and prickled broomPublication . Gonçalves, José Carlos; Skec, A.; Krnjac, A.; Delgado, Teresa; Frazão, David F.; Farinha, Nelson; Domingues, Joana Lopes; Coelho, Maria TeresaThe morphology and physiology of plants grown in vitro are regulated by various environmental factors such as light, temperature, humidity and carbon dioxide. Light, in its various parameters such as spectral quality, photon flux and photoperiod, is an important factor among these and generally influences the overall growth and development of plants in vitro. Light sources commonly used for in vitro plant culture are fluorescent lamps, although some research and commercial laboratories also use sodium metal or incandescent metal halide lamps. The spectral of those lamps range from 350 to 750 nm and contain blend lights that differentially affect in vitro plant growth. Recently, light emitting diodes (LEDs) have been developed and are nowadays used as an alternative source of fluorescent light for the development of plants both in greenhouses and in vitro culture rooms. In order to test the influence of these two types of light during multiplication phase, a multiplicity experiment was carried out using two species: a chestnut hybrid (Castanea sativa x C. crenata), clone M2 and the prickled broom (Pterospartum tridentatum (L.) Willk.), Malcata ecotype. Two types of light were tested, "cool white" fluorescent light and LED light with blue and red colors. It was found that LED illumination exerted a significant positive effect on the differentiation of shoots in the case of prickled broom (5.6 instead of 4.9 split shoots under fluorescent light). In the parameters of shoot length, we found that this type of lighting favored the elongation in both species. Regarding the parameters of fresh and dry weight, LED lighting caused a greater effect on the chestnut than on prickled broom. Some physiological parameters (chlorophylls, carotenoids and proteins) were also analyzed and showed to be influenced by the type of light during the development of microplants.
- Neglected mediterranean plant species are valuable resources: the example of Cistus ladaniferPublication . Delgado, F.M.G.; Raimundo, Joana; Frazão, David F.; Domingues, Joana Lopes; Quintela-Sabarís, Celestino; Dentinho, Teresa P.; Anjos, O.; Alves, MarcosMain conclusion: The combination of genotypic selection, targeted and improved cultivation, and processing techniques for specific applications gives C. ladanifer the potential to be used as a valuable resource in Mediterranean areas with poor agronomic advantages. Cistus ladanifer (rockrose) is a perennial shrub, well adapted to the Mediterranean climate and possibly to upcoming environmental changes. As a sequence to a thorough review on taxonomic, morphological, chemical and competitive aspects of C. ladanifer, the research team focuses here on the economic potential of C. ladanifer: from production to applications, highlighting also known biological activities of extracts and their compounds. The use of this natural resource may be a viable solution for poor and contaminated soils with no need for large agricultural techniques, because this species is highly resistant to pests, diseases and extreme environmental factors. In addition, this species reveals interesting aptitudes that can be applied to food, pharmaceutical, phytochemical and biofuel industries. The final synthesis highlights research lines toward the exploitation of this neglected resource, such as selection of plant lines for specific applications and development of agronomic and processing techniques.
- Labdanum resin from Cistus ladanifer L. as a source of compounds with anti-diabetic, neuroprotective and anti-proliferative activityPublication . Frazão, David F.; Gomes, Carlos Martins; Sosa Diaz, Teresa; Delgado, F.M.G.; Gonçalves, José Carlos; Silva, Amélia M.Labdanum resin or “gum” can be obtained from Cistus ladanifer L. by two different extraction methods: the Zamorean and the Andalusian processes. Although its main use is in the fragrance and perfumery sectors, ethnobotanical reports describe its use for medicinal purposes in managing hyperglycemia and mental illnesses. However, data concerning the bioactivities and pharmacological applications are scarce. In this work, it was found that the yield of labdanum resin extracted by the Andalusian process was 25-fold higher than the Zamorean one. Both resins were purified as absolutes, and the Andalusian absolute was purified into diterpenoid and flavonoid fractions. GC-EI-MS analysis confirmed the presence of phenylpropanoids, labdane-type diterpenoids, and methylated flavonoids, which are already described in the literature, but revealed other compounds, and showed that the different extracts presented distinct chemical profile. The potential antidiabetic activity, by inhibition of α-amylase and α-glucosidase, and the potential neuroprotective activity, by inhibition of acetylcholinesterase, were investigated. Diterpenoid fraction produced the higher α-amylase inhibitory effect (~30% and ~40% at 0.5 and 1 mg/mL, respectively). Zamorean absolute showed the highest α-glucosidase inhibitory effect (~14% and ~24%, at 0.5 and 1 mg/mL, respectively). Andalusian absolute showed the highest acetylcholinesterase inhibitory effect (~70% and ~75%, at 0.5 and 1 mg/mL, respectively). Using Caco-2 and HepG2 cell lines, Andalusian absolute and its purified fractions showed moderate cytotoxic/anti-proliferative activity at 24 h exposure (IC50 = 45–70 µg/mL, for Caco-2; IC50 = 60–80 µg/mL, for HepG2), whereas Zamorean absolute did not produce cytotoxicity (IC50 ≥ 200.00 µg/mL). Here we show, for the first time, that labdanum resin obtained by the Andalusian process, and its fractions, are composed of phytochemicals with anti-diabetic, neuroprotective and anti-proliferative potential, which are worth investigating for the pharmaceutical industry. However, toxic side-effects must also be addressed when using these products by ingestion, as done traditionally.
- Filmes ativos com resveratrol para controlo de Campylobacter spp. e Arcobacter spp. em carne de frangoPublication . Frazão, David F.; Pintado, Cristina Maria Baptista dos Santos; Domingues, Fernanda da ConceiçãoCampylobacter spp. e Arcobacter spp. têm sido associadas a doenças de origem alimentar através do consumo de, principalmente, carne de frango. O embalamento de carnes com filmes antimicrobianos pode ser uma estratégia eficaz para, ativamente, controlar contaminações microbianas durante o seu transporte e armazenamento. Assim, no presente trabalho, foram preparados filmes de quitosano (Ch) e/ou metilcelulose (MC) ativos com um complexo de inclusão (CI) de resveratrol (RV) e 2-(hidroxipropil)-γ-CD (HP-γ-CD) com o intuito de, ao embalarem carne de frango, conseguirem controlar Campylobacter spp. e Arcobacter spp. Os filmes preparados foram caracterizados relativamente às propriedades antimicrobianas, propriedades mecânicas, permeabilidade ao vapor de água e teor de humidade. A melhor formulação filmogénica foi, ainda, caracterizada quanto à atividade antimicrobiana num ensaio de embalamento de carne de frango ao longo de 10 dias. Filmes ativos MC não conseguiram ser preparados devido à formação de um complexo insolúvel e filmes ativos de Ch e de mistura igualitária de Ch/MC demonstraram, nos testes de difusão em agar, atividade antimicrobiana contra C. jejuni ATCC 33560 (21-24mm e 10-14mm), C. coli ATCC 33559 (zonas de inibição parcial) e A. butzleri LMG 6620 (13-16mm e 10-13mm) mas não contra A. butzleri LMG 10828. Embora com a mesma tensão máxima de tração (Ch=2,63MPa e Ch/MC=2,77MPa), os filmes ativos de Ch/MC apresentaram um módulo de elasticidade maior (EM=45,58MPa) mas uma capacidade de alongamento (E%=58,63%) cerca de 2 vezes inferior aos filmes ativos de Ch (EM=16,98MPa e E%=128%). A permeabilidade ao vapor de água e o teor de humidade foi similar para os dois tipos de filme ativo (WVP≈1,5x10-9g/Pa.s.m e teor de humidade≈15%). Nos ensaios em carne de frango foi observada uma redução da população microbiana microaerófila de 1-2Log UFC/g em carne de frango não inoculada ou inoculada com C. jejuni ATCC 33560 ou A. butzleri LMG 6620 embalada com filmes de Ch com e sem RV, em oposição a um aumento de 3Log UFC/g em carne embalada com sacos de poliamida/polietileno comerciais. Foi demonstrada a migração e atividade antimicrobiana do RV, em princípio na forma de CI, dos filmes de Ch e Ch/MC mas uma menor migração na presença da MC devido a uma interação, possivelmente do tipo hidrofóbica, entre a MC e a HP-γ-CD, não se concluindo a interação com o RV. Nos ensaios de embalamento de carne de frango foi concluída a atividade antimicrobiana do Ch que ultrapassou a atividade do RV como componente ativo contra a flora microbiana natural da carne de frango e possivelmente contra as estirpes bacterianas inoculadas.