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Inhibition of enzymes involved in carbohydrate and lipids metabolism is an important strategy against type 2 diabetes and obesity, by suppressing dietary sugar and fat absorption. This work reports, for the first time, the in vitro inhibition of α-glucosidase, α-amylase and lipase by watercress juice (WJ). Juice was analyzed for qualitative and quantitative composition and in vitro antioxidant activities. Several components were identified, namely hydroxycinnamic acids, flavonols, and other minor water-soluble phytochemicals. Quantitative data revealed a dimer of caffeoylmalic acid (0.73 mg mL−1 of juice), disinapoylgentibiose (0.64 mg mL−1), ferulic acid (0.56 mg mL−1), and isorhamnetin-O-sophoroside-O-malonyl(hexoside) (0.38 mg mL−1) as the predominant polyphenols. The results showed that WJ had dose-dependent inhibitory potential against targeted enzymes, displaying a more potent inhibitory effect against α-glucosidase relative to α-amylase and lipase. WJ can be considered a potential complementary dietary approach to control hyperglycaemia and hyperlipidaemia, through inhibition of digestive enzymes. Practical applications Currently, raw watercress is widely consumed in liquid form, alone or together with other fresh vegetables, as an ingredient of the “detox juices.” Studies on watercress phenolic composition and antidiabetic properties have been performed on extracts, but not on juice, which is closer to the edible form. The present study supports consumption of watercress juice as source of phytochemicals potentially capable of inhibiting digestive enzymes linked to diabetes and obesity prevention/control.

Introduction In Madeira Archipelago there are four endemic Helichyrsum species and three of them are used in the traditional medicine. Helichrysum monizii is a rare endemism with very scarce information available concerning its uses in the local traditional medicine. Objective The aim of this work was to study for the first time Helichrysum monizii in terms of its antioxidant capacity and the identification of the phenolic compounds to which that activity is due. Methodology Three different methods of extraction were performed and total phenolic and flavonoid contents of extracts were correlated to radical scavenging and antioxidant capacity by DPPH, ABTS, FRAP and β-carotene assays. An HPLC-DAD-ESI/MSn method was employed for the separation and identification of the phenolic and flavonoid components. Results The results revealed a high antioxidant potential mainly related to the phenolic profile of the plant. Polar components of methanol extracts of Helichrsyum monizii were detected by a high-performance liquid chromatography/electrospray ionisation tandem mass spectrometry (HPLC-DAD-ESI/MSn) method. Thirty-three compounds were identified and 19 of them were identified as quinic acid derivatives. Conclusions The high antioxidant potential Helichrysum monizii was for the first time established. Dicaffeoylquinic acids are the main responsible for that activity. Copyright © 2011 John Wiley & Sons, Ltd.

Helicrysum melaleucum is a medicinal plant traditionally used in the islands of the Macaronesia region for the treatment of respiratory diseases. In this work, the phenolic compounds of Helicrysum melaleucum plants collected in different geographical locations of Madeira Island and their morphological parts (total aerial parts, leaves, flowers and stems) were extracted and analyzed separately by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC-DAD/ESI-MS(n)). A total of 68 compounds were characterized based mainly on their UV and mass spectra. These included derivatives of O-glycosylated flavonoids (flavonol and flavones type), quinic acid, caffeic acid, lignans and polyphenols. The flowers were found to be the morphological part with higher variety of phenolic compounds. The large differences in the phenolic composition of plants collected from different geographical locations allowed the identification of a few components, such as pinoresinol and methoxylated flavone derivatives, likely to be useful as geographical markers. Also, these results promote further comparison of the bioactivities of the different samples analyzed. This paper marks the first report on the chemical analysis of Helichrysum melaleucum species.

The possibility of using Annona seed oil as an added value product, namely as a source of biodiesel, is explored. Milled Annona seeds were extracted with hexane at room temperature (72 h) and at solvent boiling point (6 h). Oil content was found to be 25 and 22.4% respectively. The oil was characterized in terms of lipid composition (HPLC–APCI–MS and 13C NMR), resistance to oxidation and acidity index. FAME composition was determined by GC–MS and five major peaks were identified. Production of biodiesel from Annona’s seed oil was achieved by base-catalyzed transesterification. Density, viscosity, refraction coefficient, acid value, cold filter plugging point, cloud point and oxidation stability were measured. The iodine value and the “apparent cetane number” were calculated. Density, viscosity, acid value, iodine value, cold filter plugging point and cloud point were within EN14214 specifications and the calculated “apparent cetane number” was also indicative of a suitable product.

A simple and rapid method has been used for the screening and identification of the main phenolic compounds from Helichrysumdevium using high-performance liquid chromatography with on-line UV and electrospray ionization mass spectrometric detection (LC-DAD/ESI-MSn). The total aerial parts and different morphological parts of the plant, namely leaves, flowers and stems, were analyzed separately. A total of 34 compounds present in the methanolic extract from Helichrysumdevium were identified or tentatively characterized based on their UV and mass spectra and retention times. Three of these compounds were positively identified by comparison with reference standards. The phenolic compounds included derivatives of quinic acid, O-glycosylated flavonoids, a caffeic acid derivative and a protocatechuic acid derivative. The characteristic loss of 206 Da from malonylcaffeoyl quinic acid was used to confirm the malonyl linkage to the caffeoyl group. This contribution presents one of the first reports on the analysis of phenolic compounds from Helichrysumdevium using LC-DAD/ESI-MSn and highlights the prominence of quinic acid derivatives as the main group of phenolic compounds present in these extracts. We also provide evidence that the methanolic extract from the flowers was significantly more complex when compared to that of other morphological parts. Copyright © 2009 John Wiley & Sons, Ltd.

Clinopodium ascendens (Jordan) Sampaio [synonyms = Calamintha ascendens Jordan = C. officinalis Moench ssp. ascendens (Jord.) Mateo = C. sylvatica Bromf. ssp. ascendens (Jord.) P.W. Ball] is a small herbaceous plant with a very strong and distinctive mint aroma. The plant is known for its medical uses in folk medicine and as a spice in Italian kitchens. In Madeira Island, Clinopodium ascendens, known locally as ‘neveda’, grows wild along the shady paths of the Laurissilva forest. The local population uses the leaves of calamint as a mouth freshener and to alleviate headache and toothache. The essential oil obtained by hydrodistillation of the aerial parts of C. ascendens growing wild in Madeira was analysed by a combination of CC, GC, GC–MS, 1H- and 13C-NMR. The oil was dominated by C3 oxygenated p-menthane derivatives: cis-isopulegone (75.2%), pulegone (6.9%), neoiso-isopulegol (6.0%) and trans-isopulegone (4.5%). The whole essential oil was tested against a variety of bacteria, both Gram-positive and Gram-negative, and two fungi; it exhibited remarkable activity against Escherichia coli and was active against Agrobacterium tumefasciens and Staphylococcus aureus and the phytopathogenic fungus Botrytis cinerea. It was ineffective against Streptococcus faecium, Streptococcus mutans and Candida albicans. Copyright © 2006 John Wiley & Sons, Ltd.

Mild fractionation/pretreatment processes are becoming the most preferred choices for biomass processing within the biorefinery framework. To further explore their advantages, new developments are needed, especially to increase the extent of the hydrolysis of poly- and oligosaccharides. A possible way forward is the use of solid acid catalysts that may overcome many current drawbacks of other common methods. In this Review, the advantages and limitations of the use of heterogeneous catalysis for the main groups of solid acid catalysts (zeolites, resins, carbon materials, clays, silicas, and other oxides) and their relation to the hydrolysis of model soluble disaccharides and soluble poly- and oligosaccharides are presented and discussed. Special attention is given to the hydrolysis of hemicelluloses and hemicellulose-derived saccharides into monosaccharides, the impact on process performance of potential catalyst poisons originating from biomass and biomass hydrolysates (e.g., proteins, mineral ions, etc.). The data clearly point out the need for studying hemicelluloses in natura rather than in model compound solutions that do not retain the relevant factors influencing process performance. Furthermore, the desirable traits that solid acid catalysts must possess for the efficient hemicellulose hydrolysis are also presented and discussed with regard to the design of new catalysts.

Mild fractionation/pretreatment processes are becoming the most preferred choices for biomass processing within the biorefinery framework. To further explore their advantages, new developments are needed, especially to increase the extent of the hydrolysis of poly- and oligosaccharides. A possible way forward is the use of solid acid catalysts that may overcome many current drawbacks of other common methods. In this Review, the advantages and limitations of the use of heterogeneous catalysis for the main groups of solid acid catalysts (zeolites, resins, carbon materials, clays, silicas, and other oxides) and their relation to the hydrolysis of model soluble disaccharides and soluble poly- and oligosaccharides are presented and discussed. Special attention is given to the hydrolysis of hemicelluloses and hemicellulose-derived saccharides into monosaccharides, the impact on process performance of potential catalyst poisons originating from biomass and biomass hydrolysates (e.g., proteins, mineral ions, etc.). The data clearly point out the need for studying hemicelluloses in natura rather than in model compound solutions that do not retain the relevant factors influencing process performance. Furthermore, the desirable traits that solid acid catalysts must possess for the efficient hemicellulose hydrolysis are also presented and discussed with regard to the design of new catalysts.

Synopsis Laurus novocanariensis is an endemic plant from the Madeira Island forest that derives a fatty oil, with a strong spicy odour, from its berries that has been used for centuries in traditional medicine to treat skin ailments. This work aimed to investigate the effect of the application of both the oil and its essential oil on normal skin, to assess their safety and potential benefits. Diffusion studies with Franz cells using human epidermal membranes were conducted. The steady-state fluxes of two model molecules through untreated skin were compared with those obtained after a 2-h pre-treatment with either the oil or the essential oil. Additionally, eleven volunteers participated in the in vivo study that was conducted on the forearm and involved daily application of the oil for 5 days. Measurements were performed every day in the treated site with bioengineering methods that measure erythema, irritation and loss of barrier function. Slightly higher steady-state fluxes were observed for both the lipophilic and the hydrophilic molecule when the epidermal membranes were pre-treated. Nevertheless, such differences had no statistical significance, which seems to confirm that neither the oil nor the essential oil impaired the epidermal barrier. Results collected with the Chromameter, the Laser Doppler Flowmeter and the visual scoring are in agreement with those established in the in vitro study. They indicate that the repeated application of the oil did not cause erythema, because the results observed in the first day of the study were maintained throughout the week. Application of the oil did not affect the skin barrier function, because the transepidermal water loss remained constant throughout the study. The stratum corneum hydration was slightly reduced on days 4 and 5. This work shows that both the oil and the essential oil were well tolerated by the skin and did not cause significant barrier impairment or irritation. Resume Laurus novocanariensis est une plante endemique de la foret l'ile de Madere qui contient une huile grasse de forte odeur epicee dans ses baies qui a ete utilisee pendant des siecles en medecine traditionnelle pour traiter des maladies de la peau. Ce travail visait a etudier l'effet de l'application de l'huile et de son huile essentielle sur la peau normale, afin d'evaluer leur innocuite et les avantages potentiels. Des etudes de diffusion ont ete menees avec des membranes epidermiques humaines en utilisant les cellules de Franz. Le flux a l'equilibre de deux molecules modeles a travers la peau non traitee a ete compare a celui obtenu apres quelques 2 heures de pretraitement avec soit de l'huile ou de l'huile essentielle. En outre, onze volontaires ont participe a l'etude in vivo, qui a ete menee sur l'avant-bras et a implique l'application quotidienne de l'huile pendant 5 jours. Des mesures ont ete effectuees chaque jour sur le site traite avec des methodes de bio-ingenierie qui mesurent l'erytheme, l'irritation et la perte de la fonction de barriere. Des flux a l'equilibre legerement plus eleves ont ete observes a la fois pour la molecule lipophile et la molecule hydrophile, lorsque les membranes epidermiques ont ete pretraitees. Neanmoins, ces differences n'etaient pas statistiquement significatives, ce qui semble confirmer que ni l'huile ni l'huile essentielle porte atteinte a la barriere epidermique. Les resultats recueillis avec le Chromametre, le debitmetre Laser Doppler et par la notation visuelle sont en accord avec ceux etablis dans l'etude in vitro. Ils indiquent que l'application repetee de l'huile ne cause pas d'erytheme, puisque les resultats observes lors du premier jour de l'etude ont ete maintenus tout au long de la semaine. L'application de l'huile n'a pas d'incidence sur la fonction barriere de la peau, puisque la perte insensible en eau est restee constante tout au long de l'etude. L'hydratation du stratum corneum etait legerement reduite aux jours 4 et 5. Ce travail montre que l'huile et l'huile essentielle ont ete bien tolerees par la peau et n'ont pas cause de deterioration de la barriere significative ou d'irritation.

The formation of adducts with 1 :2 and 1:3 stoichiometry by methoxide addition to nitro-activated anisoles has been examined spectrophotometrically. For these equilibria the ‘basicity’ of sodium methoxide solutions in methanol is appreciably greater than that of corresponding potassium methoxide solutions. This is in contrast with other measures of basicity and is attributed to the association of the multi-charged adducts with cations which is stronger with sodium than with potassium ions.

Artemisinin is a polycyclic sesquiterpene lactone that is highly effective against multidrug-resistant strains of Plasmodium falciparum, the etiological agent of the most severe form of malaria. Determination of artemisinin in the source plant, Artemisia annua, is a challenging problem since the compound is present in very low concentrations, is thermolabile and unstable, and lacks chromophoric or fluorophoric groups. The ain of this study was to develop a simple protocol for the quantification of artemisinin in a plant extract using an (1)H-NMR method. Samples were prepared by extraction of leaf material with acetone, treatment with activated charcoal to remove chlorophylls and removal of solvent. (1)H-NMR spectra were measured on samples dissolved in deuterochloroform with tert-butanol as internal standard. Quantification was carried out using the using the delta 5.864 signal of artemisinin and the delta 1.276 signal of tert-butanol. The method was optimised and fully validated against a reference standard of artemisinin. The results were compared with those obtained from the same samples quantified using an HPLC-refractive index (RI) method. The (1)H-NMR method gave a linear response for artemisinin within the range 9.85-97.99 mm (r(2) = 0.9968). Using the described method, yields of artemisinin in the range 0.77-1.06% were obtained from leaves of the A. annua hybrid CPQBA x POP, and these values were in agreement with those obtained using an HPLC-RI.

The fixed oil extracted from Laurus spp. fruit from Madeira Island, Portugal, is used in local traditional medicine for a wide variety of health complaints. Physical properties, density and refractive index, as well as the TAG FA composition, sterols, and waxes were determined. The oil was found to have an unusually high content of volatiles (ca. 10%), with trans-ocimene and germacrene D predominating. Oleic (30%) and linoleic (20%) acids were the main unsaturated FA, whereas lauric (18%) and palmitic (up to 22.5%) acids were the main saturated FA in the neutral lipid fraction. The oil had a sterol content on the same order as olive oil, with β-sitosterol (84%) predominating. Two sesquiterpene lactones, dehydrocostuslactone and costunolide, accounted for 5% of the overall composition. Madeira laurel oil is not currently used as an edible oil because of its very strong flavor. Its claimed medicinal properties have not yet been validated, and this is the first report on the characterization of the commercial product.