Portrait of an act: Aesthetics and ethics in The 'Portrait of a Lady' (Henry James)

Five tetrahydrofuran lignans and two known flavones were isolated from the aerial parts of Peperomia blanda. The structures of the isolated lignans were elucidated by interpretation of their spectroscopic data, including by gHMQC and gHMBC. The relative and absolute configurations of the isolates were determined from NOESY interactions and optical properties, respectively. Four of the lignans were diastercomeric whilst one was of mixed biosynthetic origin. All but one of the lignans exhibited high in vitro trypanocidal activity when assayed against epimastigotes of Trypanosoma cruzi strain Y. (C) 2007 Elsevier Ltd. All rights reserved

The phenolic complex in flaxseed

Flaxseed is the richest plant source of the lignan secoisolariciresinol diglucoside (SDG). In flaxseed, SDG exists in an oligomeric structure with 3-hydroxy-3-methyl glutaric acid (HMGA) forming a phenolic complex together with p-coumaric acid and ferulic acid glucosides and herbacetin diglucoside (HDG). Epidemiological and animal studies indicate protective effects of flaxseed and SDG towards hormone-dependent cancers and cardiovascular diseases, and reducing effect toward cholesterol levels in blood. Knowledge about the structural features and properties of the phenolic complex are required to further understand bioavailability, bioconversion and bioactivity of flaxseed lignans in humans and animals, the biosynthesis in flaxseed, as well as if it may affect technology and quality of food products containing flaxseed or the phenolic complex. A new fast and simple high-performance liquid chromatographic (HPLC) method was developed for analysing secoisolariciresinol diglucoside (SDG), p-coumaric acid glucoside and ferulic acid glucoside, based on direct hydrolysis of defatted flaxseed flour using alkali. Variations in SDG, p-coumaric acid glucoside and ferulic acid glucoside content were reported in flaxseed samples and bread products containing flaxseed. The composition and properties of flaxseed phenolic complex were studied by reversed-phase liquid chromatography and gel filtration fractionation. Results indicate that the phenolic glucosides exist in oligomers with variable molecular sizes. A complicated linkage pattern and/or possibly interactions with other components may contribute to the observed complexity. SDG and the phenolic complex showed similar hydrogen-donating abilities to ferulic acid but higher than α-tocopherol in the DPPH inhibition metod, suggesting that SDG was the only active antioxidant in the phenolic complex. Contradicting results were obtained on the effect of SDG on levels of Vitamin E and cholesterol in two rat studies

Higher usual dietary intake of phytoestrogens is associated with lower aortic stiffness in postmenopausal women

Objective¿ Phytoestrogens have been postulated to protect against cardiovascular diseases, but few studies have focused on the effect of Western dietary phytoestrogen intake. Methods and Results¿ Four hundred three women with natural menopause either between 1987 and 1989 or between 1969 and 1979 were selected from the baseline data of the PROSPECT study (n=17 395). Isoflavone and lignan intake was calculated from a food-frequency questionnaire. Aortic stiffness was noninvasively assessed by pulse-wave velocity measurement of the aorta. Linear regression analysis was used. After adjustment for age, body mass index, smoking, physical activity, mean arterial pressure, follow-up time, energy intake, dietary fiber intake, glucose, and high density lipoprotein cholesterol, increasing dietary isoflavone intake was associated with decreased aortic stiffness: -0.51 m/s (95% CI -1.00 to -0.03, fourth versus first quartile, P for trend=0.07). Increasing dietary intake of lignans was also associated with decreased aortic pulse-wave velocity: -0.42 m/s (95% CI -0.93 to 0.11, fourth versus first quartile, P for trend=0.06). Results were most pronounced in older women: for isoflavones, -0.94 m/s (95% CI -1.65 to -0.22, P for trend=0.02), and for lignans, -0.80 m/s (95% CI -1.85 to -0.05), fourth versus first quartile. Conclusions¿ The results of our study support the view that phytoestrogens have a protective effect on the risk of atherosclerosis and arterial degeneration through an effect on arterial walls, especially among older wome

Biosynthesis of lignans. Part I . Biosynthesis of Arctiin (3) and Phillyrin (5)

Lignans constitute a class of naturally occuring phenolic compounds, widely distributed in higher plants. They are formally composed of two phenylpropanoid units, stercospecifically joined at the /f-carbon atoms of their side chains. Their biosynthesis has as yet not been investigated. To sec, if these plant phenolics originate from simple phenylpropancs, various radioactively labelled, putative precursors were fed to Forsythia shoots. Chemically synthezised arylpropane derivatives, such as Ή/1 'C-glucoferulic acid, -glucoferulic aldehyde, and -coniferin were incorporated into the lignans arctiin (3) and phillyrin (5) while 3H-3,4-dimcthoxycinnamic acid was not incorporated. From these results i t may be concluded that the hydroxylated compounds are direct precursors of these dimeric phenylpropanes and are incorporated through a dimerisation step without degradation of the Q - Q skeleton

Phytoestrogens

Collectively, plants contain several different families of natural products among which are compounds with weak estrogenic or antiestrogenic activity toward mammals. These compounds, termed phytoestrogens, include certain isoflavonoids, flavonoids, stilbenes, and lignans. The best-studied dietary phytoestrogens are the soy isoflavones and the flaxseed lignans. Their perceived health beneficial properties extend beyond hormone-dependent breast and prostate cancers and osteoporosis to include cognitive function, cardiovascular disease, immunity and inflammation, and reproduction and fertility. In the future, metabolic engineering of plants could generate novel and exquisitely controlled dietary sources with which to better assess the potential health beneficial effects of phytoestrogens

Synergistic mutual potentiation of antifungal activity of Zuccagnia punctata Cav. and Larrea nitida Cav. extracts in clinical isolates of Candida albicans and Candida glabrata

Background: Zuccagnia punctata Cav. (Fabaceae) and Larrea nitida Cav. (Zygophyllaceae) are indistinctly or jointly used in traditional medicine for the treatment of fungal-related infections. Although their dichloromethane (DCM) extract have demonstrated moderate antifungal activities when tested on their own, antifungal properties of combinations of both plants have not been assessed previously. Purpose: The aim of this study was to establish with statistical rigor whether Z. punctata (ZpE) and L. nitida DCM extract (LnE) interact synergistically against the clinically important fungi Candida albicans and Candida glabrata and to characterize the most synergistic combinations. Study design: For synergism assessment, the statistical-based Boik's design was applied. Eight ZpE–LnE fixed-ratio mixtures were prepared from four different months of 1 year and tested against Candida strains. Lϕ (Loewe index) of each mixture at different fractions affected (ϕ) allowed for the finding of the most synergistic combinations, which were characterized by HPLC fingerprint and by the quantitation of the selected marker compounds. Methods: Lϕ and confidence intervals were determined in vitro with the MixLow method, once the estimated parameters from the dose–response curves of independent extracts and mixtures, were obtained. Markers (four flavonoids for ZpE and three lignans for LnE) were quantified in each extract and their combinations, with a valid HPLC–UV method. The 3D-HPLC profiles of the most synergistic mixtures were obtained by HPLC–DAD. Results: Three over four IC50ZpE/IC50LnE fixed-ratio mixtures displayed synergistic interactions at effect levels ϕ > 0.5 against C. albicans. The dosis of the most synergistic (Lϕ = 0.62) mixture was 65.96 µg/ml (ZpE = 28%; LnE = 72%) containing 8 and 36% of flavonoids and lignans respectively. On the other hand, one over four IC50ZpE/IC50LnE mixtures displays synergistic interactions at ϕ > 0.5 against C. glabrata. The dosis of the most synergistic (Lϕ = 0.67) mixture was 168.23 µg/ml (ZpE = 27%; LnE = 73%) with 9.7 and 31.6% of flavonoids and lignans respectively. Conclusions: Studies with the statistical-based MixLow method, allowed for the finding of the most ZpE–LnE synergistic mixtures, giving support to a proper joint use of both antifungal herbs in traditional medicine.Fil: Butassi, Estefanía. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Svetaz, Laura Andrea. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ivancovich, Juan J.. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; ArgentinaFil: Feresin, Gabriela Egly. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tapia, Alejandro A.. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Zacchino, Susana Alicia Stella. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Gene-to-metabolite network for biosynthesis of lignans in MeJA-elicited Isatis indigotica hairy root cultures.

Root and leaf tissue of Isatis indigotica shows notable anti-viral efficacy, and are widely used as "Banlangen" and "Daqingye" in traditional Chinese medicine. The plants' pharmacological activity is attributed to phenylpropanoids, especially a group of lignan metabolites. However, the biosynthesis of lignans in I. indigotica remains opaque. This study describes the discovery and analysis of biosynthetic genes and AP2/ERF-type transcription factors involved in lignan biosynthesis in I. indigotica. MeJA treatment revealed differential expression of three genes involved in phenylpropanoid backbone biosynthesis (IiPAL, IiC4H, Ii4CL), five genes involved in lignan biosynthesis (IiCAD, IiC3H, IiCCR, IiDIR, and IiPLR), and 112 putative AP2/ERF transcription factors. In addition, four intermediates of lariciresinol biosynthesis were found to be induced. Based on these results, a canonical correlation analysis using Pearson's correlation coefficient was performed to construct gene-to-metabolite networks and identify putative key genes and rate-limiting reactions in lignan biosynthesis. Over-expression of IiC3H, identified as a key pathway gene, was used for metabolic engineering of I. indigotica hairy roots, and resulted in an increase in lariciresinol production. These findings illustrate the utility of canonical correlation analysis for the discovery and metabolic engineering of key metabolic genes in plants

Rapid and comprehensive evaluation of (poly)phenolic compounds in pomegranate (punica granatum L.) juice by UHPLC-MSn

The comprehensive identification of phenolic compounds in food and beverages is a crucial starting point for assessing their biological, nutritional, and technological properties. Pomegranate (Punica granatum L.) has been described as a rich source of (poly)phenolic components, with a broad array of different structures (phenolic acids, flavonoids, and hydrolyzable tannins) and a quick, high throughput, and accurate screening of its complete profile is still lacking. In the present work, a method for UHPLC separation and linear ion trap mass spectrometric (MSn) characterization of pomegranate juice phenolic fraction was optimized by comparing several different analytical conditions. The best solutions for phenolic acids, anthocyanins, flavonoids, and ellagitannins have been delineated and more than 70 compounds have been identified and fully characterized in less than one hour total analysis time. Twenty-one compounds were tentatively detected for the first time in pomegranate juice. The proposed fingerprinting approach could be easily translated to other plant derived food extracts and beverages containing a wide array of phytochemical compounds