This study aimed to investigate the biotransformation capabilities of a hydroquinone-tolerant Digitalis purpurea cell line (DpHQ) for bioconverting hydroquinone (HQ) into arbutin, a compound with ...significant therapeutic and cosmetic applications. The research evaluated the influence of various HQ concentrations, feeding protocols, and carbon sources on arbutin bioconversion yield. By using HPLC-MS for the quantification of arbutin in biomass and medium, the study revealed that higher precursor (HQ) concentration led to a more pronounced growth inhibition under single dosing than sequential dosing. At lower sugar (3%) and precursor (4 mM HQ) levels, arbutin predominantly remained within the cells, whereas higher sugar (6%) and HQ (5-6 mM) levels promoted its release into the medium. Arbutin production ranged from 591 mg/L under single dosing to 3049 mg/L with sequential dosing, with the highest yield being achieved with 5 mM HQ in divided doses and 6% glucose. This study holds novelty for being the first to demonstrate the DpHQ's tolerance to high concentrations of HQ and its efficient capabilities to bioconvert HQ to arbutin, indicating that D. purpurea is equipped with the enzymes required for this process. These aspects highlight its potential as a biotechnological source for arbutin synthesis.
Abstract
Recent studies have shown that dense yeast populations often occurring in floral nectar are numerically dominated by a few species from the flower–insect interface specialized genus ...Metschnikowia, while generalist yeast species commonly occurring on leaf surfaces, soil, freshwater, and air were rarely isolated from nectar samples. This study was designed to understand the main factors responsible for the assembly of nectar yeast communities, by combining field experiments with laboratory tests characterizing the physiological abilities of all yeast species forming the pool of potential colonizers for two Spanish flowering plants (Digitalis obscura and Atropa baetica). Yeast frequency and species richness were assessed in external sources (bee glossae, air, plant phylloplane) as well as in pollinator rewards (pollen, nectar). Yeasts were most frequent in external sources (air, flower-visiting insects), less so in the proximate floral environment (phylloplane), and least in pollen and nectar. Nectar communities appeared to be considerably impoverished versions of those in insect glossae and phylloplane. Nectar, pollen, and insect yeast assemblages differed in physiological characteristics from those in other substrates. Nectarivorous Metschnikowia were not more resistant than other yeast species to plant secondary compounds and high sugar concentrations typical of nectar, but their higher growth rates may be decisive for their dominance in ephemeral nectar communities.
Summary
Plants can evolve rapidly after pollinator changes, but the response of different floral traits to novel selection can vary. Floral morphology is often expected to show high integration to ...maintain pollination accuracy, while nectar traits can be more environmentally sensitive. The relative role of genetic correlations and phenotypic plasticity (PP) in floral evolution remains unclear, particularly for nectar traits, and can be studied in the context of recent pollinator changes.
Digitalis purpurea shows rapid recent evolution of corolla morphology but not nectar traits following a range expansion with hummingbirds added as pollinators. We use this species to compare PP, heritability, evolvability and integration of floral morphology and nectar in a common garden.
Morphological traits showed higher heritability than nectar traits, and the proximal section of the corolla, which regulates access to nectar and underwent rapid change in introduced populations, presented lower integration than the rest of the floral phenotype. Nectar was more plastic than morphology, driven by highly plastic sugar concentration. Nectar production rate showed high potential to respond to selection.
These results explain the differential rapid evolution of floral traits previously observed in this species and show how intrafloral modularity determines variable evolutionary potential in morphological and nectar traits.
El autor presenta estudios comparativos de las hojas de Digitalis purpurea L. y D. lanata Ehrh. porque ambas especies son de gran interés farmacológico. El material examinado fue cultivado por el ...autor en la ciudad de Córdoba. Adjunta numerosas ilustraciones, que facilitan el reconocimiento de las diferencias existentes, y una bibliografía pertinente.
Abstract This study aimed to determine the clinical characteristics of elderly patients diagnosed with digitalis intoxication, on the Emergency Department, University Hospital Complex, A Coruña, ...Spain. During the study period (January–September 2008) cases were included in which digitalis intoxication was confirmed by plasma digoxin levels. We collected data on age, gender, base-line diseases, therapeutic indications for digoxin, functional classification, ejection fraction, plasma digoxin levels, creatinine clearance, ions, gasometry, electrocardiogram, concomitant medication, symptomatology and treatment. The results were: mean age 82.0 ± 6.6 years, predominantly female subjects (83.7%). The most prevalent pathologies were cardiac valvulopathy (81.0%), hypertension (68.3%) and ischemic cardiopathy (46.3%), 95.1% had a background of cardiac insufficiency, and 52.6% were in functional grade III. The mean digoxin level was 2.7 ± 0.69 ng/ml, 23.1% of the patients had a creatinine clearance of less than 60 ml/min/1.73 m2 and 2.6% had a severely reduced glomerular filtration rate (GFR) (clearance < 30 ml/min/1.73 m2 ). A negative correlation was found between digoxin levels and clearance ( r = −0.22; p = 0.18) and between the levels and cardiac frequency ( r = −0.35; p = 0.026). Of the patients, 47.5% presented bradycardia and 87.8% arrhythmias, most frequently auricular fibrillation. The most frequent symptoms were nausea (54.8%), fatigue (42.9%), vomiting (33.3%) and anorexia (28.6%). We conclude that clinical digestive symptoms in elderly women who are taking digitalis, with bradycardia and impaired renal functioning, should lead us to suspect digitalis intoxication.
The active components from the extracts of Digitalis, cardiotonic steroid glycosides, have been ingested by humans for more than 200 years as a medicinal therapy for heart failure and abnormal heart ...rhythms. The positive inotropic activity of the cardiotonic steroids that mediates clinically useful physiological effects in patients has been attributed largely to a high affinity inhibitory interaction with the extracellular surface of the membrane‐bound sodium pump (Na+/K+‐ATPase). However, previously unrecognized intracellular signaling pathways continue to be uncovered. This Review examines both partial and de novo synthetic approaches to the medicinally important and structurally captivating cardenolide and bufadienolide steroid families, with an emphasis on the stereocontrolled construction of the pharmacophoric aglycone (genin) framework.
Kick‐start my heart: The active components from the extracts of Digitalis, cardiotonic steroid glycosides, have been ingested by humans for more than 200 years as a medicinal therapy for heart failure and abnormal heart rhythms. This Review examines both partial and de novo synthetic approaches to the medicinally important and structurally captivating cardenolide and bufadienolide steroid families, with an emphasis on the stereocontrolled construction of the pharmacophoric aglycone (genin) framework.
The stereospecific 5β-reduction of progesterone is a required step for cardiac glycoside biosynthesis in foxglove plants. Recently, we have isolated the gene P5βR, and here we investigate the ...function and regulation of P5βR2, a new progesterone 5β-reductase gene from Digitalis purpurea. P5βR2 cDNA was isolated from a D. purpurea cDNA library and further characterized at the biochemical, structural and physiological levels. Like P5βR, P5βR2 catalyzes the 5β-reduction of the Δ⁴ double bond of several steroids and is present in all plant organs. Under stress conditions or on treatment with chemical elicitors, P5βR expression does not vary, whereas P5βR2 is highly responsive. P5βR2 expression is regulated by ethylene and hydrogen peroxide. The correlation between P5βR2 expression and cardenolide formation demonstrates the key role of this gene in cardenolide biosynthesis, and therefore in the chemical defense of foxglove plants.
Productivity variations and seasonal fluctuations of cardenolides have been studied in 10 natural populations of Digitalis obscura distributed in three bioclimatic belts. Main cardenolides in D. ...obscura plants are those of the series A and such predominance (ca. 80-85%) over the series B metabolites is independent of the population studied or the degree of maturity of the leaves. Primary glycosides represent ca. 50-60% of total cardenolides; this percentage did not vary among populations or with the leaf age but increased in summer and decreased in winter. A correlation analysis between plant biomass and cardenolide content showed a positive relationship of these parameters, which, according to the bioclimatic distribution of the populations, suggests that certain environmental conditions may cause marked decreases in plant biomass together with a reduction in productivity. Cardenolide contents changed in the timecourse of the four seasons as a multiple response to distinct plant and/or environmental factors. The lowest production was recorded in May, followed by a fast cardenolide accumulation in summer, a decreasing phase in autumn, and a stationary phase in winter. We also analysed the seasonal expression of the gene encoding the progesterone 5 beta -reductase, enzyme producing the required 5 beta -configured intermediaries of cardenolides. A fragment of the isolated partial genomic sequence was used as a probe for Northern analysis to study the seasonal gene expression in selected populations. The expression pattern showed increasing levels from February to July and a further reduction in autumn, although harmful climatic conditions seems to induce overexpression of this gene.
Dermatitis digitalis is an extremely contagious disease of cattle hooves multicausal etiology, which soon turns into a problem of the whole herd. It significantly decreases the milk, which may be in ...the global market economy can seriously undermine the competitiveness of producers who do not suppressed adequately. Analysis of data collected in 2013 and 2014 years coincides with the findings from the literature that bacterial causes of dermatitis digitalis in conditions of high temperature and humidity raised the number of infected animals in the warm period of the year. The most economical way to control this disease is constant zoohygienic implementation of measures and procedures: hygiene held at the prescribed level, proper design and construction of the reservoir, the proper design of the ventilation facility and strict implementation measures of disinfection and hoof bearing animals. The most effective way suppression diseases and hoof it to reduce the losses caused by the conditions of intensive livestock production that preventive measures and procedures as well as raising the level of biotechnology thinking of all employees in cattle production, while curative repair problems in patients with animals but does not eliminate losses manufacturer.
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