Molecular imprinting technology (MIT) was employed to fabricate polysulfone (PSf) membranes with specific nano-cavities for selective separation and enrichment of paclitaxel from a neat solution and ...also from yew tree extract. Polymer/template ratio, feed concentration, and the template extractor solvent were optimized. In accordance with the paclitaxel molecular dimension, the specific nano-cavities size was predicted to be 2.18 × 1.16 nm. The membranes were characterized in terms of pure water flux, molecular weight cut-off (MWCO), adsorption and diffusion, porosity, contact angle, and fouling. The results revealed that water flux through the molecularly imprinted membrane (MiM) is slightly less than that for the non-imprinted membrane (NiM), although the other properties relatively enhanced. For an in-depth understanding of the separation performance, the optimized membrane was analyzed by Attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), and diffuse reflectance spectroscopy (DRS). ATR-FTIR spectra and SEM images showed no significant difference between the imprinted and non-imprinted membranes, while DRS spectra revealed a spatial orientation in the polymer chain. At the optimum condition (paclitaxel concentration in the dope solution =0.5 wt%, feed initial concentration = 20 ppm, and ethanol/water ratio = 50:50 v/v) the MiM exhibited relatively high ability to recognize and separate paclitaxel with imprinting factor of 2.28. The reuse of the MiM up to 3 repeated cycles showed no obvious deterioration in the performance. Furthermore, in a single pass MiM could enrich paclitaxel from a crude yew tree extract, a real or complex solution, up to 48%, which could be quite encouraging from industrial and pharmaceutical points of view.
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The aim of the study was to evaluate the differences in heavy metal accumulation in yew (
Taxus baccata
L.) needles depending on gender and age. Trees growing in the same soil and forest conditions ...were selected for the study. The study was conducted in the botanical garden in the center of Krakow, and study plots were characterized by the same deposition of pollutants. Needles of yew and soil samples were collected for laboratory analysis. Heavy metal content and basic biochemical parameters were determined in needles samples. The study confirms the importance of gender and, to a greater extent, age of needles in the accumulation of heavy metals by yews growing in an urban agglomeration. On the basis of the results obtained, it can be concluded that male yew individuals have a high tolerance to heavy metal contamination and their high needle concentration. At the same time, female individuals, which are usually less tolerant to environmental stress, seem to have some physiological mechanisms protecting them from excessive heavy metal uptake from the soil. The accumulation of heavy metals in yew needles does not negatively affect the level of their biochemical parameters.
Abstract
Background
Ingestion of the berries of the European yew tree can result in fatal cardiac arrhythmias.
Case summary
A 53-year-old female presented to our emergency department following ...ingestion of ∼200 European yew tree berries. At presentation, she was in cardiogenic shock due to a mixture of tachy- and bradyarrhythmias including ventricular tachycardia, atrial fibrillation with slow ventricular response and prolonged ventricular conduction, and periods of asystole. She was referred to a specialist cardiac centre and promptly established on mechanical circulatory support with venoarterial extracorporeal membrane oxygenation (V-A ECMO) by a retrieval team. Following resolution of her arrhythmias, she was weaned from V-A ECMO after 4 days of support and was discharged home with full neurological recovery on Day 12.
Discussion
Poisoning can lead to acute reversible but potentially fatal cardiogenic shock. We believe that access to prompt initiation of V-A ECMO was key to this patient’s survival.
The yew tree (Taxus baccata L.) is considered in folklore a symbol of immortality due to its qualities of longevity and regeneration. Despite its poisonous reputation, the yew tree has a long history ...of medicinal use, particularly in the form of extracts from its leaves and bark. In the work presented herein, gas chromatography–mass spectrometry (GC–MS) chemical profiling was applied to the aqueous ammonia/hydromethanolic extracts of several plant organs of T. baccata, leading to the identification of different bioactive compounds than those previously characterized by high-performance liquid chromatography with tandem mass spectrometry (HPLC–MS/MS) in other extraction media. The leaf aqueous ammonia extract was rich in 2-hexylthiophene and 3-O-methyl-d-fructose; 9-octadecenoic and hexadecanoic acid were the main constituents of the bark aqueous ammonia extract; and the fruit hydromethanolic extract contained methyl 2-O-methyl-α-d-xylofuranoside, 1,3-dioxolane derivatives, and erysimoside. The antimicrobial activity of the extracts was assayed against four bacterial pathogens responsible for the soft rot and blackleg diseases of potatoes, viz. Pectobacterium carotovorum subsp. carotovorum, Pectobacterium atrosepticum, Pectobacterium parmentieri, and Dickeya chrysanthemi, resulting in minimum inhibitory concentration (MIC) values as low as 187 μg·mL−1. Bioassays on potato slices confirmed the efficacy of the leaf extract at this dose when applied as a preventive treatment before artificial inoculation with P. carotovorum subsp. carotovorum. In view of this high activity, these extracts may find application in the integrated pest management of soft rot Pectobacteriaceae (SRP) diseases.
ABSTRACT
Purpose
To explore possible ways in which yew tree tubulin is naturally resistant to paclitaxel. While the yew produces a potent cytotoxin, paclitaxel, it is immune to paclitaxel’s cytotoxic ...action.
Methods
Tubulin sequence data for plant species were obtained from Alberta 1000 Plants Initiative. Sequences were assembled with Trinity
de novo
assembly program and tubulin identified. Homology modeling using MODELLER software was done to generate structures for yew tubulin. Molecular dynamics simulations and molecular mechanics Poisson–Boltzmann calculations were performed with the Amber package to determine binding affinity of paclitaxel to yew tubulin. ClustalW2 program and PHYLIP package were used to perform phylogenetic analysis on plant tubulin sequences.
Results
We specifically analyzed several important regions in tubulin structure: the high-affinity paclitaxel binding site, as well as the intermediate binding site and microtubule nanopores. Our analysis indicates that the high-affinity binding site contains several substitutions compared to human tubulin, all of which reduce the binding energy of paclitaxel.
Conclusions
The yew has achieved a significant reduction of paclitaxel’s affinity for its tubulin by utilizing several specific residue changes in the binding pocket for paclitaxel.
The Tree That Leads to Death: Yew Fruit Özesen, Toygün Anıl; Kaya, Kenan; Malkoç, Mehmet Ali ...
Adli tıp bülteni,
8/2022, Letnik:
27, Številka:
2
Journal Article
Odprti dostop
Yew fruit can cause a large number of human and animal poisoning and can be highly toxic. This is achieved by the taxon alkaloids (Taxin A and Taxin B) that cause cardiotoxic effects in its ...structure. Taxins cause cardiac dysrhythmia with the effect of calcium channel antagonism in cardiac myocytes and cause a clinical deterioration leading to death. The diagnosis of yew fruit poisoning is usually made by identifying plant parts in the digestive system. With the recent technological developments and the development of toxicological diagnosis methods, the diagnosis of metabolites in lower doses has begun to be made more easily with clinical suspicion.
In order to study the influence of some ecological factors on distribution of yew tree and its regeneration in Arasbaran forests, two habitats of yew including Kalaleh in Ilganechay and Kooran in ...Horand regions were studied. To provide appropriate distribution of sample plots, three altitudinal levels were selected for each region in each habitat (1100-1200, 1200-1300 and 1300-1400 m.a.s.l.) and on this basis, 43 circle sample plots, each 1000 m2, were laid out by selective sampling method. Also micro sample plots, each 100 m2, were laid out within the macro sample plots to study the regeneration. Some sample characteristics including altitude, slope gradient, aspect, crown cover, diameter at breast height and total height of all trees were recorded. Results indicated that yew trees prefer 1200 to 1300 m.a.s.l., north aspects with 51-75% slope gradient. Our study reveals that yew regeneration in undisturbed habitat (Kalaleh) with 53% seed origin seedlings were more in compare to the disturbed habitat (Kooran) with only 35% seed origin seedlings.
Having analyzed the scientific literature and sophisticated primary sources of information, the region has proved to be very prospective due to the eco-tourist potential and the relic yew tree.
Having analyzed the scientific literature and sophisticated primary sources of information, the region has proved to be very prospective due to the eco-tourist potential and the relic yew tree.
The drug taxol has been hailed by many in the cancer community as a major breakthrough in the treatment of cancer. It has already been approved in use against ovarian and advanced breast cancer in ...many countries world-wide. Taxol has also promoted profound debates in the policy arena not, as one might expect, because of the characteristics or purposes of the drug itself, but because of other far-reaching effects. Taxol is a complex compound found in the bark of the Pacific yew tree, primarily in Oregon and Washington in the USA. The bark was first collected in 1962 and cytotoxicity demonstrated in 1964. Yet it was not until 1989 that the first results of clinical trials were reported. In the US taxol was then rushed through the Food and Drug Administration’s regulatory procedures, approval being granted for use in refractory ovarian cancer in 1992. The controversies surrounding taxol surfaced in 1989 and grew substantially over the next few years. In this paper we examine two principal controversies concerning taxol, the first of which focused on apparent conflicts between the needs of environmental protection and those of cancer chemotherapy. Although the media portrayed this as a clash of interests between the environment and people with cancer, we argue that it was an attempt to increase lay participation in biomedical decision making and policy formulation. The second controversy was between health policy and the transfer of public scientific property to the corporate sector. The pharmaceutical company Bristol–Myers Squibb was given exclusive rights to provide taxol from Pacific yew trees under a Co-operative Research and Development Agreement signed in 1991. While this was seen to be in the US Government’s (as well as the company’s) interest, it provoked a public reaction questioning the terms and consequences of the transfer of publicly generated scientific knowledge to the private sector.
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