Natural juglon dye was obtained from the outer shell of walnut (Juglans Regia L.) fruit by hot extraction method followed by doping using aluminium, copper and iron metals. These metal-free and ...metal-doped juglon dyes were used as sensitisers in the production of titanium dioxide (TiO2)-based dye-sensitised solar cells. The absorption results show that the metal-doped dyes have a wider absorption spectra than metal-free dyes and TiO2 alone. The best performance was achieved by the copper-doped juglon-based sensitiser, resulting in an efficiency of 1.63%. Moreover, the incident photon-to-current efficiency curve indicates that both copper- and iron-doped juglons have promise as dye-sensitised solar cells technologies. These findings confirm that metal-free and metal-doped dye-sensitised solar cells have scientific and industrial potential owing to their simple and inexpensive production method.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
La papa es una planta tuberosa cultivada alrededor del mundo, sus tubérculos pueden conservarse por largo tiempo, después de haber sido cosechados y sin perder sus parámetros de calidad, consumo y ...procesamiento. Existen varios tratamientos que permiten retrasar la aparición de brotes como la utilización de hormonas vegetales como, ácido abscísico, ácido giberélico, ácido indol acético, etileno y citoquininas que intervienen en las fases fisiológicas del tubérculo semilla especialmente en el proceso de dormancia. Agentes externos como el Chlorpropham, hidracida del ácido maleico, aceites esenciales y taninos también juegan un rol importante sobre la inhibición de los brotes. Las plantas elaboran compuestos que son empleados para regular diferentes procesos fisiológicos, entre ellos el de la generación de brotes, es por eso que la obtención de extractos vegetales y el estudio de sus compuestos activos ayudan a la reducción del uso de productos químicos entre ellos el extracto de nogal que por sus compuestos alcaloides, flavonoides, cumarinas y antroquininas que se encuentran en diferentes partes del árbol bloquean los procesos metabólicos y hormonales del tubérculo permitiendo disminuir el crecimiento activo de los brotes y alargar el proceso de dormancia. El presente artículo tiene como objetivo revisar algunos de los tratamientos que se utilizan para alargar el proceso de brotación de los tubérculos- semilla de papa.
The potatois a tuberous plant cultivated around the world, its tubers can be conserved for a long time, after having beenharvested and without losing its parameters of quality, consumption and processing. There are several treatments thatallow delay the appearance of outbreaks as the use of plant hormones these are; abscisic acid, gibberellic acid, indoleacetic acid, ethylene and cytokinins that intervene in the physiological phases of the seed tuber, especially in the dorman-cy process. External agents such as Chlorpropham, maleic acid hydrazide, essential oils and tannins also play an im-portant role in the inhibition of outbreaks. The plants elaborate compounds that are used to regulate different physiologi-cal processes, among them the one of the generation of shoots, that is why the obtaining of vegetal extracts and the studyof their active compounds help to the reduction of the use of chemical products among them the walnut extract that by itscompounds alkaloids, flavonoids, coumarins and anthroquinines that are in different parts of the tree block the metabolicand hormonal processes of the tuber allowing to decrease the active growth of the shoots and lengthen the dormancyprocess. The objective of this article is to review some of the treatments that are used to lengthen the sprouting process ofpotato seed tubers.
Walnut (Juglans regia L.) heartwood extractives were identified and their potential for protection of poplar wood was evaluated. Test specimens were prepared from poplar wood (Populus nigra L.) to ...meet BS 838:1961 requirements. Samples were impregnated with heartwood extractive solution (1.5, 2.5, and 3.5% w/w in ethanol-toluene), followed by 5 hours vacuum desiccator technique to reach complete saturation. Impregnated specimens were exposed to white-rot fungus (Trametes versicolor) for 14 weeks according to BS 838:1961 applying the kolle-flask method. The weight loss of samples was determined after exposure to white-rot fungus. The highest weight loss (36.96%) was observed for untreated control samples and the lowest weight loss (30.40%) was measured in samples treated with 1.5% extractives solution. The analyses of the extracts using GC/MS indicated that major constituents are benzoic acid,3,4,5-tri(hydroxyl) and gallic acid (44.57 %). The two toxic components in the heartwood are juglone (5.15 %) and 2,7-dimethylphenantheren (5.81 %).
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Juglon (5-hidroksi-1,4-naftokinon) ceviz allelopatisinden sorumlu bir allelokimyasaldır. Giberellik asit ($GA_3$) ve
kinetin (KIN)'in tohum çimlenmesi ve fide büyümesi üzerindeki juglon stresi ...etkisinin yenilmesindeki etkinlikleri arpa,
buğday, hıyar, yonca ve domateste araştırıldı. Bitki büyüme düzenleyicileri ile ön muamele gören tohumlar juglon stresi
sonrasında, etkisini büyüme düzenleyicilerinin ne kadar hafiflettiklerini test etmek için kullanıldı. Buğday ve domateste
tohum çimlenmesinin juglon tarafından engellendiği, ancak bunun bitki büyüme düzenleyicileri kullanılarak önemli
ölçüde azaltıldığı belirlenmiştir. Çalışmada kullanılan bütün türlerin fide uzunluğu ve kuru ağırlıkları da juglon tarafından
önemli ölçüde azaltılmış, fakat bu bitki büyütme düzenleyicilerince iyileştirilmiştir. Bu hususta $GA_3$+KIN kombinasyonu
en etkili muamele olmuş, ve fide büyümesi üzerinde en yüksek etki de domates ve buğdayda kaydedilmiştir.
Juglone (5-hydroxy-1,4-naphthoquinone) is an allelochemical responsible for walnut allelopathy. The effects
of gibberellic acid ($GA_3$) and kinetin (KIN) on overcoming the effects of juglone stress on seed germination and seedling
growth were investigated in barley, wheat, cucumber, alfalfa, and tomato. Seeds pre-treated with plant growth regulators
were used to test their effects on the alleviation of juglone stress. It was observed that seed germination in tomato and
wheat was inhibited by juglone and that the plant growth regulators alleviated it significantly. Elongation and dry weight
of the seedlings of all the species used in the study were reduced significantly by juglone, and the plant growth regulators
alleviated them. The most effective treatment was the $GA_3$+KIN combination, which was best on seedling growth in
tomato and wheat.
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The extractive efficiency of phenolic compounds from plant material is greatly depended on the solvent. In our research, methanol and ethanol were used for taking out the phenols from green walnut ...fruits. The total phenolics and some individual phenolics, such as gallic, chlorogenic, ellagic, sinapic and protocatechuic acid, (+)-catechin and juglone were detected. Total phenolic contents were determined spectrofotometric but individual phenols using HPLC. Amounts of total phenolics were higher when for extraction methanol was used compare to ethanol, in both cultivars, Elit and Franquette. Similar effect of the solvents was observed in the case some individual phenols, such as juglone, (+)- catechin, gallic, protocatechuic and chlorogenic acid. On the contrary, for ellagic and sinapic acid the extraction was better when ethanol was used compare to methanol.
Učinkovitost ekstrakcije fenolnih snovi iz rastlinskega tkiva je v veliki meri odvisna od topila. V našem poskusu smo primerjali ekstrakcijo fenolov iz zelenih plodov orehov z etanolom in metanolom. Določali smo skupne in nekatere posamezne fenolne spojine, kot so galna, klorogenska, elagna, sinapinska in protokatehulna kislina, ter (+)-katehin in juglon. Skupne fenole smo določili spektrofotometrično, posamezne pa s pomočjo HPLC sistema. Vsebnost skupnih fenolov je bila pri obeh sortah, ‘Elit’ in ‘Franquette’, večja pri ekstrakcji v metanolu kot v etanolu. Podobne rezultate smo dobili pri nekaterih posameznih fenolih, kot so juglon, (+)-katehin, galna, protokatehulna in klorogenska kislina. Nasprotno je bila ekstrakcija pri elagni in sinapinski kislini bolj uspešna v etanolu kot v metanolu.
From the Streptomyces spp. 815 and GW4184, four new 4-juglon-2-ylbutyric acid derivatives, the juglomycins G - J (3a, 4a, 4c, 5c), have been isolated and characterised. The structures were derived ...from the 1D and 2D NMR data and mass spectra and confirmed by comparison with structurally related compounds. The absolute configuration was deduced from the CD spectra. The new natural products exhibited weak antibacterial activity similar to juglomycin A (5a).
Abstrakty w j.ang na stronie WWW http://www.chem.uni.wroc.pl/WiadChem.htm
Tyt. w j.ang. Journal of Polish Chemical Society
Wydawane w ramach serii: Acta Universitatis Wratislaviensis
Tyt. in English ...Journal of Polish Chemical Society
Published as part of the series: Acta Universitatis Wratislaviensis
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