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Peñaranda Figueredo FA, Vicente J, Barquero AA, Bueno CA. Aesculus hippocastanum extract and the main bioactive constituent β-escin as antivirals agents against coronaviruses, including SARS-CoV-2. Sci Rep 2024; 14:6418. [PMID: 38494515 PMCID: PMC10944838 DOI: 10.1038/s41598-024-56759-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 03/11/2024] [Indexed: 03/19/2024] Open
Abstract
Respiratory viruses can cause life-threatening illnesses. The focus of treatment is on supportive therapies and direct antivirals. However, antivirals may cause resistance by exerting selective pressure. Modulating the host response has emerged as a viable therapeutic approach for treating respiratory infections. Additionally, considering the probable future respiratory virus outbreaks emphasizes the need for broad-spectrum therapies to be prepared for the next pandemics. One of the principal bioactive constituents found in the seed extract of Aesculus hippocastanum L. (AH) is β-escin. The clinical therapeutic role of β-escin and AH has been associated with their anti-inflammatory effects. Regarding their mechanism of action, we and others have shown that β-escin and AH affect NF-κB signaling. Furthermore, we have reported the virucidal and broad-spectrum antiviral properties of β-escin and AH against enveloped viruses such as RSV, in vitro and in vivo. In this study, we demonstrate that β-escin and AH have antiviral and virucidal activities against SARS-CoV-2 and CCoV, revealing broad-spectrum antiviral activity against coronaviruses. Likewise, they exhibited NF-κB and cytokine modulating activities in epithelial and macrophage cell lines infected with coronaviruses in vitro. Hence, β-escin and AH are promising broad-spectrum antiviral, immunomodulatory, and virucidal drugs against coronaviruses and respiratory viruses, including SARS-CoV-2.
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Affiliation(s)
- Freddy Armando Peñaranda Figueredo
- Laboratorio de Virología, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), CONICET-Universidad de Buenos Aires, C-1428GBA, Buenos Aires, Argentina
| | - Josefina Vicente
- Laboratorio de Virología, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), CONICET-Universidad de Buenos Aires, C-1428GBA, Buenos Aires, Argentina
| | - Andrea Alejandra Barquero
- Laboratorio de Virología, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), CONICET-Universidad de Buenos Aires, C-1428GBA, Buenos Aires, Argentina
| | - Carlos Alberto Bueno
- Laboratorio de Virología, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), CONICET-Universidad de Buenos Aires, C-1428GBA, Buenos Aires, Argentina.
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Cao HN, Ruan JY, Han Y, Zhao W, Zhang Y, Gao C, Wu HH, Ma L, Gao XM, Zhang Y, Wang T. NO Release Inhibitory Activity of Flavonoids from Aesculus Wilsonii Seeds through MAPK (P38), NF-κB, and STAT3 Cross-Talk Signaling Pathways. Planta Med 2023; 89:46-61. [PMID: 35253147 DOI: 10.1055/a-1789-2983] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The flavonoid constituents of Aesculus wilsonii, a source of the Chinese medicinal drug Suo Luo Zi, and their in vitro anti-inflammatory effects were investigated. Fifteen flavonoids, including aeswilflavonosides IA-IC (1: - 3: ) and aeswilflavonosides IIA-IIE (4: - 8: ), along with seven known derivatives were isolated from a seed extract. Their structures were elucidated by extensive spectroscopic methods, acid and alkaline hydrolysis, and calculated electronic circular dichroism spectra. Among them, compounds 3: and 7: possess a 5-[2-(carboxymethyl)-5-oxocyclopent-yl]pent-3-enylate or oleuropeoylate substituent, respectively, which are rarely reported in flavonoids. Compounds 2, 3, 7: , and 12: - 15: were found to inhibit lipopolysaccharide-induced nitric oxide production in RAW 264.7 cell lines. In a mechanistic assay, the flavonoid glycosides 2, 3: , and 7: reduced the expressions of interleukin-6 and tumor necrosis factor-alpha induced by lipopolysaccharide. Further investigations suggest that 2: and 3: downregulated the protein expression of tumor necrosis factor-alpha and interleukin-6 by inhibiting the phosphorylation of p38. Compound 7: was found to reduce the production of inducible nitric oxide synthase, and the secretion of tumor necrosis factor-alpha and interleukin-6 through inhibiting nuclear factor kappa-light-chain-enhancer of activated B signaling pathway. Compounds 2, 3: , and 7: possessed moderate inhibitory activity on the expression of signal transducer and activator of transcription-3. Taken together, the data indicate that the flavonoid glycosides of A. wilsonii seeds exhibit nitric oxide release inhibitory activity through mitogen-activated protein kinase (p38), nuclear factor kappa-light-chain-enhancer of activated B, and signal transducer and activator of transcription-3 cross-talk signaling pathways.
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Affiliation(s)
- Hui Na Cao
- Tianjin Key Laboratory of TCM Chemistry and Analysis, Tianjin University of Traditional Chinese Medicine, West Area, Tuanbo New Town, Jinghai District, Tianjin, China
| | - Jing Ya Ruan
- Tianjin Key Laboratory of TCM Chemistry and Analysis, Tianjin University of Traditional Chinese Medicine, West Area, Tuanbo New Town, Jinghai District, Tianjin, China
| | - Yu Han
- Institute of TCM, Tianjin University of Traditional Chinese Medicine, West Area, Tuanbo New Town, Jinghai District, Tianjin, China
| | - Wei Zhao
- Tianjin Key Laboratory of TCM Chemistry and Analysis, Tianjin University of Traditional Chinese Medicine, West Area, Tuanbo New Town, Jinghai District, Tianjin, China
| | - Ying Zhang
- Tianjin Key Laboratory of TCM Chemistry and Analysis, Tianjin University of Traditional Chinese Medicine, West Area, Tuanbo New Town, Jinghai District, Tianjin, China
| | - Chang Gao
- Institute of TCM, Tianjin University of Traditional Chinese Medicine, West Area, Tuanbo New Town, Jinghai District, Tianjin, China
| | - Hong Hua Wu
- Institute of TCM, Tianjin University of Traditional Chinese Medicine, West Area, Tuanbo New Town, Jinghai District, Tianjin, China
| | - Lin Ma
- Institute of TCM, Tianjin University of Traditional Chinese Medicine, West Area, Tuanbo New Town, Jinghai District, Tianjin, China
| | - Xiu Mei Gao
- Institute of TCM, Tianjin University of Traditional Chinese Medicine, West Area, Tuanbo New Town, Jinghai District, Tianjin, China
| | - Yi Zhang
- Tianjin Key Laboratory of TCM Chemistry and Analysis, Tianjin University of Traditional Chinese Medicine, West Area, Tuanbo New Town, Jinghai District, Tianjin, China
- Institute of TCM, Tianjin University of Traditional Chinese Medicine, West Area, Tuanbo New Town, Jinghai District, Tianjin, China
| | - Tao Wang
- Tianjin Key Laboratory of TCM Chemistry and Analysis, Tianjin University of Traditional Chinese Medicine, West Area, Tuanbo New Town, Jinghai District, Tianjin, China
- Institute of TCM, Tianjin University of Traditional Chinese Medicine, West Area, Tuanbo New Town, Jinghai District, Tianjin, China
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Liesche J, Gao C, Binczycki P, Andersen SR, Rademaker H, Schulz A, Martens HJ. Direct Comparison of Leaf Plasmodesma Structure and Function in Relation to Phloem-Loading Type. Plant Physiol 2019; 179:1768-1778. [PMID: 30723179 PMCID: PMC6446768 DOI: 10.1104/pp.18.01353] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 01/28/2019] [Indexed: 05/09/2023]
Abstract
The export of photosynthetically produced sugars from leaves depends on plasmodesmatal transport of sugar molecules from mesophyll to phloem. Traditionally, the density of plasmodesmata (PD) along this phloem-loading pathway has been used as a defining feature of different phloem-loading types, with species proposed to have either many or few PD between the phloem and surrounding cells of the leaf. However, quantitative determination of PD density has rarely been performed. Moreover, the structure of PD has not been considered, even though it could impact permeability, and functional data are only available for very few species. Here, a comparison of PD density, structure, and function using data from transmission electron microscopy and live-cell microscopy was conducted for all relevant cell-cell interfaces in leaves of nine species. These species represent the three principal phloem-loading types currently discussed in literature. Results show that relative PD density among the different cell-cell interfaces in one species, but not absolute PD density, is indicative of phloem-loading type. PD density data of single interfaces, even combined with PD diameter and length data, did not correlate with the intercellular diffusion capacity measured by the fluorescence loss in photobleaching method. This means that PD substructure not visible on standard transmission electron micrographs may have a strong influence on permeability. Furthermore, the results support a proposed passive symplasmic loading mechanism in the tree species horse chestnut (Aesculus hippocastanum), white birch (Betula pubescens), orchard apple (Malus domestica), and gray poplar (Populus x canescens) as functional cell coupling and PD structure differed from active symplasmic and apoplasmic phloem-loading species.
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Affiliation(s)
- Johannes Liesche
- College of Life Sciences, Northwest A&F University, Yangling 712100, China
- Biomass Energy Center for Arid and Semi-arid Lands, Northwest A&F University, Yangling 712100, China
| | - Chen Gao
- College of Life Sciences, Northwest A&F University, Yangling 712100, China
- Biomass Energy Center for Arid and Semi-arid Lands, Northwest A&F University, Yangling 712100, China
| | - Piotr Binczycki
- Department of Plant and Environmental Sciences, University of Copenhagen, DK-1871 Frederiksberg, Denmark
| | - Signe R Andersen
- Department of Plant and Environmental Sciences, University of Copenhagen, DK-1871 Frederiksberg, Denmark
| | - Hanna Rademaker
- Department of Physics, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Alexander Schulz
- Department of Plant and Environmental Sciences, University of Copenhagen, DK-1871 Frederiksberg, Denmark
| | - Helle Juel Martens
- Department of Plant and Environmental Sciences, University of Copenhagen, DK-1871 Frederiksberg, Denmark
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Domanski D, Zegrocka-Stendel O, Perzanowska A, Dutkiewicz M, Kowalewska M, Grabowska I, Maciejko D, Fogtman A, Dadlez M, Koziak K. Molecular Mechanism for Cellular Response to β-Escin and Its Therapeutic Implications. PLoS One 2016; 11:e0164365. [PMID: 27727329 PMCID: PMC5058498 DOI: 10.1371/journal.pone.0164365] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 09/23/2016] [Indexed: 11/18/2022] Open
Abstract
β-escin is a mixture of triterpene saponins isolated from the horse chestnut seeds (Aesculus hippocastanum L.). The anti-edematous, anti-inflammatory and venotonic properties of β-escin have been the most extensively clinically investigated effects of this plant-based drug and randomized controlled trials have proved the efficacy of β-escin for the treatment of chronic venous insufficiency. However, despite the clinical recognition of the drug its pharmacological mechanism of action still remains largely elusive. To determine the cellular and molecular basis for the therapeutic effectiveness of β-escin we performed discovery and targeted proteomic analyses and in vitro evaluation of cellular and molecular responses in human endothelial cells under inflammatory conditions. Our results demonstrate that in endothelial cells β-escin potently induces cholesterol synthesis which is rapidly followed with marked fall in actin cytoskeleton integrity. The concomitant changes in cell functioning result in a significantly diminished responses to TNF-α stimulation. These include reduced migration, alleviated endothelial monolayer permeability, and inhibition of NFκB signal transduction leading to down-expression of TNF-α-induced effector proteins. Moreover, the study provides evidence for novel therapeutic potential of β-escin beyond the current vascular indications.
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Affiliation(s)
- Dominik Domanski
- Laboratory of Mass Spectrometry, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Oliwia Zegrocka-Stendel
- Centre for Preclinical Research and Technology, Department of Immunology, Biochemistry and Nutrition, Medical University of Warsaw, Warsaw, Poland
| | - Anna Perzanowska
- Laboratory of Mass Spectrometry, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Malgorzata Dutkiewicz
- Centre for Preclinical Research and Technology, Department of Immunology, Biochemistry and Nutrition, Medical University of Warsaw, Warsaw, Poland
| | - Magdalena Kowalewska
- Department of Molecular and Translational Oncology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw, Poland
| | - Iwona Grabowska
- Department of Cytology, Faculty of Biology, University of Warsaw, Warsaw, Miecznikowa 1, 02–096 Warsaw, Poland
| | - Dorota Maciejko
- Centre for Preclinical Research and Technology, Department of Immunology, Biochemistry and Nutrition, Medical University of Warsaw, Warsaw, Poland
| | - Anna Fogtman
- Laboratory for Microarray Analysis CORELAB, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Michal Dadlez
- Laboratory of Mass Spectrometry, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Katarzyna Koziak
- Centre for Preclinical Research and Technology, Department of Immunology, Biochemistry and Nutrition, Medical University of Warsaw, Warsaw, Poland
- * E-mail:
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Solymosi K, Morandi D, Bóka K, Böddi B, Schoefs B. High biological variability of plastids, photosynthetic pigments and pigment forms of leaf primordia in buds. Planta 2012; 235:1035-49. [PMID: 22160501 DOI: 10.1007/s00425-011-1559-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Accepted: 11/07/2011] [Indexed: 05/08/2023]
Abstract
To study the formation of the photosynthetic apparatus in nature, the carotenoid and chlorophyllous pigment compositions of differently developed leaf primordia in closed and opening buds of common ash (Fraxinus excelsior L.) and horse chestnut (Aesculus hippocastanum L.) as well as in closed buds of tree of heaven (Ailanthus altissima P. Mill.) were analyzed with HPLC. The native organization of the chlorophyllous pigments was studied using 77 K fluorescence spectroscopy, and plastid ultrastructure was investigated with electron microscopy. Complete etiolation, i.e., accumulation of protochlorophyllide, and absence of chlorophylls occurred in the innermost leaf primordia of common ash buds. The other leaf primordia were partially etiolated in the buds and contained protochlorophyllide (0.5-1 μg g(-1) fresh mass), chlorophyllides (0.2-27 μg g(-1) fresh mass) and chlorophylls (0.9-643 μg g(-1) fresh mass). Etio-chloroplasts with prolamellar bodies and either regular or only low grana were found in leaves having high or low amounts of chlorophyll a and b, respectively. After bud break, etioplast-chloroplast conversion proceeded and the pigment contents increased in the leaves, similarly to the greening processes observed in illuminated etiolated seedlings under laboratory conditions. The pigment contents and the ratio of the different spectral forms had a high biological variability that could be attributed to (i) various light conditions due to light filtering in the buds resulting in differently etiolated leaf primordia, (ii) to differences in the light-exposed and inner regions of the same primordia in opening buds due to various leaf folding, and (iii) to tissue-specific slight variations of plastid ultrastructure.
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Affiliation(s)
- Katalin Solymosi
- Department of Plant Anatomy, Institute of Biology, Eötvös University, H-1117, Pázmány P. s. 1/C, Budapest, Hungary.
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Abstract
Transpiration patterns of Aesculus chinensis in relation to explanatory variables in the microclimatic, air quality, and biological phenomena categories were measured in Beijing, China using the thermal dissipation method. The highest transpiration rate measured as the sap flux density of the trees took place from 10:00 am to 13:00 pm in the summer and the lowest was found during nighttime in the winter. To sort out co-linearity, principal component analysis and variation and hierarchical partitioning methods were employed in data analyses. The evaporative demand index (EDI) consisting of air temperature, soil temperature, total radiation, vapor pressure deficit, and atmospheric ozone (O3), explained 68% and 80% of the hourly and daily variations of the tree transpiration, respectively. The independent and joint effects of EDI variables together with a three-variable joint effect exerted the greatest influences on the variance of transpiration rates. The independent effects of leaf area index and atmospheric O3 and their combined effect exhibited minor yet significant influences on tree transpiration rates.
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Affiliation(s)
- Hua Wang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
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Ramírez-Durón R, Ceniceros-Almaguer L, Salazar-Aranda R, Salazar-Cavazos MDLL, Waksman de Torres N. Evaluation of thin-layer chromatography methods for quality control of commercial products containing Aesculus hippocastanum, Turnera diffusa, Matricaria recutita, Passiflora incarnata, and Tilia occidentalis. J AOAC Int 2007; 90:920-4. [PMID: 17760328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
In Mexico, plant-derived products with health claims are sold as herbal dietary supplements, and there are no rules for their legal quality control. Aesculus hippocastanum, Turnera diffusa, Matricaria recutita, Passiflora incarnata, and Tilia occidentalis are some of the major commercial products obtained from plants used in this region. In this paper, we describe the effectiveness of thin-layer chromatography methods to provide for the quality control of several commercial products containing these plants. Standardized extracts were used. Of the 49 commercial products analyzed, only 32.65% matched the chromatographic characteristic of standardized extracts. A significant number of commercial products did not match their label, indicating a problem resulting from the lack of regulation for these products. The proposed methods are simple, sensitive, and specific and can be used for routine quality control of raw herbals and formulations of the tested plants. The results obtained show the need to develop simple and reliable analytical methods that can be performed in any laboratory for the purpose of quality control of dietary supplements or commercial herbal products sold in Mexico.
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Affiliation(s)
- Rosalba Ramírez-Durón
- Universidad Autónoma de Nuevo León, Departamento de Química Analítica, Facultad de Medicina, PO Box 2316, Sucursal Tecnológico, 64841 Monterrey Nuevo León, México
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Troch V, Van Labeke MC, Werbrouck S. Development, maturation and germination of horse chestnut somatic embryos. Commun Agric Appl Biol Sci 2007; 72:291-295. [PMID: 18018905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Affiliation(s)
- V Troch
- Department of Plant Production, University of Gent Coupure links 653, BE-9000 Gent, Belgium
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Solymosi K, Bóka K, Böddi B. Transient etiolation: protochlorophyll(ide) and chlorophyll forms in differentiating plastids of closed and breaking leaf buds of horse chestnut (Aesculus hippocastanum). Tree Physiol 2006; 26:1087-96. [PMID: 16651258 DOI: 10.1093/treephys/26.8.1087] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
An accompanying paper reports the accumulation of photoactive protochlorophyllide (Pchlide) in the innermost leaf primordia of buds of many tree species. In this paper, we describe plastid differentiation, changes in pigment concentrations and spectral properties of bud scales and leaf primordia of horse chestnut (Aesculus hippocastanum L.) from January until the end of bud break in April. The bud scales contained plastids with grana, stroma thylakoids characteristic of chloroplasts and large dense bodies within the stroma. In January, proplastids and young chloroplasts were present in the leaf primordia, and the fluorescence spectra of the primordia were similar to those of green leaves except for a minor band at 630 nm, indicative of a protochlorophyll(ide). During bud break, the pigment concentrations of the green bud scales and the outermost leaf primordia increased, and Pchlide forms with emission maxima at 633, 644 and 655 nm accumulated in the middle and innermost leaf primordia. Depending on the position of the leaf primordia within the bud, their plastids and their pigment concentrations varied. Etio-chloroplasts with prolamellar bodies (PLBs) and prothylakoids with developing grana were observed in the innermost leaves. Besides the above-mentioned Pchlide forms, the middle and innnermost leaf primordia contained only a Chl band with an emission maximum at 686 nm. The outermost leaf primordia contained etio-chloroplasts with well-developed grana and small, narrow-type PLBs. These outermost leaves contained only chlorophyll forms like the mature green leaves. No Pchlide accumulation was observed after bud break, indicating that etiolation of the innermost and middle leaves is transient. The Pchlide forms and the plastid types of the primordia in buds grown in nature were similar to those of leaves of dark-germinated seedlings and to those of the leaf primordia of dark-forced buds. We conclude that transient etiolation occurs under natural conditions. The formation of PLBs and etio-chloroplasts and the accumulation of the light-dependent NADPH:protochlorophyllide oxidoreductase are involved in the natural greening process and ontogenesis of young leaf primordia of horse chestnut buds.
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Affiliation(s)
- Katalin Solymosi
- Department of Plant Anatomy, Eötvös University, Pázmány P. s. 1/C, Budapest, H-1117, Hungary
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López C, Torrado A, Fuciños P, Guerra NP, Pastrana L. Enzymatic hydrolysis of chestnut purée: process optimization using mixtures of alpha-amylase and glucoamylase. J Agric Food Chem 2004; 52:2907-2914. [PMID: 15137834 DOI: 10.1021/jf035164o] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The enzymatic hydrolysis of starch present in chestnut purée was performed through a one-step treatment with a mixture of a commercial thermostable alpha-amylase (Termamyl 120 L, type S) and glucoamylase (AMG 300 L) at 70 degrees C. The effect of the enzyme concentration and the ratio of both amylases in the reaction mixture was studied by means of a factorial second-order rotatable design, which allowed conditions to be set leading to the total conversion of starch to glucose after 15 min of incubation (60 total enzymatic units g(-1) of chestnut; ratio of alpha-amylase/glucoamylase enzymatic units, 0.35:0.65). At lower enzyme concentration, the delay in the addition of the glucoamylase with regard to the addition of the alpha-amylase allowed a slightly higher hydrolysis percentage to be reached when compared to the simultaneous addition of both amylases at the same low enzyme concentration. The kinetics of liberation of glucose supports the existence of a synergistic effect between these two enzymes only in the first moments of the reaction. Finally, a sequential one-step hydrolysis was assayed, and more concentrated glucose syrups were thus obtained.
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Affiliation(s)
- Cristina López
- Department of Biochemistry, Genetics and Immunology, University of Vigo, Ourense, Spain
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