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S Inghelbrecht - One of the best experts on this subject based on the ideXlab platform.
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first report of blight on Buxus spp caused by cylindrocladium buxicola in belgium
Plant Disease, 2003Co-Authors: C Crepel, S InghelbrechtAbstract:In the fall of 2000, a new blight disease was observed on Buxus spp. in private gardens in Belgium. Since then, more and similar disease samples from other Belgian sites, nurseries, and several garden centers have been received, indicating that this disease is spreading. Similar observations have been made in the U.K. and France, where the disease is widespread and losses are sometimes dramatic (1). Diseased plants have dark brown-to-black leaf spots and streaky, black stem lesions which lead, in some cases, to complete defoliation. On some infected plants new leaves grew in defoliated areas, hiding the original blight symptoms. Infection was mainly observed on Buxus sempervirens cv. Suffruticosa, but B. sempervirens cv. Latifolia raculata, B. microphylla cv. Compacta, and B. microphylla var. japonica cv. Faulkner were also infected. In the U.K., infections have additionally been reported on varieties of B. sempervirens, B. sinica, and B. microphylla (1). On the basis of observed symptoms and comparison o...
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first report of blight on Buxus spp caused by cylindrocladium buxicola in belgium
Plant Disease, 2003Co-Authors: C Crepel, S InghelbrechtAbstract:In the fall of 2000, a new blight disease was observed on Buxus spp. in private gardens in Belgium. Since then, more and similar disease samples from other Belgian sites, nurseries, and several garden centers have been received, indicating that this disease is spreading. Similar observations have been made in the U.K. and France, where the disease is widespread and losses are sometimes dramatic (1). Diseased plants have dark brown-to-black leaf spots and streaky, black stem lesions which lead, in some cases, to complete defoliation. On some infected plants new leaves grew in defoliated areas, hiding the original blight symptoms. Infection was mainly observed on Buxus sempervirens cv. Suffruticosa, but B. sempervirens cv. Latifolia raculata, B. microphylla cv. Compacta, and B. microphylla var. japonica cv. Faulkner were also infected. In the U.K., infections have additionally been reported on varieties of B. sempervirens, B. sinica, and B. microphylla (1). On the basis of observed symptoms and comparison of the symptoms with descriptions by Henricot and Culham (2), we identified that this new form of Buxus blight in Belgium is caused by Cylindrocladium buxicola. Sporulating cultures on potato dextrose agar (PDA) had macroconidiophores with stipe extensions terminating in broadly ellipsoidal vesicles with pointed or papillate apices (6.5 to 11 μm in diameter) and a penicillate arrangement of fertile branches each terminating in two to five phialides. Phialides produced clusters of cylindrical conidia (42 to 68 × 4 to 6 μm) that were rounded at both ends and had a single septum. Pathogenicity of the isolate was demonstrated by inoculation of healthy stems and leaves of four 3-year-old plants of B. sempervirens cv. Suffruticosa. On each plant, agar pieces of 1-week-old cultures grown on PDA were placed on five stems and five leaves that had been wounded with a sterile scalpel, then sealed with Parafilm. As a control, five wounded stems and leaves from another B. sempervirens cv. Suffruticosa plant were inoculated with sterile agar plugs. Inoculated plants were incubated in humid chambers (approximately 95% relative humidity) on the laboratory bench. Two weeks after inoculation, no symptoms were visible on the control plant. The inoculated plants showed symptoms as previously described, and C. buxicola was successfully reisolated from diseased tissue completing Koch's postulates. To our knowledge, this is the first record of C. buxicola on Buxus spp. in Belgium. References: (1) B. Henricot et al. Plant Pathol. 49:805, 2000. (2) B. Henricot and A. Culham. Mycologia 94(6):980, 2002.
Iqbal M Choudhary - One of the best experts on this subject based on the ideXlab platform.
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structure fragmentation relationship and rapid dereplication of Buxus steroidal alkaloids by electrospray ionization quadrupole time of flight mass spectrometry
Rapid Communications in Mass Spectrometry, 2013Co-Authors: Syed Ghulam Musharraf, Madiha Goher, Salma Shahnaz, Iqbal M ChoudharyAbstract:RATIONALE Tandem mass spectrometric studies of natural products revealed the identification of key fragments which can be helpful for their rapid dereplication in plant extracts utilizing a liquid chromatography/tandem mass spectrometry (LC/MS/MS) approach, particularly for the thermally labile compounds. The knowledge of the collision-induced dissociation (CID) fragmentation pattern of the molecule is essentially required prior to the analysis by LC/MS/MS. METHODS The fragmentation patterns of eleven Buxus steroidal alkaloids were studied by using a positive ion electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-QqTOF-MS/MS) hybrid instrument. Chromatographic separation of a Buxus papillosa extract was achieved using a capillary HPLC system coupled with the mass instrument. RESULTS ESI-QqTOF-MS (positive ion mode) showed the presence of several characteristic fragments which can be used to rapidly identify various classes of Buxus steroidal alkaloids. The presence of a cyclopropane ring in the cycloartenol skeleton and the hydroxyl group at C-10 was found to effect on the fragmentation pattern and afford characteristic peaks. This study distinguishes between different types of Buxus steroidal alkaloids based on logical fragmentation pathways. This strategy was successfully applied in LC/ESI-QqTOF-MS/MS analysis of Buxus papillosa extract to investigate and characterize Buxus steroidal alkaloids and 14 compounds were identified as steroidal alkaloids. CONCLUSIONS The knowledge of the fragmentation pattern was used for the rapid identification of this bioactive group of biosynthetically unique steroidal alkaloids in complex plant extracts of Buxus species, especially in the absence of any reference material, by combining key fragments, exact mass measurements and relative abundances of diagnostic fragment ions.
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new cholinesterase inhibiting triterpenoid alkaloids from Buxus hyrcana
Chemistry & Biodiversity, 2006Co-Authors: Iqbal M Choudhary, Salma Shahnaz, Shehnaz Parveen, Asaad Khalid, Ahmed M Mesaik, Abdul Majeed S AyatollahiAbstract:The current phytochemical investigation on Buxus hyrcana Pojark. has resulted in the isolation of the triterpenoid alkaloids 1-10. The structures of five new alkaloids, hyrcanone (1), hyrcanol (2), hyrcatrienine (3), N(b)-dimethylcycloxobuxoviricine (4), and hyrcamine (5), were elucidated by means of modern spectroscopic techniques, while the known alkaloids, buxidin (6), buxandrine (7), buxabenzacinine (8), buxippine-K (9) and E-buxenone (10), were identified by comparing their spectral data with those reported earlier. Compounds 1 and 3-9 were found to be acetyl- and butyrylcholinesterase inhibitors. The IC50 values were estimated to be in the range of 83.0-468.0 microM against AChE and 1.12-350.0 microM against BChE. The structure-activity relationship studies suggested that the presence of dimethylamino moieties at C(3) and C(20) is the most important factor influencing the activity of these compounds against the cholinesterase enzymes. All compounds were also evaluated for cytotoxicity on a fibroblast cell line with incubation of 24 h. No cytotoxic effects were exerted by any compound.
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new triterpenoid alkaloid cholinesterase inhibitors from Buxus hyrcana
Journal of Natural Products, 2003Co-Authors: Iqbal M Choudhary, Salma Shahnaz, Shehnaz Parveen, Asaad Khalid, Abdul Majeed S Ayatollahi, Masood ParvezAbstract:Three new triterpenoid alkaloids, (+)-N-benzoylbuxahyrcanine [(20S)-3β-benzoylamino-20-dimethylaminobux-9(11)-ene-10α-ol] (1), (+)-N-tigloylbuxahyrcanine [(20S)-20-(dimethylamino)-3β-(2‘-methyl-2‘-butenoylamino)bux-9(11)-en-10α-ol] (2), and (+)-N-isobutyroylbuxahyrcanine [(20S)-20-(dimethylamino)-3β-(2‘-methylpropanoyl)bux-9(11)-en-10α-ol] (3), have been isolated from the leaf extracts of Buxus hyrcana collected in Iran. Their structures were determined using spectroscopic methods. The structures of compounds 1 and 2 were unambiguously confirmed by single-crystal X-ray diffraction techniques. Compounds 1−3 were evaluated for their acetylcholinesterase and butyrylcholinesterase inhibitory activities, and compound 2 was found to be active against both enzymes.
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newtriterpenoidal alkaloids from Buxus sempervirens
Zeitschrift für Naturforschung C, 2002Co-Authors: Athar Ata, Iqbal M Choudhary, Bilge Sener, Samina Naz, Songul TurkozAbstract:Phytochemical studies on the ethanolic extract of the roots of Buxus sempervirens of Turkish origin have resulted in the isolation of two new triterpenoidal alkaloids, (+)-16α, 31-diacetylbuxadine (1), (-)-N b -demethylcyclomikuranine (2) along with three known natural products, (-)-cyclomikuranine (3), (-)-cyclobuxophylline-K (4) and (+)-buxaquamarine (5) isolated for the first time from this species of genus Buxus. The structures of these new natural products were established on the basis of extensive spectroscopic studies. Compound 1 exhibited antibacterial activity against human pathogenic bacteria and weak phytotoxic activity against Lemna minor Linn.
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new steroidal alkaloids from the roots of Buxus sempervirens
Journal of Natural Products, 1997Co-Authors: Iqbal M Choudhary, Bilge Sener, Athar Ata, Samina Naz, Songul TurkozAbstract:Phytochemical studies on an EtOH-soluble extract of the roots of Buxus sempervirens of Turkish origin have resulted in the isolation of three new steroidal alkaloids, (+)-semperviraminol (1), (+)-buxamine F (2), and (+)-17-oxocycloprotobuxine (3), along with two known steroidal alkaloids, (+)-buxoxybenzamine (4) and (+)-buxapapillinine (5). The structures of 1-3 were elucidated with the aid of spectroscopic studies. Compounds 4 and 5 exhibited phytotoxic activity against Lemna minor.
C Crepel - One of the best experts on this subject based on the ideXlab platform.
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first report of blight on Buxus spp caused by cylindrocladium buxicola in belgium
Plant Disease, 2003Co-Authors: C Crepel, S InghelbrechtAbstract:In the fall of 2000, a new blight disease was observed on Buxus spp. in private gardens in Belgium. Since then, more and similar disease samples from other Belgian sites, nurseries, and several garden centers have been received, indicating that this disease is spreading. Similar observations have been made in the U.K. and France, where the disease is widespread and losses are sometimes dramatic (1). Diseased plants have dark brown-to-black leaf spots and streaky, black stem lesions which lead, in some cases, to complete defoliation. On some infected plants new leaves grew in defoliated areas, hiding the original blight symptoms. Infection was mainly observed on Buxus sempervirens cv. Suffruticosa, but B. sempervirens cv. Latifolia raculata, B. microphylla cv. Compacta, and B. microphylla var. japonica cv. Faulkner were also infected. In the U.K., infections have additionally been reported on varieties of B. sempervirens, B. sinica, and B. microphylla (1). On the basis of observed symptoms and comparison o...
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first report of blight on Buxus spp caused by cylindrocladium buxicola in belgium
Plant Disease, 2003Co-Authors: C Crepel, S InghelbrechtAbstract:In the fall of 2000, a new blight disease was observed on Buxus spp. in private gardens in Belgium. Since then, more and similar disease samples from other Belgian sites, nurseries, and several garden centers have been received, indicating that this disease is spreading. Similar observations have been made in the U.K. and France, where the disease is widespread and losses are sometimes dramatic (1). Diseased plants have dark brown-to-black leaf spots and streaky, black stem lesions which lead, in some cases, to complete defoliation. On some infected plants new leaves grew in defoliated areas, hiding the original blight symptoms. Infection was mainly observed on Buxus sempervirens cv. Suffruticosa, but B. sempervirens cv. Latifolia raculata, B. microphylla cv. Compacta, and B. microphylla var. japonica cv. Faulkner were also infected. In the U.K., infections have additionally been reported on varieties of B. sempervirens, B. sinica, and B. microphylla (1). On the basis of observed symptoms and comparison of the symptoms with descriptions by Henricot and Culham (2), we identified that this new form of Buxus blight in Belgium is caused by Cylindrocladium buxicola. Sporulating cultures on potato dextrose agar (PDA) had macroconidiophores with stipe extensions terminating in broadly ellipsoidal vesicles with pointed or papillate apices (6.5 to 11 μm in diameter) and a penicillate arrangement of fertile branches each terminating in two to five phialides. Phialides produced clusters of cylindrical conidia (42 to 68 × 4 to 6 μm) that were rounded at both ends and had a single septum. Pathogenicity of the isolate was demonstrated by inoculation of healthy stems and leaves of four 3-year-old plants of B. sempervirens cv. Suffruticosa. On each plant, agar pieces of 1-week-old cultures grown on PDA were placed on five stems and five leaves that had been wounded with a sterile scalpel, then sealed with Parafilm. As a control, five wounded stems and leaves from another B. sempervirens cv. Suffruticosa plant were inoculated with sterile agar plugs. Inoculated plants were incubated in humid chambers (approximately 95% relative humidity) on the laboratory bench. Two weeks after inoculation, no symptoms were visible on the control plant. The inoculated plants showed symptoms as previously described, and C. buxicola was successfully reisolated from diseased tissue completing Koch's postulates. To our knowledge, this is the first record of C. buxicola on Buxus spp. in Belgium. References: (1) B. Henricot et al. Plant Pathol. 49:805, 2000. (2) B. Henricot and A. Culham. Mycologia 94(6):980, 2002.
Bruno Baur - One of the best experts on this subject based on the ideXlab platform.
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Composition of alkaloids in different box tree varieties and their uptake by the box tree moth Cydalima perspectalis
Chemoecology, 2013Co-Authors: Florine L. G. Leuthardt, Gaetan Glauser, Bruno BaurAbstract:Larvae of the moth Cydalima perspectalis are specialized on box trees ( Buxus spp.). Native to eastern Asia, the moth has been introduced to Europe in 2007 and is nowadays causing severe damage to box trees in private and public gardens, as well as in semi-natural box tree forests. Box trees contain highly toxic triterpenoid alkaloids which may be sequestered by specialized herbivores such as C. perspectalis. We determined the alkaloid composition in leaves of the five most common box tree varieties in Europe belonging to two Buxus species using liquid chromatography–mass spectrometry (LC–MS) metabolite profiling. We also examined whether larvae and moths of C. perspectalis accumulate alkaloids from the different box tree varieties. The differences in alkaloid composition observed between the box tree species Buxus sempervirens and Buxus microphylla were mirrored in the tissue of C. perspectalis larvae fed on either of the different box tree species, indicating uptake of alkaloids. The larvae stored large amounts of dibasic alkaloids in their body, while monobasic alkaloids were metabolized and/or excreted. Newly emerged adult moths contained no traces of alkaloids.
Toshihiro Idei - One of the best experts on this subject based on the ideXlab platform.
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distribution of guaiacyl and syringyl lignins in normal and compression wood of Buxus microphylla var insularis nakai
Iawa Journal, 1993Co-Authors: Nobuo Yoshizawa, Sbinso Yokota, Naomi Watanabe, Toshihiro IdeiAbstract:The distribution of guaiacyl and syringyl lignins in the secondary xylem tissues of normal and compression wood of Buxus microphylla var. insularis Nakai was examined by visible light (VL) microspectrophotometry coupled with the Maule and Wiesner colour reactions and by UV -microspectrophotometry, and compared with normal wood of Betula ermani Cham. Buxus formed compression wood on the lower side of the leaning sterns, and the secondary walls of the vessels and fibre-tracheids showed excessive lignification, resembling the S2 (L) layer of compression wood tracheids in gymnosperms.In normal wood of both species, the Maule colour reaction indicated that in Betula the secondary walls of fibres contain larger amounts of syringyl units in the lignins than other tissues, and that in Buxus the secondary walls of fibre-tracheids contain both syringyl and guaiacyl units. The vessel walls of both speeies contained higher amounts of guaiacyl units. Heterogeneity of the syringyl-Jignin distribution was found in the secondary walls of Buxus fibre-tracheids.In compression wood of Buxus, on the other hand, the spectra of the secondary walls of the vessels and fibretracheids after the Maule reaction showed low absorbances compared with the normal wood, whereas, after the Wiesner reaction, their secondary walls gave high absorbances. In addition, the UV -absorption maximum of the secondary fibre walls shifted from 274 nm to 279 nrn, and the UV -absorbances of the vessei and fibre-tracheid walls greatly increased in compression wood. The results obtained in the present study demonstrated that in normal Buxus wood the secondary walls of the vessels and fibre-tracheids contain both guaiacyl and syringyl units, though the syringyl unit is a rninor constituent in the vessel walls, and that both cell types increase their contents of guaiacyl units, especially in the outer parts of the secondary walls during their changes from normal wood to compression wood. The present study also suggested that the Wiesner reaction may be used for examining the content of lignin and the proportion of guaiacyl to syringyl units in lignins.
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Formation and structure of reaction wood in Buxus microphylla var. insularis Nakai
Wood Science and Technology, 1992Co-Authors: Nobuo Yoshizawa, Sbinso Yokota, M. Satoh, Toshihiro IdeiAbstract:Anatomical differences in xylem between the upper and lower sides formed in the inclined stems of Buxus microphylla with different angular displacement from the vertical were examined microscopically. B. microphylla exhibited a pronounced growth promotion on the lower side of the inclined stems. Formation of tension wood (gelatinous fibers) was not observed. Xylem formed on the lower side showed some interesting features resembling the compression wood formed in gymnosperms. The reaction wood tracheids and vessels showed an excessive lignification in their secondary walls but lacked both helical cavities and an S_3 layer, features that were almost the same as those of primitive gymnosperms. These results indicate that B. microphylla has an ability to form compression wood, suggesting that in the genus Buxus a different mechanism in the conducting elements was developed in the phylogenetic evolution.
