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Gabriella Pasqua - One of the best experts on this subject based on the ideXlab platform.
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trichomes in Camptotheca acuminata decaisne nyssaceae morphology distribution structure and secretion
Plant Biosystems, 2013Co-Authors: Alessio Valletta, Anna Rita Santamaria, Antonella Canini, Lorena Canuti, Gabriella PasquaAbstract:Camptotheca acuminata is a main source of the anti-cancer drug camptothecin (CPT). In this species, several studies have observed non-glandular trichomes (NGTs) and glandular trichomes (GTs). It has been assumed that GTs contain CPT, yet this has not been proven and no information is available on the accumulation of other secondary metabolites. The objective of this study was to describe the morphology, distribution and structure of C. acuminata trichomes and to investigate the chemical nature of the substances secreted by GTs. Light and fluorescence microscope, scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to determine the morphology, distribution and structure of GTs and NGTs. Thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) analyses were carried out to confirm the presence of CPT in GTs, and histochemical tests were performed to investigate the presence of other secondary metabolites. C. acuminata possesses two types of GTs (GT1...
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cell specific expression of tryptophan decarboxylase and 10 hydroxygeraniol oxidoreductase key genes involved in camptothecin biosynthesis in Camptotheca acuminata decne nyssaceae
BMC Plant Biology, 2010Co-Authors: Alessio Valletta, Livio Trainotti, Anna Rita Santamaria, Gabriella PasquaAbstract:Background Camptotheca acuminata is a major natural source of the terpenoid indole alkaloid camptothecin (CPT). At present, little is known about the cellular distribution of the biosynthesis of CPT, which would be useful knowledge for developing new strategies and technologies for improving alkaloid production.
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anthocyanic vacuolar inclusions in cell suspension cultures of Camptotheca acuminata decne
Caryologia, 2007Co-Authors: Valletta Alessio, Isabella Moro, Nicoletta Rascio, Gabriella PasquaAbstract:W edemonstrated the presence of anthocyanic vacuolar inclusion (AVI) in anthocyanin-producing cells of Camptotheca acuminata Decne cultured in vitro. During the four cell growth cycles, the number of cells with a col- ourless vacuole decreased. The percentage of cells with AVIs increased during the first and second cell growth cycles and then decreased. This decrease was accompanied by a considerable increase in the percentage of cells with no AVIs, with anthocyanins dissolved in the vacuolar solution. The cytochemical analysis applied to the transmission electron microscopy, revealed the presence of a protein component in the shell of the AVIs.
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triterpenoids and ellagic acid derivatives from in vitro cultures of Camptotheca acuminata decaisne
Plant Physiology and Biochemistry, 2006Co-Authors: Gabriella Pasqua, Andrea Silvestrini, Barbara Monacelli, Nadia Mulinacci, Pilar Menendez, Bruno BottaAbstract:Abstract The metabolic profile of secondary products in calli and cell suspension cultures of Camptotheca acuminata Decaisne was investigated and compared to that of the leaves and roots taken from the plant. Neither in vitro system produced the anticancer quinoline alkaloid camptothecin (CPT); they accumulated discrete quantities of polyhydroxylated triterpenoids, different from those found in the plant organs, and ellagic acid derivatives. Nine ellagic acid derivatives ( 1a – 1d and 2a – 2e ) and eight triterpenoid acids ( 3a – 3e and 4a – 4c ) were isolated and characterised. All the identified triterpenes were related to ursane- or oleanane-type skeletons and their concentrations rose to 4.5% in suspended cells.
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laticifers in Camptotheca acuminata decne distribution and structure
Protoplasma, 2005Co-Authors: Barbara Monacelli, Isabella Moro, Nicoletta Rascio, Alessio Valletta, Gabriella PasquaAbstract:In this paper, a system of laticifers in Camptotheca acuminata Decne (Nyssaceae) is described. Laticifers were already present in the leaf primordia of the shoot apex. In the mature leaves, laticifers were found in the midrib and in the larger veins, both in the parenchymatic region delimited by vascular bundles and in the cortex just external to the phloem. In the stem, laticifers were present in both the primary and secondary body, running parallel to the longitudinal axis. They were located in the pith and in the cortex proximal to the phloem. No laticifers were found in the roots. The histochemical analyses indicated that the main compounds accumulated in laticifers were phenols. Neutral lipids and fatty acids were also present. Ultrastructural observations showed osmiophilic globules both in the vacuoles and in the peripheral regions of the cytoplasm of the laticifer cells. Plastids were present, although altered, with some parallel membranes and lacking starch grains. The discovery in C. acuminata of a laticifer system, which had never been described for the order Cornales, could be of taxonomic value, also considering that this order has traditionally represented one of the most problematic groups of flowering plants.
Craig L Nessler - One of the best experts on this subject based on the ideXlab platform.
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camptothecin and 10 hydroxycamptothecin from Camptotheca acuminata hairy roots
Plant Cell Reports, 2004Co-Authors: Argelia Lorence, Fabricio Medinabolivar, Craig L NesslerAbstract:Camptothecin (CPT) is an anticancer and antiviral alkaloid produced by the Chinese tree Camptotheca acuminata (Nyssaceae) and some other species belonging to the families Apocynaceae, Olacaceae, and Rubiaceae. Bark and seeds are currently used as sources for the drug. Several attempts have been made to produce CPT from cell suspensions; however, the low yields obtained limit this approach. Cultures of differentiated cell types may be an alternative source of alkaloid production. Hairy root cultures of C. acuminata were established from tissue transformed with Agrobacterium rhizogenes strains ATCC 15834 and R-1000. Integration of the genes responsible for the hairy-root phenotype (rol genes) into the plant genome was verified by DNA gel blot analysis. The hairy roots produce and secrete CPT as well as the more potent and less toxic natural derivative, 10-hydroxycamptothecin (HCPT), into the medium. Remarkably, the cultures were able to synthesize the alkaloids at levels equal to, and sometimes greater than, the roots in planta, i.e., 1.0 and 0.15 mg/g dry weight for CPT and the HCPT, respectively.
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sustained harvest of camptothecin from the leaves of Camptotheca acuminata
Journal of Natural Products, 1997Co-Authors: Rebecca M Vincent, Melina Lopezmeyer, Thomas D Mcknight, Craig L NesslerAbstract:Over a 12-week period, new growth was collected at different intervals from Camptotheca acuminata trees to determine whether a leaf harvest strategy would be an efficient means for the production of the alkaloid camptothecin. Because camptothecin accumulates in young leaves and because the harvesting of young tissue stimulates axillary bud outgrowth, this strategy increased the harvestable amount of camptothecin from trees in a nondestructive manner.
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clonal propagation of Camptotheca acuminata through shoot bud culture
Plant Cell Tissue and Organ Culture, 1996Co-Authors: Ashok K Jain, Craig L NesslerAbstract:The chinese tree Camptotheca acuminata produces the anti-cancer and anti-retroviral drug camptothecin. Methods were developed for the clonal propagation of this important medicinal plant through shoot bud culture. Shoot buds were excised from 25 to 30 day old seedlings, presoaked for 48 h in three different liquid media containing either BA (2.22–17.4 μM), kinetin (2.32–18.58 μM), or thidiazuron (0.1–10 μM) and were subsequently cultured on semi-solid medium of the same composition. Multiple shoots only developed from the 6-benzyladenine presoaked explants with the maximum number of shoots initiated from buds presoaked in and grown on B5 medium containing 17.4 μM 6-benzyladenine. Individual shoots were removed from clusters and rooted on B5 supplemented with indole-3-butyric acid (4.9–19.6 μM). The lowest concentration of indole-3-butyric acid (4.9 μM) gave the highest percentage of rooting (82%) and the shortest root initiation period (18 d). Over 90% of the in vitro rooted plantlets survived transfer to soil.
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sites of accumulation of the antitumor alkaloid camptothecin in Camptotheca acuminata
Planta Medica, 1994Co-Authors: Melina Lopezmeyer, Craig L Nessler, Thomas D McknightAbstract:: Camptothecin is an anticancer and anti-viral alkaloid produced by the Chinese tree Camptotheca acuminata (Nyssaceae). Despite previous reports of low levels of anticancer activity in leaves of Camptotheca acuminata, we have discovered that camptothecin accumulates to approximately 0.4% of the dry weight of young leaves. This level is 1.5-fold higher than that of the seeds and 2.5-fold higher than that of the bark, the two currently used sources of the drug. As the leaves mature, the concentration and absolute amount of camptothecin decreases rapidly. The high levels of camptothecin in young leaves could provide an easily harvested, non-destructive source of this important drug.
Kexuan Tang - One of the best experts on this subject based on the ideXlab platform.
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examination of camptothecin and 10 hydroxycamptothecin in Camptotheca acuminata plant and cell culture and the affected yields under several cell culture treatments
Biocell, 2010Co-Authors: Yan Pi, Yifu Gong, Kexuan Tang, Keji JiangAbstract:Camptothecin and its derivatives are monoterpenoid indole alkaloids exhibiting significant anti-tumor actions. With the aim of improving the production of these pharmaceuticals, the contents of camptothecin and 10-hydroxycamptothecin in different tissues including roots, stems, leaves, young flower buds, opening flowers, fading flowers and seeds from Camptotheca acuminata, were investigated. The young flower buds had the highest alkaloid concentrations (camptothecin, 2.46 mg/g of dry weight; 10- hydroxycamptothecin, 1.41 mg/g of dry weight). Callus showed lower concentrations but it should also be considered as a potential source of these pharmaceuticals. In the present study, the growth rate of Camptotheca acuminata cells in culture did not correlate with contents of camptothecin and 10-hydroxycamptothecin. Alkaloid accumulation by cells under various treatments (heavy metal ions, UV-B), methyl-jasmonate, absci- sic acid, salicylic acid and hydrogen peroxide was examined, and the most notable effects appeared in the cells induced by UV-B light (which showed an 11-fold increase in camptothecin concentration) and by sali- cylic acid (which showed a 25-fold increase in 10-hydroxycamptothecin concentration). These results are significant in the context of the production of both pharmaceuticals.
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molecular cloning and characterization of a novel stem specific gene from Camptotheca acuminata
Journal of Biochemistry and Molecular Biology, 2006Co-Authors: Yan Pi, Zhihua Liao, Yourong Chai, Hainian Zeng, Peng Wang, Yifu Gong, Yongzhen Pang, Kexuan TangAbstract:: In higher plants, P450s participate in the biosynthesis of many important secondary metabolites. Here we reported for the first time the isolation of a new cytochrome P450 cDNA that expressed in a stem-specific manner from Camptotheca acuminata (designated as CaSS), a native medicinal plant species in China, using RACE-PCR. The full-length cDNA of CaSS was 1735 bp long containing a 1530 bp open reading frame (ORF) encoding a polypeptide of 509 amino acids. Bioinformatic analysis revealed that CASS contained a heme-binding domain PFGXGRRXCX and showed homology to other plant cytochrome P450 monooxygenases and hydroxylases. Southern blotting analysis revealed that there was only one copy of the CaSS present in the genome of Camptotheca acuminata. Northern blotting analysis revealed that CaSS expressed, in a tissuespecific manner, highly in stem and lowly in root, leaf and flower. Our study suggests that CaSS is likely to be involved in the phenylpropanoid pathway.
Bruno Botta - One of the best experts on this subject based on the ideXlab platform.
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triterpenoids and ellagic acid derivatives from in vitro cultures of Camptotheca acuminata decaisne
Plant Physiology and Biochemistry, 2006Co-Authors: Gabriella Pasqua, Andrea Silvestrini, Barbara Monacelli, Nadia Mulinacci, Pilar Menendez, Bruno BottaAbstract:Abstract The metabolic profile of secondary products in calli and cell suspension cultures of Camptotheca acuminata Decaisne was investigated and compared to that of the leaves and roots taken from the plant. Neither in vitro system produced the anticancer quinoline alkaloid camptothecin (CPT); they accumulated discrete quantities of polyhydroxylated triterpenoids, different from those found in the plant organs, and ellagic acid derivatives. Nine ellagic acid derivatives ( 1a – 1d and 2a – 2e ) and eight triterpenoid acids ( 3a – 3e and 4a – 4c ) were isolated and characterised. All the identified triterpenes were related to ursane- or oleanane-type skeletons and their concentrations rose to 4.5% in suspended cells.
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effects of alkaloid precursor feeding on a Camptotheca acuminata cell line
Plant Physiology and Biochemistry, 2002Co-Authors: Andrea Silvestrini, Gabriella Pasqua, Barbara Monacelli, Bruno Botta, Robert Van Der Heijden, Robert VerpoorteAbstract:Abstract To better understand the biosynthesis of Camptotheca acuminata alkaloids, the effect on camptothecin production of feeding with potential precursors of biosynthesis was studied (i.e., tryptamine and loganin combined, secologanin, and strictosidine). Two key enzymes in alkaloid biosynthesis 〚i.e., tryptophan decarboxylase (TDC; EC 4.1.1.28) and strictosidine synthase (STR; EC 4.3.3.2)〛 were also studied. The analyses were conducted using a C. acuminata CG1 cell line that does not produce alkaloids, which could be useful in better understanding the biosynthetic pathway and in identifying possible limiting factors. The activity of TDC was 5 pkat mg–1; the activity of STR was 1.1 pkat mg–1. Feeding with strictosidine revealed that this precursor is easily biotransformed by two enzymes (i.e., a hydroxylase and a dehydrogenase) in hydroxystrictosidine and didehydrostrictosidine, but camptothecin was never detected. The indole pathway and the low level of STR activity could be limiting factors in the production of camptothecin in the cell line used.
Barbara Monacelli - One of the best experts on this subject based on the ideXlab platform.
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triterpenoids and ellagic acid derivatives from in vitro cultures of Camptotheca acuminata decaisne
Plant Physiology and Biochemistry, 2006Co-Authors: Gabriella Pasqua, Andrea Silvestrini, Barbara Monacelli, Nadia Mulinacci, Pilar Menendez, Bruno BottaAbstract:Abstract The metabolic profile of secondary products in calli and cell suspension cultures of Camptotheca acuminata Decaisne was investigated and compared to that of the leaves and roots taken from the plant. Neither in vitro system produced the anticancer quinoline alkaloid camptothecin (CPT); they accumulated discrete quantities of polyhydroxylated triterpenoids, different from those found in the plant organs, and ellagic acid derivatives. Nine ellagic acid derivatives ( 1a – 1d and 2a – 2e ) and eight triterpenoid acids ( 3a – 3e and 4a – 4c ) were isolated and characterised. All the identified triterpenes were related to ursane- or oleanane-type skeletons and their concentrations rose to 4.5% in suspended cells.
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laticifers in Camptotheca acuminata decne distribution and structure
Protoplasma, 2005Co-Authors: Barbara Monacelli, Isabella Moro, Nicoletta Rascio, Alessio Valletta, Gabriella PasquaAbstract:In this paper, a system of laticifers in Camptotheca acuminata Decne (Nyssaceae) is described. Laticifers were already present in the leaf primordia of the shoot apex. In the mature leaves, laticifers were found in the midrib and in the larger veins, both in the parenchymatic region delimited by vascular bundles and in the cortex just external to the phloem. In the stem, laticifers were present in both the primary and secondary body, running parallel to the longitudinal axis. They were located in the pith and in the cortex proximal to the phloem. No laticifers were found in the roots. The histochemical analyses indicated that the main compounds accumulated in laticifers were phenols. Neutral lipids and fatty acids were also present. Ultrastructural observations showed osmiophilic globules both in the vacuoles and in the peripheral regions of the cytoplasm of the laticifer cells. Plastids were present, although altered, with some parallel membranes and lacking starch grains. The discovery in C. acuminata of a laticifer system, which had never been described for the order Cornales, could be of taxonomic value, also considering that this order has traditionally represented one of the most problematic groups of flowering plants.
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cellular localisation of the anti cancer drug camptothecin in Camptotheca acuminata decne nyssaceae
European Journal of Histochemistry, 2004Co-Authors: Gabriella Pasqua, Barbara Monacelli, Alessio VallettaAbstract:In Camptotheca acuminata, we studied the cellular sites of accumulation of the alkaloid camptothecin (CPT), in both plants grown in the field and those grown in a greenhouse, subjecting the latter to stress (i.e., draught, nutritional deficit, and pruning). Fresh sections of the leaf, stem, and root were analysed for the presence of CPT by examining the autofluorescence that the CPT molecule emits when exposed to UV radiation. In the plants grown in the field, CPT was observed only rarely. In the greenhouse plants, CPT had accumulated in crystalline form in the vacuole of specialised cells (i.e., segregator idioblasts), which were not morphologically distinguishable from the cells of the surrounding tissues. In the organs examined, the segregator idioblasts were localised in parenchymatic and epidermal tissues. CPT crystals were also detected in the glandular trichomes on both the stem and leaf.
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effects of alkaloid precursor feeding on a Camptotheca acuminata cell line
Plant Physiology and Biochemistry, 2002Co-Authors: Andrea Silvestrini, Gabriella Pasqua, Barbara Monacelli, Bruno Botta, Robert Van Der Heijden, Robert VerpoorteAbstract:Abstract To better understand the biosynthesis of Camptotheca acuminata alkaloids, the effect on camptothecin production of feeding with potential precursors of biosynthesis was studied (i.e., tryptamine and loganin combined, secologanin, and strictosidine). Two key enzymes in alkaloid biosynthesis 〚i.e., tryptophan decarboxylase (TDC; EC 4.1.1.28) and strictosidine synthase (STR; EC 4.3.3.2)〛 were also studied. The analyses were conducted using a C. acuminata CG1 cell line that does not produce alkaloids, which could be useful in better understanding the biosynthetic pathway and in identifying possible limiting factors. The activity of TDC was 5 pkat mg–1; the activity of STR was 1.1 pkat mg–1. Feeding with strictosidine revealed that this precursor is easily biotransformed by two enzymes (i.e., a hydroxylase and a dehydrogenase) in hydroxystrictosidine and didehydrostrictosidine, but camptothecin was never detected. The indole pathway and the low level of STR activity could be limiting factors in the production of camptothecin in the cell line used.
