Camptotheca: A plant genus of the family NYSSACEAE (sometimes classified in the CORNACEAE family). It is a source of CAMPTOTHECIN.Plants, Medicinal: Plants whose roots, leaves, seeds, bark, or other constituent parts possess therapeutic, tonic, purgative, curative or other pharmacologic attributes, when administered to man or animals.Camptothecin: An alkaloid isolated from the stem wood of the Chinese tree, Camptotheca acuminata. This compound selectively inhibits the nuclear enzyme DNA TOPOISOMERASES, TYPE I. Several semisynthetic analogs of camptothecin have demonstrated antitumor activity.
Camptotheca: Camptotheca (happy tree, cancer tree, or tree of life) is a genus of medium-sized deciduous trees growing to tall, native to southern China and Tibet. The genus is usually included in the tupelo family Nyssaceae, but sometimes included (with the tupelos) in the dogwood family Cornaceae.Medicinal plants of the American West: Many plants that grow in the American West have use in traditional and herbal medicine.Irinotecan
(1/13) Wound-induced expression of the ferulate 5-hydroxylase gene in Camptotheca acuminata.
The phenylpropanoid pathway plays important roles in plants following exposure to environmental stresses, such as wounding and pathogen attack, which lead to the production of a variety of compounds, including lignin, flavonoids and phytoalexins. Ferulate 5-hydroxylase (F5H) is a cytochrome P450-dependent monooxygenase that catalyses the hydroxylation of ferulic acid, coniferaldehyde and coniferyl alcohol, leading to sinapic acid and syringyl lignin biosynthesis. We isolated F5H cDNA and genomic DNA from Camptotheca acuminata and investigated the expression pattern of the C. acuminata F5H (CaF5H1) gene in response to wounding. A search against the BLOCKS database of conserved protein motifs indicated that CaF5H1 retains features in common with F5Hs reported from other plants. 5'-flanking region analysis using the PLACE database showed that putative regulatory elements related to various abiotic and biotic stresses, such as drought, wounding, low temperature and pathogens, exist in the 5'-flanking region of CaF5H1. Based upon these analysis results, we investigated the expression pattern of CaF5H1 gene in response to wounding and stress-related molecules. Here, we show that CaF5H1 transcripts accumulated in the leaves in response to mechanical wounding or the application of molecules involved in the stress response, such as ethylene, ABA and hydrogen peroxide (H2O2). The application of salicylic acid and diphenylene iodonium (DPI) inhibited the wound-induced expression of CaF5H1. Taken together, we suggest that wound-induced expression of CaF5H1 may be mediated by MJ and H2O2 and enhanced phenylpropanoid contents via CaF5H1 maybe function in response to various stresses, including wounding, in plants. (+info)
(2/13) Molecular cloning and characterization of a novel stem-specific gene from Camptotheca acuminata.
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. (+info)
(3/13) Total synthesis and biological evaluation of 22-hydroxyacuminatine.
A total synthesis of 22-hydroxyacuminatine, a cytotoxic alkaloid isolated from Camptotheca acuminata, is reported. The key step in the synthesis involves the reaction of 2,3-dihydro-1H-pyrrolo[3,4-b]quinoline with a brominated phthalide to generate a substituted pentacyclic 12H-5,11a-diazadibenzo[b,h]fluoren-11-one intermediate. Despite its structural resemblance to camptothecin and luotonin A, a biological evaluation of 22-hydroxyacuminatine in a topoisomerase I-deficient cell line P388/CPT45 has confirmed that the observed cytotoxicity is not due to topoisomerase I inhibition, even though 22-hydroxyacuminatine has a hydroxyl group that can theoretically hydrogen bond to Asp533. This result is consistent with the hypothesis that pi-pi stacking is more important than hydrogen-bonding interactions in determining topoisomerase I inhibitor binding in the ternary cleavage complex. (+info)
(4/13) Molecular cloning and characterization of 1-hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate reductase (CaHDR) from Camptotheca acuminata and its functional identification in Escherichia coli.
Camptothecin is an anti-cancer monoterpene indole alkaloid. The gene encoding 1-hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate reductase (designated as CaHDR), the last catalytic enzyme of the MEP pathway for terpenoid biosynthesis, was isolated from camptothecin-producing Camptotheca acuminata. The full-length cDNA of CaHDR was 1686 bp encoding 459 amino acids. Comparison of the cDNA and genomic DNA of CaHDR revealed that there was no intron in genomic CaHDR. Southern blot analysis indicated that CaHDR belonged to a low-copy gene family. RT-PCR analysis revealed that CaHDR expressed constitutively in all tested plant organs with the highest expression level in flowers, and the expression of CaHDR could be induced by 100 microM methyl-jasmonate (MeJA), but not by 100 mg/L salicylic acid (SA) in the callus of C. acuminata. The complementation of CaHDR in Escherichia coli ispH mutant MG1655 demonstrated its function. (+info)
(5/13) Molecular cloning, characterization and expression of a jasmonate biosynthetic pathway gene encoding allene oxide cyclase from Camptotheca acuminata.
(6/13) Cell-specific expression of tryptophan decarboxylase and 10-hydroxygeraniol oxidoreductase, key genes involved in camptothecin biosynthesis in Camptotheca acuminata Decne (Nyssaceae).
(7/13) Rhizobium kunmingense sp. nov., isolated from rhizosphere soil of Camptotheca acuminata Decne.
Strain LXD30(T) was isolated from rhizosphere soil of a plant of the species Camptotheca acuminata Decne which is native to warm, humid stream banks in southern China. Analysis of the 16S rRNA gene sequence revealed that the Gram-negative, rod-shaped bacterium fell within the realm of the genus Rhizobium and was most closely related to Rhizobium huautlense SO2(T) (96.4% sequence similarity) and Rhizobium cellulosilyticum LMG 23642(T) (96.4%). The isolate grew optimally at pH7.0 and 25-28 degrees C in the presence of 0-1% (w/v) NaCl. Major fatty acids were C16:0 (17.5%) and summed feature 7 (C18:1omega7c/omega9t/omega12t, 58.3%). Unequivocally low 16S rRNA (<97%), recA (<92%) and atpD (<90%) gene sequence similarities to all existing species of the genus and phenotypic characteristics all suggested that strain LXD30(T) (=KCTC 22609(T)=CGMCC 1.8903(T)) represents a novel Rhizobium species, for which the name Rhizobium kunmingense sp. nov. is proposed. (+info)
(8/13) Evaluation of antimicrobial activity of endophytic fungi from Camptotheca acuminata (Nyssaceae).
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