CCLII.—The constituents of taraxacum root

Power, Frederick B.; Browning, Henry C.

doi:10.1039/ct9120102411

Cited by 18 publications

(6 citation statements)

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“…The roasted root is also used as a substitute for coffee. Taraxacum roots contain high amounts of triterpenes of four different skeletons, namely lupeol, b-amyrin, aamyrin and taraxasterol, as free alcohols and their esters (Power and Browing 1912;Burrows and Shimpson 1938). Triterpene synthase genes have been cloned from Taraxacum officinale roots (Masaaki et al 1999).…”

Section: Introductionmentioning

confidence: 98%

Agrobacterium rhizogenes -mediated transformation of Taraxacum platycarpum and changes of morphological characters

et al. 2004

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Transformed hairy roots were efficiently induced from seedlings of Taraxacum platycarpum by infection with Agrobacterium rhizogenes 15834. Root explants produced transformed roots at a higher frequency (76.5+/-3.5%) as compared to stem (32.7+/-4.8%) or cotyledon (16.2+/-5.7%). Hairy roots exhibited active elongation with high branching of roots on growth regulator-free medium. The competence of plant regeneration from non-transformed adventitious roots and transformed hairy roots was compared. The frequency of adventitious shoot formation from transformed roots was much higher (88.5+/-9.8%) than that of non-transformed roots (31.7 +/-9.5%) on hormone-free medium. Rooting of hairy root-derived adventitious shoots occurred easily on growth regulator-free medium but no rooting was observed on non-transformed shoots. The stable introduction of rol genes into Taraxacum plants was confirmed by PCR and Southern hybridization. Transgenic plantlets showed considerable differences in their morphology when compared to the corresponding wild-type (non-transgenic) plants. Plantlets formed from transformed roots had numerous fibrous roots with abundant lateral branches instead of the thickened taproots in non-transformed plants. The differences observed may reflect the modification of morphological root characters by introduction of rol genes.

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Section: Introductionmentioning

confidence: 98%

Agrobacterium rhizogenes -mediated transformation of Taraxacum platycarpum and changes of morphological characters

et al. 2004

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“…2 In the course of a screening of microorganisms from the North Sea, a new indole derivative, 2,5-bis(3-indolylmethyl)pyrazine (2), and a natural p-cyclophane named pharacine (5) were isolated from the extracts of a Cytophaga strain AM13.1, and their structures were assigned spectroscopically. Additionally we report tryptamine isovalerate (madugin, 1) 3 and p-hydroxyphenylacetamide (4) 4 as secondary metabolites from a microorganism for the first time. The known compounds tryptamine acetate, 5 2-phenylethylacetamide, 6 3-indolylcarboxylic acid, 7,8 cyclo(tyrosylprolyl), 9 cyclo(phenylalanylprolyl), 10 cyclo(valylprolyl), 11 cyclo(isoleucylvalyl), 12 2-(3indolyl)ethanol, 13 2-phenylethylisovaleramide, 1 3-indolylacetic acid, 8,14 2,2-dimethylbenzopyrimid-4-one, 15 o-aminobenzamide, 16 o-acetylaminobenzamide (3), 17 phenylacetamide, 18 2-(p-hydroxyphenyl)ethanol, 19 phenylacetic acid, 20 3-phenyllactic acid, 21 uracil, and thymidine were also found in the extracts.…”

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Pharacine, a Natural p-Cyclophane and Other Indole Derivatives from Cytophaga sp. Strain AM13.1

et al. 2002

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From the ethyl acetate extract of the bacterial strain Cytophaga sp. AM13.1, among many known compounds, the new natural products 2,5-bis(3-indolylmethyl)pyrazine (2) and a highly symmetrical p-cyclophane named pharacine (5) were identified. In addition, tryptamine isovalerate (1) and p-hydroxyphenylacetamide (4), known as plant metabolites, were isolated and characterized from a microorganism for the first time. The new natural products showed no activity against three microalgae, the fungus Mucor miehei, the yeast Candida albicans, and the bacteria Staphylococcus aureus, Bacillussubtilis, Escherichia coli, and Streptomyces viridochromogenes.

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“…This high content of oleanolic acid is suggestive of high expression of its biosynthetic genes, and led us to search for b-amyrin synthase cDNA from olive leaves although the actual biosynthetic site of triterpenes in this plant has not been identified. On the other hand, dandelion roots (Taraxacum officinale) contain high amount of triterpenes of four different skeletons, namely lupeol, b-amyrin, a-amyrin and taraxasterol, as free alcohols and their esters [12,13]. This situation makes dandelion roots very attractive for cDNA cloning and investigation of molecular evolution of triterpene synthases and thus have been chosen in this study.…”

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Two branches of the lupeol synthase gene in the molecular evolution of plant oxidosqualene cyclases

Shibuya

Zhang

Endo

et al. 1999

European Journal of Biochemistry

106

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Two new triterpene synthase cDNAs, named as OEW and TRW, were cloned from olive leaves (Olea europaea) and from dandelion roots (Taraxacum officinale), respectively, by the PCR method with primers designed from the conserved sequences found in the known oxidosqualene cyclases. Their ORFs consisted of 2274 bp nucleotides and coded for 758 amino acid long polypeptides. They shared high sequence identity (78%) to each other, while they showed only about 60% identities to the known triterpene synthases LUPI (lupeol synthase clone from Arabidopsis thaliana) and PNY (b-amyrin synthase clone from Panax ginseng) at amino acid level. To determine the enzyme functions of the translates, they were expressed in an ERG7 deficient yeast mutant. Accumulation of lupeol in the cells of yeast transformants proved both of these clones code for lupeol synthase proteins. An EST (expression sequence tag) clone isolated from Medicago truncatula roots as a homologue of cycloartenol synthase gene, exhibits high sequence identity (75±77%) to these two lupeol synthase cDNAs, suggesting it to be another lupeol synthase clone. Comparatively low identity (< 57%) of LUP1 from Arabidopsis thaliana to either one of these clones leaves LUP1 as a distinct clone among lupeol synthases. From these sequence comparisons, now we propose that two branches of lupeol synthase gene have been generated in higher plants during the course of evolution.Keywords: lupeol synthase; Olea europaea; Taraxacum officinale; triterpene synthase; molecular evolution.In mammals, plants, fungi and yeasts, sterols serve as essential membrane constituents, growth regulating substances and precursors of various hormones [1,2]. In the plant kingdom, besides sterols, a large number of nonsteroidal triterpene derivatives exist that are recognized as secondary metabolites due to their apparent lack of physiological functions in the producing plants [3]. They are produced species specifically, and thus could be considered as a chemical expression of plant species. It is reasonable to assume the ability of sterol biosynthesis to be inherent to all plants and highly conserved from the progenitors, while the ability to produce characteristic triterpenoids by individual plant species to be acquired in the process of plant evolution.Biosynthetic pathways leading to sterols and triterpenes are completely identical to each other up to the formation of 2,3-oxidosqualene and branch at its cyclization step [4]. As structural diversity of triterpene is primarily generated at this cyclization step catalyzed by triterpene synthases, it can be said that diversity of these synthases reflects diversity of plant species (Fig. 1). Up to now, cDNA cloning of four cycloartenol synthases (from Arabidopsis thaliana (CAS1) [5], Pisum sativum [6], Panax ginseng [7] and Allium macrostemon [8]), three triterpene synthases two b-amyrin synthases (PNY and PNY2) from P. ginseng [7,9], and a lupeol synthase (LUP1) from A. thaliana [10] and another oxidosqualene cyclase (OSC) of unknown function from P. ginsen...

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CCLII.—The constituents of taraxacum root

Cited by 18 publications

References 0 publications

Agrobacterium rhizogenes -mediated transformation of Taraxacum platycarpum and changes of morphological characters

Agrobacterium rhizogenes -mediated transformation of Taraxacum platycarpum and changes of morphological characters

Pharacine, a Natural p-Cyclophane and Other Indole Derivatives from Cytophaga sp. Strain AM13.1

Two branches of the lupeol synthase gene in the molecular evolution of plant oxidosqualene cyclases

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