XCIX.—The constituents of rhubarb

Tutin, Frank; Clewer, Hubert William Bentley

doi:10.1039/ct9119900946

Cited by 38 publications

(12 citation statements)

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“…An array of secondary metabolites is produced by living organisms under different conditions, which are beneficial to the organisms and have a variety of applications for humans [4]. Anthraquinones is one of secondary metabolites that are produced by various plants and are applied in a wide range of applications, for example, as coloring agents in the food and textile industries and as therapeutic agents for various diseases [5,6]. They are derived from 9,10-anthracenedione.…”

Section: Introductionmentioning

confidence: 99%

Chrysophanol: A Natural Anthraquinone with Multifaceted Biotherapeutic Potential

et al. 2019

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Chrysophanol is a unique anthraquinone having broad-spectrum therapeutic potential along with ecological importance. It is the first polyketide that has been reported to be biosynthesized in an organism-specific manner. The traditional Chinese and Korean medicinal systems provide evidence of the beneficial effects of chrysophanol on human health. The global distribution of chrysophanol encountered in two domains of life (bacteria and eukaryota) has motivated researchers to critically evaluate the properties of this compound. A plethora of literature is available on the pharmacological properties of chrysophanol, which include anticancer, hepatoprotective, neuroprotective, anti-inflammatory, antiulcer, and antimicrobial activities. However, the pharmacokinetics and toxicity studies on chrysophanol demand further investigations for it to be used as a drug. This is the first comprehensive review on the natural sources, biosynthetic pathways, and pharmacology of chrysophanol. Here we reviewed recent advancements made on the pharmacokinetics of the chrysophanol. Additionally, we have highlighted the knowledge gaps of its mechanism of action against diseases and toxicity aspects.

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Section: Introductionmentioning

confidence: 99%

Chrysophanol: A Natural Anthraquinone with Multifaceted Biotherapeutic Potential

et al. 2019

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Cytogenetic studies of some members of Polygonaceae of Kashmir. III Rheum L.

Gohil

Rather

1986

CYTOLOGIA

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Commonly called rhubarb, species of Rheum L. are important source for a number of chemical compounds like emodin, chrysophanic acid and rhaponticin, used as purgatives (Tutin and Clewer 1911). Although these chemicals are present in nearly all the species of Rheum whose chemical analysis has been done, R. emodi and Ri frazenbachii are very rich in them. The two species of this genus namely R. emodi and R. webbianum, growing wild in Kashmir Himalaya, are used as edibles and medicinals both by the people inhabiting this region and the nomads. In view of their economic importance it was decided to study these species critically. The present paper puts on record meiotic details of these two species. Materials and methodsThe material of R. emodi was collected from Mahadev (3,900m) and Baltal (2,900m) and that of R. webbianum from Kangan (1,800m). For the study of male meiosis anthers from the floral buds, fixed in modified Carnoy's 1:1:1 (acetic acid, aboslute ethanol and chloroform) fluid were squashed in I % acetocarmine. For studying pollen fertility, pollen grains from fresh, ripe but undehisced anthers were stained in acetocarmine. The shrivelled and unstained pollen grains were scored as sterile. All the observations were made from temporary mounts which were later made permanent by passing through acetic acid-n butyl alcohol series with euparol as the mounting medium. ObservationsRheum emodi: All the plants collected from Baltal and Mahadev were diploid with different anthers of a bud at different stages of development. In addition to the 22 chromosomes of this species forming eleven bivalents, in the pollen mother cells, an accessory chromosome was also observed in 96.6% of the cells scored (Fig. 1). This accessory chromosome was very small as compared to other chromo somes.At diplotene one or two bivalents remained attached to a large, round and 1 Present address:

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“…Since their UV absorption properties are similar, all these compounds act as UV shields. Anthraquinones such as emodin and aloe-emodin, and proanthocyanidins have been isolated from the roots, seedlings, and callus culture of the Rheum species as the substances having absorption maxima in the UV range (Tutin and Clewer 1911;Rai 1978;Kashiwada et al 1986). However, anthraquinones and proanthocyanidins were not found from the translucent bracts and leaves of R. nobile, showing that flavonol glycosides only act as UV shields in this species.…”

Section: Compounds D5 and B1mentioning

confidence: 99%

Flavonoids in translucent bracts of the Himalayan Rheum nobile (Polygonaceae) as ultraviolet shields

Iwashina

Omori

Kitajima

et al. 2004

Journal of Plant Research

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UV-absorbing substances were isolated from the translucent bracts of Rheum nobile, which grows in the alpine zone of the eastern Himalayas. Nine kinds of the UV-absorbing substances were found by high performance liquid chromatography (HPLC) and paper chromatography (PC) surveys. All of the five major compounds are flavonoids, and were identified as quercetin 3- O-glucoside, quercetin 3- O-galactoside, quercetin 3- O-rutinoside, quercetin 3- O-arabinoside and quercetin 3- O-[6"-(3-hydroxy-3-methylglutaroyl)-glucoside] by UV, 1H and 13C NMR, mass spectra, and acid hydrolysis of the original glycosides, and direct PC and HPLC comparisons with authentic specimens. The four minor compounds were characterised as quercetin itself, quercetin 7- O-glycoside, kaempferol glycoside and feruloyl ester. Of those compounds, quercetin 3- O-[6"-(3-hydroxy-3-methylglutaroyl)-glucoside] was found in nature for the first time. The translucent bracts of R. nobile accumulate a substantial quantity of flavonoids (3.3-5 mg per g dry material for the major compounds). Moreover, it was clarified by quantitative HPLC survey that much more of the UV-absorbing substances is present in the bracts than in rosulate leaves. Although the flavonoid compounds have been presumed to be the important UV shields in higher plants, there has been little characterisation of these compounds. In this paper, the UV-absorbing substances of the Himalayan R. nobile were characterised as flavonol glycosides based on quercetin.

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XCIX.—The constituents of rhubarb

Cited by 38 publications

References 0 publications

Chrysophanol: A Natural Anthraquinone with Multifaceted Biotherapeutic Potential

Chrysophanol: A Natural Anthraquinone with Multifaceted Biotherapeutic Potential

Cytogenetic studies of some members of Polygonaceae of Kashmir. III Rheum L.

Flavonoids in translucent bracts of the Himalayan Rheum nobile (Polygonaceae) as ultraviolet shields

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