Cayaponia tayuya

Some active species have been studied and their pharmacological activity confirmed in different experimental models. In general, the active fractions of such plants were those containing cucurbitacins, as demonstrated by Rios et al. [10] in their work with Cayaponia tayuya roots. This species is used in the Amazon region of South America as an analgesic, anti-inflammatory, and anti-rheumatic agent while the extracts of this species are widely employed in the treatment of skin disorders such as dermatosis and other irritations. The chloroform fraction obtained from the active root methanol extract was found to be more active than the ethyl acetate and butanol fractions. Subsequent phytochemical analysis demonstrated that the chloroform fraction is rich in cucurbitacins, whereas the ethyl acetate and butanol fractions are principally comprised of C-glycosil flavonoids [10]. 

In general, cucurbitacins are distinguished by use of correlative letters, e.g. cucurbitacin B however, some of these compounds are described by evoking a chemical modification, e.g. 23-dihydrocucurbitacin B or 3-epi-cucurbitacin F [2]. In still other cases, the name of the compound comes from the genus or species in which it was originally isolated, e.g. briogenin from Bryonia [9] or cayaponosides from Cayaponia tayuya [32-36],... 

Delporte et al. [13] isolated two cucurbitacins from Kageneckia oblonga using a complex method involving column chromatography on Amberlite, Sephadex LH-20, and MPLC. However, to separate the two major components of Cayaponia tayuya, Recio et al. [43] used a simple method based on gel-filtration through Sephadex LH-20 with dichloromethane as the mobile phase. 

In another paper, Rios et al. [10] reported the anti-inflammatory activity of the chloroform extract from Cayaponia tayuya, which exhibited a high potency against carrageenan-induced mouse paw edema, with an ED50 of 122.5 mg/kg (p.o.) and 27.8 (i.p.). From the active extract, Recio et al. [43] isolated two cucurbitacins which were identified as cucurbitacin R and 23,24-dihydrocucurbitacin B, Fig. (7). 

In a similar screening, Konoshima et al. [72] studied the inhibitory effects of twenty-four 29-nor-cucurbitacin glucosides isolated from the roots of Cayaponia tayuya and found that five of them, cayaponosides B, B3, D, D3b, and C2, exhibited significant inhibitory effects on EBV activation induced by the tumor promoter TPA. Moreover, two of the cucurbitacins shown to be active in vitro, cayaponosides B and C2, Fig. (14), inhibited mouse skin tumor promotion in a two-stage in vivo carcinogenesis test. 

Further, many kinds of 29-nor-cucurbitane glycosides, cayaponosides (128 - 143), had been isolated from the root of Cayaponia tayuya (Cucurbitaceae) which have been used as laxatives, diuretics and antirheumatics in Brazilian traditional medicine, and their structural elucidation had also been reported [59]. 

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