Bitter Principles from Echinocystis Fabacea¹

Cucurbitacins and cucurbitane glycosides: structures and biological activities

“…15 Deacetoxycucurbitacin B 2-O-glucoside (5) was obtained from the roots of Picrorhiza kurrooa (Scrophulariaceae), together with the 2-O-glucoside of 23,24-dihydrocucurbitacin B (4). 19 It was shown that 2 and 6 have a hepatoprotective effect in rats with experimental cholestasis. 19 It was shown that 2 and 6 have a hepatoprotective effect in rats with experimental cholestasis.…”

“…35 Cucurbitacin D and 23,24dihydrocucurbitacin D (13), were isolated by activity-guided fractionation from the roots of Trichosanthes kirilowii, as the active components responsible for the inhibition of tyrosinase (IC 50 0.18 and 6.7 lM, respectively) and melanin synthesis (IC 50 0.16 lM and 7.5 lM, respectively) in B16/F10 melanoma cells. 34 Several cytotoxic glycosides with structures similar to cucurbitacin D, trivially named datiscosides (16)(17)(18)(19), have been isolated from Datisca glomerata (Datiscaceae). 34 Several cytotoxic glycosides with structures similar to cucurbitacin D, trivially named datiscosides (16)(17)(18)(19), have been isolated from Datisca glomerata (Datiscaceae).…”

Plant Anticancer Agents XXX: Cucurbitacins from Ipomopsis aggregata (Polemoniaceae)

“…Characterization of Biologically Active Isolates-Isocucurbitacin B (I, 33 mg, 0.00033%) crystallized in the form of colorless needles, mp 3550,3400,2950,1720,1680,1620,1450,1360,1230,1120,1050,1020 viously for cucurbitacin B (7)(8)(9)(10)(11)(12)(13)(14)(15). Identity as cucurbitacin B was established by direct comparison with an authentic sample* (MS, co-TLC).…”

“…In its lH-NMR spectrum, I was typified by the presence of a singlet assignable for the C-3 methine proton a t 6 3.89, which, since it was shifted downfield in isocucurbitacin B diacetate (IV) to 6 4.93, suggested the presence of a 2-keto-3-hydroxy ring A moiety in I (8.15). Isdcucurbitacin B (I) is a relatively rare compound, previously being reported only from three species of two Cucurbitaceae genera (9).…”

“…Cucurbitacin B (111), on the other hand, appears to be the most widely distrjbuted cucurbitacin known, since it occurs in more than 15 genera of the Cucurbitaceae, and in species of the Begoniaceae, Cruciferae, and Euphorbiaceae (9,12,16,17). Cucurbitacins have not previously been reported from the family Polemoniaceae.…”