Licorice-saponins A3, B2, C2, D3, and E2, five new oleanene-type triterpene oligoglycosides from Chinese Glycyrrhizae Radix.

Palmitoleate (=(9Z)‐Hexadeca‐9‐enoate) Esters of Oleanane Triterpenoids from the Golden Flowers of Tagetes erecta: Isolation and Autoxidation Products

“…The 2D-NMR spectra run for further strengthening of the structure of the new natural product 1 revealed its decomposition to a mixture of compounds by autoxidation (aerial oxidation). The 1 H-NMR spectrum of the 2D-NMR sample of 1 confirmed this observation, which showed traces of peaks for HÀC (12), HÀC(28), C(11), C(12), C(13), and C(28) for structure 1, besides prominent signals at d 2.91, 3.21, 3.26, 3.31, 3.46, 3.68, 3.75, 5.36, 5.56, and 5.82. The mixture was separated by prep.…”

“…This was confirmed by the 13 C-NMR spectrum (Table 2) [12]. The a,bunsaturated-ketone moiety was also substantiated by the HR-EI-MS, which showed two important fragments at m/z 273.2201 (C 19 Autoxidation Products of 1 and 5.…”

“…The 1 H-NMR spectrum of 1 in CDCl 3 (500 MHz, Table 1) displayed s (d 1.14, 0.93, 0.92, 0.87, 0.85 (6 H), and 0.83) for seven tertiary Me groups, an AB system (d 3.19 (d, J 11.0 Hz) and 3.53 (d, J 11.0 Hz)) for a CH 2 OH group, a dd (d 4.48 (J 9.0 and 7.0 Hz)) characteristic of the axial HÀC(3) of a triterpene geminal to an ester function, and a t (d 5.18 (J 3.5 Hz)) typical for HÀC (12), the trisubstituted olefinic proton of olean-12-ene derivatives. These data are compatible with those reported for erythrodiol ( (3b)-olean-12-ene-3,28-diol) and its derivatives [5b] [6] [7].…”

“…It is worth mentioning that many natural products of these types have been cited in the literature [6] [9b] [10 ± 12] [19] [20] [21a] as genuine compounds; however, there is one report that demonstrates artifact formation during the extraction procedure for the isolation of triterpenes [21b]. It is important to note that triterpenoids bearing an a,b-unsaturated-ketone moiety in ring C have important biological activities [12] [21]. Moreover, triterpenoid esters like 1 ± 6 have also been reported to possess significant pharmaceutical properties [22] [23].…”

Phenolic Constituents of Licorice (Glycyrrhiza Species)

“…KITAGAWA et al have reported the isolation of a new bisdesmoside, licorice-saponin A3 (58), and ten new monodesmosides, licoricesaponins B2, C2, D3, E2, F3, G2, H2, J2, K2, L3 (59)(60)(61)(62)(63)(64)(65)(66)(67)(68) together with the known saponins glycyrrhizic acid (2) and 18et-glycyrrhizin (69) from G. uralensis (100,(203)(204)(205)(206). Methanolysis of the trimethyl ester of licorice-saponin D3 (61a) liberates 22~-acetoxy-3~-hydroxy-12-olea nene-30-oic acid (46) as a methyl ester, and subsequent hydrolysis gives ll-deoxoglabrolide (8) (205).…”