Showing papers by "Dong Wang published in 2008"

Dammarane-Type Glycosides from Steamed Notoginseng

Abstract: Notoginseng, the root of Panax notoginseng (Burk.) F.H. Chen (Araliaceae), is a Chinese traditional medicine, which is used in both raw and processed forms due to their different pharmacological activities. Detailed chemical investigation on steamed notoginseng led to the isolation of 27 dammarane-type triterpenoids (1-27), including 4 new glycosides, namely, notoginsenosides ST-1-ST-3 and ST-5 (1-4), in addition to 3 other known compounds. Of the new compounds, 1-3 possess new aglycones. Their structures were elucidated on the basis of detailed analyses of their 1 D and 2D NMR spectra and chemical reactions. The known compounds, koryoginsenoside-R(1) (19), yesanchinoside D (20), 6 ''-O-acetylginsenoside Rg(3) (24), and 3 beta,6 alpha,12 beta-trihyclroxyclammar-20(21),24-diene (25), were isolated from notoginseng for the first time.

Two New Dammarane-Type Bisdesmosides from the Fruit Pedicels of Panax notoginseng

Abstract: Two new dammarane-type triterpenoidal saponins, notoginsenosides FP1 (1) and FP2 (2), were isolated from the fruit pedicels of Panax notoginseng, along with 22 known compounds. Their structures were elucidated on the basis of spectroscopic evidences and chemical methods. The known compounds were identified as ginsenosides Rg(1) (3), Re (4), Rb-3 (5), Re (6), Rd (7), Rb-2 (8), Rb-1 (9), F-2 (10), and F-1 (11); as notoginsenosides R-1 (12), Fa (13), and Fc (14); as vina-ginsenoside R-7 (15); as gypenosides IX (16), XVII (17), and XIII (18), and as chikusetsusaponin-L-5 (19), quercetin 3-O-beta-D-glucopyranosyl-(1 -> 2)-beta-D-galactopyranoside (20), kaempferol 3-O-beta-D-glucopyranosyl-(1 -> 2)-beta-D-galactopyranoside (21), benzyl-beta-primeveroside (22), (S)-tryptophan (23), and icariside B-6 (24). Compounds 15, 19 and 22-24 are reported for the first time from the title plant.

Efficient construction of pyrazolo[1,5-a]pyrimidine scaffold and its exploration as a new heterocyclic fluorescent platform.

Abstract: An efficient, fast and facile pyrazolo[1,5-a]pyrimidine synthetic protocol has been established by the condensation of aminopyrazoles with 1,3-dicarbonyl components in AcOH/H2SO4 system. The pyrazolo[1,5-a]pyrimidine sulfides were selectively oxidized to the sulfones via a temperature-controlled stepwise oxidative fashion. The correlation between the substitution patterns of these pyrazolo[1,5-a]pyrimidines and their fluorescent spectroscopic properties were further examined, which provided the fundamentals for their potential applications in the development of new fluorescent probes. Red-shifts were easily achieved by the incorporation of unsaturated groups at the 5- and 7-positions, which suggested an approach for synthesizing long wavelength pyrazolo[1,5-a]pyrimidine dyes. The fluorescent spectroscopic properties were found to be sensitive to the hydroxy-containing and carbonyl-containing media such as alcohol and acetone, which helps to confirm the promising perspectives of further investigations in this area.