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Qinghaosu acid

Study on the reactions of qinghaosu is heuristic, not only for determination of its structure, but also especially for understanding chemical properties and hence for the modification and utilization of the qinghaosu molecule to develop a new medicinal apphcation. Among them, reduction and acidic degradation have been paid the most attention and have received more practical application. [Pg.197]

Treatment of qinghaosu in a mixture of glacial acetic acid and concentrated sulfuric acid (10 1) at room temperature yields a mixture of one carbon less products, among which several ketone-lactone or a,p-unsaturated ketone can be isolated."° X-ray crystal analysis of the major component 103 shows that its C-7 configuration is inverted in comparison with that of qinghaosu. " An intermediate 102 for the formation of these products has been proposed (Scheme 5-4). [Pg.199]

Since then, several laboratories also report in their research that artemisinic acid (20) is confirmed to be the biogenetic intermediate of qinghaosu, and dihydro-artemisinic acid (23) can also be biotransferred to qinghaosu. Furthermore, on incubation with the cell-free extracts of qinghao leaves, 20 can also be transferred into 10 and in turn 10 as well as dihydro-10 can be transferred to qinghaosu. [Pg.204]

Another type of (9-glycosides (127), 12-(3 aryl ethers of dihydroartemisinin, was synthesized by a reaction of acetyl dihydroartemisinin or trifluoroacetyl dihydroartemisinin with various substituted phenols in the presence of trifluoroacetic acid. Most of these compounds were proved to have better antimalarial activity against P. berghei in mice than qinghaosu, but less activity than artemether. Unexpectedly,... [Pg.208]

Dihydroartemisinin or trifluoroacetyl dihydroartemisinin reacted with aromatic amines or heterocycles, such as triazole and benzotriazole, in the presence of acidic catalyst to afford its iV-glycosides, which were more active in vivo than qinghaosu (Scheme 5-12). ... [Pg.209]

A series of qinghaosu analogs of C-3 or/and C-13 modification were prepared from artemisinic acid by Lee et al. (Scheme 5-19). Among these analogs, only 13-nitromethyl qinghaosu had antimalarial activity comparable with qinghaosu. [Pg.216]

Jung et al. prepared 11-substituted deoxoartemisinin 136 from artemisinic acid (20) using photooxidation as the key step (Scheme 5-21). Compound 136 (R = CH2OH) was more active than qinghaosu and artesunate in vitro. [Pg.217]

Some components of A. annua L., such as qinghaosu (1), artemisinin B (10), arte-misinic acid (20), artemisitene (26), flavnoids, and other terpenoids, showed antitumor activities at varying concentrations against L-1210, P-388, A-549, HT-29, MCF-7, and KB in vitro. ... [Pg.223]

The successful identification of cysteine adducts encouraged us to study the reaction of 170 and GSH-cat Fe(III). After careful isolation, an adduct 174, similar to 167, was obtained in 1% yield from the aqueous layer, which was easily rearranged to compound 175 in acidic medium. Thereafter, a similar adduct 176 between GSH and the primary C-radical derived from qinghaosu was isolated and structurally confirmed by NMR and other spectroscopy (Stmcture 5-26). ... [Pg.236]

Haynes, R. K. Vonwiller, S. C. Catalysed oxygenation of allyhc hydroperoxides derived from Qinghao (artemisinic) acid. Conversion of qinghao acid into dehydroqinghaosu (artemisitene) and qinghaosu (artemisinin). J. Chem. Soc. Chem. Commun., 1990, 451 53. [Pg.246]

Artemisia annua, known in China as Qinghaosu, contains artemisinin, which has antimalarial activity. Several derivatives of the original compound have proved effective in the treatment of Plasmodium falciparum malaria and are currently available in a variety of formulations artesunate (intravenous, rectal, oral), artelinate (oral), artemisinin (intravenous, rectal, oral), dihydroartemisinin (oral), arte-mether (intravenous, oral, rectal), and artemotil (intravenous). Artemisinic acid (qinghao acid), the precursor of artemisin, is present in the plant in a concentration up to 10 times that of artemisinin. Several semisynthetic derivatives have been developed from dihydroartemisinin (11). The artemisinin derivatives are the subject of a separate monograph. [Pg.362]

A short and practical synthesis of qinghaosu and deoxyqinghaosu (102) from arteannuic acid (101) has been developed by Ye and Wu [99] (Scheme 11). [Pg.365]


See other pages where Qinghaosu acid is mentioned: [Pg.209]    [Pg.209]    [Pg.274]    [Pg.199]    [Pg.188]    [Pg.189]    [Pg.198]    [Pg.199]    [Pg.200]    [Pg.201]    [Pg.202]    [Pg.204]    [Pg.204]    [Pg.208]    [Pg.214]    [Pg.228]    [Pg.244]    [Pg.245]    [Pg.245]    [Pg.246]    [Pg.439]    [Pg.163]    [Pg.358]    [Pg.374]    [Pg.274]    [Pg.729]    [Pg.962]    [Pg.129]   
See also in sourсe #XX -- [ Pg.209 ]




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