Chemical investigation of the aerial parts of Atraphaxis frutescens resulted in the isolation of five 7-methoxyflavonols with pyrogallol B-ring moieties (1-5), a fisetinidol glucoside (13), and a benzyl glycoside (18), together with 26 known compounds including flavonoids, phenylpropanoid amides, anthraquinone glycosides, lignans, and a benzyl derivative. The principal chemical structural feature of the isolated compounds was either a pyrogallol or catechol B-ring moiety, and they showed potent 1,1-diphenyl-2-picrylhydrazyl radical scavenging activities. To assess the effects of these antioxidants on biological enzymes, their inhibitory effects against an insect phenoloxidase and a mushroom tyrosinase were evaluated. This study indicated that insect phenoloxidase was inhibited by phenylpropanoid amides and that mushroom tyrosinase was inhibited by the characteristic 7-methoxyflavonol 3-O-rhamnopyranosides.
Eight new flavonoid-based 3'-O-β-d-glucopyranosides (1-8) and three new galloyl glucosides (9, 11, 12), were isolated from the aerial parts of Saxifraga spinulosa, along with 25 known compounds. The structures of the new compounds were elucidated by spectroscopic methods. Most of the isolated compounds exhibited potent DPPH radical-scavenging activities. Further, their inhibitory activities were evaluated against Babesia bovis, Babesia bigemina, Babesia caballi, and Theileria equi, protozoan parasites that cause piroplasmosis in livestock. The results indicated that several of these compounds showed growth-inhibitory effects on such organisms that cause piroplasmosis.
Fomitopsis officinalis is a medicinal fungus, known as 'Agarikon', and is used traditionally in the treatment of asthma and rheumatism in Mongolia. The investigation of the chemical constituents of F. officinalis led to the isolation of 4 new lanostane triterpenoids together with 4 known triterpenoids. Inhibitory activity against Trypanosoma congolense, which causes fatal diseases in animals including livestock, was estimated for the isolated compounds. Compounds 2-5 and 8 exhibited moderate inhibition activities with IC values ranging from 7.0-27.1 µM.
Eight isovaleryllignans (1−4 and 8−11), three isovalerylphenylpropanoids (5−7), three known lignans (12− 14), and four known compounds were isolated from an extract of the aerial part of Brachanthemum gobicum. The structures of the isolated compounds were elucidated based on NMR and MS data analyses. The enantiomers of compounds 1−3, 5, 8, and 9 were isolated using chiral-phase HPLC, and the absolute configurations of 1a/1b−3a/3b, 5a/5b, 8a/8b, and 9a/9b were elucidated from their optical rotations and ECD spectra; the other lignans were assumed to be racemic or scalemic by chiralphase HPLC analyses and optical rotation data. Some of the acylated lignans (racemic mixtures) (1−4, 8, 9, and 12−14) exhibited moderate inhibitory activities against Trypanosoma congolense, the causative agent of nagana disease in animals.
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