Site-Directed Mutagenesis Study Revealed Three Important Residues in Hc-DAF-22, a Key Enzyme Regulating Diapause of .

() is one of the most important parasites of small ruminants, especially goats and sheep. The complex life cycle of this nematode is a main obstacle for the control and prevention of haemonchosis. So far, a special form of arrested development called diapause different from the dauer stage in () has been found in many parasitic nematodes.

Characterization and function analysis of a novel gene, Hc-maoc-1, in the parasitic nematode Haemonochus contortus.

Background: Enoyl-CoA hydratase (MAOC) is required for the biosynthesis of the fatty acid-derive side chains of the ascaroside via peroxisome β-oxidation in the free-living nematode Caenorhabditis elegans. The derivative of dideoxy-sugar, ascarylose is used as dauer pheromones or daumones to induce development of the stress-resistant dauer larvae stage.

Methods: Hc-maoc-1 gene was obtained by searching the Wellcome Trusts Sanger Institute's H.

Rapid Identification of unstable acyl glucoside flavonoids of Oxytropis racemosa Turcz by high-performance liquid chromatography-diode array detection-electrospray ionisation/multi-stage mass spectrometry.

Introduction: Oxytropis racemosa Turcz is an important minority medicine that is used mainly to improve children's indigestion, especially in inner Mongolia and Tibet. Previous studies indicated that the characteristic constituents of this plant are acylated flavonoids.

Objective: Rapidly identify the characteristic chemical constituents of O.

3-Hydroxymethylglutaryl flavonol glycosides from a Mongolian and Tibetan medicine, Oxytropis racemosa.

Three new flavonol 3-O-glycosides, rhamnetin 3-O-[(S)-3-hydroxy-3-methyl-glutaroyl(1→6)]-β-D-glucopyranoside (1), rhamnocitrin 3-O-[(S)-3-hydroxy-3-methylglutaroyl(1→6)]-β-D-glucopyranoside (2), and isorhamnetin 3-O-[(S)-3-hydroxy-3-methylglutaroyl(1→6)]-α-L-rhamnopyranosyl(1→2)-β-D-glucopyranoside (3), along with 13 known compounds, were isolated from Oxytropis racemosa TURCZ. Their structures were deduced by means of spectroscopic methods and chemical evidence. 2 and 6 showed cytotoxic activities against HCT-8 (IC₅₀ 6.

Flavonol glycosides and monoterpenoids from Potentilla anserina.

Potentilin A (1), a rare diflavonol ester of mu-truxinic acid and a new normonoterpenoid, 2,6-dimethyl-2,3-dihydro-4-oxo-4H-pyran-2-acetic acid (2), was isolated from Potentilla anserina, together with 19 known flavonol glycosides (3-21) and 2 known monterpenoids (22,23). Their structures were elucidated by means of UV, IR, HR-ESI-MS, 1D and 2D NMR spectroscopic data.