A novel reaction-based fluorescent probe for the detection of cysteine in milk and water samples.

A novel fluorescent probe 3'-hydroxy-3-oxo-3H-spiro [isobenzofuran-1,9'-xanthene]-6'-yl-2,4-dinitrobenzenesulfonate (probe 1) was designed and synthesized as a visual sensor for the detection of cysteine levels in milk and water samples. The addition of cysteine to the solution of probe 1 resulted in an increase in fluorescence intensity and color change, from light yellow to yellow-green. The distinct color response indicated that probe 1 could be used as a visual sensor for cysteine. Cysteine can be detected quantitatively at concentrations between 0 and 400 µM and the detection limit of the fluorescence response to the probe was 6.5 µM. This suggests that probe 1 could be used as a signaling tool to determine the cysteine levels in samples, such as milk and water.

A Fluorescent Probe for Sensitive Detection of Hydrazine and Its Application in Red Wine and Water.

A fluorescent probe, 7-(diethylamino)-2-oxo-2H-chromene-4-carbaldehyde (probe 1), was designed and synthesized for the sensitive detection of hydrazine. The addition of N2H4 caused the fluorescence intensity of probe 1 to decrease. The probe's fluorescence was turn-off after adding N2H4, which could be observed under UV light at 365 nm. Moreover, once treated with different concentrations N2H4 solutions, the solution color change could be distinguished, which indicates that probe 1 could be used as a visual sensor for hydrazine. Moreover, probe 1 can be used as a signal tool to determine hydrazine levels in solutions, such as red wine and water.

Selective catalytic dehydration of furfuryl alcohol to 2, 2'-difurfuryl ether using a polyoxometalate catalyst.

The spice flavour compound 2, 2'-difurfuryl ether (DFE) is widely utilised in the food industry as it has a coffee-like, nutty, earthy, mushroom-like odour. However, despite intensive research efforts, to date, an environmentally friendly and practical synthetic preparation technique for 2, 2'-difurfuryl ether is still unavailable. Here, we investigate a new approach using polyoxometalate catalysts to selectively catalytically dehydrate furfuryl alcohol to 2, 2'-difurfuryl ether. We have successfully applied this methodology using the polyoxometalate (POMs) catalyst {[(CH3CH2CH2CH2)4N]2[SMo12O40]} to produce 2,2'-difurfuryl ether in a 30.86% isolated yield.

Rapidly Responsive and Highly Selective Fluorescent Probe for Bisulfite Detection in Food.

The new fluorescent probe 4-hydroxy-3-((2E,4E)-5-phenylpenta-2,4-dienoyl)-2H-chromen-2-one (probe 1) was designed and synthesized for selective detection of sulfite. The fluorescence intensity of the probe was decreased only in the presence of HSO3-; all other anions assessed resulted in an increased fluorescence response. Hence, probe 1 acts as a highly selective sensor for HSO3-. This sulfite sensitivity can also be readily monitored visually, as once treated with sulfite the solution shows a marked color change from yellow to colorless. Moreover, probe 1 can be conveniently used as a signal tool to determine the HSO3- levels in various sugar samples.

One-pot synthesis of (-)-Ambrox.

(-)-Ambrox is recognised as the prototype of all ambergris odorants. Widely used in perfumery, (-)-Ambrox is an important ingredient due to its unique scent and excellent fixative function. An environmentally friendly and practical preparation of (-)-Ambrox is still unavailable at present although a lot of attention has been paid to this hot research topic for many years. A one-pot synthesis of (-)-Ambrox was studied starting from (-)-sclareol through oxidation with hydrogen peroxide in the presence of a quaternary ammonium phosphomolybdate catalyst {[C5H5NC16H33] [H2PMo12O40]}, which gave the product a 20% overall yield.

[Difference of Toxoplasma gondii infection status between urban and rural childbearing age women visiting to hospitals in southwest region of Shandong Province].

A total of 1,839 obstetrics and gynecology clinical childbearing age women in southwest region of Shandong Province were tested for Toxoplasma gondii IgM antibody by ELISA. The results showed that the total Toxoplasma gondii infection rate was 3.10%, the infection rate was 1.66% in urban women and that was 4.49% in rural women, and there was a significant difference (P < 0.05), The infection rates were related to pet rising and the occupations that were closely contacted with animal slaughter, processing and sales (P < 0.05 for all). These results suggested that the corresponding prevention and control measures of toxoplasmosis should be formulated on the basis of different areas and occupations.