A ratiometric fluorescent probe for selective detection of thiophenol derivatives.

Though a number of on-off or off-on fluorescent probes have been developed for the detection of thiophenol by using its unique recognition groups, such as 2, 4-dinitrophenyl ether, 2, 4-dinitrophenyl sulfonamide, and 2, 4-dinitrophenyl sulfonate, up to now, there are few probes that can detect thiophenol by the proportional fluorescence signal. We developed a ratiometric fluorescent probe with coumarin pyridine derivative as fluorophore and 2, 4-dinitrophenyl ether moiety as the sensing unit which could be used to detect thiophenol derivatives by the aromatic nucleophilic substitution reaction. This probe (CPBPN) displayed significant change in fluorescence ratio (256 fold) to result in a more reliable analysis by self-calibration and a relatively low detection limit of 24 nM toward 4-methylthiophenol (MTP) within 30 min to achieve more sensitivity.

A fluorescent probe based on ICT for selective detection of benzenethiol derivatives.

This work presented a benzothiazole-based fluorescent probe for the detection of benzenethiol derivatives using 2, 4-dinitrobenzene moiety as a sensing unit. This probe (NCABT) was able to instantaneously respond to 4-methylbenzenethiol (MTP) within 5 min. In detecting MTP, this probe displayed a low limit of detection (49 nM).

Antifungal and wound healing promotive compounds from the resins of Dracaena cochinchinensis.

Five new compounds (xuejieins A-E), including three new phenolic glycosides (1, 2, and 5) and two new flavonoids (10 and 11), together with six known compounds were isolated from the resins of Dracaena cochinchinensis (Chinese dragon's blood). The structures of the new compounds were confirmed by extensive spectroscopic methods and electronic circular dichroism (ECD) data analysis. Especially, the absolute configurations of the sugar moieties in compounds 1, 2, and 5 were clarified by GC analysis after acid hydrolysis.

Structurally diverse terpenoids with neuroprotective activities from the resins of Populus euphratica.

Five new terpenoids including one new abietane diterpenoid (1), one new aromadendrane diterpenoid (6), two new norsesquiterpenoids (8 and 9), and a new cembrane-derived diterpenoid (12), together with seven known compounds were isolated from Populus euphratica resins. The structures of these new compounds, including their absolute configurations, were characterized by spectroscopic and computational methods. All the compounds except 8 were test for their neuroprotective activities.