A novel quinoline-based turn-on fluorescent probe for the highly selective detection of Al (III) and its bioimaging in living cells, plants tissues and zebrafish.

A novel quinoline fluorescent probe QNP ((E)-N'-(5-chloro-2-hydroxybenzylidene) quinoline-2-carbohydrazide) for detection of Al3+ ion was designed, synthesized and characterized. QNP displayed a high fluorescence enhancement in the presence of Al3+ ion in DMF:PBS (99:1, v/v) solution and the detection limit was as low as 1.25 µM with high selectivity and excellent sensitivity from 0 to 3 µM. The sensing ability of QNP towards Al3+ ion is attributed to the synergistic effect of PET and ICT. Furthermore, the binding stoichiometry between QNP and Al3+ ion is of 1:1 by Job's plot and mass spectrum, and the calculated binding constant is 4.29 × 108 M-1. The detection of Al3+ ion in water samples illustrates that QNP could be applied to the detection of practical samples in the environment. Bioimaging experiments on Hela cells, zebrafish and soybean root tissues demonstrate that it has potential application to investigate biological processes involving Al3+ ion within living cells. A quinoline-based turn-on fluorescence probe for the detection of Al3+ and its bioimaging in living cells, plant, and zebrafish.

Kaempferol as an AIE-active natural product probe for selective Al3+ detection in Arabidopsis thaliana.

In this work, a natural product probe, kaempferol, which exhibited aggregation-induced emission (AIE) characteristic in water/tetrahydrofuran (THF) binary solvent was explored. The probe showed high resistance to photobleaching capacity and excellent selectivity towards Al3+ in the aggregation state. Upon the addition of Al3+, the probe displayed more than 12-fold (I486/I421) fluorescence intensity enhancement, accompanied by a color change, suggesting that the aggregated kaempferol can be used as a ratiometric probe for Al3+ detecting. Notably, promising selectivity to Al3+ within the pH range of 6-8 made the probe suitable for physiological conditions. Further Arabidopsis thaliana root imaging experiment demonstrated that the probe could image Al3+ in the plant.

Synthesis, antiproliferative activities, and DNA binding of coumarin-3-formamido derivatives.

Ten coumarin-3-formamido derivatives, N-benzyl-coumarin-3-carboxamide (2), N-fluorobenzyl-coumarin-3-carboxamide (3-5), N-methoxybenzyl-coumarin-3-carboxamide (6-8), N-((1-methyl-1H-imidazol-5-yl)methyl)-coumarin-3-carboxamide (9), N-(thiophen-2-ylmethyl)-coumarin-3-carboxamide (10), and N-(furan-2-ylmethyl)-coumarin-3-carboxamide (11), were synthesized and characterized. Compound 5 crystallizes in a monoclinic system P21 /c space group with four chemical formulas in a unit cell; molecules of compound 5 are self-assembled into a two-dimensional supramolecular structure by intermolecular hydrogen bonds and C⋯C π stacking. The potential anticancer effects of these compounds on HeLa (cervical carcinoma), MCF-7 (breast), A549 (lung), HepG2 (liver), and human umbilical vein (HUVEC) cells were examined. Compared with compounds 1-8 and 10-11, compound 9 exhibits potent in vitro cytotoxicity against HeLa cells and lower cytotoxicity against normal cells. Therefore, further in-depth investigations of compound 9 were performed. Absorption titration experiments and fluorescence spectroscopy studies suggested that compound 9 binds to DNA through the intercalation mode.

Synthesis of novel, DNA binding heterocyclic dehydroabietylamine derivatives as potential antiproliferative and apoptosis-inducing agents.

Several dehydroabietylamine derivatives containing heterocyclic moieties such as thiophene and pyrazine ring were successfully synthesized. The antiproliferative activities of these thiophene-based Schiff-bases, thiophene amides, and pyrazine amides were investigated in vitro against Hela (cervix), MCF-7 (breast), A549 (lung), HepG2 (liver), and HUVEC (umbilical vein) cells by MTT assay. The toxicity of L1-L10 (IC50 = 5.92- >100 µM) was lower than L0 (1.27 µM) and DOX (4.40 µM) in every case. Compound L1 had higher anti-HepG2 (0.66 µM), anti-MCF-7 (5.33 µM), and anti-A549 (2.11 µM) and compound L3 had higher anti-HepG2 (1.63 µM) and anti-MCF-7 (2.65 µM) activities. Both of these compounds were recognized with high efficiency in apoptosis induction in HepG2 cells and intercalated binding modes with DNA. Moreover, with average IC50 values of 0.66 and 5.98 µM, L1 was nine times more effective at suppressing cultured HepG2 cells viability than normal cells (SI = 9). The relative tumor proliferation rate (T/C) was 38.6%, the tumor inhibition rate was up to 61.2%, which indicated that L1 had no significant toxicity but high anti-HepG2 activity in vivo. Thus, it may be a potential antiproliferation drug with nontoxic side effects.

Synthesis and potential antineoplastic activity of dehydroabietylamine imidazole derivatives.

To seek more efficient and lower toxicity anticancer compounds, several imidazole combining dehydroabietylamine derivatives including organic salts (L 1 -L 2 ) and amides (L 3 -L 5 ) were synthesized. Their antineoplastic activity against HeLa (cervix), MCF-7 (breast), A549 (lung) and HepG2 (liver) cells and HUVECs (umbilical vein, normal cells) in vitro were evaluated by MTT assay. The results unequivocally showed that nearly all compounds had better antineoplastic activity and lower toxicity than dehydroabietylamine (L 0 ). For MCF-7 cells, L 2 (0.75 µM) and L 5 (2.17 µM) had higher anti-MCF-7 activity than L 0 and DOX. For A549 cells, L 1 (1.85 µM) and L 2 (4.37 µM) had higher anti-A549 activity than L 0 ; in particular, the IC50 value of L 1 was much lower than that of DOX. Among these investigated compounds, L 2 and L 5 had lower IC50 values (0.75 µM and 2.17 µM) against MCF-7 cells and lower toxicity, which suggested that they may be potential future anticancer drugs. In addition, L 1 and L 2 could suppress cancer cell proliferation by inducing apoptosis. L 1 -L 5 could bind with DNA through intercalation.