Insect β-N-acetyl-D-hexosaminidase, a chitin degrading enzyme, is physiologically important during the unique life cycle of the insect. OfHex1, a β-N-acetyl-D-hexosaminidase from the insect, Ostrinia furna, which was obtained by our laboratory (Gen Bank No.: ABI81756.1), was studied by molecular modeling as well as by molecular docking with its inhibitor, allosamidin. 3D model of OfHex1 was built through the ligand-supported homology modeling approach. The binding modes of its substrate and inhibitor were proposed through docking and cluster analysis. The pocket’s size and shape of OfHex1 differ from that of human β-N-acetyl-D-hexosaminidase, which determined that allosamidin can selectively inhibit OfHex1 instead of human β-N-acetyl-D-hexosaminidase. Moreover, the multi-target characteristics of allosamidin that inhibit enzymes from different families, OfHex1 (EC 3.2.1.52; GH20) and chitinase (EC 3.2.1.14; GH18), were compared. The common −1/+1 sugar-binding site of chitinase and OfHex1, and the −2/−3 sugar-binding site in chitinase contribute to the binding of allosamidin. This work, at molecular level, proved that OfHex1 could be a potential species-specific target for novel green pesticide design and also provide the possibility to develop allosamidin or its derivatives as a new type of insecticide to ‘hit two birds with one stone’, which maybe become a novel strategy in pest control.

An amphiphilic fluorescent probe, 3-dodecylamino dihydrogen imidazo[2,1-α]benz[de]isoquinolin-7-one (compound 3), was used to sense the aggregate formation process of bovine serum albumine (BSA), sodium dodecyl sulfate (SDS) and their mixed system. The fluorescence intensity of 3 was significantly affected by the adding order of SDS and BSA, and SDS can be distinguished from other surfactants with the aid of BSA, but only when 3 is allowed to interact with BSA first. The results revealed that compound 3 is preferentially sited in the hydrophobic region of BSA, and thermodynamically in SDS-BSA mixed aggregate. Sodium phosphate buffer solution (PBS) and BSA played important but distinct roles in distinguishing SDS micelle from the others.

We have connected a borondipyrromethene (BODIPY) donor to the 5′ position of a tetramethylrhodamine (TMR) acceptor to form a high efficiency (over 99 %) intramolecular fluorescence resonance energy transfer (FRET) cassette, BODIPY–rhodamine platform (BRP). While the good spectral overlap between the emission of BODIPY and the absorption of TMR was one favorable factor, another feature of this FRET system was the rigid and short biphenyl spacer that favored efficient through-bond energy transfer. More importantly, in this system, the 2′-carboxyl group of the rhodamine unit was preserved for the further modifications, which was as convenient as those carbonyl groups on the original rhodamines without connection to donors. For this reason, BRP is clearly differentiated from the previous ratiometric sensors based on donor rhodamine systems. To illustrate its value as a versatile platform, we introduced typical Hg²⁺ receptors into BRP, through convenient one-pot reactions on the 2′-carboxyl group, and successfully developed two ratiometric sensors, BRP-1 and BRP-2, with different spirocyclic receptors that recognized Hg²⁺ on different reaction mechanisms. Upon excitation at a single wavelength (488 nm), at which only BODIPY absorbed, both of the FRET sensors exhibited clear Hg²⁺-induced changes in the intensity ratio of the two strong emission bands of BODIPY and rhodamine. It should be noted that these ratiometric Hg²⁺ sensors exhibited excellent sensitivity and selectivity Hg²⁺, as well as pH insensitivity, which was similar to the corresponding ‘turn-on’ rhodamine sensors. While both ratiometric probes were applicable for Hg²⁺ imaging in living cells, BRP-1 exhibited higher sensitivity and faster responses than BRP-2. Our investigation indicated that on a versatile platform, such as BRP, a large number of highly efficient ratiometric sensors for transition-metal ions could be conveniently developed.

BACKGROUND: Ketones and aldehydes are important organic chemicals as intermediates for the pharmaceutical and fine-chemical industries. The existing oxidation reactions to obtain ketones and aldehydes are no longer sustainable because of the large amount of waste generated and use of stoichiometric reagents: a cleaner catalytic oxidation system needs to be developed.

RESULTS: The experimental results show that cobalt (II) tetra-(perfluorohexyl) phthalocyaninate delivered a high catalytic activity for the oxidation of ethyl benzene (35% conversion and 86% selectivity to acetophenone) at 90 °C under ambient pressure of oxygen. The catalyst could be recycled for at least four runs. For the oxidation of benzyl alcohol to benzaldehyde, a conversion of 6% was achieved but with a selectivity of 100% at 90 °C under 2 × 10⁵ Pa O₂.

CONCLUSION: Perfluoroalkyl metallophthalocyanines can be used for the fluorous biphasic oxidation of ethyl benzene and benzyl alcohol with molecular oxygen. The cobalt (II) tetra-(perfluorohexyl) phthalocyaninate exhibited the highest catalytic activity for the oxidation of ethyl benzene. The catalytic oxidation of benzyl alcohol using our method may be feasible in industrial applications. Copyright © 2009 Society of Chemical Industry

A series of unsymmetrical difluoro-boron(BF₂) complexes with pyridine and imidazoline were synthesized by reaction of new chelating ligands (arylmethyl-imidazolidinylidene)-pyridin-2-yl-amine with boron trifluoride diethyl etherate. All the ligands and BF₂ complexes were structurally characterized by IR, HRMS, ¹H, ¹³C,¹¹B, and ¹⁹F NMR, indicating the bidentate complexation of imidazoline nitrogen and the pyridine nitrogen to the boron center. Evaluation of agricultural bioactivities showed that some of the BF₂ complexes exhibited moderate fungicidal activities, and most of the BF₂ complexes exhibited higher activities than the none-BF₂ complexed substrates. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 20:418–424, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20567

Two molecular logic gates, FS1 and FS2, which display a UV and fluorescence behavior that is dependent on the pH value and the sodium dodecyl sulfate (SDS) surfactant concentration, are demonstrated based on the intramolecular charge-transfer mechanism. They are constructed according to the inorganic salts that induce transformation from premicelle to micelle. The absorption band of FS1 at 480 nm is significantly enhanced only when both SDS and Na₂SO₄ are the input at high concentrations, in accordance with an AND logic gate. The OR logic function can be realized in a 3.5 mM SDS/FS2 aqueous solution with SDS and Na₂SO₄ as inputs along with the emission intensity as output. Furthermore, half addition and half subtraction can be incorporated in FS1. This is facilitated by the surfactant, due to its versatility.