Butyl-isobutyl-phthalate (BIP), isolated from the rhizoid of Laminaria japonica, is a potential α-glucosidase inhibitor for Type II diabetes treatment. In the present study, a synthetic route was established as a useful approach to obtain enough BIP. Fluorescence analysis, circular dichroism spectra and molecular docking methods were employed to elucidate the underlying molecular mechanisms of BIP inhibition on α-glucosidase. The results revealed that BIP could be synthesized in two steps and the synthesized BIP bound with α-glucosidase and induced conformational changes of the enzyme. The interaction between BIP and α-glucosidase was driven by both hydrophobic forces and hydrogen bond. The docking results indicated that the benzene ring and the isopropyl group of the BIP could fit into the hydrophobic pocket composed of Phe177, Phe157, Leu176, Leu218, Ala278 and the propyl group fitted into another nearby hydrophobic pocket formed by Trp154, Pro240, Leu174 and Ala162, respectively. This study provides useful information for the understanding of the BIP-α-glucosidase interaction and development of new α-glucosidase inhibitors.

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This is the first report of novel chiral N-trifluoroacetyl sulfilimines during research for new environmentally benign and ecologically safe novel insecticides with new modes of action. Four series of phthalamides containing 20 new structures were designed, synthesized, and evaluated against oriental armyworm (Pseudaletia separata Walker) and diamondback moth (Plutella xylostella (L.)) for their insecticidal activities. The target compounds were established by corresponding (1)H NMR, HRMS (or elemental analysis), X-ray diffraction analysis, and optical polarimetry. Introduction of chiral N-trifluoroacetyl sulfiliminyl moieties into the new scaffolds showed that some target compounds possessed impressive activities as commercial flubendiamide. These N-trifluoroacetyl sulfilimines exhibited the sequence of activity against oriental armyworm as (Sc, Ss) ≥ (Sc, Rs) ≫ (Rc, Rs) > (Rc, Ss), in which the chiral carbon influenced the activities stronger than sulfur. For diamondback moth, compounds If, IIa, and IIc exhibited even stronger activity than flubendiamide; especially If displayed a death rate of 100% at 10(-6) mg L(-1), much better than that of flubendiamide (0% at 10(-4) mg L(-1)). Comparative molecular field analysis calculation indicated that stereoisomers with Sc configurations containing more electronegative group as COCF3 are favorable to the insecticidal activity. The present work demonstrated that chiral N-trifluoroacetyl sulfilimines can be considered as potential insect ryanodine receptor modulators. From the standpoint of molecular design, it was concluded that the conventional second methyl group in the aliphatic amido side chain of dicarboxamide might not be a requisite in our research on novel sulfiliminyl insecticides.