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GPR119 is a promising target for discovery of anti-type 2 diabetes mellitus agents. We described the optimisation of a novel series of pyrimido[5,4-b][1,4]oxazine derivatives as GPR119 agonists. Most designed compounds exhibited good agonistic activities. Among them, compound 10 and 15 demonstrated the potent EC50 values (13 and 12 nM, respectively) and strong inherent activities. Moreover, significant hypoglycaemic effect of compound 15 was observed by reducing the blood glucose AUC0–2h at the dose of 30 mg/kg, which is stronger than Vildagliptin (23.4% reduction vs. 17.9% reduction). [ABSTRACT FROM AUTHOR]

A trimeric tri-Tb3+-including antimonotungstate (AMT) hybrid Na17{(WO4)[Tb(H2O)(Ac)(B-α-SbW9O31(OH)2)]3}·50H2O (Tb3W28) was successfully synthesized, in which the capped tetrahedral {WO4} group plays a significant template role in directing the aggregation of three [B-α-SbW9O33]9− fragments and three Tb3+ ions. Eu3+/Tb3+/Dy3+/Gd3+-codoped AMT materials based on Tb3W28 were firstly prepared and their luminescence properties were investigated. The red emitter Eu3+, yellow emitter Dy3+, and nonluminous Gd3+ ions were codoped into Tb3W28 to substitute Tb3+ ions for investigating the energy transfer (ET) mechanism among Eu3+, Tb3+, and Dy3+ ions. Upon the 6H15/2 → 4I13/2 excitation at 389 nm of the Dy3+ ion, the ET1 mechanism (Dy3+ → Tb3+) was confirmed as a non-radiative dipole–dipole interaction. Under the 7F6 → 5L10 excitation at 370 nm of the Tb3+ ion, the ET2 mechanism (Tb3+ → Eu3+) was identified as a non-radiative quadrupole–quadrupole interaction. Under excitation at 389 nm, the two-step successive Dy3+ → Tb3+ → Eu3+ ET3 process was proved in Dy1.2Tb3zEu0.03Gd1.77−3zW28. Through changing the excitation wavelengths, the emission color of Dy1.2Tb1.2Eu0.03Gd0.57W28 can vary from blue to yellow, in which a near-white-light emission case was observed upon excitation at 378 nm. This work not only provides a systematic ET mechanism study of hetero-Ln-codoped AMTs, but also offers some useful guidance for designing novel performance-oriented Ln-codoped polyoxometalate-based materials. [ABSTRACT FROM AUTHOR]

Advances in polyoxometalate (POM) self-assembly chemistry are always accompanied by new developments in molecular blocks. The exploration and discovery of uncommon building blocks offer great possibilities for generating unprecedented POM clusters. An intriguing Sb III -W VI -cotemplated antimonotungstate [H 2 N(CH 3 ) 2 ] 11 Na[SbW 9 O 33 ]Er 2 (H 2 O) 2 Sb 2 [SbW VI W 15 O 57 ]·22H 2 O ( 1 ) was synthesized, which comprises a classical trivacant Keggin [SbW 9 O 33 ] 9- ({SbW 9 }) fragment and an unclassical lacunary Dawson-like [SbW VI W 15 O 57 ] 15- ({SbW VI W 15 }) subunit. Notably, the Dawson-like {SbW VI W 15 } subunit is the first example of a [SbO 3 ] 3- and [W VI O 6 ] 6- mixed-heteroatom-directing POM segment. Hexacoordinated [W VI O 6 ] 6- can not only serve as the heteroatom function but its additional oxygen sites can also link to lanthanide, main-group metal, and transition-metal centers to form the innovative structure. {SbW VI W 15 } and {SbW 9 } subunits are joined by the heterometallic [Er 2 (H 2 O) 2 Sb 2 O 17 ] 22- cluster to give rise to an asymmetric sandwich-type architecture. To further realize its potential application in electrochemical sensing, a conductive 1 @rGO composite was obtained by the electrochemical deposition of 1 with graphene oxide (GO). Using a 1 @rGO-modified glassy carbon electrode as the working electrode, an electrochemical biosensor for detecting the antidepressant drug paroxetine (PRX) was successfully constructed. This work can provide a viable strategy for synthesizing mixed-heteroatom-directing POMs and demonstrates the application of POM-based materials for the electrochemical detection of drug molecules.

Template-directed assembly of giant cluster-based nanomaterials is an everlasting theme in cluster science. In this work, ethylenediamine tetramethylphosphonic acid [H 8 EDTPA = (POCH 2 (OH) 2 ) 4 C 2 H 4 N 2 ] and [B-α-SbW 9 O 33 ] 9- were, respectively, used as an organic template and an inorganic template to prepare an organophosphonic acid-regulating P V -Sb III -heteroatom-inserted polyoxotungstate aggregate [H 2 N(CH 3 ) 2 ] 5 Na 11 H 9 [CeW 4 O 10 (HEDTPA)SbW 15 O 50 ][B-α-SbW 9 O 33 ] 2 ·36H 2 O ( 1 ). Noteworthily, organophosphonic acid ligand not only works as an organic template leading to the assembly of a [HEDTPASbW 15 O 50 ] 14- building block but also further bridges the sandwich-type [CeW 4 O 10 (B-α-SbW 9 O 33 ) 2 ] 11- entity. To extend its potential application in electrochemical sensing properties, we prepared a three-dimensional 1 @EGO composite (EGO = reduced graphene oxide functionalized by ethylenediamine) with porous architecture and a prominent conducting ability. Furthermore, the 1 @EGO composite was explored as a modification material for glassy carbon electrodes to build a dual-signal readout electrochemical aptasensor for carcinogens, which shows much better detection performance for aflatoxin B1 compared with traditional single-signal biosensors.

Antimicrobial peptides (AMPs) are promising antibacterial agents often hindered by their undesired hemolytic activity. Inspired by gramicidin S (GS), a well-known cyclodecapeptide, we synthesized a panel of antibacterial cyclopeptidomimetics using β,γ-diamino acids (β,γ-DiAAs). We observed that peptidomimetic CP-2 displays a bactericidal activity similar to that of GS while possessing lower side-effects. Moreover, extensive studies revealed that CP-2 likely kills bacteria through membrane disruption. Altogether, CP-2 is a promising membrane-active antibiotic with therapeutic potential., (© 2020 Wiley-VCH GmbH.)

GPR119 is a promising target for discovery of anti-type 2 diabetes mellitus agents. We described the optimisation of a novel series of pyrimido[5,4- b ][1,4]oxazine derivatives as GPR119 agonists. Most designed compounds exhibited good agonistic activities. Among them, compound 10 and 15 demonstrated the potent EC 50 values (13 and 12 nM, respectively) and strong inherent activities. Moreover, significant hypoglycaemic effect of compound 15 was observed by reducing the blood glucose AUC 0-2h at the dose of 30 mg/kg, which is stronger than Vildagliptin (23.4% reduction vs. 17.9% reduction).

A trimeric tri-Tb3+-including antimonotungstate (AMT) hybrid Na17{(WO4)[Tb(H2O)(Ac)(B-α-SbW9O31(OH)2)]3}·50H2O (Tb3W28) was successfully synthesized, in which the capped tetrahedral {WO4} group plays a significant template role in directing the aggregation of three [B-α-SbW9O33]9- fragments and three Tb3+ ions. Eu3+/Tb3+/Dy3+/Gd3+-codoped AMT materials based on Tb3W28 were firstly prepared and their luminescence properties were investigated. The red emitter Eu3+, yellow emitter Dy3+, and nonluminous Gd3+ ions were codoped into Tb3W28 to substitute Tb3+ ions for investigating the energy transfer (ET) mechanism among Eu3+, Tb3+, and Dy3+ ions. Upon the 6H15/2 → 4I13/2 excitation at 389 nm of the Dy3+ ion, the ET1 mechanism (Dy3+ → Tb3+) was confirmed as a non-radiative dipole-dipole interaction. Under the 7F6 → 5L10 excitation at 370 nm of the Tb3+ ion, the ET2 mechanism (Tb3+ → Eu3+) was identified as a non-radiative quadrupole-quadrupole interaction. Under excitation at 389 nm, the two-step successive Dy3+ → Tb3+ → Eu3+ ET3 process was proved in Dy1.2Tb3zEu0.03Gd1.77-3zW28. Through changing the excitation wavelengths, the emission color of Dy1.2Tb1.2Eu0.03Gd0.57W28 can vary from blue to yellow, in which a near-white-light emission case was observed upon excitation at 378 nm. This work not only provides a systematic ET mechanism study of hetero-Ln-codoped AMTs, but also offers some useful guidance for designing novel performance-oriented Ln-codoped polyoxometalate-based materials.