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Two unique windmill-like aziridine-containing indole alkaloids, possessing an unprecedented 6/5/5/6/6/5/3 rigid ring system and an unusual azabicyclo[3.1.0]hexane core, were isolated from Alstonia scholaris. Their structures were established by spectroscopy, X-ray diffraction, and electronic circular dichroism calculations. The novel compounds exhibited significant anti-inflammatory bioactivity in vitro and alleviated LPS-induced acute lung injury in mice. [ABSTRACT FROM AUTHOR]

Veratrazine A (1), a steroidal alkaloid with a unique 6/5/5 triheterocyclic scaffold as the side chain, was isolated from Veratrum stenophyllum, and its structure was established via spectroscopic analyses and X-ray diffraction. A plausible biosynthetic pathway for 1 is proposed. Bioassy exhibits moderate anti-inflammatory activities in vitro and in vivo. [ABSTRACT FROM AUTHOR]

The interactions between water molecules and aromatic rings are known to be common and important in physics, chemistry and life sciences. Benzene–water complexes are the main prototype systems for O–H…π and lone-pair (lp)…π interactions in theoretical research, however solid state examples are very rare. Here, the solid state example of water sandwiched by a pair of aromatic rings is observed in a silver-mellitate framework, where lp…π and O–H…π interactions coexist. The coexistence of these two interactions has been further verified by theoretical calculations. In addition, ammonium ions and water molecules as proton sources, and strongly H-bonded nets as the pathway of proton transport, make the reported MOFs (metal–organic frameworks) exhibit distinct proton conduction. [ABSTRACT FROM AUTHOR]

The interactions between water molecules and aromatic rings are known to be common and important in physics, chemistry and life sciences. Benzene-water complexes are the main prototype systems for O-Hπ and lone-pair (lp)π interactions in theoretical research, however solid state examples are very rare. Here, the solid state example of water sandwiched by a pair of aromatic rings is observed in a silver-mellitate framework, where lpπ and O-Hπ interactions coexist. The coexistence of these two interactions has been further verified by theoretical calculations. In addition, ammonium ions and water molecules as proton sources, and strongly H-bonded nets as the pathway of proton transport, make the reported MOFs (metal-organic frameworks) exhibit distinct proton conduction.

A water-soluble rhodamine-based derivative (L) has been rationally designed for selective recognition of Al(3+) in aqueous medium with good sensitivity. The addition of Al(3+) to the aqueous solution of L induces a remarkable fluorescence enhancement along with obvious color change detected by the naked eye, due to the ring-opening mechanism of the rhodamine spirolactam, which has been proved by single crystal diffraction analyses directly. The recognizing behavior has been investigated both experimentally and computationally. Furthermore, the fluorescent probe can also be used as a bioimaging reagent for detection of Al(3+) in living cells.

The coordination features of an imidazole dicarboxylate ligand, 2-(3-methoxyphenyl)-1H-imidazole-4,5-dicarboxylic acid (m-H(3)MOPhIDC) has been explored. Consequently, seven coordination polymers, namely [Sr(m-HMOPhIDC)(H(2)O)](n) (1), [Sr(m-H(2)MOPhIDC)(2)](n) (2), [Cd(3)(m-H(2)MOPhIDC)(2)(m-HMOPhIDC)(2)(H(2)O)(2)](n) (3), [Cu(m-HMOPhIDC)(phen)](n) (phen = 1,10-phenanthroline) (4), [Cd(2)(m-HMOPhIDC)(2)(phen)(2)](n) (5) [Cd(2)(m-HMOPhIDC)(2)(2,2'-bipy)(2)](n) (2,2'-bipy = 2,2'-bipyridine) (6) and [Co(m-HMOPhIDC)(H(2)O)(2)](n) (7) have been hydro(solvo)thermally synthesized by fine control over synthetic conditions, and structurally characterized. X-ray single-crystal analyses reveal that these polymers indicate rich structural chemistry ranging from one-dimensional (4-7), two-dimensional (1 and 3) to three-dimensional (2) structures, and the m-H(3)MOPhIDC ligand in these polymers can be singly deprotonated or doubly deprotonated, and coordinates to metal ions by various modes. The thermal and fluorescence properties of the complexes 1-7 have been determined as well.