1. (2-Methoxy-3-pyridyl)boronic acid
Marek Dabrowski, Sergiusz Lulinski, Janusz Serwatowski, Magdalena Szczerbinska Acta Crystallogr C. 2006 Dec;62(Pt 12):o702-4. doi: 10.1107/S0108270106048268. Epub 2006 Nov 30.
The structure of the title compound, 2-CH3O-C5H3N-3-B(OH)2 or C6H8BNO3, comprises two crystallographically independent molecules. The molecules are linked to each other by intermolecular O-H...N and C-H...O bonds to produce an infinite chain, while a two-dimensional structure is formed as a result of pi-pi interactions of planar molecules.
2. Assessment of nicotine delivery and uptake in users of various tobacco/nicotine products
Gerhard Scherer, Janina Mütze, Nikola Pluym, Max Scherer Curr Res Toxicol. 2022 Mar 11;3:100067. doi: 10.1016/j.crtox.2022.100067. eCollection 2022.
Today various tobacco and nicotine products are available, many of them can be regarded as potentially risk-reduced products when compared to the most frequently used product, combustible cigarettes (CCs). A commonality of these products is that they deliver nicotine, although in quite different amounts and uptake routes, the most common of which are inhalation through the lung and absorption through the oral mucosa. Product-specific nicotine delivery as well as the subject-related use patterns are important factors which determine the pharmacokinetics and achieved internal dose levels of the alkaloid. The latter two parameters are highly relevant for the long-term product loyalty and, consequently, for the implicated health risks, since the risk-reduced products will replace CCs in the long-term only when users will experience a similar level of satisfaction. We measured nicotine and its major metabolites in plasma, saliva and urine samples collected in a controlled clinical study with habitual users (10 per group) of CCs, electronic cigarettes (ECs), heated tobacco products (HTP), oral tobacco (OT), and nicotine replacement therapy (NRT). Non-users (NU) of any tobacco/nicotine products served as (negative) control group. Moderate to strong correlations were observed between the daily consumption and the urinary nicotine equivalents (comprising nicotine and its 10 major metabolites, Nic + 10) or plasma and saliva cotinine concentrations. The average daily nicotine dose as measured by the urinary excretion of Nic + 10 (reflecting approximately 95 % of the absorbed nicotine) amounted to 17 and 22 mg/24 h for smokers (CC) and OT users, respectively, while it was in the range of 6-12 mg/24 h for users of ECs, HTP and NRT products, with high inter-individual variations in each user group. The individual daily nicotine intake, which was calculated by applying product-specific models, showed none to good agreement with the corresponding internal nicotine dose measured by Nic + 10 excretion. Possible reasons for the observed deviations between calculated and objectively measured nicotine doses are discussed.
3. "Tree"-like Multidentate Ligand-Assisted Synthesis of Polymolybdate-Based Architectures with Multinuclear Metal Clusters: Supercapacitor and Electrochemical Sensing Performances
Yongzhen Chen, Zhihan Chang, Yuchen Zhang, Keke Chen, Xiuli Wang Inorg Chem. 2022 Oct 10;61(40):16020-16027. doi: 10.1021/acs.inorgchem.2c02424. Epub 2022 Sep 30.
In this work, aiming for constructing multinuclear metal cluster-modified polymolybdate-based architectures with novel conformation, the "tree"-like multidentate ligand 5-(3-pyridyl)-1H-tetrazole) (3-ptzH) is introduced into the polymolybdate reaction system. Three new polymolybdate-based architectures with various multinuclear metal clusters, H4[Cu6(μ3-OH)2(3-ptz)6(γ-Mo8O28) (H2O)2]·2H2O (BOHU-1), H2[Ag4(3-ptz)2(Mo8O26)] (BOHU-2), and H4[Cu5(3-ptzH)2(3-ptz)2(MnMo9O32)2(H2O)4] (BOHU-3) (BOHU = Bohai University), have been prepared via the hydrothermal method and structurally characterized. In BOHU-1, a kind of pentanuclear copper cluster unit: [Cu5(μ3-OH)2(3-ptz)6]2+ is formed, which connects to construct a one-dimensional (1D) cluster-based chain. The 1D chains are extended to a two-dimensional (2D) layer via the Cu ions, which are further linked by the 4-connected [γ-Mo8O28]8- anions to build a three-dimensional (3D) framework. In BOHU-2, when a AgI ion was used as the central metal, the 3-ptz adopts different coordination modes to link the Ag ions, forming hexanuclear [Ag6(3-ptz)4]2+ cluster and finally 1D chains. These 1D cluster-based chains are connected by the 6-connected [γ-Mo8O26]4- anions to establish a 2D layer, which is further extended by [Mo8O26]n4n- 1D chains to a 3D framework. For BOHU-3, the chiral [MnMo9O32]6- anions are introduced and coordinated with the Cu ions to build left- and right-handed 1D chains, which are connected via the [Cu3(3-ptz)4]2+ cluster to form a 1D ladder-like chain. The effects of 3-ptz on the formation of multinuclear clusters, as well as the metals and polymolybdates on the multinuclear clusters and final structures of BOHU-1~3, are discussed. The electrochemical performances of BOHU-1~3 as electrode materials for supercapacitors and electrochemical sensors are investigated.
