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C16H14Cl2O5, orthorhombic, P212121 (no. 19), a = 8.6429 (4) Å, b = 11.3361 (6) Å, c = 33.9029 (11) Å, V = 3321.7 (3) Å3, Z = 8, R gt(F) = 0.0635, wR ref(F 2) = 0.1630, T = 293(2) K.

C16H14Cl2O5, orthorhombic, P212121 (no. 19), a = 23.2297(5) Å, b = 16.3509(3) Å, c = 8.7300(2) Å, V = 3315.89(12) Å3, Z = 8, Rgt(F) = 0.0472, wRref(F2) = 0.1268, T = 293 K.

The [2+2] cycloaddition is a versatile strategy for the synthesis of strained cyclobutenes of high synthetic value. In this study, two efficient intermolecular [2+2] cycloadditions between two different types of chloroalkynes and unactivated alkene are realized with gold catalysis. Of significance is that the reaction works with challenging monosubstituted unactivated alkenes, which is unprecedented in gold catalysis and scarcely documented in other metal-catalyzed/promoted reactions; moreover, the reaction exhibits excellent regioselectivities, which are much better than those reported in literature. With 1,2-disubstituted unactivated alkenes, the reaction is largely stereospecific. The cyclobutene products can be prepared in nearly gram scale and readily undergo further reactions including various cross-coupling reactions using the C(sp2)-Cl and/or C(sp2)-SPh bond, which in turn substantially broaden the scope of accessible cyclobutenes and enhance the synthetic utility of this bimolecular reaction.

C16H14Cl2O5, orthorhombic, P212121 (no. 19), a = 8.6429 (4) Å, b = 11.3361 (6) Å, c = 33.9029 (11) Å, V = 3321.7 (3) Å3, Z = 8, Rgt(F) = 0.0635, wRref(F2) = 0.1630, T = 293(2) K. [ABSTRACT FROM AUTHOR]

C16H14Cl2O5, orthorhombic, P212121 (no. 19), a = 23.2297(5) Å, b = 16.3509(3) Å, c = 8.7300(2) Å, V = 3315.89(12) Å3, Z = 8, Rgt(F) = 0.0472, wRref(F2) = 0.1268, T = 293 K. [ABSTRACT FROM AUTHOR]

C16H14Cl2O5, orthorhombic, P212121 (no. 19), a = 23.2297(5) Å, b = 16.3509(3) Å, c = 8.7300(2) Å, V = 3315.89(12) Å3, Z = 8, Rgt(F) = 0.0472, wRref(F2) = 0.1268, T = 293 K. [ABSTRACT FROM AUTHOR]

C16H14Cl2O5, orthorhombic, P212121 (no. 19), a = 8.6429 (4) Å, b = 11.3361 (6) Å, c = 33.9029 (11) Å, V = 3321.7 (3) Å3, Z = 8, Rgt(F) = 0.0635, wRref(F2) = 0.1630, T = 293(2) K. [ABSTRACT FROM AUTHOR]

Natural plant-derived compounds with broad-spectrum antimicrobial activity have become an effective strategy against multidrug-resistant bacteria. The present study was designed to compare the antibacterial activity of six chlorogenic acid (CA) isomers extracted from stevia and investigated the underlying antibacterial mechanisms involved. The results indicated that isochlorogenic acid C (ICAC) exhibited the strongest antibacterial activity against the tested bacteria, especially E. coli , at a 2 mg/mL minimum inhibitory concentration (MIC) and 8 mg/mL minimum bactericidal concentration (MBC). At the MBC, ICAC inhibited 72.66% of the clinical multidrug-resistant strains. Scanning electron microscopy (SEM) revealed that ICAC induced considerable morphological alterations in E. coli ATCC25922 and C4E2. The significant increase in the activity of extracellular alkaline phosphatase (AKP) indicated that ICAC damages the permeability of the bacterial cell wall. Additionally, the intracellular membrane (IM) permeability and the content of lipopolysaccharide (LPS), a main component of the outer membrane (OM), were determined. The significant decrease in LPS content and increased leakage of intracellular proteins and K + from E. coli indicated that ICAC could induce the exfoliation of OM and disrupt IM permeability, resulting in the loss of barrier function. The uptake of propidium iodide (PI), a compromised cell membrane nucleic acid stain, and confocal laser scanning microscopy (CLSM) further demonstrated that ICAC disrupted IM integrity. Moreover, the bactericidal effect and damage to bacterial microstructural function occurred in a dose-dependent manner. These data demonstrate that ICAC has excellent antibacterial activity and is a promising approach for overcoming the antibiotic resistance of pathogenic bacteria., Competing Interests: M-LX and L-FW were employed by Chenguang Biological Technology Group Co, Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Chen, Yi, Bai, Cao, Wang, Shang, Li, Xu, Wu, Zhu and Zhang.)