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Hu H, Liu Y, Li J, Zhang C, Gao C, Sun C, Du Y, Hu B. Phenolylazoindole scaffold for facilely synthesized and bis-functional photoswitches combining controllable fluorescence and antifungal properties using theoretical methods. Org Biomol Chem 2024; 22:1225-1233. [PMID: 38231009 DOI: 10.1039/d3ob01751f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
Functionalization is a major challenge for the application of photoswitches. With the aim to develop novel bis-functional azo photoswitches with stationary photophysical properties, a series of phenolylazoindole derivatives were designed, synthesized, and characterized via NMR spectroscopy studies and high-resolution mass spectrometry (HRMS). Herein, UV/Vis and 1H NMR spectra revealed that the photostationary state (PSS) proportions for PSScis and PSStrans were 76-80% and 68-81%, respectively. Furthermore, the thermal half-lives (t1/2) of compounds A2-A4 and B2 ranged from 0.9 to 5.3 h, affected by the diverse substituents at the R1 and R2 positions. The results indicated that azo photoswitches based on the phenolylazoindole scaffold had stationary photophysical properties and wouldn't be excessively affected by modifying the functional groups. Compounds A4 and B2, which were modified with an aryl group, also exhibited fluorescence emission properties (the quantum yields of A4 and B2 were 2.32% and 13.34%) through the modification of the flexible conjugated structure (benzene) at the R2 position. Significantly, compound C1 was obtained via modification with a pharmacophore in order to acquire antifungal activities against three plant fungi, Rhizoctonia solani (R. solani), Botrytis cinerea (B. cinerea), and Fusarium graminearum (F. graminearum). Strikingly, the inhibitory activity of the cis-isomer of compound C1towards R. solani (53.3%) was significantly better than that of the trans-isomer (34.2%) at 50 μg mL-1. In order to further reveal the antifungal mechanism, molecular docking simulations demonstrated that compound C1 effectively integrates into the cavity of succinate dehydrogenase (SDH); the optically controlled cis-isomer showed a lower binding energy with SDH than that of the trans-isomer. This research confirmed that phenolylazoindole photoswitches can be appropriately applied as molecular regulatory devices and functional photoswitch molecules via bis-functionalization.
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Affiliation(s)
- Haoran Hu
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China.
| | - Yu Liu
- College of Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Junqi Li
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China.
| | - Chong Zhang
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China.
| | - Chao Gao
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China.
| | - Chengguo Sun
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China.
| | - Yang Du
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China.
| | - Bingcheng Hu
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China.
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Hu H, Chen L, Jing T, Zhang C, Sun C, Gao C, Du Y, Hu B. Novel salicylic acid derivatives connecting to five-membered cycle through an acyl hydrazone bond as multi-stimuli responsive fluorescent smart materials with photoswitching properties. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 303:123118. [PMID: 37467590 DOI: 10.1016/j.saa.2023.123118] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 06/14/2023] [Accepted: 07/07/2023] [Indexed: 07/21/2023]
Abstract
In order to exploit novel multi-stimuli responsive fluorescent materials, a series of novel fluorescent molecules of salicylic acid derivatives were designed and synthesized via introducing pyrazole or cyclopentane to the salicylic acid scaffold through a special Schiff base-acylhydrazone, and the molecular structures of representative compounds A2 and A4 were verified via single crystal X-ray diffraction. All title molecules could exhibit obvious solvatofluorochromism from cyan to indigo in several solutions with different polarity. The fluorescence titration data exhibited compound A2 and complex A2-Cu2+ with prime detection limits to Cu2+ (0.24 μM) and S2- ions (2.83 μM). The sensitive recognition of A2 to trifluoroacetic (TFA) and A2-TFA to triethylamine (TEA) were also confirmed via fluorescent titration experiments in various solutions, respectively. What's more, the 1H NMR and UV/Vis absorption spectra further explained the mechanism between molecules and ions or molecules and TFA/TEA. Besides, the photoswitching properties of the compounds A2 and A3 could be demonstrated via the irradiation of special wavelength light or heating accompanied with changes in quantum yields. In addition, these phenomena of multiple responses were explained via Density Functional Theory (DFT) based on the Gaussian calculations. Thus, this work provided a preliminary basis for the research of multi-stimuli responsive fluorescent molecules with photoswitching properties.
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Affiliation(s)
- Haoran Hu
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Lei Chen
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Tongtong Jing
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Chong Zhang
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Chengguo Sun
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Chao Gao
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Yang Du
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Bingcheng Hu
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China.
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