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da Silva UP, de Sousa BL, Ferreira BW, Barreto RW, Amarante GW, da Silva RR, Vaz BG, Varejão EVV. Daylight LED promotes photochemical ring contraction of 2-amine-4H-pyran-3-carbonitriles with consequent loss of their antifungal activity. Photochem Photobiol Sci 2021; 20:1309-1321. [PMID: 34562236 DOI: 10.1007/s43630-021-00108-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 09/16/2021] [Indexed: 11/24/2022]
Abstract
The initial objective of our work was to synthesize a series of 2-amino-4H-pyran-3-carbonitriles to be tested for their antifungal activities against economically relevant phytopathogenic fungi. Fourteen compounds were prepared in up to 94% yield and shown percentages of Botrytis cinerea inhibition above 70%. Despite the promising biological results, we observed that stock solutions prepared for biological tests showed color changing when kept for a few days on the laboratory bench, under room conditions, illuminated by common LED daylight tubes (4500-6000 k). This prompted us to investigate the possible photo-induced degradation of our compounds. FT-IR ATR experiments evidenced variations in the expected bands for functional of -amino-4H-pyran-3-carbonitriles stored under LED daylight. Following, HPLC-UV analysis showed reductions in the intensity of chromatographic peaks of 2-amino-4H-pyran-3-carbonitriles, and but not for solutions kept in the dark. A solution of (E)-2-amino-8-(4-nitrobenzylidene)-4-(4-nitrophenyl)-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile underwent 84.4% of conversion after 72 h of exposure to continuous LED daylight in a BOD chamber, and the reaction product was isolated in 36% yield and characterized as (E)-7-cyano-5-(4-nitrobenzylidene)-8-(4-nitrophenyl)bicyclo[4.2.0]oct-1(6)-ene-7-carboxamide (7*). Despite freshly prepared solutions of 2-amino-4H-pyran-3-carbonitriles produced antifungal activities, these solutions lost biological activity when left on the bench for a week. Besides, compound 7* formed from photo-induced degradation of 7 also showed no antifungal activity. With this, we hope to bring two contributions: (1) production of cyclobutenes through photochemical reactions of 2-amino-4H-pyran-3-carbonitriles can be carried out through exposure to simple white LED daylight; (2) biological applications of such 2-amino-4H-pyran-3-carbonitriles may be impaired by their poor photostability.
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Affiliation(s)
- Ueveton Pimentel da Silva
- Department of Chemistry, Universidade Federal de Viçosa, Av PH Rolfs sn, Viçosa, MG, 36.570-900, Brazil
| | - Bianca Lana de Sousa
- Department of Chemistry, Universidade Federal de Viçosa, Av PH Rolfs sn, Viçosa, MG, 36.570-900, Brazil
| | - Bruno Wesley Ferreira
- Department of Phytopathology, Universidade Federal de Viçosa, Av PH Rolfs sn, Viçosa, MG, 36.570-900, Brazil
| | - Robert Weingart Barreto
- Department of Phytopathology, Universidade Federal de Viçosa, Av PH Rolfs sn, Viçosa, MG, 36.570-900, Brazil
| | - Giovanni Wilson Amarante
- Department of Chemistry, Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer sn, Juiz de Fora, MG, 36.036-900, Brazil
| | - Rodolfo Rodrigues da Silva
- Institute of Chemistry, Universidade Federal de Goiás, Av Esperança, sn, Samambaia, Goiânia, 74.690-900, Brazil
| | - Boniek Gontijo Vaz
- Institute of Chemistry, Universidade Federal de Goiás, Av Esperança, sn, Samambaia, Goiânia, 74.690-900, Brazil
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Wang D, Ma F, Xiao Q, Zhang C, Huang M, Liu X. One‐pot synthesis of 3‐(sulfonyl)‐5,6,7,8‐tetrahydro‐4H‐pyrano[3,2‐c]pyridines through a cascade Michael/cyclization reaction. J CHIN CHEM SOC-TAIP 2019. [DOI: 10.1002/jccs.201900125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Dao‐Cai Wang
- Hubei Key Laboratory of Biological Resources Protection and Utilization, College of Biological Science and TechnologyHubei Minzu University Enshi China
| | - Fei Ma
- Hubei Key Laboratory of Biological Resources Protection and Utilization, College of Biological Science and TechnologyHubei Minzu University Enshi China
| | - Qiang Xiao
- Hubei Key Laboratory of Biological Resources Protection and Utilization, College of Biological Science and TechnologyHubei Minzu University Enshi China
| | - Chi Zhang
- Hubei Key Laboratory of Biological Resources Protection and Utilization, College of Biological Science and TechnologyHubei Minzu University Enshi China
| | - Mian Huang
- Hubei Key Laboratory of Biological Resources Protection and Utilization, College of Biological Science and TechnologyHubei Minzu University Enshi China
| | - Xiao‐Peng Liu
- Hubei Key Laboratory of Biological Resources Protection and Utilization, College of Biological Science and TechnologyHubei Minzu University Enshi China
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