Pub Date : 2024-10-02DOI: 10.1016/j.tet.2024.134288
Mao-Juan Tian, Hua-Qing Tian, Tao Jiang, Huan-Huan Yu, Chao Huang, Bi-Xue Zhu, Chun Zhu
A racemic salicylaldehyde Schiff base (L) containing a pyridine-2,6-dicarboxamide scaffold was successfully synthesized and characterized. L exhibited a typical aggregation-induced emission (AIE) characteristic in the mixed solvent of THF/H2O. The UV–Vis absorption spectra and fluorescence emission spectra showed a high selectivity and sensitivity of L for the recognition of Cu2+ over other ions in the solution of THF/H2O (2:3), and indicated L can be used as a turn-off fluorescent probe for Cu2+. The stoichiometric ratio, association constant, and the detection limit of probe L toward Cu2+ were estimated using Job's plot method, UV–Vis spectra titration, and fluorescence spectra titration. More importantly, a Cu(II) complex was synthesized from the coordination interaction of probe L with Cu2+ and characterized by X-ray crystal diffraction technique. The crystal structure well illustrated the binding mode of L with Cu2+, contributing to the further understanding of the coordination mechanism.
成功合成并表征了一种含有吡啶-2,6-二甲酰胺支架的外消旋水杨醛席夫碱（L）。在 THF/H2O 混合溶剂中，L 表现出典型的聚集诱导发射（AIE）特征。紫外可见吸收光谱和荧光发射光谱显示，在 THF/H2O 溶液（2:3）中，L 对 Cu2+ 的识别具有较高的选择性和灵敏度，表明 L 可用作 Cu2+ 的熄灭荧光探针。利用约伯图法、紫外可见光谱滴定法和荧光光谱滴定法估算了探针 L 对 Cu2+ 的化学计量比、关联常数和检测限。更重要的是，利用探针 L 与 Cu2+ 的配位相互作用合成了一种 Cu（II）配合物，并利用 X 射线晶体衍射技术对其进行了表征。晶体结构很好地展示了 L 与 Cu2+ 的结合模式，有助于进一步了解配位机理。
{"title":"A helical salicylaldehyde Schiff base exhibiting aggregation-induced emission and selective recognition of Cu2+ ions","authors":"Mao-Juan Tian, Hua-Qing Tian, Tao Jiang, Huan-Huan Yu, Chao Huang, Bi-Xue Zhu, Chun Zhu","doi":"10.1016/j.tet.2024.134288","DOIUrl":"10.1016/j.tet.2024.134288","url":null,"abstract":"<div><div>A racemic salicylaldehyde Schiff base (<strong>L</strong>) containing a pyridine-2,6-dicarboxamide scaffold was successfully synthesized and characterized. <strong>L</strong> exhibited a typical aggregation-induced emission (AIE) characteristic in the mixed solvent of THF/H<sub>2</sub>O. The UV–Vis absorption spectra and fluorescence emission spectra showed a high selectivity and sensitivity of <strong>L</strong> for the recognition of Cu<sup>2+</sup> over other ions in the solution of THF/H<sub>2</sub>O (2:3), and indicated <strong>L</strong> can be used as a turn-off fluorescent probe for Cu<sup>2+</sup>. The stoichiometric ratio, association constant, and the detection limit of probe <strong>L</strong> toward Cu<sup>2+</sup> were estimated using Job's plot method, UV–Vis spectra titration, and fluorescence spectra titration. More importantly, a Cu(II) complex was synthesized from the coordination interaction of probe <strong>L</strong> with Cu<sup>2+</sup> and characterized by X-ray crystal diffraction technique. The crystal structure well illustrated the binding mode of <strong>L</strong> with Cu<sup>2+</sup>, contributing to the further understanding of the coordination mechanism.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"167 ","pages":"Article 134288"},"PeriodicalIF":2.1,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142425568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-30DOI: 10.1016/j.tet.2024.134287
Di Hao , Zhen Yang , Luigi Vaccaro , Ping Liu , Bin Dai
An I2-promoted C–H arylselenylation of pyrrolo[1,2-a]quinoxalines with diaryl diselenides is developed, providing an efficient route to a series of 1 (or 3)-arylselenylated and/or 1,3-diaryl diselenylated pyrrolo[1,2-a]quinoxalines. The methodology is characterised by a wide range of substrates, good functional group tolerance and gram-level synthesis. Further transformations of the products to form structurally diverse pyrrolo[1,2-a]quinoxalines were successfully achieved. Similarly, I2-promoted C–H sulfenylation of pyrrolo[1,2-a]quinoxaline with 1,2-diphenyldisulfane were investigated. We believe that these novel pyrrolo[1,2-a]quinoxaline compounds will have promising applications in pharmaceutical synthesis.
{"title":"I2-promoted direct C–H arylselenylation of pyrrolo[1,2-a]quinoxalines","authors":"Di Hao , Zhen Yang , Luigi Vaccaro , Ping Liu , Bin Dai","doi":"10.1016/j.tet.2024.134287","DOIUrl":"10.1016/j.tet.2024.134287","url":null,"abstract":"<div><div>An I<sub>2</sub>-promoted C–H arylselenylation of pyrrolo[1,2-<em>a</em>]quinoxalines with diaryl diselenides is developed, providing an efficient route to a series of 1 (or 3)-arylselenylated and/or 1,3-diaryl diselenylated pyrrolo[1,2-<em>a</em>]quinoxalines. The methodology is characterised by a wide range of substrates, good functional group tolerance and gram-level synthesis. Further transformations of the products to form structurally diverse pyrrolo[1,2-<em>a</em>]quinoxalines were successfully achieved. Similarly, I<sub>2</sub>-promoted C–H sulfenylation of pyrrolo[1,2-<em>a</em>]quinoxaline with 1,2-diphenyldisulfane were investigated. We believe that these novel pyrrolo[1,2-<em>a</em>]quinoxaline compounds will have promising applications in pharmaceutical synthesis.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"167 ","pages":"Article 134287"},"PeriodicalIF":2.1,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142425565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present an efficient, acid-mediated cascade strategy for the construction of 1,3- and 1,2,3-substituted naphthalenes from readily accessible starting materials. This method employs ortho-alkynyl or arynyl tertiary benzylic alcohols as the substrates, which undergo a Lewis acid-triggered dehydration to form ortho-(alkynyl)-styrene intermediates. These intermediates subsequently undergo intramolecular cycloaromatization, resulting in the formation of substituted naphthalenes in a one-pot reaction. A significant advantage of this approach is its ability to proceed under sustainable and neat reaction conditions using ZnCl₂ as the sole Lewis acid, highlighting the simplicity and practicality of the process. Additionally, the strategy exhibits a broad substrate scope, efficiently yielding the desired naphthalene derivatives with practical and consistent yields. This method not only simplifies the synthetic pathway but also aligns with green chemistry principles by minimizing the use of solvents and reagents.
{"title":"An acid-mediated synthesis of substituted naphthalenes from ortho-alkynyl tertiary benzylic alcohols","authors":"Puja Singh, Sreenivasulu Chinnabattigalla, Komal Goel, Ravi Kishore Dakoju, Satyanarayana Gedu","doi":"10.1016/j.tet.2024.134285","DOIUrl":"10.1016/j.tet.2024.134285","url":null,"abstract":"<div><div>We present an efficient, acid-mediated cascade strategy for the construction of 1,3- and 1,2,3-substituted naphthalenes from readily accessible starting materials. This method employs <em>ortho</em>-alkynyl or arynyl tertiary benzylic alcohols as the substrates, which undergo a Lewis acid-triggered dehydration to form ortho-(alkynyl)-styrene intermediates. These intermediates subsequently undergo intramolecular cycloaromatization, resulting in the formation of substituted naphthalenes in a one-pot reaction. A significant advantage of this approach is its ability to proceed under sustainable and neat reaction conditions using ZnCl₂ as the sole Lewis acid, highlighting the simplicity and practicality of the process. Additionally, the strategy exhibits a broad substrate scope, efficiently yielding the desired naphthalene derivatives with practical and consistent yields. This method not only simplifies the synthetic pathway but also aligns with green chemistry principles by minimizing the use of solvents and reagents.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"167 ","pages":"Article 134285"},"PeriodicalIF":2.1,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142425572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-29DOI: 10.1016/j.tet.2024.134286
Ulises F. Reyes-González , Edson Barrera , Daniela Martínez-López , R. Israel Hernández-Benitez , Julio López , Omar Gómez-García , Dulce Andrade-Pavón , Lourdes Villa-Tanaca , Paola Castillo-Juárez , Francisco Delgado , Joaquín Tamariz
A highly efficient and stereoselective synthesis of (E)-5-(dimethylamino)methylene thiohydantoins is herein reported. It was carried out through a one-pot, two-step reaction between methyl N-arylglycinates, isothiocyanates, and DMFDMA under microwave irradiation. The thermal and catalyst-free reaction of the (dimethylamino)methylene thiohydantoins with anilines led to the stereoselective formation of (E)-(anilinomethylene) thiohydantoins. The antifungal activity of the products was evaluated with a series of five Candida spp., finding a potent effect, even against a fluconazole-resistant C. glabrata strain. The docking studies suggest that this inhibitory effect is due to the binding of the compounds to the active site of fungal HMGR.
{"title":"Synthesis of exocyclic enaminone-based thiohydantoins as potent antifungal agents","authors":"Ulises F. Reyes-González , Edson Barrera , Daniela Martínez-López , R. Israel Hernández-Benitez , Julio López , Omar Gómez-García , Dulce Andrade-Pavón , Lourdes Villa-Tanaca , Paola Castillo-Juárez , Francisco Delgado , Joaquín Tamariz","doi":"10.1016/j.tet.2024.134286","DOIUrl":"10.1016/j.tet.2024.134286","url":null,"abstract":"<div><div>A highly efficient and stereoselective synthesis of (<em>E</em>)-5-(dimethylamino)methylene thiohydantoins is herein reported. It was carried out through a one-pot, two-step reaction between methyl <em>N-</em>arylglycinates, isothiocyanates, and DMFDMA under microwave irradiation. The thermal and catalyst-free reaction of the (dimethylamino)methylene thiohydantoins with anilines led to the stereoselective formation of (<em>E</em>)-(anilinomethylene) thiohydantoins. The antifungal activity of the products was evaluated with a series of five <em>Candida</em> spp., finding a potent effect, even against a fluconazole-resistant <em>C. glabrata</em> strain. The docking studies suggest that this inhibitory effect is due to the binding of the compounds to the active site of fungal HMGR.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"167 ","pages":"Article 134286"},"PeriodicalIF":2.1,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142425573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-26DOI: 10.1016/j.tet.2024.134284
Leticia Almazán-Sánchez , María Teresa Ramírez-Apan , David Morales-Morales , Marco A. García-Eleno , Erick Cuevas-Yañez
Using the CuAAC reaction as a key step, a novel series of Nilotinib analogues was prepared by replacing the imidazole ring in the Nilotinib molecule with 1,2,3-triazole moiety via a divergent synthetic approach. The synthesized compounds were tested for cytotoxic activity against a series of tumor cell lines which included U251, PC-3, K562, HCT-15, MCF-7 and SKLU. Inhibition growth up to 85.6 % was observed for some compounds.
{"title":"1,2,3-Triazole nilotinib analogues: Synthesis and Cytotoxic activity","authors":"Leticia Almazán-Sánchez , María Teresa Ramírez-Apan , David Morales-Morales , Marco A. García-Eleno , Erick Cuevas-Yañez","doi":"10.1016/j.tet.2024.134284","DOIUrl":"10.1016/j.tet.2024.134284","url":null,"abstract":"<div><div>Using the CuAAC reaction as a key step, a novel series of Nilotinib analogues was prepared by replacing the imidazole ring in the Nilotinib molecule with 1,2,3-triazole moiety via a divergent synthetic approach. The synthesized compounds were tested for cytotoxic activity against a series of tumor cell lines which included U251, PC-3, K562, HCT-15, MCF-7 and SKLU. Inhibition growth up to 85.6 % was observed for some compounds.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"167 ","pages":"Article 134284"},"PeriodicalIF":2.1,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142425122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Among the various copper-catalyzed coupling reactions, C–S and C–N bond-forming reactions have carried off plentiful recognition due to their demand in the synthesis of molecules having biological and pharmaceutical impact. Organo-copper complex has an incontestable supremacy over the other catalytic complex due to its low cost and the use of readily accessible and stable ligands. As a consequence and in continuation of our explorative studies in this direction, an efficient and novel organo-copper complex has been synthesized and characterized by spectroscopic (NMR, FT-IR) and single crystal X-ray diffraction (XRD) methods. The synthesized stable metal complex has fascinating physical, chemical, biological and catalytic properties. In the chemical exploration refer to protein-metal interactions; we have often used Bovine Serum Albumin (BSA) protein. The synthesized copper complex has the potential to form coordinate bonds with functional groups present in BSA, together with amino acid residues and the protein backbone. The binding of metal complexes to BSA has outstanding imputation in medicinal chemistry. For enhancement of the catalytic activity of the organo-copper complex, we have evaluated it in carbon-hetero bond formation reactions where it proffered an influential tool for the establishment of C–S and C–N bonds.
{"title":"Synthesis and BSA binding study of the Cu(II) complex and applications of it to enhance catalytic activity for C(Sp2)-H bond functionalization and for the synthesis of polyhydroquinolines","authors":"Aminul Islam , Kakoli Malakar , Marappan Velusamy , Pranab Ghosh","doi":"10.1016/j.tet.2024.134278","DOIUrl":"10.1016/j.tet.2024.134278","url":null,"abstract":"<div><div>Among the various copper-catalyzed coupling reactions, <em>C</em>–S and <em>C</em>–N bond-forming reactions have carried off plentiful recognition due to their demand in the synthesis of molecules having biological and pharmaceutical impact. Organo-copper complex has an incontestable supremacy over the other catalytic complex due to its low cost and the use of readily accessible and stable ligands. As a consequence and in continuation of our explorative studies in this direction, an efficient and novel organo-copper complex has been synthesized and characterized by spectroscopic (NMR, FT-IR) and single crystal X-ray diffraction (XRD) methods. The synthesized stable metal complex has fascinating physical, chemical, biological and catalytic properties. In the chemical exploration refer to protein-metal interactions; we have often used Bovine Serum Albumin (BSA) protein. The synthesized copper complex has the potential to form coordinate bonds with functional groups present in BSA, together with amino acid residues and the protein backbone. The binding of metal complexes to BSA has outstanding imputation in medicinal chemistry. For enhancement of the catalytic activity of the organo-copper complex, we have evaluated it in carbon-hetero bond formation reactions where it proffered an influential tool for the establishment of <em>C</em>–S and <em>C</em>–N bonds.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"167 ","pages":"Article 134278"},"PeriodicalIF":2.1,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142425567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-21DOI: 10.1016/j.tet.2024.134277
Pengfei Sun , Xin Yu , Fang Wei
The development of a transition-metal-catalyzed [3 + 2] cycloaddition for one-pot synthesis of 2-substituted benzofurans from vinyl azides and benzoquinone is reported. This reaction could be carried out under mild conditions without the need to isolate air, giving desired products in good to excellent yields.
{"title":"Facile synthesis of 2-substituted benzofurans by intermolecular [3+2] cycloaddition of benzoquinone and vinyl azides under air","authors":"Pengfei Sun , Xin Yu , Fang Wei","doi":"10.1016/j.tet.2024.134277","DOIUrl":"10.1016/j.tet.2024.134277","url":null,"abstract":"<div><div>The development of a transition-metal-catalyzed [3 + 2] cycloaddition for one-pot synthesis of 2-substituted benzofurans from vinyl azides and benzoquinone is reported. This reaction could be carried out under mild conditions without the need to isolate air, giving desired products in good to excellent yields.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"167 ","pages":"Article 134277"},"PeriodicalIF":2.1,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Three novel compounds 1 to 3, named trichoglutamides A to C, respectively, were isolated from the fruiting bodies of yellow Tricholoma species, T. flavovirens, T. auratum, and T. sulphureum. Their structures were determined by the interpretation of spectroscopic data and by X-ray crystallographic analysis. The structure of trichoglutamide consists of a glutamic acid residue and a C-10 polyketide unit.
从黄色毛果芸香科植物 T. flavovirens、T. auratum 和 T. sulphureum 的子实体中分离出三种新型化合物 1 至 3，分别命名为毛果芸香酰胺 A 至 C。通过解释光谱数据和 X 射线晶体分析确定了它们的结构。Trichoglutamide 的结构由一个谷氨酸残基和一个 C-10 聚酮单元组成。
{"title":"Trichoglutamides A to C from yellow Tricholoma species","authors":"Yumiko Oba , Yuri Nakamura , Mitsuru Kondo , Jing Wu , Makoto Urai , Motohiro Tomizawa , Hirokazu Kawagishi , Kimiko Hashimoto","doi":"10.1016/j.tet.2024.134276","DOIUrl":"10.1016/j.tet.2024.134276","url":null,"abstract":"<div><div>Three novel compounds <strong>1</strong> to <strong>3</strong>, named trichoglutamides A to C, respectively, were isolated from the fruiting bodies of yellow <em>Tricholoma</em> species, <em>T. flavovirens</em>, <em>T. auratum</em>, a<em>nd T. sulphureum</em>. Their structures were determined by the interpretation of spectroscopic data and by X-ray crystallographic analysis. The structure of trichoglutamide consists of a glutamic acid residue and a C-10 polyketide unit.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"167 ","pages":"Article 134276"},"PeriodicalIF":2.1,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-20DOI: 10.1016/j.tet.2024.134283
Enrique Aguilar-Ramírez, José Rivera-Chávez, Valeria Abogado-Aponte, Beatriz Quiroz-García, Adriana Romo-Pérez
Talaromyces sp. (strain IQ-313) produces duclauxin-type molecules under standard fermentation conditions in rice and oat cereal. Such molecules are of great interest due to their structural complexity and biological activity. Interestingly, application of an OSMAC (One Strain Many Compounds) approach, revealed that the biosynthetic machinery of this fungus can be directed towards the production of other types of molecules, while completely suppressing the biosynthesis of duclauxin (1). To exploit the metabolic potential of Talaromyces sp. (strain IQ-313), it was grown on solid media supplemented with dimethyl sulfoxide (DMSO), an ectopic epigenetic modulator. Metabolomic analysis of the fermentation extract from the strain grown under standard and DMSO-supplemented conditions, using molecular networking, revealed notable differences in the profiles. Chemical investigation of the extract obtained under abiotic stress led to the isolation and characterization of 15 molecules not detected under standard conditions, including nine polyketides, one sesquiterpenoid, two sesterterpenoids, and three meroterpenoids. Among these, talaromophilane (2), an eremophilane sesquiterpenoid, and talaroisochromane (8), an oxoisochromen, have not been previously reported in the literature. The structures of all isolates were established using a combination of spectroscopic and spectrometric data. The absolute configuration of compound 2 was established based on the analysis of NOESY interactions and by comparison of the experimental and theoretical electronic circular dichroism (ECD) curves.
{"title":"DMSO suppresses duclauxin biosynthetic pathway in Talaromyces sp. (strain IQ-313) and untaps terpenoids, polyketides and meroterpenoids biosynthesis","authors":"Enrique Aguilar-Ramírez, José Rivera-Chávez, Valeria Abogado-Aponte, Beatriz Quiroz-García, Adriana Romo-Pérez","doi":"10.1016/j.tet.2024.134283","DOIUrl":"10.1016/j.tet.2024.134283","url":null,"abstract":"<div><div><em>Talaromyces</em> sp. (strain IQ-313) produces duclauxin-type molecules under standard fermentation conditions in rice and oat cereal. Such molecules are of great interest due to their structural complexity and biological activity. Interestingly, application of an OSMAC (<em>One Strain Many Compounds</em>) approach, revealed that the biosynthetic machinery of this fungus can be directed towards the production of other types of molecules, while completely suppressing the biosynthesis of duclauxin (<strong>1</strong>). To exploit the metabolic potential of <em>Talaromyces</em> sp. (strain IQ-313), it was grown on solid media supplemented with dimethyl sulfoxide (DMSO), an ectopic epigenetic modulator. Metabolomic analysis of the fermentation extract from the strain grown under standard and DMSO-supplemented conditions, using molecular networking, revealed notable differences in the profiles. Chemical investigation of the extract obtained under abiotic stress led to the isolation and characterization of 15 molecules not detected under standard conditions, including nine polyketides, one sesquiterpenoid, two sesterterpenoids, and three meroterpenoids. Among these, talaromophilane (<strong>2</strong>), an eremophilane sesquiterpenoid, and talaroisochromane (<strong>8</strong>), an oxoisochromen, have not been previously reported in the literature. The structures of all isolates were established using a combination of spectroscopic and spectrometric data. The absolute configuration of compound <strong>2</strong> was established based on the analysis of NOESY interactions and by comparison of the experimental and theoretical electronic circular dichroism (ECD) curves.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"167 ","pages":"Article 134283"},"PeriodicalIF":2.1,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0040402024004642/pdfft?md5=f41bf2a92a1c3589c2cb0c13de276092&pid=1-s2.0-S0040402024004642-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142310472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-20DOI: 10.1016/j.tet.2024.134281
Dipankar Das , Bishwajit Ganguly
Kemp's triacid derivative have been reported as a candidate for sensing of nerve agents employing the photoinduced electron transfer (PET) processes. The sensor probe molecules were prepared with primary alcohol in very close proximity to a tertiary amine to acylate the alcohol with rapid intramolecular N-alkylation to produce quaternary ammonium salt. The reaction pathways for the formation of quaternary ammonium salt and isomethyl propyl phosphonate remain unexplored. In this report, the mechanistic pathways of G-series nerve agents sarin and its simulant diethylcholorophosphate (DCP) with Kemp's triacid derivatives has been explored computationally. The calculations performed with B3LYP-D3/6-311+G(d,p) level of theory in DCM solvent revealed that the reaction proceeds via intermolecular and intramolecular SN2 pathways. The probe molecule is sterically hindered, therefore, the frontside and backside SN2 reaction pathways have been examined. The computed results suggest that the first intermolecular SN2 reaction of Kemp's triacid derivatives (I & II) with sarin for the backside attack is energetically favored compared to the frontside attack and the following intramolecular SN2 reaction is a barrierless process. The calculations performed with simulant diethylcholorophosphate (DCP) and Kemp's triacid derivatives (I & II) show that the reactions are energetically more facile compared to the nerve agent sarin molecule. The Distortion-Interaction model and ΔNBOSteric analysis showed that the back side is energetically favored over the front side attack in such SN2 reactions. The designed Kemp's triacid derivative (II) with phosphorus center for sensing sarin and (DCP) suggests that the size of the hetero centers are important to facilitate the reaction in the probe molecule.
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