Angela Schincaglia, M. Seegobin, Craig R. Brunetti, R. J. N. Emery
Cytokinins are small signaling molecules present in all kingdoms of life; however, their biological relevance outside of plants is poorly characterized. Cytokinin detection across kingdoms has been shown to be inconsistent and is often organism or cell line dependent. To ensure optimal detection in epithelioma papulosum cyprini (EPC), a cold-blooded vertebrate cell line, a range of biomasses were evaluated. Cytokinins were extracted by solid-phase extraction and then detected using high performance liquid chromatography and tandem mass spectrometry. The objectives were to establish endogenous CK profiles and characterize their biosynthesis in EPC cells. Among the fourteen CKs that were scanned for, only four forms were detected overall within the samples analyzed, including, N6-(Δ2-isopentenyl) adenine-9-riboside (iPR), N6-(Δ2-isopentenyl) adenine-9-riboside-5’ (mono/di/tri)phosphate (iPNT), and cis-zeatin-9-riboside-5’ (mono/di/tri)phosphate (cZNT) and 2‐methylthio‐zeatin (2MeSZ). The total cytokinin concentrations ranged from 0.03 pmol/g to 681.025 pmol/gfwt. The results from this study provided evidence that EPC cells can produce and process cytokinins.
{"title":"The occurrence of cytokinins and their biosynthesis pathways in epithelioma papulosum cyprini cells","authors":"Angela Schincaglia, M. Seegobin, Craig R. Brunetti, R. J. N. Emery","doi":"10.1139/cjc-2023-0108","DOIUrl":"https://doi.org/10.1139/cjc-2023-0108","url":null,"abstract":"Cytokinins are small signaling molecules present in all kingdoms of life; however, their biological relevance outside of plants is poorly characterized. Cytokinin detection across kingdoms has been shown to be inconsistent and is often organism or cell line dependent. To ensure optimal detection in epithelioma papulosum cyprini (EPC), a cold-blooded vertebrate cell line, a range of biomasses were evaluated. Cytokinins were extracted by solid-phase extraction and then detected using high performance liquid chromatography and tandem mass spectrometry. The objectives were to establish endogenous CK profiles and characterize their biosynthesis in EPC cells. Among the fourteen CKs that were scanned for, only four forms were detected overall within the samples analyzed, including, N6-(Δ2-isopentenyl) adenine-9-riboside (iPR), N6-(Δ2-isopentenyl) adenine-9-riboside-5’ (mono/di/tri)phosphate (iPNT), and cis-zeatin-9-riboside-5’ (mono/di/tri)phosphate (cZNT) and 2‐methylthio‐zeatin (2MeSZ). The total cytokinin concentrations ranged from 0.03 pmol/g to 681.025 pmol/gfwt. The results from this study provided evidence that EPC cells can produce and process cytokinins.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"31 8","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138948546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
McKenzie Franz, Melanie Kebel, Pardeepak Sandhu, Denisa Moldovan, Taylor Adamitz, Rajwinder Kaur, Ye Eun Rebecca Jeong, S. Wetmore
Pyrrolizidine alkaloids (PAs) are found in many plants worldwide, including some in Canada. PAs have been linked to losses in livestock populations and development of human PA-diseases. Four PA-derived dehydrosupinidine (DHP) adducts formed at the exocyclic amino groups of DNA purines have been found in tumor tissue and flagged as potential biomarkers for tumor formation (denoted DHP-G/A–3 and DHP-G/A–4). Four additional adducts (DHP-G/A–1 and DHP-G/A–2) have also been identified, which differ in the stereochemistry at the DHP–nucleobase linker or DHP ring carbon containing the hydroxy group, as well as the length of the DHP–nucleobase linker. Since the impact of these distinct chemical features on adduct mutagenicity is currently unclear, the present work uses density functional theory calculations to uncover the structures and base-pairing properties of these experimentally-observed DHP-derived purine adducts. Adduct Watson-Crick base pairs involving the canonical partner are energetically and structurally feasible. However, the G/A–3 and G/A–4 adducts are also highly susceptible to mispairing with G. Indeed, the longer and more flexible DHP–nucleobase linker in these adducts affords interactions between the DHP moiety and the pairing G that are not possible for the G/A–1 and G/A–2 counterparts. Our data thus rationalize the experimental identification of this subset of adducts in liver tumor tissue, and provide key insights to guide future experimental and computational studies that investigate the replication and broader biological outcomes of DHP-derived lesions.
吡咯里西啶生物碱（PAs）存在于世界各地的许多植物中，包括加拿大的一些植物。PAs 与牲畜数量减少和人类 PA 疾病的发生有关。在肿瘤组织中发现了在 DNA 嘌呤外环氨基上形成的四种 PA 衍生的脱水苏必啶（DHP）加合物，并被标记为肿瘤形成的潜在生物标志物（标记为 DHP-G/A-3 和 DHP-G/A-4）。此外，还发现了另外四种加合物（DHP-G/A-1 和 DHP-G/A-2），它们在 DHP-核碱基连接体或含有羟基的 DHP 环碳的立体化学结构以及 DHP-核碱基连接体的长度方面存在差异。由于这些不同的化学特征对加合物诱变性的影响目前尚不清楚，本研究利用密度泛函理论计算揭示了这些实验观察到的 DHP 衍生嘌呤加合物的结构和碱基配对特性。涉及典型伙伴的加合物 Watson-Crick 碱基配对在能量和结构上都是可行的。然而，G/A-3 和 G/A-4 加合物也非常容易与 G 配对错误。事实上，这些加合物中更长、更灵活的 DHP 核碱基连接体使 DHP 分子与配对的 G 之间产生了相互作用，而 G/A-1 和 G/A-2 加合物则不可能产生这种相互作用。因此，我们的数据合理地解释了肝脏肿瘤组织中这一亚群加合物的实验鉴定，并为指导未来研究 DHP 衍生病变的复制和更广泛的生物学结果的实验和计算研究提供了重要见解。
{"title":"A computational study of the structures and base-pairing properties of pyrrolizidine alkaloid-derived DNA adducts","authors":"McKenzie Franz, Melanie Kebel, Pardeepak Sandhu, Denisa Moldovan, Taylor Adamitz, Rajwinder Kaur, Ye Eun Rebecca Jeong, S. Wetmore","doi":"10.1139/cjc-2023-0177","DOIUrl":"https://doi.org/10.1139/cjc-2023-0177","url":null,"abstract":"Pyrrolizidine alkaloids (PAs) are found in many plants worldwide, including some in Canada. PAs have been linked to losses in livestock populations and development of human PA-diseases. Four PA-derived dehydrosupinidine (DHP) adducts formed at the exocyclic amino groups of DNA purines have been found in tumor tissue and flagged as potential biomarkers for tumor formation (denoted DHP-G/A–3 and DHP-G/A–4). Four additional adducts (DHP-G/A–1 and DHP-G/A–2) have also been identified, which differ in the stereochemistry at the DHP–nucleobase linker or DHP ring carbon containing the hydroxy group, as well as the length of the DHP–nucleobase linker. Since the impact of these distinct chemical features on adduct mutagenicity is currently unclear, the present work uses density functional theory calculations to uncover the structures and base-pairing properties of these experimentally-observed DHP-derived purine adducts. Adduct Watson-Crick base pairs involving the canonical partner are energetically and structurally feasible. However, the G/A–3 and G/A–4 adducts are also highly susceptible to mispairing with G. Indeed, the longer and more flexible DHP–nucleobase linker in these adducts affords interactions between the DHP moiety and the pairing G that are not possible for the G/A–1 and G/A–2 counterparts. Our data thus rationalize the experimental identification of this subset of adducts in liver tumor tissue, and provide key insights to guide future experimental and computational studies that investigate the replication and broader biological outcomes of DHP-derived lesions.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"18 5","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138948726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Megan Danielle Schroeder, Victor Hellgren, Frederic Menard
Herein, we report the synthesis of a chemical probe for real-time visualization of L-type voltage-gated calcium channels (LTCCs) using fluorescence microscopy. The probe, FluoBar2, is based on a barbiturate ligand selective for LTCCs. FluoBar2 contains the organic fluorophore 5-carboxyfluorescein and was synthesized in seven total steps with a 22% overall yield.
在此，我们报告了利用荧光显微镜实时观察 L 型电压门控钙通道（LTCC）的化学探针的合成过程。该探针名为 FluoBar2，是基于对 LTCCs 有选择性的巴比妥配体。FluoBar2 含有有机荧光团 5-羧基荧光素，共分七步合成，总产率为 22%。
{"title":"Synthesis of a Fluorescent Chemical Probe for Imaging of L-Type Voltage Gated Calcium Channels","authors":"Megan Danielle Schroeder, Victor Hellgren, Frederic Menard","doi":"10.1139/cjc-2023-0149","DOIUrl":"https://doi.org/10.1139/cjc-2023-0149","url":null,"abstract":"Herein, we report the synthesis of a chemical probe for real-time visualization of L-type voltage-gated calcium channels (LTCCs) using fluorescence microscopy. The probe, FluoBar2, is based on a barbiturate ligand selective for LTCCs. FluoBar2 contains the organic fluorophore 5-carboxyfluorescein and was synthesized in seven total steps with a 22% overall yield.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"55 45","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138949418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jacob G Hoare, Tanner George, Jason D. Masuda, Robert Douglas Singer
N-heterocyclic carbenes (NHCs) are a versatile class of ligands that have been widely applied in transition metal catalysis. However, NHCs are soft bases, and as such, complexes of NHCs with hard acids – such as many first-row transition metals – are typically sensitive to air and moisture, hence requiring multistep preparations. In this work, two examples of rare copper(II)-NHC complexes were prepared directly from 1,3-bis(pyridylmethyl)imidazolium chloride and 1,3-bis(2-pyridylmethyl)benzimidazolium chloride in protic conditions with no effort to exclude air or moisture. X-ray crystallographic analysis showed that both species display distorted square pyramidal geometry. A probe reaction demonstrated both complexes displayed poor catalytic activity for Chan-Evans-Lam coupling reactions.
{"title":"Synthesis of two air and moisture-stable copper(II)-N-heterocyclic carbene complexes","authors":"Jacob G Hoare, Tanner George, Jason D. Masuda, Robert Douglas Singer","doi":"10.1139/cjc-2023-0101","DOIUrl":"https://doi.org/10.1139/cjc-2023-0101","url":null,"abstract":"N-heterocyclic carbenes (NHCs) are a versatile class of ligands that have been widely applied in transition metal catalysis. However, NHCs are soft bases, and as such, complexes of NHCs with hard acids – such as many first-row transition metals – are typically sensitive to air and moisture, hence requiring multistep preparations. In this work, two examples of rare copper(II)-NHC complexes were prepared directly from 1,3-bis(pyridylmethyl)imidazolium chloride and 1,3-bis(2-pyridylmethyl)benzimidazolium chloride in protic conditions with no effort to exclude air or moisture. X-ray crystallographic analysis showed that both species display distorted square pyramidal geometry. A probe reaction demonstrated both complexes displayed poor catalytic activity for Chan-Evans-Lam coupling reactions.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"136 51","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138953272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jenna Hanrahan, Katherine L. Steeves, Grace V. Mercer, Thomas M. O'Brien, Drew P. Locke, Nikita E. Harvey, Alexandre S. Maekawa, Amy N. Stephenson, Céline M. Schneider, Lindsay S. Cahill
A proper functioning placenta is essential for normal fetal development. The placenta has a vital function as a protective barrier and is critical for nutrient and waste exchange for the developing fetus. Our group and others have reported sex differences in both placental structure and function; however, differences in the placental metabolome between female and male fetuses have been understudied. Here, placental tissue samples were collected from healthy pregnant CD-1 mice in late gestation ( n = 26 female and n = 27 male placentas from 17 dams at embryonic day 17.5). Metabolite profiles were determined using 1H magic angle spinning nuclear magnetic resonance. The relative concentration of alanine was significantly higher in male placentas whereas, threonine was higher in female placentas ( p < 0.05). This study adds to the growing literature demonstrating sex differences in healthy placental function and emphasizes the importance of examining both female and male placentas in metabolomics studies.
{"title":"Sex differences in mouse placental metabolite profiles: an NMR metabolomics study","authors":"Jenna Hanrahan, Katherine L. Steeves, Grace V. Mercer, Thomas M. O'Brien, Drew P. Locke, Nikita E. Harvey, Alexandre S. Maekawa, Amy N. Stephenson, Céline M. Schneider, Lindsay S. Cahill","doi":"10.1139/cjc-2023-0113","DOIUrl":"https://doi.org/10.1139/cjc-2023-0113","url":null,"abstract":"A proper functioning placenta is essential for normal fetal development. The placenta has a vital function as a protective barrier and is critical for nutrient and waste exchange for the developing fetus. Our group and others have reported sex differences in both placental structure and function; however, differences in the placental metabolome between female and male fetuses have been understudied. Here, placental tissue samples were collected from healthy pregnant CD-1 mice in late gestation ( n = 26 female and n = 27 male placentas from 17 dams at embryonic day 17.5). Metabolite profiles were determined using 1H magic angle spinning nuclear magnetic resonance. The relative concentration of alanine was significantly higher in male placentas whereas, threonine was higher in female placentas ( p < 0.05). This study adds to the growing literature demonstrating sex differences in healthy placental function and emphasizes the importance of examining both female and male placentas in metabolomics studies.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"13 3","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138589224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Joseph Ricardo-Noordberg, Zujhar Singh, Mohammadamin Nikpayam, Jahnai Francis, Marek Majewski
The development of sustainable alternatives to fossil fuel derived chemical feedstocks is imperative as we move towards decarbonization. Here, we report two Cu(I) chromophore-acceptor dyads bearing a 1,8-naphthalene monoimide electron-accepting moiety with a pendant Lewis basic pyridine for halogen bonding in the hopes of driving C-Br cleavage reactions using visible light. The photophysical and electrochemical properties are documented and both complexes were found to have favorable driving force for intramolecular charge shift in the excited state. However, neither complex was capable of C-Br cleavage and C-C bond formation in our hands. This study highlights that there are many structural and electronic factors that must be considered to successfully drive photoredox transformations, and the reported photosensitizers have potential uses in other applications owing to the synthetically versatile pyridine on the accepting ligand.
{"title":"Synthesis and Preliminary Characterization of Two Copper(I) Chromophore-Acceptor Dyads as Potential Photoredox Catalysts","authors":"Joseph Ricardo-Noordberg, Zujhar Singh, Mohammadamin Nikpayam, Jahnai Francis, Marek Majewski","doi":"10.1139/cjc-2023-0140","DOIUrl":"https://doi.org/10.1139/cjc-2023-0140","url":null,"abstract":"The development of sustainable alternatives to fossil fuel derived chemical feedstocks is imperative as we move towards decarbonization. Here, we report two Cu(I) chromophore-acceptor dyads bearing a 1,8-naphthalene monoimide electron-accepting moiety with a pendant Lewis basic pyridine for halogen bonding in the hopes of driving C-Br cleavage reactions using visible light. The photophysical and electrochemical properties are documented and both complexes were found to have favorable driving force for intramolecular charge shift in the excited state. However, neither complex was capable of C-Br cleavage and C-C bond formation in our hands. This study highlights that there are many structural and electronic factors that must be considered to successfully drive photoredox transformations, and the reported photosensitizers have potential uses in other applications owing to the synthetically versatile pyridine on the accepting ligand.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"5 2","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138589633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hannah F Cahill, Bryn S Scott, Olaiya Peter Oni, Grace VL Stapleton, T. MacCormack, Vicki Meli, Jillian Rourke
The highly tunable surface chemistry of gold nanoparticles (AuNPs) make them ideal candidates for cancer treatments. Modification of AuNP surface chemistry creates linkage points for different surface coatings whose chemical structure regulates AuNP interactions with cells and thus plays a key role in AuNP cytotoxicity. This study looked at AuNPs functionalized with three polyethylene glycol (PEG) coatings, differing in end group functionality: PEG methyl terminated thiol (PEGCH3), PEG amine terminated thiol (PEGNH2), and PEG carboxylic acid terminated thiol (PEGCOOH). Cytotoxic effects were compared across three cell lines: Human embryonic kidney (HEK293T/17), prostate cancer (PC-3), and ovarian cancer (SKOV3). Biochemical assays measured the effect AuNPs elicit on the ability of single cells to form colonies, metabolize thiazolyl blue tetrazolium bromide (MTT), or produce reactive oxygen species (ROS) using 2',7’-dichlorofluorescein. Overall, AuNP-PEG particles were minimally toxic. HEK293T/17 colony formation was significantly decreased with all but PEGCOOH particle types, and PEGNH2 treatments significantly decreased colony formation for all three tested cell lines. ROS production was significantly increased when treated with 100 μg mL-1 AuNP PEGNH2 in all three cell lines, with PEGCH3 also showing increased ROS in PC-3 cells. PEGCH3 reduced metabolic function (MTT metabolism) in only SKOV3 cells, while PEGCOOH was toxic to HEK293T/17 cells at 100 μg mL-1. These results suggest that differing end group chemistry leads to modest cytotoxic profiles for each AuNP that are cell line and coating dependent. Elucidation of AuNP mechanisms of toxicity is a critical step in the evaluation of the future therapeutic potential for these particles.
{"title":"Multiparametric cytotoxicity profiling reveals cell-line and ligand-dependent toxicity for pegylated gold nanoparticles (AuNP-PEG)","authors":"Hannah F Cahill, Bryn S Scott, Olaiya Peter Oni, Grace VL Stapleton, T. MacCormack, Vicki Meli, Jillian Rourke","doi":"10.1139/cjc-2023-0137","DOIUrl":"https://doi.org/10.1139/cjc-2023-0137","url":null,"abstract":"The highly tunable surface chemistry of gold nanoparticles (AuNPs) make them ideal candidates for cancer treatments. Modification of AuNP surface chemistry creates linkage points for different surface coatings whose chemical structure regulates AuNP interactions with cells and thus plays a key role in AuNP cytotoxicity. This study looked at AuNPs functionalized with three polyethylene glycol (PEG) coatings, differing in end group functionality: PEG methyl terminated thiol (PEGCH3), PEG amine terminated thiol (PEGNH2), and PEG carboxylic acid terminated thiol (PEGCOOH). Cytotoxic effects were compared across three cell lines: Human embryonic kidney (HEK293T/17), prostate cancer (PC-3), and ovarian cancer (SKOV3). Biochemical assays measured the effect AuNPs elicit on the ability of single cells to form colonies, metabolize thiazolyl blue tetrazolium bromide (MTT), or produce reactive oxygen species (ROS) using 2',7’-dichlorofluorescein. Overall, AuNP-PEG particles were minimally toxic. HEK293T/17 colony formation was significantly decreased with all but PEGCOOH particle types, and PEGNH2 treatments significantly decreased colony formation for all three tested cell lines. ROS production was significantly increased when treated with 100 μg mL-1 AuNP PEGNH2 in all three cell lines, with PEGCH3 also showing increased ROS in PC-3 cells. PEGCH3 reduced metabolic function (MTT metabolism) in only SKOV3 cells, while PEGCOOH was toxic to HEK293T/17 cells at 100 μg mL-1. These results suggest that differing end group chemistry leads to modest cytotoxic profiles for each AuNP that are cell line and coating dependent. Elucidation of AuNP mechanisms of toxicity is a critical step in the evaluation of the future therapeutic potential for these particles.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"123 31","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138599360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lithium salts continue to find pharmaceutical applications, particularly as psychiatric medications. As with any active pharmaceutical ingredient, structural polymorphism is an important concern for lithium-based medications which can influence solubility and other physicochemical properties. Here we report a 13C, 1H, and 7Li magic-angle spinning solid-state nuclear magnetic resonance (MAS SSNMR) study of two 1:1 polymorphic ionic cocrystals of lithium 4-methoxybenzoate and L-proline (L4MPRO(α) and L4MPRO(β)). One-dimensional 13C cross-polarization magic-angle spinning and two-dimensional heteronuclear correlation NMR spectra hint at differential mobilities of the proline and benzoate moieties for the two polymorphs. Five key resonances differ in 13C chemical shift by more than 1 ppm between the two polymorphs, clearly distinguishing between them. Gauge-including projector-augmented-wave density functional theory (GIPAW DFT) calculations of 13C and 1H magnetic shielding constants correlate strongly with the experimental chemical shifts for both polymorphs. R2 and root-mean-square deviation metrics are shown to be insufficient in the case of 13C, but sufficient in the case of 1H, for differentiating between the polymorphs. 7Li satellite-transition MAS NMR of both polymorphs are identical, as are the computed lithium magnetic shielding constants, demonstrating the insensitivity of 7Li NMR to polymorphism in these samples. This work highlights the utility of solid-state NMR spectroscopy for examining ionic salt cocrystals and also highlights some caveats in this regard.
{"title":"Ionic Salt Cocrystals Studied via Multinuclear Solid-State Magnetic Resonance. A Case Study of Lithium 4-Methoxybenzoate:L-Proline Polymorphs","authors":"Yishu Shi, David L. Bryce","doi":"10.1139/cjc-2023-0176","DOIUrl":"https://doi.org/10.1139/cjc-2023-0176","url":null,"abstract":"Lithium salts continue to find pharmaceutical applications, particularly as psychiatric medications. As with any active pharmaceutical ingredient, structural polymorphism is an important concern for lithium-based medications which can influence solubility and other physicochemical properties. Here we report a 13C, 1H, and 7Li magic-angle spinning solid-state nuclear magnetic resonance (MAS SSNMR) study of two 1:1 polymorphic ionic cocrystals of lithium 4-methoxybenzoate and L-proline (L4MPRO(α) and L4MPRO(β)). One-dimensional 13C cross-polarization magic-angle spinning and two-dimensional heteronuclear correlation NMR spectra hint at differential mobilities of the proline and benzoate moieties for the two polymorphs. Five key resonances differ in 13C chemical shift by more than 1 ppm between the two polymorphs, clearly distinguishing between them. Gauge-including projector-augmented-wave density functional theory (GIPAW DFT) calculations of 13C and 1H magnetic shielding constants correlate strongly with the experimental chemical shifts for both polymorphs. R2 and root-mean-square deviation metrics are shown to be insufficient in the case of 13C, but sufficient in the case of 1H, for differentiating between the polymorphs. 7Li satellite-transition MAS NMR of both polymorphs are identical, as are the computed lithium magnetic shielding constants, demonstrating the insensitivity of 7Li NMR to polymorphism in these samples. This work highlights the utility of solid-state NMR spectroscopy for examining ionic salt cocrystals and also highlights some caveats in this regard.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"18 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139208187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
p97/VCP is an essential AAA+ ATPase involved in diverse cellular activities by interacting with an array of protein adapters that recruit p97 for specific tasks. p47 is one of the adapters that targets p97 for membrane remodeling by forming a stable complex with p97 through multivalent interactions. Here we report a pair of previously unidentified interactions between the N-terminal part of p47 (residue 1-94) and the N-terminal domain (NTD) of p97. Using NMR spectroscopy, we identify two binding sites on p47, one located on the UBA domain and the other on the intrinsically disordered linker, that interact with the same basic patch on p97 NTD, driven by electrostatic forces. Reciprocal NMR titration experiments between p47 (residue 1-94) and p97 NTD reveal that these interactions are relatively weak in nature with dissociation constants on the order of hundreds of micromolar to millimolar in trans. Structural models of the two interactions are developed based on NMR chemical shift perturbations, which reveal details of the tentative binding interfaces. Our findings provide new insights into the mechanism by which ubiquitinated substrates are delivered from p47 to p97 for unfolding.
{"title":"NMR characterization of novel interactions between p97 AAA+ ATPase and the p47 adapter revealing insights into substrate delivery mechanism","authors":"Peter Kim, Megan Black, Felipe Perez, Rui Huang","doi":"10.1139/cjc-2023-0160","DOIUrl":"https://doi.org/10.1139/cjc-2023-0160","url":null,"abstract":"p97/VCP is an essential AAA+ ATPase involved in diverse cellular activities by interacting with an array of protein adapters that recruit p97 for specific tasks. p47 is one of the adapters that targets p97 for membrane remodeling by forming a stable complex with p97 through multivalent interactions. Here we report a pair of previously unidentified interactions between the N-terminal part of p47 (residue 1-94) and the N-terminal domain (NTD) of p97. Using NMR spectroscopy, we identify two binding sites on p47, one located on the UBA domain and the other on the intrinsically disordered linker, that interact with the same basic patch on p97 NTD, driven by electrostatic forces. Reciprocal NMR titration experiments between p47 (residue 1-94) and p97 NTD reveal that these interactions are relatively weak in nature with dissociation constants on the order of hundreds of micromolar to millimolar in trans. Structural models of the two interactions are developed based on NMR chemical shift perturbations, which reveal details of the tentative binding interfaces. Our findings provide new insights into the mechanism by which ubiquitinated substrates are delivered from p47 to p97 for unfolding.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"29 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139253429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Drug combination therapies have been a promising strategy to overcome drug resistance. However, unexpected Drug-Drug interaction may cause adverse reactions, which puts patients in danger. Keeping this in mind, the interactions between pain killers, paracetamol (PCM) and ibuprofen sodium (IBU) with caffeine (CAF) have been studied. Apparent molar volumes (V2,ϕ) and apparent molar isentropic compression (Ks,2,ϕ)for analgesic drugs in aqueous (1, 2, 5 and 10 mmol·kg-1) caffeine (CAF) solutions have been determined from measured densities, ρ and speeds of sound, u, respectively at T = (288.15 to 318.15) K and at pressure p = 101.3 kPa. The results have also been interpreted in terms of various interactions occurring in the mixed solution. Calorimetrically determined negative values of ΔtrΔdilH0, indicate the exothermicity and thus the occurrence of energetically more favorable process. The hyperchromic shift (UV-absorption) in the spectra of PCM in aqueous solution of CAF suggest the dominance of solute-cosolute interactions through the hydrophobic-hydrophobic/hydrophilic groups (1H NMR) of PCM + CAF system.
{"title":"Interactional Behaviour of analgesic drugs in Aqueous Solution of Caffeine at different temperatures using multi-technique Approach","authors":"Aashima Beri, R. Kant, T. S. Banipal","doi":"10.1139/cjc-2023-0097","DOIUrl":"https://doi.org/10.1139/cjc-2023-0097","url":null,"abstract":"Drug combination therapies have been a promising strategy to overcome drug resistance. However, unexpected Drug-Drug interaction may cause adverse reactions, which puts patients in danger. Keeping this in mind, the interactions between pain killers, paracetamol (PCM) and ibuprofen sodium (IBU) with caffeine (CAF) have been studied. Apparent molar volumes (V2,ϕ) and apparent molar isentropic compression (Ks,2,ϕ)for analgesic drugs in aqueous (1, 2, 5 and 10 mmol·kg-1) caffeine (CAF) solutions have been determined from measured densities, ρ and speeds of sound, u, respectively at T = (288.15 to 318.15) K and at pressure p = 101.3 kPa. The results have also been interpreted in terms of various interactions occurring in the mixed solution. Calorimetrically determined negative values of ΔtrΔdilH0, indicate the exothermicity and thus the occurrence of energetically more favorable process. The hyperchromic shift (UV-absorption) in the spectra of PCM in aqueous solution of CAF suggest the dominance of solute-cosolute interactions through the hydrophobic-hydrophobic/hydrophilic groups (1H NMR) of PCM + CAF system.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"66 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139255427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：