Synthesis,Crystal Structures,and Anti‐cervical Cancer Activity Evaluation of Three Trinuclear Transition Metal(II) Complexes with N,O‐Donor Schiff Base Ligand

A new bi‐nucleating Schiff base ligand, 2‐(((3‐(dimethylamino)propyl)imino)methyl)‐6‐methoxyphenol (HL₁) was prepared by a one‐pot condensation reaction, which was further used in the construction of three trinuclear Schiff base transition metal(II) complexes [Cu₃(L1)₂(OH)₂(H₂O)₂](NO₃)₂ ( 1 ), [Co₃(L1)₂(OH)₂(H₂O)₂](NO₃)₂ ( 2 ), and [Cu₃(L1)₂(N₃)₄] ( 3 ). Furthermore, a green hand grinding technique was implemented to reduce the particle size of the coordination complexes to generate the nanoscale compounds. The SEM studies reveal the formation of square and spherical particles for nano 1 and 2 , and nanorod for nano 3 . In addition, the anti‐proliferation activity of nano 1 – 3 was detected on the human cervical cancer Hela cells with CCK‐8 assay. The cell viability curves and IC₅₀ values indicated that only nano 1 has anti‐proliferation activity on Hela cells. To further investigate the mechanism of nano 1 induced Hela cell death, the Annexin V‐FITC/PI double staining assay, western blot assay, and ROS level detection was conducted.     

Hexanuclear Co4Dy2, Zn4Dy2, and Co4Y2 Complexes with Defect Tetracubane Cores: Syntheses,Structures, and Magnetic Properties

A hexanuclear heterometallic cluster of composition [Dy₂Co₄(L)₄(NO₃)₂(OH)₄(C₂H₅OH)₂] ⋅ 2 C₂H₅OH ( 1 ) was synthesized by employing a Schiff base 2-(((2-hydroxy-3-methoxybenzyl) imino)methyl)-4-methoxyphenol (H₂L) as ligand and utilizing Dy(NO₃)₃ ⋅ 6H₂O and Co(NO₃)₂ ⋅ 6H₂O as metal ion sources. X-ray single-crystal diffraction analysis indicated that complex 1 contains a defect tetracubane core and possesses central symmetric structure, with two Dy^III ions being in the central body position of the molecule and four Co^II ions being arranged at the outer sites. Magnetic studies reveal that complex 1 behaves as single-molecule magnet (SMM) with energy barrier of 27.50 K. To investigate the individual contribution of Dy^III and Co^II ions to the SMM behavior, another two complexes of formulae [Dy₂Zn₄(L)₄(NO₃)₂(OH)₄] ⋅ 4CH₃OH ( 2 ) and [Y₂Co₄(L)₄(NO₃)₂(OH)₄(C₂H₅OH)₂] ⋅ 2 C₂H₅OH ( 3 ) were prepared. Complexes 1 and 3 are isomorphous. The coordination geometries of Dy^III ions in 1 and 2 are different. The Dy^III ions are eight-coordinated in 2 and nine-coordinated in 1 . Complex 2 exhibits SMM behavior with energy barrier of 69.67 K, but complex 3 does not display SMM property. These results reveal that the SMM behaviors of 1 and 2 are mainly originated from Dy^III ions. It might be the higher symmetry of Dy^III ions in 2 that results in the higher energy barrier.     

The synthesis and characterization of a new (E,E)-dioxime and its mono and heterotrinuclear complexes containing dioxadithiadiazamacrobicyclic moieties

A new (E,E)-dioxime (2Z,3Z)-1,4,7,8,15,16-hexahydro-9,14-(ethanothioethanothioethano)quinoxalino[6,7-e] [4,7,1,10]benzodioxadiazacyclododecine-2,3,19,26-tetrone2,3-dioxime (H₂L) has been synthesized by reacting cyanogen-di-N-oxide with 2,3-diamino-6,7,14,15-tetrahydro-8,13-(ethanothioethanothioethano)dibenzo[b,h] [1,4,7,10]dioxadiazacyclodecine-17,24-dione (6). Mononuclear complexes (8, 9) of this ligand have been synthesized by reacting the vic-dioxime (H₂L) with NiCl₂ · 6H_2O and COCl₂ · 6H₂O respectively. The BF ₂ ⁺ capped cobalt(III) complex (10) of the new (E,E) vic-dioxime has been synthesized by using as precursor a hydrogen-bridged mononuclear cobalt(III) complex (9). The heterotrinuclear complex (11) has been prepared by reacting one mononuclear cobalt(III) complex (10) with [Cu(MeCN)₄]PF₆. The new compounds were characterized by a combination of elemental analysis, ¹H- and ¹³C-n.m.r, i.r. and m.s. spectral data.     

Preparation,crystal structure,spectroscopic studies,DFT calculations,antibacterial activities and molecular docking of a tridentate Schiff base ligand and its cis‐MoO2 complex

We synthesized a tridentate Schiff base ligand, 6‐(((2‐hydroxyphenyl)amino)methylene)‐2‐methoxycyclohexa‐2,4‐dienone [H₂L], as well as its Mo(VI) complex [MoO₂(L)(DMSO)], and then characterized them completely using elemental analysis, FT‐IR, UV–Vis and ¹HNMR spectroscopy techniques. X‐ray single crystal diffraction method was used for the determination of the structure of the synthesized ligand and complex. All other spectroscopic techniques performed, confirmed that [MoO₂(L)(DMSO)]had an octahedral geometry around the Mo(VI) central ion coordinated by the donor atoms of the deprotonated ligand, two oxido groups and one oxygen atom of DMSO molecule. Hybrid functional B3LYP with DGDZVP as basis set was applied for DFT calculations of the compounds in their ground state. The MEP, Mulliken, HOMO‐LUMO energy gap and thermodynamic properties of the compounds were also theoretically predicted. In‐vitro antimicrobial studies on the synthesized compounds indicated the great antibacterial activities of the Mo(VI) complex against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus cereus bacteria.     

Synthesis and Structural Features of New Schiff Base Complexes of Mononuclear MnIV,Dinuclear CoIICoIII,and Tetranuclear CuII

2‐(((2‐Hydroxy‐3‐methoxyphenyl)methylene)amino)‐2(hydroxymethyl)‐1,3‐propanediol (LH₄, as abbreviation) reacts with MnCl₂ · 4H₂O, CoCl₂ · 6H₂O, and Cu(ClO₄)₂ · 6H₂O to give the new complexes [Mn(LH₂)₂] ( 1 ), [Co₂Cl(H₂O)(LH₂)₂] · 4H₂O ( 2 ), and [Cu₄(LH₂)₄(H₂O)₄] ( 3 ). Complex 1 is formed by the assembly of two molecules of the ligand with one manganese(IV) ion. In the mixed‐valence cobalt complex 2 there is an asymmetry between the coordination spheres of cobalt(II) and cobalt(III). In the tetramer 3 four copper(II) ions attain a distorted tetrahedral configuration surrounded by four molecules of the ligand.     

Synthesis,characterization, crystal structure and toxicity evaluation of Co (II), Cu (II), Mn (II), Ni (II), Pd (II) and Pt (II) complexes with Schiff base derived from 2-chloro-5-(trifluoromethyl)aniline

A bidentate NO donor Schiff base, 2-(((2-chloro-5- (trifluoromethyl)phenyl)imino)methyl) phenol ( HL ¹ ) and its complexes [Co(L¹)₂(H₂O)₂] ( 1 ), [Cu(L¹)₂] ( 2 ), [Mn(L¹)₂(H₂O)₂] ( 3 ), [Ni(L¹)₂(H₂O)₂] ( 4 ), [Pd₂(L¹)₂(OAc)₂·1.16H₂O] ( 5 ), [Pt(L¹)₂] ( 6 ) were synthesized and characterized by different physico-chemical techniques including elemental and thermal analysis, magnetic susceptibility measurements, molar electric conductivity, IR, ¹H-NMR, ¹³C-NMR, UV–Vis, mass spectroscopies and X-ray powder diffraction (XRD). The molecular structures of ligand HL ¹ and two complexes ( 2 and 5 ) were confirmed by X-ray crystallography analysis on the monocrystal. In this complexes, the metal ions are in distorted square-planar environments. The copper (II) complex is mononuclear and crystallized in a monoclinic space group P21/c, whereas palladium (II) complex is dinuclear and crystallized in the trigonal crystal system R-3. The toxicity of the ligand and complexes was evaluated on both plant and animal cells, using the plant species Triticum aestivum L. and the crustacean Artemia franciscana Kellogg. At concentrations up to 100 μM the compounds presented very little toxicity on Artemia franciscana Kellogg. Moreover, the palladium (II) complex was devoid of any toxicity on the plant cells.     

Nano silver particles catalyzed synthesis,molecular docking and bioactivity of α-thiazolyl aminomethylene bisphosphonates

Abstract

A new series of α-thiazolyl aminomethylene bisphosphonates were synthesized by a three component reaction of 4-aryl substituted thiazol-2-amine with different dialkyl/aryl phosphites and triethyl orthoformate in the presence of Ag NPs (nano particles) as a catalyst under solvent free conditions. All the synthesized target compounds were characterized by ¹H, ¹³C, ³¹P, mass and elemental analysis. The target compounds were screened for their in vitro antioxidant, antibacterial and antifungal activity. Molecular docking studies were also performed. The results revealed that among the synthesized compounds tetramethyl(((4-(4-methoxyphenyl)thiazol-2-yl)amino) methylene)bis(phosphonate) (5d), tetramethyl(((4-(4-fluorophenyl)thiazol-2-yl)amino) methylene) bis(phosphonate) (5h), and tetramethyl(((4-(4-bromophenyl)thiazol-2-yl)amino)methylene) bis (phosphonate) (5j) showed remarkably higher antioxidant activity by DPPH and H₂O₂ than the standard ascorbic acid. Compounds tetramethyl(((4-phenyl thiazol-2-yl)amino) methylene) bis(phosphonate) (5a), 5d, 5h and tetraethyl(((4-(4-bromophenyl)thiazol-2-yl) amino)methylene)bis (phosphonate) (5k) showed good antibacterial activity. 5a, 5d, and 5h also showed rather higher antifungal activity than the standard flucanozole. Computational docking methods have been used to predict how several aminomethylene bisphosphonate derivatives compete against the inhibitor BPH-1330 at the crystal enzyme structure of the 4H3A protein active site and how R and R₁ influence their binding ability.     

Synthesis of two new tripodal ligands and their cyclocondensation with 2-[2-(2-formylphenoxy)ethoxy]benzaldehyde in the presence of manganese(II) and cadmium(II) metal ions

Two new asymmetric tripodal tetraamine ligands, 2-((bis(2-aminoethyl)amino)methyl)benzenamine (L²) and 2-(((2-aminoethyl)(3-aminopropyl)amino)methyl)benzenamine (L³) were synthesized and characterized. [1+1] Macrocyclic Schiff-base complexes containing 1,2-diphenoxyethane head units and a 2-aminobenzyl pendant arm, were synthesized as [MnL⁴(MeOH)](ClO₄)₂ (1), [MnL⁵(MeOH)](ClO₄)₂ (2), [CdL⁴(H₂O)](NO₃)₂ (3) and [CdL⁵(H₂O)](NO₃)₂ (4) from the metal ion templated cyclocondensation reactions of 2-[2-(2-formylphenoxy)ethoxy]benzaldehyde with the (L²) or (L³) tripodal tetraamine ligands. The crystal structure determination of (1) and (4) showed that the complex cations that had formed consisted of pentagonal bipyramidally coordinated Mn(II) and Cd(II) ions, centrally located in a N₃O₂ macrocycle, with one 2-aminobenzyl pendant arm. Supporting ab initio HF-MO calculations have been undertaken using the standard 3-21G^∗ and 6-31G^∗ basis sets.     

基于半刚性三角形羧酸配体构筑的配位聚合物的合成,结构及其荧光性质

通过使用一个半刚性的多齿羧酸配体3,3',3"-(((2,4,6-trimethylbenzene-1,3,5-triyl)tris(methylene))tris(oxy))tribenzoic acid (H₃L),在溶剂热条件下合成了4个配位聚合物{[Cd₃(L)₂(H₂O)₂]·5DMF·6H₂O}_n (1),{[Co₃(L)₂(H₂O)₂]·2DMF·6H₂O}_n (2),{[Mn₃(L)₂(H₂O)₂]·3DMF·6H₂O}_n (3),{[Zn₃(L)₂(H₂O)₂]·5DMA·5H₂O}_n (4),并通过X射线单晶衍射,热重分析对配合物结构进行了表征。4个化合物都是同构的,由沙漏型的M₃簇和L^3-配体作为次级结构单元,从而给出了一个金属-有机纳米笼的三维结构,从拓扑学的观点看,4个配合物的结构可以看作是三节点的(3,3,6)-连接的网络。荧光光谱测试表明配合物1和4在激发波长为272 nm下,在385 nm处显示了强的宽发射峰。荧光传感测试结果表明,配合物1是一种潜在的硝基苯类化合物的传感材料。     

Uranyl ion complexes with long chain aminoalcoholbis(phenolate) [O,N,O,O′] donor ligands

The reaction between uranyl nitrate hexahydrate and phenolic ligand precursor [(N,N-bis(2-hydroxy-3,5-dimethylbenzyl)-4-amino-1-butanol) · HCl], H₃L1 · HCl, leads to a uranyl complex [UO₂(H₂L1)₂] (1a) and [UO₂(H₂L1)₂] · 2CH₃CN (1b). The ligand [(N,N-bis(2-hydroxy-5-tert-butyl-3-methylbenzyl)-4-amino-1-butanol)H₃L2 · HCl], H₃L2 · HCl, yields a uranyl complex with a formula [UO₂(H₂L2)₂] · CH₃CN (2). The ligand [(N,N-bis(2-hydroxy-3,5-dimethylbenzyl)-5-amino-1-pentanol) · HCl], H₃L3 · HCl, produces a uranyl complex with a formula [UO₂(H₂L3)₂] · 2CH₃CN (3) and the ligand [(N,N-bis(2-hydroxy-5-tert-butyl-3-methylbenzyl)-5-amino-1-pentanol) · HCl], H₃L4 · HCl, leads to a uranyl complex with a formula [UO₂(H₂L4)₂] · 2CH₃CN (4). The ligand [(N,N-bis(2-hydroxy-5-tert-butyl-3-methylbenzyl)-6-amino-1-hexanol) · HCl], H₃L5 · HCl, leads to a uranyl complex with a formula [UO₂(H₂L5)₂] · 4toluene (5). The complexes 1–5 are obtained using a molar ratio of 1:2 (U to L) in the presence of a base (triethylamine). The molecular structures of 1a, 1b, 3, 4 and 5 were verified by X-ray crystallography. All complexes are neutral zwitterions and have similar centrosymmetric, mononuclear, distorted octahedral uranyl structures with the four coordinating phenoxo ligands in an equatorial plane. In uranyl ion extraction studies from water to dichloromethane with ligands H₃L1 · HCl–H₃L5 · HCl, ligands H₃L1 · HCl, H₃L4 · HCl and H₃L5 · HCl are the most effective ones.     

2‐Amino‐5‐(2‐pyridyl)‐thiadiazole as Bidentate Ligand

The amino substituted bidentate chelating ligand 2‐amino‐5‐(2‐pyridyl)‐1,3,4‐thiadiazole (H₂ L ) was used to prepare 3:1‐type coordination compounds of iron(II), cobalt(II) and nickel(II). In the iron(II) perchlorate complex [Fe^II(H₂ L )₃](ClO₄)₂·0.6MeOH·0.9H₂O a 1:1 mixture of mer and fac isomers is present whereas [Fe^II(H₂ L )₃](BF₄)₂·MeOH·H₂O, [Co^II(H₂ L )₃](ClO₄)₂·2H₂O and [Ni^II(H₂ L )₃](ClO₄)₂·MeOH·H₂O feature merely mer derivatives. Moessbauer spectroscopy and variable temperature magnetic measurements revealed the [Fe^II(H₂ L )₃]²⁺ complex core to exist in the low‐spin state, whereas the [Co^II(H₂ L )₃]²⁺ complex core resides in its high‐spin state, even at very low temperatures.     

Design,synthesis, and antilung adenocarcinoma activity research of novel paeonol Schiff base derivatives containing a 1,2,3-triazole moiety

A new series of paeonol Schiff base derivatives containing a 1,2,3-triazole moiety were synthesized using the copper(I) catalyzed azide-alkynecycloaddition (CuAAC) reaction and evaluated for their cytotoxicity in vitro against human cervical carcinoma HeLa cells, human lung cancer A549 cells, and human liver cancer HepG2 cells. Unfortunately, all the tested compounds showed poor activities toward the human cervical carcinoma HeLa cells and human liver cancer HepG2 cells. However, compounds (E)-2-(1-(((1-[2-fluorophenyl]-1H-1,2,3-triazol-4-yl)methyl)imino)ethyl)-5-methoxyphenol ( 4c ) and (E)-2-(1-(((1-[3- chlorophenyl]-1H-1,2,3-triazol-4-yl)methyl)imino)ethyl)-5-methoxyphenol ( 4i ) exhibited inhibitory activities toward human lung cancer A549 cells (IC₅₀ = 45.1 μM for 4c and 78.9 μM for 4i ) compared with that of paeonol, which indicated that such paeonol Schiff base derivatives containing a 1,2,3-triazole moiety could be further modified to obtain good cytotoxicity in vitro against human lung cancer A549 cells.     

Structural and theoretical studies of (E,E)-benzaldehyde azine and its rhenium(IV) complex

The azine bridged dicatechol ligand (E,E)-benzaldehyde azine (H₄L) was fully characterized by X-ray analysis. The reaction of [ReCl₆]²⁻ with this compound was studied and the novel Re(IV) complex (HNEt₃)(NBu₄)[ReCl₄(H₂L)] was prepared and characterized. The structure and spectroscopy of the compound H₄L and its Re(IV) complex were studied experimentally and by means of density functional calculations.     

A new mixed-ligand coordination polymer based on V-shape carboxylate and pyridinyl co-linkers: Crystal structure,molecular docking,and antibladder cancer activity evolution

By applying the mixed-ligand approach, a new Cu(II)-containing coordination polymer [Cu₄(L)₄(4,4′-bpy)(H₂O)₂]·3H₂O ( 1 ) was successfully prepared through hydrothermal method using linear 4,4′-bipyridine (4,4′-bpy) and the V-shape carboxylate ligand 4,4′-(phenylazanediyl)dibenzoic acid (H₂L). The as-prepared complex 1 was determined by single-crystal X-ray crystallography and elemental analysis. Furthermore, we use the grinding method to prepare the samples of complex 1 in the nanoscale. In this research, the CCK-8 was performed first to detect the inhibitory activity of complex 1 on J82 bladder cancer cell viability. The apoptotic effect of complex 1 on J82 cancer cells was evaluated by Annexin V-FITC/PI staining. The reactive oxygen species (ROS) was also detected by detection kit in this study after complex 1 treatment. Beyond the experimental results, the molecular docking technique has been used to probe the anticancer activity that originated at the molecular level.     

Syntheses and crystal structures of phthalato-, succinato-, maleato-, acetylenedicarboxylato-bridged [bis(2-pyridylcarbonyl)amide]copper(II) complexes

Self-assemblies of the 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz) and Cu(OH)₂ in the presence of dicarboxylate ligands yielded four new complexes, [Cu₄(bpca)₄(L1)₂(H₂O)₂]·5H₂O (1), [Cu₂(bpca)₂(L2)(H₂O)₂]·2H₂O (2), [Cu₂(bpca)₂(L3)(H₂O)₂]·H₂O (3), and [Cu₂(bpca)₂(L4)(H₂O)₂]·3H₂O (4) (bpca = bis(2-pyridylcarbonyl)amide anion, H₂L1 = phthalic acid, H₂L2 = succinic acid, H₂L3 = maleic acid, H₂L4 = acetylenedicarboxylic acid). Their structures were determined by single-crystal X-ray diffraction analyzes and further characterized by IR spectra and thermogravimetric analyzes. The five-coordinate Cu ions in 1 are bridged by phthalate to form 1-D chains, which are assembled into 3-D frameworks by extensive hydrogen bonds. Compounds 2–4 possess similar structures, built up of [Cu₂(bpca)₂(L)(H₂O)₂] (L = L2 for 2, L3 for 3, L4 for 4) and lattice molecules. The 3-D frameworks of 2–4 are completed by hydrogen bond interactions.     

Syntheses,Crystal Structure and Property of a Heterometallic Heptanuclear Cluster

A novel heterometallic heptanuclear cluster [(hmbame)₂ \(Co_{4}^{III}\)Co^IINa₂(N₃)₈ (OH)₂]·4H₂O (1), (H₃hmbame is 6,6′-((1Z,1′E)-(((3-ethoxy-2-hydroxyphenyl) methylene)bis(azanylylidene))bis(methanylylidene))bis (2-ethoxy phenol)) was synthesized by in situ reaction. Complex 1 was structurally characterized by elemental analysis, IR, UV–Vis spectroscopy and single crystal X-ray diffraction. Complex 1 crystallizes in the triclinic space group Pī, showing a disc-like configuration. Luminescent property of 1 has been studied. The results indicate that it may be good candidate for useful photoactive material.     

3-(2-吡啶基)-1,2,4-三唑配体Co(II)Cu(II)和Cd(II)配合物的合成、结构及荧光性质

利用3-（2-吡啶基）-1,2,4-三唑配体（HL）和不同的金属盐设计合成了5个配合物[Co（HL）₂（H₂O）₂]（NO₃）₂（1）、[Cu₂（L）₂（NO₃）₂（H₂O）₄] （2）、[Cu₂（L）₂（AcO）₂（H₂O）₂]·6H₂O （3）、[Cu₂（L）₂（HL）₂（ClO₄）₂]·2CH₃CN （4）和[Cd₂（L）₂（HL）₂（NO₃）₂]·2H₂O （5）,并通过X射线单晶衍射、红外、元素分析、X射线粉末衍射和热重对配合物结构进行了表征。测试结果表明配合物1具有单核结构,并且可以通过氢键的相互作用形成二维超分子结构。配合物2~5为双核结构。配合物2和5可以通过氢键的相互作用形成二维超分子结构。配合物3通过氢键的相互作用形成三维超分子结构。研究了配合物中HL配体的配位模式。此外,研究了配体HL和配合物1和5的固态荧光性质及荧光寿命。     

Synthesis, characterization and antitumor activity of Cu(II), Co(II), Zn(II) and Mn(II) complex compounds with aminothiazole acetate derivative

This paper presents the synthesis of complex compounds of type [M(L1)₂], where M(II)= Cu (1), Co (2), Zn (3), L1=2-aminothiazole-4-acetate and [Mn(L1)₂(H₂O)] (4) using ethyl 2-(2-aminothiazole-4-yl) acetate (L), and characterization by elemental analysis, magnetic susceptibilities, IR, 1H-NMR, UV-Vis spectroscopy and for [Mn(L1)₂(H₂O)] also by X-ray diffraction. In vitro cytotoxicity studies were performed on human cervix adenocarcinoma, HeLa cells. The antitumor selectivity was assessed using normal human peripheral blood mononuclear cells, PBMC as control.      

Hexanuclear Fe(III) wheels functionalized by amino-acetonitrile derivatives

Three new hexanuclear Fe(III) coordination wheels [Fe₆Cl₆(L1)₆]·5(MeCN) (1), [Na_0.5Fe₆Cl₆(L1)₆](N₃)_0.5·4.5(MeCN) (2), and [Fe₆Cl₆(L2)₆]·2(MeCN) (3) have been synthesized with new prepared amino-acetonitrile derivatives 2-[bis(2-hydroxyethyl)amino]acetonitrile hydrochloride (H₂L1) and 3-[bis(2-hydroxyethyl)amino]propanenitrile hydrochloride (H₂L2). They were structurally characterized by single-crystal X-ray diffraction. Mößbauer spectroscopy and magnetic susceptibility measurements indicate dominant antiferromagnetic behavior between the Fe(III) centers.     

Development of a Derivatization Reagent with a 2-Nitrophenylsulfonyl Moiety for UHPLC-HRMS/MS and Its Application to Detect Amino Acids Including Taurine

Taurine (Tau) has some important ameliorating effects on human health and is present in bivalve. For the selective analysis of Tau with other amino acids, we designed a derivatization reagent, 2,5-dioxopyrrolidin-1-yl(4-(((2-nitrophenyl)sulfonyl)oxy)-6-(3-oxomorpholino)quinoline-2-carbonyl)pyrrolidine-3-carboxylate (Ns-MOK-β-Pro-OSu). After derivatization with Ns-MOK-β-Pro-OSu, amino acids with Tau in Japanese littleneck clams were determined through ultra-high-performance-liquid chromatography with high-resolution tandem mass spectrometry (UHPLC-HRMS/MS) using an octadecyl silica column. We could detect 18 amino acids within 10 min. Tau, valine, glutamine, glutamic acid, and arginine in the clams were determined in the negative ion mode using the characteristic fragment ion, C₆H₄N₁O₅S, which corresponded to the 2-nitrobenzenesulfonylate moiety. The fragment ion, C₆H₄N₁O₅S, was recognized as a common feature regardless of the amino acid to be derivatized, and it was convenient for detecting amino acid derivatives with high selectivity and sensitivity. Therefore, highly selective quantification using UHPLC-HRMS/MS was possible using Ns-MOK-β-Pro-OSu.