液相色谱-串联质谱法测定固体及液体药物中27种新型毒品芬太尼类物质

采用QuEChERS法及固相萃取(SPE)法净化样品,结合液相色谱-串联质谱(LC-MS/MS),建立了固体和液体药物中27种新型毒品芬太尼类物质(芬太尼类似物和代谢物)的测定方法。分析物采用电喷雾离子源,正离子多反应监测(MRM)模式检测,外标法定量。结果表明,27种芬太尼类物质在0.5～50.0μg/L质量浓度范围内呈良好线性关系,相关系数(r²)均大于0.99,方法的定量下限为10.0μg/kg(固体药物)、10.0μg/L(液体药物);3个加标水平的回收率为84.8%～109%;相对标准偏差(RSD)为0.86%～8.5%。该方法快速简便,耗时短,灵敏度高,稳定性好,可用于药物中芬太尼类物质的定性鉴定及定量检测,有助于落实我国对该类物质的整类列管。     

New chlorogenic acid derivatives and triterpenoids from Scorzonera aucheriana

Chromatographic separation ofn-hexane and ethyl acetate fraction of a crude methanol extract obtained from aerial parts of theScorzonera aucherianaDC collected from Sivas province of Turkey yielded nine natural compounds; two new 3-caffeoyl-quinic acid analogs (1-2), one new taraxasterol oleate (3), and six known triterpenoids taraxasterol (4), taraxasterol acetate (5), ptiloepoxide (6), lupeol (7), lupeol acetate (8), andβ-sitosterol (9) were characterized. The structures of the isolated compounds were elucidated on the basis of NMR (¹H,¹³C, COSY, HMBC, HSQC, and TOCSY), UV, FT-IR and LC-Q-TOF-MS spectrometric data.     

Novel Synthetic Route Toward Benzofuran-pyridine–Based Spirans

A novel domino reaction of tetrahydrobenzofuro[3,2-c] or [2,3-c]pyridines with dimethylacetylene dicarboxylate (DMAD) or methyl propiolate (MP) resulted in the formation of spirobenzofuranpyridines in moderate yields. The spirobenzofuran derivatives reported may be considered analogs of the antifungal drug griseofulvin.     

Rational Design and Engineering of Nanomaterials Derived from Prussian Blue and Its Analogs for Electrochemical Water Splitting

Electrochemical water splitting (EWS) is a sustainable and promising technology for producing hydrogen as an ideal energy carrier to address environmental and energy issues. Developing highly‐efficient electrocatalysts for hydrogen and oxygen evolution reactions (HER and OER) is critical for increasing the efficiency of water electrolysis. Recently, nanomaterials derived from Prussian blue (PB) and its analogs (PBA) have received increasing attention in EWS applications owing to their unique composition and structure properties. In this Minireview, the latest progress of PB/PBA‐derived materials for EWS is presented. Firstly, the catalyst design principles and the advantages of preparing electrocatalysts with PB/PBA as precursors are briefly introduced. Then, strategies for enhancing the electrocatalytic performance (HER, OER or overall water splitting) were discussed in detail, and the recent development and applications of PB/PBA‐derived catalysts for EWS were summarized. Finally, major challenges and possible future trends related to PB/PBA‐derived functional materials are proposed.     

Identification of a Suspicious Drug by Using Spectroscopic Techniques: A Forensic Analytical Chemistry Project

We identified a drug analog by using screening and confirmatory tests. Total ion chromatogram showed a major peak with a molecular ion of 190 m/z, but no mass spectrum match from the NIST library. A minor peak was identified as 1-benzylpiperazine (molecular ion = 176 m/z). Molecular ions of both peaks differed by 14 m/z units, suggesting a –CH₂ – group. Both peaks had the same base peak of 91 m/z. Derivatizing the drug analog with trifluoroacetic anhydride confirmed the presence of 1-benzylpiperazine. No reaction occurred with the major peak. We proposed a benzyl-4-methylpiperazine structure, which was confirmed by NMR studies.     

Complexes of carbene analogs with Lewis bases: matrix IR spectroscopy and quantum-chemical studies

The results of studies on complexes of carbene analogs ER₂ (E = Si, Ge, Sn, Pb) with Lewis bases by matrix IR spectroscopy and quantum chemistry methods are considered. Trends in changes in the spectral characteristics, structures, and stability of the complexes are outlined.     

Polynitrogen clusters containing five-membered rings

Possible structures of N₁₅ cluster were examined by ab initio (MP2) and density functional theory (DFT) methods with the 6-31G* basis set. Their stabilities were compared together with other polynitrogen clusters N_n (n = 8, 10–14) reported in the literature. The order of stability was made respectively according to even or odd numbers of the total nitrogen atoms in clusters. It is found that both for even-numbered clusters N_2n (n = 4–7) and odd-numbered clusters N_{2n + 1} (n = 5–7) the thermodynamically most stable isomers are all based on pentazole units; for each one of N_n (n = 8, 10–15) clusters, the more conjugated the five-membered ring the more stable is the isomer; and, the more side-chains the N₅ ring links the less stable is the isomer. Another finding is that the larger the cluster the less stable is the cluster for every series of clusters of (a) containing two five-membered rings with an even number of total nitrogen atoms [N₁₀ (D_2d), N₁₂ (C_2h), N₁₄ (C_2h)], (c) containing one five-membered ring and a side-chain with an even number of total nitrogen atoms [N₈ (C_S), N₁₀ (C_S), N₁₂ (C_S), N₁₄ (C_S)], (d) containing one five-membered ring and a side-chain with an odd number of total nitrogen atoms [N₁₁ (C_S), N₁₃ (C_S), N₁₅ (C_S)], (e) chain clusters with an even number of total nitrogen atoms [N₈ (C_2h), N₁₀ (C_2h), N₁₂ (C_2h), N₁₄ (C_2h)], and (f) chain clusters with an odd number of total nitrogen atoms [N₁₁ (C_2v), N₁₃ (C_2v), N₁₅ (C_2v)]. For another series of clusters with two five-membered ring units [N₁₁ (C₂), N₁₃ (C_2v), and N₁₅ (C_2v)] (series b) the N₁₃ (C_2v) shows the best stability. It is also found that the even-numbered nitrogen clusters are more stable than the odd-numbered ones in comparison of series (a) with (b), (c) with (d), and (e) with (f). © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004     

An efficient Mitsunobu coupling to adenine-derived carbocyclic nucleosides

Adenine is a poor substrate for the Mitsunobu process to carbocyclic nucleosides. However, N-6 amino bis-Boc-protected adenine is reported herein to undergo an efficient coupling under these conditions as a result of its increased solubility and the reduced competing nucleophilicity of the free adenine amino substituent. Products from this reaction are readily converted to aristeromycin, neplanocin, and analogs there from, including 5′-homoaristeromycin, a promising antiviral agent.     

Hydroxylated oxanes as xyloside analogs for determination of the minimal binding requirements of β4GalT7

β-1,4-Galactosyltransferase 7 (β4GalT7) is a key enzyme in the biosynthesis of glycosaminoglycan (GAG) chains. Natural and synthetic xylosides can be used to both inhibit and prime GAG synthesis by acting as inhibitors or substrates for β4GalT7. In this report, we exploit hydroxylated oxanes as deoxygenated xyloside analogs to clarify the minimum protein-ligand interactions required for galactosylation and/or inhibition. Enantiomerically pure substances were synthesized using a chiral pool approach whereas the corresponding racemates were obtained from simple starting materials. The results of a β4GalT7 assay show that a single hydroxyl group on an oxane ring is insufficient to induce galactosylation or inhibition, which implies that at least two substituents, one of which being 3-OH, needs to be present.     

Optoelectronic characteristics and application of black phosphorus and its analogs

The tunable bandgap from 0.3 eV to 2 eV of black phosphorus (BP) makes it to fill the gap in graphene. When studying the properties of BP more comprehensive, scientists have discovered that many twodimensional materials, such as tellurene, antimonene, bismuthene, indium selenide and tin sulfide, have similar structures and properties to black phosphorus thus called black phosphorus analogs. In this review, we briefly introduce preparation methods of black phosphorus and its analogs, with emphasis on the method of mechanical exfoliation (ME), liquid phase exfoliation (LPE) and chemical vapor deposition (CVD). And their characterization and properties according to their classification of singleelement materials and multi-element materials are described. We focus on the performance of passively mode-locked fiber lasers using BP and its analogs as saturable absorbers (SA) and demonstrated this part through classification of working wavelength. Finally, we introduce the application of BP and its analogs, and discuss their future research prospects.