Anthracene carboxyimides and their dimers

Soluble anthracenedicarboxyimides have been prepared and undergo a photodimerisation of the anthracene skeleton, which is important for their application as antitumour agents, such as azonafides. Reaction under strongly alkaline conditions causes C-C coupling to form soluble dimeric fluorescent dyes with bathochromic absorption and fluorescence in the NIR region. These dyes are of special interest because of their absorption at longer wavelengths.     

Enantioseparation and impurity determination of the enantiomers of novel phenylethanolamine derivatives by high performance liquid chromatography on amylose stationary phase

Simple and efficient analytical HPLC methods using Chiralpak AS-H as chiral stationary phase were developed for direct enantioseparation of 11 novel phenylethanolamine derivatives. The chromatographic experiments were performed in normal phase mode with n-hexane–ethanol–triethylamine (TEA) as mobile phase. Excellent baseline enantioseparation was obtained for most of compounds. The effects of the concentration of organic modifiers and column temperature were studied for the enantiomeric separation. The mechanism of chiral recognition was discussed based on the relationship between the thermodynamic parameters and structures of compounds. It was found that the enantioseparations were all enthalpy driven, and the tert-butyl groups of compounds had significant influence on the chiral recognition. Trantinterol enantiomers were resolved (R_s = 2.73) within 14 min using n-hexane–ethanol–TEA (98:2:0.1, v/v/v) as mobile phase with a flow rate of 0.8 mL min⁻¹ at 30 °C. The optimized method was validated for linearity, precision, accuracy and stability in solution and proved to be robust. The limits of detection (LOD) and quantification (LOQ) for (+)-trantinterol were 0.15 and 0.46 μg mL⁻¹. The method was applied for enantiomeric impurity determination of (−)-trantinterol bulk samples.     

Fe3+‐Montmorillonite: An Efficient Solid Catalyst for One‐Pot Synthesis of Decahydroacridine Derivatives

Fe³⁺‐montmorillonite was used as a solid acidic catalyst for the synthesis of decahydroacridine derivatives through the condensation of aromatic aldehydes, dimedone and aniline in ethanol. The influence of reaction time, reaction temperature, and the amount of catalyst were studied. All the compounds were characterized by IR, Mp, ¹H NMR and ¹³C NMR analysis.     

2，7′-(乙烯基)-二-8-羟基喹啉及其金属有机配合物的密度泛函和自然键轨道理论计算

采用密度泛函理论(DFT),在B3LYP/6-31G水平上对2,7′-(乙烯基)-二-8-羟基喹啉(2,7′-Ethq₂)及其3种金属M(M=Zn,Mg,Be)有机配合物M(2,7′-Ethq₂)₂的结构进行了全优化,并用ZINDO和TDDFT方法计算了它们的吸收光谱。同时,利用自然键轨道理论(NBO)对分子内氢键进行了分析。结果表明,光谱计算值与实验值基本符合,该类化合物均具有较大的电子亲和能,改变中心金属原子对配合物吸收光谱性质影响不大。和2,7′-Ethq₂相比,M(2,7′-Ethq₂)₂的吸收光谱产生明显红移。2,7′-Ethq₂及其M(2,7′-Ethq₂)₂分子内存在较强的氢键,氢键与环上的碳原子形成五元环,分子内氢键的存在使分子的稳定性增加。     

Increasing Complexity in Adamantyl Thioethers Characterized by Rotational Spectroscopy

We report on the synthesis and characterization using high-resolution rotational spectroscopy of three bulky thioethers that feature an adamantyl group connected to a sulfur atom. Detailed experimental and theoretical structures are provided and compared with the 1,1′-diadamantyl ether. In addition, we expand on previous findings concerning microsolvation of adamantyl derivatives by investigating the cluster formation between these thioethers and a water molecule. The investigation of such clusters provides valuable insights into the sulfur-centered hydrogen bonding in thioethers with increasing size and steric repulsion.     

In silico study of novel niclosamide derivatives,SARS-CoV-2 nonstructural proteins catalytic residue-targeting small molecules drug candidates

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)-mediated coronavirus disease 2019 (COVID-19) infection remains a global pandemic and health emergency with overwhelming social and economic impacts throughout the world. Therapeutics for COVID-19 are limited to only remdesivir; therefore, there is a need for combined, multidisciplinary efforts to develop new therapeutic molecules and explore the effectiveness of existing drugs against SARS-CoV-2. In the present study, we reported eight (SCOV-L-02, SCOV-L-09, SCOV-L-10, SCOV-L-11, SCOV-L-15, SCOV-L-18, SCOV-L-22, and SCOV-L-23) novel structurally related small-molecule derivatives of niclosamide (SCOV-L series) for their targeting potential against angiotensin-converting enzyme-2 (ACE2), type II transmembrane serine protease (TMPRSS2), and SARS-COV-2 nonstructural proteins (NSPs) including NSP5 (3CLpro), NSP3 (PLpro), and RdRp. Our correlation analysis suggested that ACE2 and TMPRSS2 modulate host immune response via regulation of immune-infiltrating cells at the site of tissue/organs entries. In addition, we identified some TMPRSS2 and ACE2 microRNAs target regulatory networks in SARS-CoV-2 infection and thus open up a new window for microRNAs-based therapy for the treatment of SARS-CoV-2 infection. Our in vitro study revealed that with the exception of SCOV-L-11 and SCOV-L-23 which were non-active, the SCOV-L series exhibited strict antiproliferative activities and non-cytotoxic effects against ACE2- and TMPRSS2-expressing cells. Our molecular docking for the analysis of receptor-ligand interactions revealed that SCOV-L series demonstrated high ligand binding efficacies (at higher levels than clinical drugs) against the ACE2, TMPRSS2, and SARS-COV-2 NSPs. SCOV-L-18, SCOV-L-15, and SCOV-L-09 were particularly found to exhibit strong binding affinities with three key SARS-CoV-2’s proteins: 3CLpro, PLpro, and RdRp. These compounds bind to the several catalytic residues of the proteins, and satisfied the criteria of drug-like candidates, having good adsorption, distribution, metabolism, excretion, and toxicity (ADMET) pharmacokinetic profile. Altogether, the present study suggests the therapeutic potential of SCOV-L series for preventing and managing SARs-COV-2 infection and are currently under detailed investigation in our lab.     

Synthesis and liquid crystalline behaviour of substituted (E)-phenyl-4-(phenyldiazenyl) benzoate derivatives and their photo switching ability

Azobenzene derivatives containing phenyl/4-halogen-phenyl 4-{(E)-[4-(pent-4-en-1-yloxy)phenyl]diazenyl}benzoate group with different electronegative substituent (H, F, Cl, Br and I) at other end was synthesised. These azo-based benzoate derivatives have been characterised by FTIR, ¹H-NMR, ¹³C-NMR, elemental analyser, POM and UV-Vis spectroscopy. Photosaturation at 358 nm obtained after 82 s of UV irradiation and the longest thermal back relaxation time of 45 h recorded by UV-Vis. The azo derivative could be possible photolock under UV light, as observed by the improved thermal back relaxation time. The resulting photolockable chain of azobenzene might prove valuable in the development of optical device application. These azobenzene moieties also exhibit liquid crystalline behaviour with respect to the halogen substitution as an electron withdrawing group shows that strong structure property relationship exists among them.     

Noncovalent Interaction of Graphene with Heterocyclic Compounds: Benzene,Imidazole, Tetracene,and Imidazophenazines

Noncovalent functionalization of graphene with organic molecules offers a direct route to multifunctional modification of this nanomaterial, leading to its various possible practical applications. In this work, the structures of hybrids formed by linear heterocyclic compounds such as imidazophenazine (F1) and its derivatives (F2‐F4) with graphene and the corresponding interaction energies are studied by using the DFT method. Special attention is paid to the hybrids where the attached molecule is located along the graphene zigzag ( G_ZZ) and armchair ( G_AC ) directions. The interaction energies corresponding to the graphene hybrids of the F1‐F4 compounds for the two directions are found to be distinct, while tetracene (being a symmetrical molecule) shows a small difference between these binding energies. It is found that the back‐side CH₃ and CF₃ groups have an important influence on the arrangements of F1 derivatives on graphene and on their binding energies. The contribution of the CF₃ group to the total binding energy of the F3 molecule with graphene is the largest (3.4 kcal mol^?1) (the G_ZZ direction) while the CH₃ group increases this energy of F2 only by 2.0 kcal mol^?1 (the G_AC direction). It is shown that replacing the carbons with other atoms or adding a back‐side group enables one to vary the polarizability of graphene.