Regulating the NLO response of anthraquinone-supported thiourea-linked crown ether macrocycle by introducing metal cations: A DFT study

Recently, an anthraquinone-supported thiourea group linking a 1-aza-18-crown-6 macrocycle L has been the subject of extensive attention due to the perfect affinity towards metal cations. This work systematically researched the effects of different metal cations ([Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text]) on the second-order nonlinear optical (NLO) properties of macrocycle L by density functional theory (DFT). DFT calculations revealed that the values of first hyperpolarizabilities ([Formula: see text] decrease significantly when alkaline earth metal cations ([Formula: see text] and [Formula: see text]) were injected into macrocycle L due to the smaller charge transfer (CT) transition and larger transition energy. Conversely, the variations of [Formula: see text] values in alkali metal cations ([Formula: see text] and [Formula: see text] and transition metal cations ([Formula: see text] and [Formula: see text]) derivatives are not obvious compared to the [Formula: see text] value of macrocycle L. Therefore, the NLO properties of macrocycle can be effectively regulated by alkaline earth metal cations. Furthermore, we found that the [Formula: see text] value of anion-controlled complex Na(L)(ClO4) is larger than that of L*Na+ complex because the anion [Formula: see text] improves the planarity of anthraquinone-supported thiourea group leading to the enhancement of the CT ability. In addition, the influence of frequency-dependent on the first hyperpolarizabilities is weak for the current systems. Hence, we look forward to the conception of this work will offer a fundamental guideline and reference for further research for novel NLO materials.

Nanovesicles displaying functional linear and branched oligomannose self-assembled from sequence-defined Janus glycodendrimers

Cell surfaces are often decorated with glycoconjugates that contain linear and more complex symmetrically and asymmetrically branched carbohydrates essential for cellular recognition and communication processes. Mannose is one of the fundamental building blocks of glycans in many biological membranes. Moreover, oligomannoses are commonly found on the surface of pathogens such as bacteria and viruses as both glycolipids and glycoproteins. However, their mechanism of action is not well understood, even though this is of great potential interest for translational medicine. Sequence-defined amphiphilic Janus glycodendrimers containing simple mono- and disaccharides that mimic glycolipids are known to self-assemble into glycodendrimersomes, which in turn resemble the surface of a cell by encoding carbohydrate activity via supramolecular multivalency. The synthetic challenge of preparing Janus glycodendrimers containing more complex linear and branched glycans has so far prevented access to more realistic cell mimics. However, the present work reports the use of an isothiocyanate-amine “click”-like reaction between isothiocyanate-containing sequence-defined amphiphilic Janus dendrimers and either linear or branched oligosaccharides containing up to six monosaccharide units attached to a hydrophobic amino-pentyl linker, a construct not expected to assemble into glycodendrimersomes. Unexpectedly, these oligoMan-containing dendrimers, which have their hydrophobic linker connected via a thiourea group to the amphiphilic part of Janus glycodendrimers, self-organize into nanoscale glycodendrimersomes. Specifically, the mannose-binding lectins that best agglutinate glycodendrimersomes are those displaying hexamannose. Lamellar “raft-like” nanomorphologies on the surface of glycodendrimersomes, self-organized from these sequence-defined glycans, endow these membrane mimics with high biological activity.

Synthesis and Biological Activity of Some Novel (Oxazol-5-yl-phenyl)-thiourea Derivatives

Aims: Synthesis and biological evaluation of some [(5-oxazolyl)-phenyl]-thiourea derivatives as potential antiviral agents. Background: (5-Oxazolyl)-phenyl derivatives were derived from the design of mycophenolic acid structurally related analogues. The (5-oxazolyl)-phenyl fragment is an excellent composition for many novel structure compounds having good pharmaceutical properties, such as immunosuppressive, antiviral and anticancer. In the present study, we present combinations of thiourea group and (5-oxazolyl)-phenyl fragment. The antiviral activity, cytotoxicity and IMPDH activity of the title compounds were evaluated in vitro bioassay. Objective: [(5-Oxazolyl)-phenyl]-thiourea derivatives containing different substituted benzene rings were synthesized by introducing thiourea linker. All the synthesized derivatives were screened for their in vitro antiviral evaluation and inosine monophosphate dehydrogenase activity. Method: A series of [(5-oxazolyl)-phenyl]-thiourea derivatives were synthesized by the reaction of thiocarbonyldiimidazole with amines. This was an effective method for introducing the thiourea group in the (5-oxazolyl)-phenyl structure. All of the synthesized derivatives were screened for their in vitro antiviral activity against influenza A virus, coxsackievirus B3, herpes simplex virus type 1 and inosine monophosphate dehydrogenase activity. Result: The results of the screening revealed that compounds 4i, 4j, 4k, 7m, 7n and 7o showed comparable activity towards IMPDH compared the control drug. Compounds 4k, 4l, 7m and 7n exhibited potent activity towards both RNA virus influenza A virus, coxsackievirus B3 and DNA virus HSV-1 at low micromolar concentrations. The activities of most compounds directly linked to the substituted benzene ring by the thiourea group were superior to those of the compounds which had the methylene linkage. Conclusion: The in vitro biological assays indicated that most of target molecules having combinations of thiourea group and (5-oxazolyl)-phenyl fragment exhibited antiviral activity and IMPDH activity compared the control drugs.

Enhancement of physical endurance in animals by means of compounds with thiourea group (review of literature)

At the Department of Pharmacology of the S.M. Kirov Military Medical Academy, Saint Petersburg, Russia, a number of chemical compounds with thiourea group was synthesized and studied pharmacologically for some decades. Of them gutimin and amtizol are the most known for pharmacologists. They were the first antihypoxic drugs, passed clinical investigations and were approved for reanimatology practice. Bemithyl (bemaktor, metaprot) was another known drug used in clinical urgent practice as an antihypoxic drug, it was used in earthquake in Armenia (1988), in military practice in Afghanistan etc. Antihypoxic drugs were shown to possess polyvalent pharmacological activity. This review is devoted to original compounds synthesized at the Department of Pharmacology and containing pharmacophor thiourea group in mono-, bi- and tricyclic structures. The antihypoxic activity was revealed in majority of the compounds of this row. The influence of these compounds on physical activity and endurance in different situations has been considered in the article.

Asymmetric Michael addition reactions catalyzed by calix[4]thiourea cyclohexanediamine derivatives

A number of upper rim-functionalized calix[4]thiourea cyclohexanediamine derivatives have been designed, synthesized and used as catalysts for enantioselective Michael addition reactions between nitroolefins and acetylacetone. The optimal catalyst 2 with a mono-thiourea group exhibited good performance in the presence of water/toluene (v/v = 1:2). Under the optimal reaction conditions, high yields of up to 99% and moderate to good enantioselectivities up to 94% ee were achieved. Detailed experiments clearly showed that the upper rim-functionalized hydrophobic calixarene scaffold played an important role in cooperation with the catalytic center to the good reactivities and enantioselectivities.

Iodobenzene-Promoted Pd-Catalysed ortho-Directed C–H Activation: The Synthesis of Benzothiazoles via Intramolecular Coupling

A series of 2-aminobenzothiazoles were synthesized by a palladium-catalysed oxidative coupling with good yields (62–89%). Iodobenzene was found to be effective as an additive in this intramolecular C–S bond-formation reaction. The directing thiourea group attached to the aryl ring is essential for the activation of the ortho C–H bond.

Diafenthiuron: 1-tert-butyl-3-(2,6-diisopropyl-4-phenoxyphenyl)thiourea

The title compound, C23H32N2OS, is a thiourea-based insecticide. The dihedral angle between the phenyl ring and the diisopropyl benzene ring plane is 73.18 (6)°, while that between the plane of the thiourea group and the diisopropyl benzene ring is 86.00 (5)°. Disorder was modelled for the S atom and the two methyl C atoms of the isopropyl group over two sets of sites with an occupancy ratio of 0.742 (4):0.258 (4). In the crystal, N—H...S hydrogen bonds link adjacent molecules, formingR22(8) inversion dimers that pack into chains along theb-axis direction.

1-(4-Chlorobutanoyl)-3-(3-chlorophenyl)thiourea

The two independent molecules in the asymmetric unit of the title compound, C11H12Cl2N2OS, exhibit different conformations, with the benzene ring and the N2CS thiourea group forming dihedral angles of 87.40 (18) and 69.42 (15)°. An intramolecular N—H...O hydrogen bond is present in each molecule. Two further N—H...O hydrogen bonds link the independent molecules into a dimer. In the crystal, the dimers are linked by N—H...S and C—H...S hydrogen bonds, forming chains parallel to thecaxis.

5-(4-Fluorophenyl)-3-[5-methyl-1-(4-methylphenyl)-1H-1,2,3-triazol-4-yl]-4,5-dihydro-1H-pyrazole-1-carbothioamide

In the title compound, C20H19FN6S, the pyrazole ring has an envelope conformation, with the methine C atom being the flap atom. The dihedral angle between the least-squares plane through the pyrazole and triazole rings is 7.59 (9)°, and the triazole and attached benzene ring form a dihedral angle of 74.79 (9)°. The thiourea group is coplanar with the pyrazole ring [N—N—C—S torsion angle = −179.93 (11)°], which enables the formation of an intramolecular N—H...N hydrogen bond. In the crystal, inversion-related molecules associate via N—H...S hydrogen bonds and eight-membered {...HNCS}2 synthons feature in the crystal packing. These synthons are connected into supramolecular chains along the a axis via N—H...F hydrogen bonds, and the chains are consolidated into layers in the ab plane via C—H...S and C—H...F contacts.