Simple and Convenient Synthesis of 21‐Thioalkylether Derivatives of Methyl 16‐Prednisolone Carboxylates

The antedrug approach for corticosteroids has been described as a fundamentally sound approach for the development of safer anti‐inflammatory and anti‐asthmatic therapy. However, the derivatization of prednisolone and its congeners have been considered to be major pitfalls, because their syntheses are complicated by the presence of numerous carboxylate esters and hydroxyl functions in the steroid nucleus. A simple and direct synthesis of 21‐thioalkylether derivatives of methyl 16‐prednisolonecarboxylates is described. The 21‐mesylate of the methyl 16‐prednisolonecarboxylate and 9‐fluoro‐17‐dehydro methyl 16‐prednisolonecarboxylate were reacted with Na‐thioalkoxides to furnish the desired thioethers in good yields. A previously published method for the methanolysis of 16‐cyanoprednisolone to methylcarboxylate has been reexamined, and the conditions are explained clearly. The reaction conditions for all these reactions were critical.     

Inhibition effect of horehound (Marrubium vulgare L.) extract towards C38 steel corrosion in HCl solution

The corrosion inhibition properties of horehound (Marrubium vulgare L.) extract (HE) in 1 M hydrochloric acid medium was carried out using electrochemical methods (polarization curve and electrochemical impedance spectroscopy). Experiments were performed by concentration of the inhibitor and temperature effect. The results showed variation in inhibition performance of this plant extract. The Langmuir model was tested to describe the adsorption behavior of the inhibitor on the C38 steel surface. Some thermodynamic functions of dissolution processes were also determined.     

Synthesis of some new pyrimidine derivatives and evaluation of their anticancer and antibacterial activities

Starting from the reaction of ethyl cyanoacetate with thiourea and the appropriate aldehydes, a series of new pyrimidine derivatives were prepared. Ten selected pyrimidine derivatives were subjected to a screening system for the investigation of their antitumor potency against liver (HEPG2) cell line. The antitumor activity results indicated that most of the selected pyrimidine derivatives showed moderate growth inhibition activity against the tested cell line, but with varying intensities in comparison to the known anticancer drugs: 5-fluorouracil and doxorubicin. Some of the synthesized compounds were also tested for their antimicrobial activity against bacteria as well as fungal isolates.     

Three‐Dimensional Architectures Incorporating Stereoregular Donor–Acceptor Stacks

We report the synthesis of two [2]catenane‐containing struts that are composed of a tetracationic cyclophane (TC⁴⁺) encircling a 1,5‐dioxynaphthalene (DNP)‐based crown ether, which bears two terphenylene arms. The TC⁴⁺ rings comprise either 1) two bipyridinium (BIPY²⁺) units or 2) a BIPY²⁺ and a diazapyrenium (DAP²⁺) unit. These degenerate and nondegenerate catenanes were reacted in the presence of Cu(NO₃)₂?2.5 H₂O to yield Cu‐paddlewheel‐based MOF‐1050 and MOF‐1051. The solid‐state structures of these MOFs reveal that the metal clusters serve to join the heptaphenylene struts into grid‐like 2D networks. These 2D sheets are then held together by infinite donor–acceptor stacks involving the [2]catenanes to produce interpenetrated 3D architectures. As a consequence of the planar chirality associated with both the DNP and hydroquinone (HQ) units present in the crown ether, each catenane can exist as four stereoisomers. In the case of the nondegenerate (bistable) catenane, the situation is further complicated by the presence of translational isomers. Upon crystallization, however, only two of the four possible stereoisomers—namely, the enantiomeric RR and SS forms—are observed in the crystals. An additional element of co‐conformational selectivity is present in MOF‐1051 as a consequence of the substitution of one of the BIPY²⁺ units by a DAP²⁺ unit: only the translational isomer in which the DAP²⁺ unit is encircled by the crown ether is observed. The overall topologies of MOF‐1050 and MOF‐1051, and the selective formation of stereoisomers and translational isomers during the kinetically driven crystallization, provide evidence that weak noncovalent bonding interactions play a significant role in the assembly of these extended (super)structures.     

In search for chelating TAMLs (tetraamido macrocyclic ligands) with peripheral bidentate donor centers: a cobalt(III) complex of the 3,3′-(2,2′-bipyridindiyl)-tailed TAML

The synthesis of 1,2-C₆H₄(NHCOCMe₂NHCO)₂-3,3′-(2,2′-bpy) (3), a TAML (tetraamido macrocyclic ligand) incorporating the peripheral 2,2′-bipyridine unit, is described. Its geometry after optimization by density functional theory (DFT) indicated a rather unfavorable conformation of four N–H amide units for forming macrocyclic transition metal complexes. This explains why the iron(III) derivative of 3 could not be obtained even after deprotonation of the N–H bonds by n-BuLi. Nevertheless, the macrocyclic complex of Co^III was synthesized in moderate yield, characterized, and explored by DFT. Our data suggest a strongly distorted square-planar geometry of the macrocyclic complex between Co^III and 3. The dihedral angle between the pyridine rings equals 80° ruling out the possibility of metal chelation by the bipyridine unit.     

Synthesis,Aromaticity, and Application of peri-Pentacenopentacene: Localized Representation of Benzenoid Aromatic Compounds

We report the synthesis and optoelectronic properties of TIPS-peri-pentacenopentacene ( TIPS-PPP ), a vertical extension of TIPS-pentacene ( TIPS-PEN ) and a low-band-gap material with remarkable stability. We found the synthetic conditions to avoid the competition between 1,2- and 1,4-addition of lithium acetylide on the large aromatic dione. The high stability of TIPS-PPP is due to the peri-fusion which increases the aromaticity by generating two localized aromatic sextets that are flanked with 2 diene fragments, similar to two fused-anthracenes. Like TIPS-PEN , TIPS-PPP shows the archetypal 2D brickwall motif in crystals with a larger transfer integral and smaller reorganization energy. The high mobility of up to 1 cm² V^?1 s^?1 was obtained in an organic field-effect transistor fabricated by a wet process. Also, TIPS-PPP was used as a near-infrared (NIR) emitter for NIR organic-light-emitting-diode devices resulting in a high external quantum efficiency at 800 nm.     

Synthesis and Antifungal Activity of New Valine-Azole Hybrids

Russian Journal of General Chemistry - Herein, the synthesis of six new derivatives via molecular hybridization of imidazole or triazole and valine methyl ester as a rational design for accessing...     

The Effects of Food on Cannabidiol Bioaccessibility

Cannabidiol (CBD) is a hydrophobic non-psychoactive compound with therapeutic characteristics. Animal and human studies have shown its poor oral bioavailability in vivo, and the impact of consuming lipid-soluble CBD with and without food on gut bioaccessibility has not been explored. The purpose of this research was to study the bioaccessibility of CBD after a three-phase upper digestion experiment with and without food, and to test lipase activity with different substrate concentrations. Our results showed that lipase enzyme activity and fatty acid absorption increased in the presence of bile salts, which may also contribute to an increase in CBD bioaccessibility. The food matrix used was a mixture of olive oil and baby food. Overall, the fed-state digestion revealed significantly higher micellarization efficiency for CBD (14.15 ± 0.6% for 10 mg and 22.67 ± 2.1% for 100 mg CBD ingested) than the fasted state digestion of CBD (0.65 ± 0.7% for 10 mg and 0.14 ± 0.1% for 100 mg CBD ingested). The increase in bioaccessibility of CBD with food could be explained by the fact that micelle formation from hydrolyzed lipids aid in bioaccessibility of hydrophobic molecules. In conclusion, the bioaccessibility of CBD depends on the food matrix and the presence of lipase and bile salts.     

Synthesis,Characterization and Biological Evaluation of New 3,5-Disubstituted-Pyrazoline Derivatives as Potential Anti-Mycobacterium tuberculosis H37Ra Compounds

A total of fourteen pyrazoline derivatives were synthesized through cyclo-condensation reactions by chalcone derivatives with different types of semicarbazide. These compounds were characterized by IR, 1D-NMR (¹H, ¹³C and Distortionless Enhancement by Polarization Transfer - DEPT-135) and 2D-NMR (COSY, HSQC and HMBC) as well as mass spectroscopy analysis (HRMS). The synthesized compounds were tested for their antituberculosis activity against Mycobacterium tuberculosis H37Ra in vitro. Based on this activity, compound 4a showed the most potent inhibitory activity, with a minimum inhibitory concentration (MIC) value of 17 μM. In addition, six other synthesized compounds, 5a and 5c–5g, exhibited moderate activity, with MIC ranges between 60 μM to 140 μM. Compound 4a showed good bactericidal activity with a minimum bactericidal concentration (MBC) value of 34 μM against Mycobacterium tuberculosis H37Ra. Molecular docking studies for compound 4a on alpha-sterol demethylase was done to understand and explore ligand–receptor interactions, and to hypothesize potential refinements for the compound.