Synthesis of Tetrahydro-β-carboline Derivatives under Electrochemical Conditions in Deep Eutectic Solvents

In this work, a novel, green, and atom-efficient method for the synthesis of tetrahydro-β-carboline derivatives using electrochemistry (EC) in deep eutectic solvents (DESs) was reported. The EC reaction conditions were optimized to achieve the highest yield. The experimental design was also optimized to perform the reaction in a two-step, one-pot reaction, thereby the time, workup procedure, and solvents needed were all reduced. The new approach achieved our strategy as EC served to decrease the time of reaction, eliminate the use of hazardous catalysts, and lower the energy required for the synthesis of the targeted compounds. On the other side, DESs were used as catalysts, in situ electrolytes, and noninflammable green solvents. The scope of the reaction was investigated using different aromatic aldehydes. Finally, the scalability of the reaction was investigated using a gram-scale reaction that afforded the product in an excellent yield.

The use of ultrasound in the South Cone region. Advances in organic and inorganic synthesis and in analytical methods

In organic and inorganic synthesis and in analytical methods, an external conventional heat source is usually applied to carry out a chemical reaction at a high temperature, or an extraction procedure. In the last decades, the use of ultrasound as an alternative energy source has become an interesting field of research in these topics in the South Cone region (Argentina, Chile, Uruguay, Southern Brazil and Paraguay). For this reason, the present review, covering the period 2009 to mid-2021, is a compilation of ultrasound-assisted synthetic and analytical methodologies.

Design and synthesis of β-carboline and combretastatin derivatives as anti-neutrophilic inflammatory agents

A series of β-carboline derivatives was synthesized by the Pictet-Spengler reaction with or without the combretastatin skeleton. The structures of these derivatives were elucidated by spectroscopic techniques. All synthesized compounds were evaluated for their anti-inflammatory activity in human neutrophils. Among them, two compounds, NTU-228 and HK-72, showed significant inhibitory effects on N-formyl-Met-Leu-Phe (fMLF)-induced superoxide anion generation in human neutrophils with IC₅₀ values of 5.58 ± 0.56 and 2.81 ± 0.07 μM, respectively. Neither NTU-228 nor HK-72 caused cytotoxicity in human neutrophils. NTU-228 inhibited the phosphorylation of p38 mitogen-activated protein kinase (MAPK) and intracellular Ca²⁺ levels ([Ca²⁺]_i) in fMLF-activated human neutrophils. Additionally, HK-72 selectively inhibited the fMLF-induced phosphorylation of p38 and [Ca²⁺]_i in human neutrophils. Molecular docking analysis showed a favorable binding affinity of HK-72 toward p38 MAPK. The proposed synthetic strategy opens up new opportunities for the synthesis of novel potential candidates against neutrophilic inflammation.