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Carbon quantum dots (CQDs) are a new carbon-based nanomaterial that has attracted tremendous attention due to their excellent fluorescent properties, chemical stability, water solubility, and biocompatibility features. Here, fluorescent CQDs synthesized by a green nanoarchitectonic method using Cinchona Pubescens Vahl extract were evaluated as drug nanocarriers for carboplatin (CBP) delivery. The characterization methods showed CQDs with semispherical shapes and sizes around 5 nm, temperature- and pH-dependent functional groups that interact with the CBP molecule adding specificity to the drug-delivery system. Based on the load efficiency results, it seems that the CQDs can carry almost 100 μg of carboplatin for every 1 mg of CQDs. This is possible due to the self-assembly process that takes place through the interaction between the protonation/deprotonation functional groups of CQDs and the hydrolyzed CBP molecule. Through this process, it is created spherical nanoparticles with an average size of 77.44 nm. The CQDs-CBP nanoparticles release the drug through a diffusion-controlled release mechanism where the acidic media is preferred, and the EPR effect also plays a helpful role. Besides, the viability test shows that the CQDs have almost null cytotoxicity suggesting that they could be used as a promising cancer treatment, improving the efficiency of cell internalization and significantly increasing their drug delivery., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The enantioselective separation of newly synthesized fluorine-substituted β-phenylalanines has been performed utilizing Cinchona alkaloid-based ion-exchanger chiral stationary phases. Experiments were designed to study the effect of eluent composition, counterion content, and temperature on the chromatographic properties in a systematic manner. Mobile phase systems containing methanol or mixtures of methanol and acetonitrile together with acid and base additives ensured highly efficient enantioseparations. Zwitterionic phases [Chiralpak ZWIX (+) and ZWIX(-)] were found to provide superior performance compared to that by the anion-exchangers (Chiralpak QN-AX and QD-AX). A detailed thermodynamic characterization was also performed by employing van't Hoff analysis. Using typical liquid chromatographic experimental conditions, no marked effect of the flow rate could be observed on the calculated thermodynamic parameters. In contrast, a clear tendency has been revealed about the effect of the eluent composition on the thermodynamics for the zwitterionic phases., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier B.V.)

Selenium-containing amino acids are valuable targets but methods for the stereoselective α-selenation of simple amino acid precursors are rare. We herein report the enantioselective electrophilic α-selenation of azlactones (masked α-amino acid derivatives) and isoxazolidin-5-ones (masked β-amino acids) using Cinchona alkaloids as easily accessible organocatalysts. A variety of differently substituted derivatives was accessed with reasonable levels of enantioselectivities and further studies concerning the stability and suitability of these compounds for further manipulations have been carried out as well.

Organocatalysis has unique modes of activation, mild reaction conditions, and good catalyst structural amenability. The integration of green techniques such as catalyst recovery and one-pot reactions makes organocatalysis more efficient and attractive. Presented in this article are the recyclable cinchona alkaloid-catalyzed reactions including fluorination and Michael addition-initiated cascade reactions in asymmetric synthesis of functionalized compounds of biological interest.