Related Experiment Video
Updated: Feb 11, 2026
Synthesis of Core-shell Lanthanide-doped Upconversion Nanocrystals for Cellular Applications
Published on: November 10, 2017
Synthesis, screening and nanocrystals preparation of rhein amide derivatives
Lijiang Chen1,2,3, Jinfeng Zhang1, Jinghong Rong1
1a Department of Pharmaceutics, School of Pharmaceutical Sciences , Liaoning University , Shenyang , P.R. China.
Abstract:
Rhein (RH) has many bioactivities, but the application was limited of its poor solubility. The present study aimed to establish an efficient method for the synthesis of rhein amide derivatives (RAD) to increase the solubility and anti-tumour activity. RAD exhibited stronger anti-tumour activity than RH in MTT assay. The solubility and oil/water partition coefficient results indicated that rhein-phenylalanine and rhein-isoleucine have better absorption effect, which was consolidated in pharmacokinetic study. Then, rhein-phenylalanine and rhein-isoleucine were prepared into nanocrystals via the precipitation high-pressure homogenisation method. Additionally, the nanocrystals both displayed much higher dissolution profiles than the bulk drugs. Pharmacokinetics study indicated that the AUC0-∞ and Cmax of nanocrystals increased markedly (p < 0.01). However, the concentration of RH-Phe-NC was far less than RH-Ile-NC in plasma. Consequently, RH-Ile-NC was validated to be an applicable way to improve the bioavailability of RH, which owns a promising future in clinical application.
Related Concept Videos
01:29Preparation of Amides
The DCC-promoted synthesis of amides begins with the protonation of DCC by carboxylic acid. The protonation makes it a better acceptor. Next, the addition of carboxylate to the protonated carbodiimide gives a reactive acylating agent.
Subsequently, the amine acts as a nucleophile that attacks the acylating agent to form a tetrahedral intermediate. In the...
01:13Preparation of Amines: Reduction of Amides and Nitriles
Amides can be reduced to primary, secondary, and tertiary amines using catalytic hydrogenation, active metals like Fe,...
01:11Nomenclature of Carboxylic Acid Derivatives: Amides and Nitriles
The IUPAC and common names of amides are derived from the parent carboxylic acid, by replacing the suffix “oic acid” and “ic acid,” respectively, with “amide.” In the following example, the IUPAC name ethanamide is derived from ethanoic acid, and the common name, acetamide, is obtained from acetic acid.
01:28Preparation of 1° Amines: Gabriel Synthesis
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...
01:22Preparation of 1° Amines: Azide Synthesis
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...
01:28Amides to Carboxylic Acids: Hydrolysis
Acid-catalyzed hydrolysis:
Hydrolysis of amides under acidic conditions yields carboxylic acids. Since the reaction occurs slowly, hydrolysis requires the conditions of heat.
The mechanism begins with the protonation of the carbonyl oxygen by the acid catalyst. The protonation makes the amide carbonyl carbon more...