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Preparation of Enantiopure Non-Activated Aziridines and Synthesis of Biemamide B, D, and epiallo-Isomuscarine
Published on: June 13, 2022
(+)-Usnic acid enamines with remarkable cicatrizing properties
Michela Bruno1, Beatrice Trucchi, Bruno Burlando
1Dipartimento di Chimica, Universita' degli Studi di Milano, via C. Golgi 19, 20133 Milano, Italy.
Bioorganic & Medicinal Chemistry
|February 26, 2013
Summary
Researchers synthesized new usnic acid derivatives to improve wound healing. Compounds 8 and 9 showed significant wound repair properties with low cytotoxicity, indicating potential for skin preparations.
Area of Science:
- Natural Product Chemistry
- Dermatology
- Pharmacology
Background:
- Wound healing is crucial in various medical conditions, necessitating novel therapeutic agents.
- (+)-Usnic acid, a lichen compound, exhibits bacteriostatic and antioxidant properties, and promotes keratinocyte wound closure.
- Existing treatments for wound repair can be limited, driving the search for new chemical entities.
Purpose of the Study:
- To design and synthesize novel usnic acid derivatives (enamines).
- To evaluate the in vitro and in vivo wound healing potential of these new compounds.
- To identify derivatives with enhanced efficacy and safety for dermatological applications.
Main Methods:
- Synthesis of usnic acid enamines (compounds 2-11) via nucleophilic attack on the enolized 1,3 diketone.
- In vitro assays to assess cytotoxicity and wound closure effects.
- In vivo studies to evaluate the wound repair performance of promising candidates.
Main Results:
- Several usnic acid enamines were successfully synthesized.
- Compounds 8 and 9 demonstrated significant wound healing activity.
- These compounds exhibited low cytotoxicity, suggesting a favorable safety profile.
Conclusions:
- Usnic acid enamines represent a promising class of compounds for wound healing.
- Compounds 8 and 9 are potential candidates for wound repair and anti-aging skin formulations.
- Further investigation into these derivatives could lead to advanced dermatological treatments.
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Primary amines react with carbonyl compounds—aldehydes and ketones—to generate imines. Imines consist of a C=N double bond and are named Schiff bases after its discoverer—the German chemist Hugo Schiff. On the other hand, secondary amines react with carbonyl compounds to give enamines. In enamines, the presence of a C=C double bond adjacent to the nitrogen atom leads to the delocalization of the lone pair.
01:11Nomenclature of Carboxylic Acid Derivatives: Amides and Nitriles
Naming Amides
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.
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.
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Enamine formation involves the addition of carbonyl compounds to a secondary amine through a series of reactions. The mechanism begins with the generation of carbinolamine, a nucleophilic attack followed by several proton transfer reactions. The hydroxyl group of the carbinolamine is converted into water to make a better leaving group that can push the reaction forward by eliminating a water molecule. In enamine formation, the last step involves the abstraction of a proton from the α carbon to...
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01:19Types of Enols and Enolates
Aldehydes and ketones form enols, although only about 1% of the enol is present at the equilibrium for simple monocarbonyl compounds. The enol form is undetectable for acetaldehyde, present as only 1.5 × 10−4 % of acetone, and present as only 1.2% of cyclohexanone. Two kinds of regioisomeric enols are possible for unsymmetrical ketones, and their net composition is 1% at equilibrium. This instability is due to the lower bond energy of C=C than the C=O group. The additional instability of enols...
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