Molecular Basis of the Therapeutical Potential of Clove (Syzygium aromaticum L.) and Clues to Its Anti-COVID-19 Utility

The current COronaVIrus Disease 19 (COVID-19) pandemic caused by SARS-CoV-2 infection is enormously affecting the worldwide health and economy. In the wait for an effective global immunization, the development of a specific therapeutic protocol to treat COVID-19 patients is clearly necessary as a short-term solution of the problem. Drug repurposing and herbal medicine represent two of the most explored strategies for an anti-COVID-19 drug discovery. Clove (Syzygium aromaticum L.) is a well-known culinary spice that has been used for centuries in folk medicine in many disorders. Interestingly, traditional medicines have used clove since ancient times to treat respiratory ailments, whilst clove ingredients show antiviral and anti-inflammatory properties. Other interesting features are the clove antithrombotic, immunostimulatory, and antibacterial effects. Thus, in this review, we discuss the potential role of clove in the frame of anti-COVID-19 therapy, focusing on the antiviral, anti-inflammatory, and antithrombotic effects of clove and its molecular constituents described in the scientific literature.     

Quantification through TLC‐densitometric analysis,repellency and anticholinesterase activity of the homemade extract of Indian cloves

The rise of the mosquitoes‐transmitted diseases, like dengue, zika and chikungunya in Brazil in the last years has increased concerns on protection against mosquitoes bites. However, the prohibitive prices of the commercially available repellents for the majority of the Brazilian population has provoked a search for cheaper solutions, like the use of the homemade ethanolic extract of Indian clove (Syzygium aromaticum L.) as repellent, which has been reported as quite efficient by the local press. In order to verify this, we performed here the quantification of the main components of this extract through high‐performance thin‐layer chromatography (HPTLC)–densitometry and evaluated its efficiency as a repellent and its acetylcholinesterase (AChE) inhibition capacity. Our results have proved HPTLC–densitometry as an efficient and appropriate method for this quantification and confirmed the repellency activity, as well as its capacity of AChE inhibition.     

Crystal Structure Determination for Eugenyl Acetate

Abstract  Essential oils are good candidates for the substitution of conventional medicinal treatments. Many articles and patents for their use have been published in recent years. The most attractive aspects of using essential oils as medicaments are their natural source and rapid permeability. Besides permeability, the solubility behavior of a drug is a key determinant of its oral bioavailability. Based on these characteristics, the aim of this study was to synthesize an essential oil derivative compound, using the raw oil extracted from Syzygium aromaticum L., without previous purification. The Eugenol molecular modification may diminish the problems of water solubility and bioavailability. The Eugenyl acetate molecule was characterized and its molecular modification investigated, including its structural properties and stereochemistry. This study was performed applying techniques, such as carbon-13 nuclear magnetic resonance spectroscopy (C-13 NMR), X-ray crystallographic analysis (XRD), powder X-ray diffraction (PXRD) and microscopic recording. Graphical Abstract  Eugenol and its structure have been known for many years, where as Eugenyl acetate’s structure has never been elucidated nor confirmed until now.