In Silico Study and Excito-Repellent Activity of Vitex negundo L. Essential Oil against Anopheles gambiae

(1) Background: Essential oil from Vitex negundo is known to have repellent and insecticidal properties toward the Anopheles gambiae and this is linked to its monoterpene and sesquiterpene content. In this work, an effort is made to delineate the constitution of V. negundo essential oil (VNEO) and their interaction with odorant-binding proteins (OBPs) of A. gambiae and hence access its repellent efficiency as cost-effective and safer malaria vector control alternatives. (2) Methods: Anopheles species authentication was performed by genomic DNA analysis and was subjected to behavioral analysis. GC-MS profiling was used to identify individual components of VNEO. Anopheles OBPs were obtained from the RCSB protein data bank and used for docking studies. Determination of ligand efficiency metrics and QSAR studies were performed using Hyper Chem Professional 8.0.3, and molecular dynamics simulations were performed using the Desmond module. (3) Results: GC-MS analysis of VNEO showed 28 compounds (monoterpenes, 80.16%;sesquiterpenes, 7.63%;and unknown constituents, 10.88%). The ligand efficiency metrics of all four ligands against the OBP 7 were within acceptable ranges. β-selinene (−12.2 kcal/mol), β-caryophellene (−9.5 kcal/mol), sulcatone (−10.9 kcal/mol), and α-ylangene (−9.3 kcal/mol) showed the strongest binding affinities for the target proteins. The most stable hydrophobic interactions were observed between β-selinene (Phe111 and Phe120), Sulcatone (Phe54 and Phe120), and α-ylangene (Phe111), while only sulcatone (Tyr49) presented H-bond interactions in the simulated environment. (4) Conclusions: Sulcatone and β-caryophyllene presented the best log p values, 6.45 and 5.20, respectively. These lead phytocompounds can be used in their purest as repellent supplement or as a natural anti-mosquito agent in product formulations.

Synthesis and Antiviral Properties of Camphor-Derived Iminothiazolidine-4-Ones and 2,3-Dihydrothiazoles.

A set of heterocyclic products was synthesized from natural (+)-camphor and semi-synthetic (-)-camphor. Then, 2-Imino-4-thiazolidinones and 2,3-dihydrothiazoles were obtained using a three-step procedure. For the synthesized compounds, their antiviral activity against the vaccinia virus and Marburg virus was studied. New promising agents active against both viruses were found among the tested compounds.

Source appointment of volatile organic compounds and evaluation of anthropogenic monoterpene emission estimates in Atlanta, Georgia

Emissions of monoterpenes from volatile chemical products (VCPs) have been shown to contribute substantially to secondary organic aerosol (SOA) formation in a number of cities across the US. In the southeast US (SE US), monoterpenes are the dominant precursor to SOA production. Previous studies have assumed that monoterpenes are primarily biogenic in origin. We examine that assumption here using a total of nine months of volatile organic compound (VOC) observations spanning across 2020 and 2021 which are made via proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) in Atlanta, Georgia. The dataset is resolved via non-negative matrix factorization (NNMF) into two biogenic, four anthropogenic, and two secondary factors. NNMF results show that VCP sources contribute to 0.28 ± 0.17 ppb of monoterpenes, or about 26% of all monoterpenes in the summer and 53% in the winter. Interannual comparison suggest minimum impact of the COVID-19 pandemic on atmospheric VOC composition in Atlanta during the second half of 2020. Comparison of NNMF anthropogenic monoterpenes-to-benzene ([Manthro/B]) and anthropogenic-to-total monoterpenes ([Manthro/MT]) ratios with emission ratios in the National Emission Inventory 2016v1 modeling platform (NEI16) and Fuel-Based Inventory of Vehicle Emissions and Volatile Chemical Products (FIVE-VCP) suggests that NEI16 underestimates anthropogenic monoterpene emissions by as much as 70% in Atlanta. FIVE-VCP estimates higher anthropogenic monoterpene emissions than NEI16 and provides better agreement with observations, especially during winter months. Anthropogenic monoterpenes may impact as much as 17% of total summertime SOA formation in Atlanta and the SE US, with potential additional influence of limonene from anthropogenic monoterpene sources due to its higher reactivity and SOA yield potential.

d-Limonene challenging anti-inflammatory strategies

Aging and senescence seem linked by fundamental, yet still ill-understood mechanisms. For this reason, this paper expands on the background of a discovery that still has to gain acknowledgement by public policies to find its place in a market hungry for a non-toxic anti-inflammatory molecule. Reversibility of the senescent cell phenotype was the starting-point of a research that turned out to identify the monoterpenes class of molecules as able to achieve this goal. Indeed, these compounds strongly inhibit the circulation of pro-inflammatory cytokines as well as the expression of cell-anchored adhesive molecules, liable to recruit activated immune cells. Starting from cell-based studies, the pre-clinical and clinical assays reported here confirmed the capacities of these compounds, both in experimental colitis, dermatitis and stress murine models, but also inhuman studies addressing the latent chronic inflammation associated with age or psoriasis. Last but not least, because of an intriguing mechanism yet not totally unraveled and most probably depending on the effect of monoterpenes on gut microbiota strains-apart from assuring a constant gut barrier repair-a consistent Quality of Life amelioration, i.e. mood modulation probably due to enhanced dopamine secretion was also demonstrated. Finally, after entering in more pharmacologic considerations on toxicity and bio-availability studies as for the safety of this class of compounds, a strategic positioning of the precious role of anti-inflammatory drugs in a market that has yet to overcome common chronic diseases because of their predisposing condition not only to cancer and neuro-degenerative diseases but now also to COVID-19 is envisioned.

Computational Study on SARS-CoV-2 Viral Protein Interaction with Natural Compounds of Coriandrum sativum L

The SARS-COV-2 become a global pandemic causing significant mortality and morbidity all around the world. Until now there are no effective drugs or vaccines available against SARS-CoV-2. In this regard, medicinal plants captured enormous attention, as natural products are safe and easily available bioactive compounds in which maintain the disease homeostasis. Amongst, natural compounds of Coriandrum sativum L (coriander) have proved to be effective in viral infection, as they possess antiviral and anti-inflammatory activities. However, molecular regulation of such bioactivities remains elusive. We performed molecular docking analyses using AutoDock Vina to investigate the potential inhibitory activities of the seven natural compounds of coriander (limonene, geraniol, gamma-terpinene, geranyl acetate, caffeic acid, ferulic acid, gallic acid) against the essential proteins of SARS-CoV-2 (main protease (Mpro), nonstructural protein-13 (NSP-13), Papaine like protease (PLpro) and RNA dependent RNA polymerase(RdRp)) together with two main inflammatory proteins ( cyclooxygenase-2 (COX-2) and interleukin-6 (IL- 6)). The empirical and knowledge-based algorithm of AutoDock Vina was utilized to calculate free binding energies of ligands and BIOVIA discovery studio 2020 tool was used to visualize docking results. Our results reveal that gallic acid has a strong binding affinity to Mpro (-5.8 kcal/mol) and NSP13 (-7.0 kcal/mol) forming five and three conventional hydrogen bonds respectively. Further, caffeic acid demonstrates a higher binding affinity to PLpro (-7.4 kcal/mol) and RdRp (-6.7 kcal/mol) while securing four and three conventional hydrogen bonds respectively. Interestingly, both COX-2 (-6.9 kcal/mol) and IL-6 (-6.3 kcal/mol) also show a higher binding affinity to gallic acids. In addition, gallic acid stabilizes three conventional hydrogen bonds with COX-2 whereas it forms four conventional hydrogen bonds with IL-6. Further, drug-likeness properties of gallic acid and caffeic acid were determined using the SWISSADME server. Our results show that both gallic acid and caffeic do not violate Lipinski rules suggesting these compounds as new antiviral and anti-inflammatory drug candidates for SARS-CoV-2. © 2022 IEEE.

Volatile molecules for COVID-19: A possible pharmacological strategy?

COVID-19 is a novel coronavirus disease with a higher incidence of bilateral pneumonia and pleural effusion. The high pulmonary tropism and contagiousness of the virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), have stimulated new approaches to combat its widespread diffusion. In developing new pharmacological strategies, the chemical characteristic of volatility can add therapeutic value to the hypothetical drug candidate. Volatile molecules are characterized by a high vapor pressure and are consequently easily exhaled by the lungs after ingestion. This feature could be exploited from a pharmacological point of view, reaching the site of action in an uncommon way but allowing for drug delivery. In this way, a hypothetical molecule for COVID-19 should have a balance between its lung exhalation characteristics and both antiviral and anti-inflammatory pharmacological action. Here, the feasibility, advantages, and disadvantages of a therapy based on oral administration of possible volatile drugs for COVID-19 will be discussed. Both aerosolized antiviral therapy and oral intake of volatile molecules are briefly reviewed, and an evaluation of 1,8-cineole is provided in view of a possible clinical use and also for asymptomatic COVID-19.