Structural, Hirshfeld, spectroscopic, quantum chemical and molecular docking studies on 6b′, 7′, 8′, 9′-Tetrahydro-2H,6′H-spiro[acenaphthylene-1,11′-chromeno [3,4-a]pyrrolizine]-2,6′(6a′H,11a′H)-dione

In Silico Drug Design and Analysis of Dual Amyloid-Beta and Tau Protein-Aggregation Inhibitors for Alzheimer's Disease Treatment

Alzheimer's disease (AD) is a progressive and irreversible neurodegenerative disorder that gradually leads to the state of dementia. The main features of AD include the deposition of amyloid-beta peptides (Aβ), forming senile plaques, and the development of neurofibrillary tangles due to the accumulation of hyperphosphorylated Tau protein (p-tau) within the brain cells. In this report, seven dual-inhibitor molecules (L_1-7) that can prevent the aggregation of both Aβ and p-tau are suggested. The drug-like features and identification of the target proteins are analyzed by the in silico method. L_1-7 show positive results in both Blood-Brain Barrier (BBB) crossing and gastrointestinal absorption, rendering to the results of the permeation method. The molecular docking test performed for L_1-7 shows binding energies in the range of -4.9 to -6.0 kcal/mol towards Aβ, and -4.6 to -5.6 kcal/mol for p-tau. The drug's effectiveness under physiological conditions is assessed by the use of solvation models on the investigated systems. Further, the photophysical properties of L_1-3 are predicted using TD-DFT studies.

Natural Compounds as DPP-4 Inhibitors: 3D-Similarity Search, ADME Toxicity, and Molecular Docking Approaches

Type 2 diabetes mellitus is one of the most common diseases of the 21st century, caused by a sedentary lifestyle, poor diet, high blood pressure, family history, and obesity. To date, there are no known complete cures for type 2 diabetes. To identify bioactive natural products (NPs) to manage type 2 diabetes, the NPs from the ZINC15 database (ZINC-NPs DB) were screened using a 3D shape similarity search, molecular docking approaches, and ADMETox approaches. Frequently, in silico studies result in asymmetric structures as “hit” molecules. Therefore, the asymmetrical FDA-approved diabetes drugs linagliptin (8-[(3R)-3-aminopiperidin-1-yl]-7-but-2-ynyl-3-methyl-1-[(4-methylquinazolin-2-yl)methyl]purine-2,6-dione), sitagliptin ((3R)-3-amino-1-[3-(trifluoromethyl)-6,8-dihydro-5H-[1,2,4]triazolo[4,3-a]pyrazin-7-yl]-4-(2,4,5-trifluorophenyl)butan-1-one), and alogliptin (2-[[6-[(3R)-3-aminopiperidin-1-yl]-3-methyl-2,4-dioxopyrimidin-1-yl]methyl]benzonitrile) were used as queries to virtually screen the ZINC-NPs DB and detect novel potential dipeptidyl peptidase-4 (DPP-4) inhibitors. The most promising NPs, characterized by the best sets of similarity and ADMETox features, were used during the molecular docking stage. The results highlight that 11 asymmetrical NPs out of 224,205 NPs are potential DPP-4 candidates from natural sources and deserve consideration for further in vitro/in vivo tests.

m-Carborane as a Novel Core for Periphery-Decorated Macromolecules

Closom-C₂B₁₀H₁₂ can perform as a novel core of globular periphery-decorated macromolecules. To do this, a new class of di and tetrabranched m-carborane derivatives has been synthesized by a judicious choice of the synthetic procedure, starting with 9,10-I₂-1,7-closo-C₂B₁₀H₁₀. The 2a-NPA (sum of the natural charges of the two bonded atoms) value for a bond, which is defined as the sum of the NPA charges of the two bonded atoms, matches the order of electrophilic reaction at the different cluster bonds of the icosahedral o-and m- carboranes that lead to the formation of B-I bonds. As for m-carborane, most of the 2a-NPA values of B-H vertexes are positive, and their functionalization is more challenging. The synthesis and full characterization of dibranched 9,10-R₂-1,7-closo-carborane (R = CH₂CHCH₂, HO(CH₂)₃, Cl(CH₂)₃, TsO(CH₂)₃, C₆H₅COO(CH₂)₃, C₆H₅COO(CH₂)₃, N₃(CH₂)₃, CH₃CHCH, and C₆H₅C₂N₃(CH₂)₃) compounds as well as the tetrabranched 9,10-R₂-1,7-R₂-closo-C₂B₁₀H₈ (R = CH₂CHCH₂, HO(CH₂)₃) are presented. The X-ray diffraction of 9,10-(HO(CH₂)₃)₂-1,7-closo-C₂B₁₀H₁₀ and 9,10-(CH₃CHCH)₂-1,7-closo-C₂B₁₀H₁₀, as well as their Hirshfeld surface analysis and decomposed fingerprint plots, are described. These new reported tetrabranched m-carborane derivatives provide a sort of novel core for the synthesis of 3D radially grown periphery-decorated macromolecules that are different to the 2D radially grown core of the tetrabranched o-carborane framework.