Design and synthesis of garlic-related unsymmetrical thiosulfonates as potential Alzheimer's disease therapeutics: In vitro and in silico study

Harnessing Essential Oils for Acetylcholinesterase Inhibition: A Literature Review

Aromatherapy, a branch of herbal and alternative medicine, has emerged as a promising non-pharmacological approach to treating Alzheimer's disease (AD) due to its potential to enhance cognitive function. This comprehensive review evaluates the inhibitory effects of various plant essential oils (EOs) on acetylcholinesterase (AChE) activity, a key enzyme implicated in the pathophysiology of AD. Our analysis highlights EOs from the Lamiaceae family, particularly rosemary (Salvia rosmarinus) and lavender (Lavandula officinalis), which demonstrated the most potent AChE inhibitory effects. Key chemical constituents such as α- and β-pinene, limonene, linalool, 1,8-cineole, caryophyllene, estragole, eugenol, and asarone were identified as the primary active components responsible for these effects. Additionally, we discuss the biochemical mechanisms underlying the neuroprotective properties of these EOs and their potential role in developing effective therapies for AD. Our findings underscore the therapeutic promise of specific EOs and their constituents in managing cognitive decline associated with neurodegenerative disorders.

I2-Cs2CO3 Mediated Intramolecular C2-Amination and Oxidative Rearrangement Cascade of C-3 Phenylthio Indoles: A Route to Synthesize Thiosulfonate-Embedded 2-Iminoindolin-3-ones

An efficient, transition-metal-free protocol employing I2/Cs2CO3 for the synthesis of thiosulfonate containing 2-iminoindolin-3-ones motifs has been developed from C-3 phenylthio indoles. The reaction proceeded through intramolecular cyclization involving C-N bond formation, leading to the formation of indole-fused benzothiazines as a key intermediate. Remarkably, Cs2CO3 played a crucial role in the reaction as an oxygen source, enabling oxidative rearrangement with [1,4]-sulfonyl migration to furnish the final products with the formation of multiple functional groups such as C═O, C═N, and S-SO2.

A general copper-catalysed enantioconvergent C(sp3)-S cross-coupling via biomimetic radical homolytic substitution

Although α-chiral C(sp3)-S bonds are of enormous importance in organic synthesis and related areas, the transition-metal-catalysed enantioselective C(sp3)-S bond construction still represents an underdeveloped domain probably due to the difficult heterolytic metal-sulfur bond cleavage and notorious catalyst-poisoning capability of sulfur nucleophiles. Here we demonstrate the use of chiral tridentate anionic ligands in combination with Cu(I) catalysts to enable a biomimetic enantioconvergent radical C(sp3)-S cross-coupling reaction of both racemic secondary and tertiary alkyl halides with highly transformable sulfur nucleophiles. This protocol not only exhibits a broad substrate scope with high enantioselectivity but also provides universal access to a range of useful α-chiral alkyl organosulfur compounds with different sulfur oxidation states, thus providing a complementary approach to known asymmetric C(sp3)-S bond formation methods. Mechanistic results support a biomimetic radical homolytic substitution pathway for the critical C(sp3)-S bond formation step.

A safe alternative synthesis of primary carbamates from alcohols; in vitro and in silico assessments as an alternative acetylcholinesterase inhibitors

Carbamates are important molecules because they are used in various biochemical processes. In this study, effective alternative method for the synthesis of primary carbamates from alcohols was developed in the presence of chlorosulfonyl isocyanate (CSI) in pyridine at room temperature in mild conditions. The primary carbamates were synthesized excellent yield. This method is easy, practical, and inexpensive without any additive, metal, or catalyst. Alzheimer's disease (AD) is a neurodegenerative disease and has been reported to affect approximately 50 million people worldwide in 2020. Drugs that reversibly inhibit the acetylcholinesterase (AChE) activity are used for the treatment of AD. For this reason, there is a growing interest in developing alternative AChE inhibitors. Concordantly, Anti-anticholinesterase activity of synthesized carbamate derivatives was investigated as an alternative AChE inhibitors. In order to determine the inhibitory effect of these molecules, IC50, and Ki values and inhibition types were determined. According to the Ki results, the most effective inhibitors were 3 b and 3e with the Ki values of 22 and 38 µM, respectively. It was found that all molecules showed competitive inhibition type. For clarify the inhibitors-enzyme interactions, molecular docking studies were performed and possible binding interactions between the synthesized molecules and AChE were determined. Additionally, the pharmacokinetic and properties of the synthesized molecules were evaluated in silico.Communicated by Ramaswamy H. Sarma.

Optimization of the Black Garlic Processing Method and Development of Black Garlic Jam Using High-Pressure Processing

Black garlic has many beneficial effects, and it has a less spicy flavor. However, its aging conditions and related products still need to be further investigated. The present study aims to analyze the beneficial effects under different processing conditions and utilize high-pressure processing (HPP) in the production of black garlic jam. The highest antioxidant activities, including the DPPH scavenging, total antioxidant capacity, and reducing power (86.23%, 88.44%, and A₇₀₀ = 2.48, respectively), were observed in black garlic that had been aged for 30 days. Similarly, the highest total phenols and flavonoids were observed in black garlic that had been aged for 30 days (76.86 GAE/g dw and 13.28 mg RE/g dw, respectively). The reducing sugar in black garlic was significantly increased to about 380 (mg GE/g dw) after 20 days of aging. The free amino acids in black garlic were decreased time-dependently to about 0.2 mg leucine/g dw after 30 days of aging. For the browning indexes of black garlic, the uncolored intermediate and browning products were increased in a time-dependent manner and reached a plateau at day 30. Another intermediate product in the Maillard reaction, 5-hydroxymethylfurfural (5-HMF), was observed in concentrations that increased to 1.81 and 3.04 (mg/g dw) at day 30 and 40, respectively. Furthermore, the black garlic jam made by HPP was analyzed for its texture and sensory acceptance, showing that a 1:1.5:2 ratio of black garlic/water/sugar was the most preferred and was classified as "still acceptable". Our study suggests suitable processing conditions for black garlic and outlines the prominent beneficial effects after 30 days of aging. These results could be further applied in HPP jam production and increase the diversity of black garlic products.

Evaluation of Mollugo oppositifolia Linn. as cholinesterase and β-secretase enzymes inhibitor

Mollugo oppositifolia Linn. is traditionally used in neurological complications. The study aimed to investigate in-vitro neuroprotective effect of the plant extracts through testing against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and β-secretase linked to Alzheimer's disease (AD). To understand the safety aspects, the extracts were tested for CYP450 isozymes and human hepatocellular carcinoma cell (HepG2) inhibitory potential. The heavy metal contents were estimated using atomic absorption spectroscopy (AAS). Further, the antioxidant capacities as well as total phenolic content and total flavonoid content (TFC) were measured spectrophotometrically. UPLC-QTOF-MS/MS analysis was employed to identify phytometabolites present in the extract. The interactions of the ligands with the target proteins (AChE, BChE, and BACE-1) were studied using AutoDockTools 1.5.6. The results showed that M. oppositifolia extract has more selectivity towards BChE (IC₅₀ = 278.23 ± 1.89 μg/ml) as compared to AChE (IC₅₀ = 322.87 ± 2.05 μg/ml). The IC₅₀ value against β-secretase was 173.93 μg/ml. The extract showed a CC₅₀ value of 965.45 ± 3.07 μg/ml against HepG2 cells and the AAS analysis showed traces of lead 0.02 ± 0.001 which was found to be within the WHO prescribed limits. Moreover, the IC₅₀ values against CYP3A4 (477.03 ± 2.01 μg/ml) and CYP2D6 (249.65 ± 2.46 μg/ml) isozymes justify the safety aspects of the extract. The in silico molecular docking analysis of the target enzymes showed that the compound menthoside was found to be the most stable and showed a good docking score among all the identified metabolites. Keeping in mind the multi-targeted drug approach, the present findings suggested that M. oppositifolia extract have anti-Alzheimer's potential.