Synthesis and biological evaluation of geniposide derivatives as potent and selective PTPlB inhibitors

Modification of iridoids in focus: Bridging structural complexity with biological innovation

Iridoids, a class of oxygenated monoterpene compounds with a methylcyclopentan-[c]-pyran skeletal, widely exist in plants and microorganisms. Iridoids are mainly classified into cyclopentane iridoids and secoiridoids. The unique structure makes it exhibit varieties of biological activities, such as neuroprotective, anti-tumor, anti-viral, anti-oxidant and anti-inflammatory effects. In order to take a deep dive into the structural properties of iridoid derivatives, as well as to facilitate the development of them, we recapitulate the modification strategies of representative iridoids and biological activities of iridoid derivatives, especially discuss their structure-activity relationship in this review. This article will provide the latest overview and offer insights for structural modification of iridoids in future.

Pyrimidine-based sulfonamides and acetamides as potent antimicrobial Agents: Synthesis, Computational Studies, and biological assessment

A series of novel sulfonamide and acetamide derivatives of pyrimidine were synthesized and their antimicrobial activities were assessed. Based on the Microbroth dilution method, the minimum inhibitory concentration (MIC) of the synthesized compounds demonstrated moderate to good levels of antifungal and antibacterial activity. Structure-activity relationship analysis suggested that the presence of electron-withdrawing groups, such as halogens, nitrile, and nitro groups, on the pyrimidine ring contributed to the enhanced antimicrobial potency, while electron-donating substituents led to a decrease in activity. Computational studies, including density functional theory (DFT), frontier molecular orbitals (FMO), and molecular electrostatic potential (MEP) analysis, provided insights into the electronic properties and charge distribution of the compounds. Drug-likeness evaluation using ADME/Tox analysis indicated that the synthesized compounds possess favorable physicochemical properties and could be potential drug candidates. Molecular docking against the Mycobacterium TB protein tyrosine phosphatase B (MtbPtpB) revealed that the synthesized compounds exhibited strong binding affinities (-46 kcal/mol to - 61 kcal/mol) and formed stable protein-ligand complexes through hydrogen bonding and π-π stacking interactions with key residues in the active site. The observed interactions from the docking simulations were consistent with the predicted interaction sites identified in the FMO and MEP analyses. These findings suggest that the synthesized pyrimidine derivatives could serve as promising antimicrobial agents and warrant further investigation for drug development.

Discovery, optimization and biological activity evaluation of genipin derivatives as potential KRAS G12D inhibitors

A series of genipin derivatives were designed and synthesized as potential inhibitors targeted KRAS G12D mutation. The majority of these compounds demonstrated potential antiproliferative effects against KRAS G12D mutant tumor cells (CT26 and A427). Notably, seven compounds exhibited the anticancer effects with IC50 values ranging from 7.06 to 9.21 µM in CT26 (KRASG12D) and A427 (KRASG12D) cells and effectively suppressed the colony formation of CT26 cells. One representative compound SK12 was selected for further investigation into biological activity and action mechanisms. SK12 markedly induced apoptosis in CT26 cells in a concentration-dependent manner. Moreover, SK12 elevated the levels of reactive oxygen species (ROS) in tumor cells and exhibited a modulatory effect on the KRAS signaling pathway, thereby inhibiting the activation of downstream phosphorylated proteins. The binding affinity of SK12 to KRAS G12D protein was further confirmed by the surface plasmon resonance (SPR) assay with a binding KD of 157 µM. SK12 also exhibited notable anticancer efficacy in a nude mice tumor model. The relative tumor proliferation rate (T/C) of the experimental group (50 mg/kg) was 31.04 % (P < 0.05), while maintaining a commendable safety profile.

Electrochemical Multicomponent Synthesis of Alkyl Alkenesulfonates using Styrenes, SO2 and Alcohols

A novel electrochemical approach to access alkyl alkenesulfonates via a multicomponent reaction was developed. The metal-free method features easy-to-use SO2 stock solution forming monoalkylsulfites from alcohols with an auxiliary base in-situ. These intermediates serve a dual role as starting materials and as supporting electrolyte enabling conductivity. Anodic oxidation of the substrate styrene, radical addition of these monoalkylsulfites and consecutive second oxidation and deprotonation preserve the double bond and form alkyl β-styrenesulfonates in a highly regio- and stereoselective fashion. The feasibility of this electrosynthetic method is demonstrated in 44 examples with yields up to 81 %, employing various styrenes and related substrates as well as a diverse set of alcohols. A gram-scale experiment underlines the applicability of this process, which uses inexpensive and readily available electrode materials.

Design and synthesis of novel 3-amino-5-phenylpyrazole derivatives as tubulin polymerization inhibitors targeting the colchicine-binding site

As the basic unit of microtubules, tubulin is one of the most important targets in the study of anticarcinogens. A novel series of 3-amino-5-phenylpyrazole derivatives were designed and synthesized, and evaluates for their biological activities. Among them, a majority of compounds exerted excellent inhibitory activities against five cancer cell lines in vitro. Especially, compound 5b showed a strong antiproliferative activity against MCF-7 cells, with IC50 value of 38.37 nM. Further research indicated that compound 5b can inhibit the polymerization of tubulin targeting the tubulin colchicine-binding sites. Furthermore, 5b could arrest MCF-7 cells at the G2/M phase and induce MCF-7 cells apoptotic in a dose-dependent and time-dependent manners, and regulate the level of related proteins expression. Besides, compound 5b could inhibit the cancer cell migration and angiogenesis. In addition, 5b could inhibit tumor growth in MCF-7 xenograft model without obvious toxicity. All these results indicating that 5b could be a promising antitumor agent targeting tubulin colchicine-binding site and it was worth further study.

New chromone derivatives bearing thiazolidine-2,4-dione moiety as potent PTP1B inhibitors: Synthesis and biological activity evaluation

A series of chromone derivatives bearing thiazolidine-2,4-dione moiety (5 ∼ 37) were synthesized and evaluated for their PTP1B inhibitory activity, interaction analysis and effects on insulin pathway in palmitic acid (PA)-induced HepG2 cells. The results showed that all derivatives presented potential PTP1B inhibitory activity with IC50 values of 1.40 ± 0.04 ∼ 16.83 ± 0.54 μM comparing to that of positive control lithocholic acid (IC50: 9.62 ± 0.14 μM). Among them, compound 9 had the strongest PTP1B inhibitory activity with the IC50 value of 1.40 ± 0.04 μM. Inhibition kinetic study revealed that compound 9 was a reversible mixed-type inhibitor against PTP1B. CD spectra results confirmed that compound 9 changed the secondary structure of PTP1B by their interaction. Molecular docking explained the detailed binding between compound 9 and PTP1B. Compound 9 also showed 19-fold of selectivity for PTP1B over TCPTP. Moreover compound 9 could recovery PA-induced insulin resistance by increasing the phosphorylation of IRSI and AKT. CETSA results showed that compound 9 significantly increased the thermal stability of PTP1B.

Study on the chemical reactivity difference of primary hydroxyl groups in iridoid glycosides

Iridoid glycoside, which belongs to the polyhydroxy compound, is a kind of active ingredient of traditional Chinese medicine with a wide range of sources, and has many pharmacological effects such as anti-cancer, anti-inflammatory, anti-virus, hypoglycemic and so on. Its structure contains many hydroxyl groups, including two primary hydroxyl groups. The chemical reactivity of primary hydroxyl groups has very little difference, so it is very important to control the selectivity of hydroxyl groups under certain conditions. In this paper, the difference between the two primary hydroxyl groups in iridoid glycoside was calculated based on computer simulation and verified this result through designed experiments. This study will provide an important way for site-directed modification of hydroxyl in iridoid glycoside in the future.

A comprehensive review on the research progress of PTP1B inhibitors as antidiabetics

Diabetes mellitus (DM) is a serious global health concern affecting over 500 million people. To put it simply, it is one of the most dangerous metabolic illnesses. Insulin resistance is the root cause of 90% of all instances of diabetes, all of which are classified as Type 2 DM. Untreated, it poses a hazard to civilization since it can lead to terrifying consequences and even death. Oral hypoglycemic medicines presently available act in a variety of ways, targeting various organs and pathways. The use of protein tyrosine phosphatase 1B (PTP1B) inhibitors, on the contrary, is a novel and effective method of controlling type 2 diabetes. PTP1B is a negative insulin signaling pathway regulator; hence, inhibiting PTP1B increases insulin sensitivity, glucose absorption, and energy expenditure. PTP1B inhibitors also restore leptin signaling and are considered a potential obesity target. In this review, we have compiled a summary of the most recent advances in synthetic PTP1B inhibitors from 2015 to 2022 which have scope to be developed as clinical antidiabetic drugs.

Research progress on hydroxyl protection of iridoid glycosides

Iridoids, an important active ingredient, are widely distributed in varieties of Chinese herbal medicines and have varieties of pharmacological activities, such as anti-tumor, hypoglycemic, anti-inflammatory and so on, most of which exist in the form of glycosides in nature. However, its clinical application is limited by poor lipid solubility, low bioavailability and short half-life. It is necessary to optimize the structure of iridoids. It is hard to modify the hydroxyl groups at specific sites because iridoid glycosides are polyhydroxy compounds and very complex. In this paper, the words of ‘Iridoid glycosides’ and ‘Hydroxyl protection’ were used as the keywords, more than 200 articles from 1965 to 2021 were obtained from databases, such as CNKI, PubMed, Scifinder and so on. Finally, 60 articles were selected to summarize the hydroxyl protection of iridoid glycosides, which will provide a theoretical basis for their structural modification and stimulate their application potential in the field of drug research and development.

Evaluation of the Hypoglycemic Activity of Morchella conica by Targeting Protein Tyrosine Phosphatase 1B

Morchella conica (M. conica) Pers. is one of six wild edible mushrooms that are widely used by Asian and European countries for their nutritional value. The present study assessed the anti-diabetic potential of M. conica methanolic extract (100 mg/kg body weight) on streptozotocin (STZ)-induced diabetic mice. STZ was used in a single dose of 65 mg/kg to establish diabetic models. Body weights, water/food intake and fasting blood glucose levels were measured. Histopathological analysis of the pancreas and liver were performed to evaluate STZ-induced tissue injuries. In addition, in vitro assays such as α-amylase and protein tyrosine phosphatase 1B (PTP1B) inhibitory, antiglycation, antioxidant and cytotoxicity were performed. The in vitro study indicated potent PTP1B inhibitory potential of M. conica with an IC₅₀ value of 26.5 μg/ml as compared to the positive control, oleanolic acid (IC₅₀ 36.2 μg/ml). In vivo investigation showed a gradual decrease in blood sugar level in M. conica-treated mice (132 mg/dl) at a concentration of 100 mg/kg as compared to diabetic mice (346 mg/dl). The extract positively improved liver and kidney damages as were shown by their serum glutamic pyruvic transaminase, serum glutamic oxaloacetate, alkaline phosphatase, serum creatinine and urea levels. Histopathological analysis revealed slight liver and pancreas improvement of mice treated with extract. Cytotoxicity assays displayed lower IC₅₀ values. Based on the present results of the study, it may be inferred that M. conica are rich in bioactive compounds responsible for antidiabetic activity and this mushroom may be a potential source of antidiabetic drug. However, further studies are required in terms of isolation of bioactive compounds to validate the observed results.