Discovery of N-hydroxy-3-alkoxybenzamides as direct acid sphingomyelinase inhibitors using a ligand-based pharmacophore model.

Acid sphingomyelinase (ASM) has been shown to be involved in many physiological processes, emerging to be a promising drug target. In this study, we constructed a ligand-based pharmacophore model of ASM inhibitors and applied this model to optimize the lead compound α-mangostin, a known inhibitor of ASM. 23 compounds were designed and evaluated in vitro for ASM inhibition, of these, 10 compounds were found to be more potent than α-mangostin. This high hit ratio confirmed that the presented model is very effective and practical. The most potent hit, 1c, was found to selectively and competitively inhibit the enzyme and inhibit the generation of ceramide in a dose-dependent manner. Furthermore, 1c showed favorable anti-apoptosis and anti-inflammatory activity. Interactions with key residues and the Zn2+ cofactor of 1c were found by docking simulation. These results provide promising leads and important guidance for further development of efficient ASM inhibitors and drug candidates.

Synthesis and biological evaluation of novel tanshinone IIA derivatives for treating pain.

Due to ineffectiveness and side effects of existing analgesics, chronic pain has become one of the most complex and difficult problems in the clinic. Monoacylglycerol lipase (MAGL) is an essential hydrolase in the endocannabinoid system and has been identified as a potential target for the treatment of pain. In the present study, we designed and synthesized twelve tanshinone IIA analogs and screened their activity against MAGL. Selected compounds were tested for analgesic activity in vivo, with the acetic acid writhing test model. Among the test compounds, compound III-3 (IC50 120 nmol·L-1) showed significant activity against MAGL and ameliorated the clinical progression in the mouse pain model. Additionally, compound III-3, substitution with N-methyl-2-morpholinoacetamide, demonstrated improved solubility relative to tanshinone IIA.

I2-Catalyzed cross dehydrogenative coupling: rapid access to benzoxazinones and quinazolinones.

An efficient and applicable I2-catalyzed intramolecular dehydrogenative C-O/C-N coupling reaction via activating the C-H bond adjacent to the N atom has been developed to provide dozens of substituted benzoxazinones (31 examples) and quinazolinones (5 examples) in good to excellent yields (up to 98%). This one-pot methodology has significant advantages, including a metal-free process, broad substrate scope, high atom economy, and simple operation. This strategy goes through an iminium intermediate followed by nucleophilic attack to provide the desired products.

Synthesis and biological evaluation of tanshinone IIA derivatives as novel endothelial protective agents.

AIM: Oxidative stress-induced endothelial injury is a main risk factor in the pathogenesis of cardiovascular diseases. Tanshinone IIA (Tan IIA) exerts protective functions on endothelial cells in response to oxidative stress. To exploit new bioactive compounds from this natural product, 12 derivatives were first synthesized and evaluated for endothelial protective activities. MATERIALS & METHODS: Title compounds were prepared according to high-yielded synthetic routes, and their protective effects on human endothelial EA.hy926 cells were evaluated. To explore the mechanism, their inhibition on apoptosis of endothelial cells and Nrf2 activating activities were investigated. Furthermore, computational ADME prediction and water solubility assay were carried out for active compounds. RESULTS: Most of them exhibited potent endothelial protective effects on EA.hy926 cells injured by H2O2. In particular, compounds I-2 and II showed increased activity and water solubility compared with Tan IIA. Moreover, they reduced H2O2-induced apoptosis of EA.hy926 cells. A further exploration on the two compounds suggested that their actions were mediated by upregulation of antioxidant genes through activating Nrf2 pathway. CONCLUSION: These Tan IIA derivatives clearly showed related activities for the development of a new type of endothelial protective agents. [Formula: see text].

Pharmacology of mangostins and their derivatives: A comprehensive review.

Mangosteen (Garcinia mangostana Linn.) is a well-known tropical tree indigenous to Southeast Asia. Its fruit's pericarp abounds with a class of isoprenylated xanthones which are referred as mangostins. Numerous in vitro and in vivo studies have shown that mangostins and their derivatives possess diverse pharmacological activities, such as antibacterial, antifungal, antimalarial, anticarcinogenic, antiatherogenic activities as well as neuroprotective properties in Alzheimer's disease (AD). This review article provides a comprehensive review of the pharmacological activities of mangostins and their derivatives to reveal their promising utilities in the treatment of certain important diseases, mainly focusing on the discussions of the underlying molecular targets/pathways, modes of action, and relevant structure-activity relationships (SARs). Meanwhile, the pharmacokinetics (PK) profile and recent toxicological studies of mangostins are also described for further druggability exploration in the future.

Anticarcinogenic Effects of α-Mangostin: A Review.

Cancer chemoprevention is a promising strategy taken to block, reverse, or retard carcinogenesis. α-Mangostin, a natural xanthone isolated from the pericarps of mangosteen, represents one of the most studied chemopreventive agents. This compound has been reported to interfere with all the major stages of carcinogenesis: initiation, promotion, and progression. A number of mechanisms have been proposed for its anticarcinogenic activities. This review summarizes the current knowledge on the mechanisms that contribute to the observed activity of α-mangostin related to (i) modulation of carcinogenic biotransformation and mitigation of oxidative damage, (ii) induction of growth arrest and apoptosis, (iii) suppression of angiogenesis and metastasis, and (iv) combination with clinical chemotherapy drugs enhancing their efficacy and decreasing the toxic side effects. In addition, pharmacokinetic and toxicological studies of α-mangostin have also been highlighted in this review. Despite an overwhelming amount of knowledge in preclinical studies, there was almost no translation of α-mangostin into the clinic. It is hoped that continuous extensive and profound research will lead to the application of α-mangostin from experimental studies to evidence-based, clinically applicable pharmacotherapy.