Synthesis of a new 2-prenylated quinoline as potential drug for metabolic syndrome with pan-PPAR activity and anti-inflammatory effects.

We have previously reported the total synthesis and structure-activity relationships (SAR) of 2-prenylated benzopyrans with PPAR agonist activity. Herein, we have described the synthesis and PPAR activity of 2-prenylated benzopyrans and 2-prenylated quinolines. The benzopyran nucleus was generated via enamine-catalyzed Kabbe condensation, and the quinoline nucleus via Friedländer condensation. Results demonstrated that both benzopyran (5a) and quinoline (4b) derivatives bearing a γ,δ-unsaturated ester displayed a pan-PPAR agonism. They were full PPARα agonists, but showed different preferences for PPARγ and PPARß/δ activation. It was noteworthy that quinoline 4b displayed full hPPARα activation (2-fold than WY-14,643), weak PPARß/δ and partial PPARγ activation. In addition, quinoline 4b showed anti-inflammatory effects on macrophages by reducing LPS-induced expression of both MCP-1 and IL-6. Therefore, 4b emerges as a first-in-class promising hit compound for the development of potential therapeutics aimed at treating metabolic syndrome, metabolic dysfunction-associated fatty liver disease (MAFLD), and its associated cardiovascular comorbidities.

Synthesis of 2-aminopropyl benzopyran derivatives as potential agents against triple-negative breast cancer.

Synthesis of three series of 2-aminopropyl derivatives containing a benzopyran nucleus was performed to evaluate their performance against triple-negative breast cancer cell lines (MDA-MB-231 and MDA-MB-436) and normal breast epithelial cells (MCF10A). For the three series, the cytotoxic activity was as follows: N-methylated derivatives (tertiary amines) 5b, 6b, and 7b > secondary amine benzopyrans 5, 6, and 7 > quaternary amine salts 5c, 6c, and 7c > free phenolic derivatives 5a, 6a, and 7a. The structure-activity relationship showed the importance of the presence of an amine group and a p-fluorobenzyloxy substituent in the chromanol ring (IC50 values from 1.5 µM to 58.4 µM). In addition, 5a, 5b, 6a, and 7b displayed slight selectivity towards tumor cells. Compounds 5, 5a, 5b, 6, 6a, 6c, 7, and 7b showed apoptotic/necrotic effects due to, at least in part, an increase in reactive oxygen species generation, whereas 5b, 5c, 6b, 7a, and 7c caused cell cycle arrest in the G1 phase. Further cell-based mechanistic studies revealed that 5a, 6a, and 7b, which were the most promising compounds, downregulated the expression of Bcl-2, while 5b downregulated the expression of cyclins CCND1 and CCND2. Therefore, 2-aminopropyl benzopyran derivatives emerge as new hits and potential leads for developing useful agents against breast cancer.

Anti-inflammatory effects and improved metabolic derangements in ob/ob mice by a newly synthesized prenylated benzopyran with pan-PPAR activity.

BACKGROUND AND PURPOSE: Selective peroxisome proliferator-activated receptors (PPARs) are widely used to treat metabolic complications; however, the limited effect of PPARα agonists on glucose metabolism and the adverse effects associated with selective PPARγ activators have stimulated the development of novel pan-PPAR agonists to treat metabolic disorders. Here, we synthesized a new prenylated benzopyran (BP-2) and evaluated its PPAR-activating properties, anti-inflammatory effects and impact on metabolic derangements. EXPERIMENTAL APPROACH: BP-2 was used in transactivation assays to evaluate its agonism to PPARα, PPARß/δ and PPARγ. A parallel-plate flow chamber was employed to investigate its effect on TNFα-induced leukocyte-endothelium interactions. Flow cytometry and immunofluorescence were used to determine its effects on the expression of endothelial cell adhesion molecules (CAMs) and chemokines and p38-MAPK/NF-κB activation. PPARs/RXRα interactions were determined using a gene silencing approach. Analysis of its impact on metabolic abnormalities and inflammation was performed in ob/ob mice. KEY RESULTS: BP-2 displayed strong PPARα activity, with moderate and weak activity against PPARß/δ and PPARγ, respectively. In vitro, BP-2 reduced TNFα-induced endothelial ICAM-1, VCAM-1 and fractalkine/CX3CL1 expression, suppressed mononuclear cell arrest via PPARß/δ-RXRα interactions and decreased p38-MAPK/NF-κB activation. In vivo, BP-2 improved the circulating levels of glucose and triglycerides in ob/ob mice, suppressed T-lymphocyte/macrophage infiltration and proinflammatory markers in the liver and white adipose tissue, but increased the expression of the M2-like macrophage marker CD206. CONCLUSION AND IMPLICATIONS: BP-2 emerges as a novel pan-PPAR lead candidate to normalize glycemia/triglyceridemia and minimize inflammation in metabolic disorders, likely preventing the development of further cardiovascular complications.

Synthesis and biological studies of "Polycerasoidol" and "trans-δ-Tocotrienolic acid" derivatives as PPARα and/or PPARγ agonists.

2-Prenylated benzopyrans represent a class of natural and synthetic compounds showing a wide range of significant activities. Polycerasoidol is a natural prenylated benzopyran isolated from the stem bark of Polyalthia cerasoides (Annonaceae) that exhibits dual PPARα/γ agonism and an anti-inflammatory effect by inhibiting mononuclear leukocyte adhesion to the dysfunctional endothelium. Herein, we report the synthesis of three new series of prenylated benzopyrans containing one (series 1), two (series 2, "polycerasoidol" analogs) and three (series 3, "trans-δ-tocotrienolic acid" analogs) isoprenoid units in the hydrocarbon side chain at the 2-position of the chroman-6-ol (6-hydroxy-dihydrobenzopyran) scaffold. Isoprenoid moieties were introduced through a Grignard reaction sequence, followed by Johnson-Claisen rearrangement and subsequent Wittig olefination. hPPAR transactivation activity and the structure activity relationships (SAR) of eleven novel synthesized 2-prenylated benzopyrans were explored. PPAR transactivation activity demonstrated that the seven-carbon side chain analogs (series 1) displayed selectivity for hPPARα, while the nine-carbon side chain analogs (polycerasoidol analogs, series 2) did so for hPPARγ. The side chain elongation to 11 or 13 carbons (series 3) resulted in weak dual PPARα/γ activation. Therefore, 2-prenylated benzopyrans of seven- and nine-carbon side chain (polycerasoidol analogs) are good lead compounds for developing useful candidates to prevent cardiovascular diseases associated with metabolic disorders.

Synthesis of 2-Prenylated Alkoxylated Benzopyrans by Horner-Wadsworth-Emmons Olefination with PPARα/γ Agonist Activity.

We have synthesized series of 2-prenylated benzopyrans as analogues of the natural polycerasoidol, a dual PPARα/γ agonist with anti-inflammatory effects. The prenylated side chain consists of five or nine carbons with an α-alkoxy-α,ß-unsaturated ester moiety. Prenylation was introduced via the Grignard reaction, followed by Johnson-Claisen rearrangement, and the α-alkoxy-α,ß-unsaturated ester moiety was introduced by the Horner-Wadsworth-Emmons reaction. Synthetic derivatives showed high efficacy to activate both hPPARα and hPPARγ as dual PPARα/γ agonists. These prenylated benzopyrans emerge as lead compounds potentially useful for preventing cardiometabolic diseases.

Natural products and analogs as preventive agents for metabolic syndrome via peroxisome proliferator-activated receptors: An overview.

Natural products and synthetic analogs have drawn much attention as potential therapeutical drugs to treat metabolic syndrome. We reviewed the underlying mechanisms of 32 natural products and analogs with potential pharmacological effects in vitro, and especially in rodent models and/or patients, that usually act on the PPAR pathway, along with other molecular targets. Recent outstanding total syntheses or semisyntheses of these lead compounds are stated. In general, they can activate the transcriptional activity of PPARα, PPARγ, PPARα/γ, PPARß/δ, PPARα/δ, PPARγ/δ and panPPAR as weak, partial agonists or selective PPARγ modulators (SPPARγM), which may be useful for managing obesity, type 2 diabetes (T2D), dyslipidemia and non-fatty liver disease (NAFLD). Terpenoids is the largest group of compounds that act as potential modulators on PPARs and are comprised from small lipophilic cannabinoids to lipophilic pentacyclic triterpenes and polar saponins. Shikimates-phenylpropanoids include polar heterocyclic flavonoids and phenolic compounds containing at least one C3-C6 unit and usually a double bond on the propyl chain. Quercetin (19), resveratrol (24) and curcumin (27), stand out from this group for exhibiting beneficial effects on patients. Alkaloids, the minor group of potential modulators on PPARs, include berberine (30), which has been widely explored in preclinical and clinical studies for its potential beneficial effects on T2D and dyslipidemia. However, large-scale clinical trials may be warranted for the promising compounds.

Yeast Translation Elongation Factor eIF5A Expression Is Regulated by Nutrient Availability through Different Signalling Pathways.

Translation elongation factor eIF5A binds to ribosomes to promote peptide bonds between problematic amino acids for the reaction like prolines. eIF5A is highly conserved and essential in eukaryotes, which usually contain two similar but differentially expressed paralogue genes. The human eIF5A-1 isoform is abundant and implicated in some cancer types; the eIF5A-2 isoform is absent in most cells but becomes overexpressed in many metastatic cancers. Several reports have connected eIF5A and mitochondria because it co-purifies with the organelle or its inhibition reduces respiration and mitochondrial enzyme levels. However, the mechanisms of eIF5A mitochondrial function, and whether eIF5A expression is regulated by the mitochondrial metabolism, are unknown. We analysed the expression of yeast eIF5A isoforms Tif51A and Tif51B under several metabolic conditions and in mutants. The depletion of Tif51A, but not Tif51B, compromised yeast growth under respiration and reduced oxygen consumption. Tif51A expression followed dual positive regulation: by high glucose through TORC1 signalling, like other translation factors, to promote growth and by low glucose or non-fermentative carbon sources through Snf1 and heme-dependent transcription factor Hap1 to promote respiration. Upon iron depletion, Tif51A was down-regulated and Tif51B up-regulated. Both were Hap1-dependent. Our results demonstrate eIF5A expression regulation by cellular metabolic status.