A protectin DX (PDX) analog with in vitro activity against influenza A(H1N1) viruses.

Antiviral therapy based on neuraminidase (oseltamivir) or polymerase (baloxavir marboxil) inhibitors plays an important role in the management of influenza infections. However, the emergence of drug resistance and the uncontrolled inflammatory response are major limitations in the treatment of severe influenza disease. Protectins D1 (PD1) and DX (PDX), part of a family of pro-resolving mediators, have previously demonstrated anti-influenza activity as well as anti-inflammatory properties in various clinical contexts. Herein, we synthetized a series of simplified PDX analogs and assessed their in vitro antiviral activity against influenza A(H1N1) viruses, including oseltamivir- and baloxavir-resistant variants. In ST6GalI-MDCK cells, the PDX analog AN-137B reduced viral replication in a dose-dependent manner with IC50 values of 23.8 for A/Puerto Rico/8/1934 (H1N1) and between 32.6 and 36.7 µM for susceptible and resistant A(H1N1)pdm09 viruses. In MTS-based cell viability experiments, AN-137B showed a 50% cellular cytotoxicity (CC50 ) of 638.7 µM with a resulting selectivity index of 26.8. Of greater importance, the combination of AN-137B with oseltamivir or baloxavir resulted in synergistic and additive in vitro effects, respectively. Treatment of lipopolysaccharide (LPS)-stimulated macrophages with AN-137B resulted in a decrease of iNOS activity as shown by the reduction of nitrite production, suggesting an anti-inflammatory effect. In conclusion, our results indicate that the protectin analog AN-137B constitutes an interesting therapeutic modality against influenza A virus, warranting further evaluation in animal models.

14 C-radiolabeling of a new steroidal antiandrogen with a C-18 angular methyl extension.

The synthesis of a 14 C-labeled C-18 functionalized steroid (as referred as EM-6798) that will serve as a probe for the research of novel antiandrogens has been accomplished. This radioactive steroid was obtained in nine steps by coupling racemic N-cyclohexyl-1-(3'-hydroxy[U-14 C]phenyl)propylamine with protected 18-bromomethyl-3,17-androstenedione. Incorporation of the radiolabel on the C-18 side chain was achieved using commercially available 3-bromo[U-14 C]phenol. Alkylation of N-cyclohexyl-1-(3'-hydroxy[U-14 C]phenyl)propylamine with 3-ethylenedioxy-18-bromomethyl-3,17-androstenedione furnished after reduction and deprotection, [phenyl-U-14 C]EM-6798 in a 20% overall yield from 3-bromo[U-14 C]phenol at a specific activity of 156 µCi/mg with 97.9% radiochemical purity as determined by HPLC.

A Concise, Gram-Scale Total Synthesis of Protectin DX and Related Labeled Versions via a Key Stereoselective Reduction of Enediyne.

We report a gram-scale total synthesis of protectin DX (PDX) following a convergent synthetic route (24 steps) from l-malic acid. This novel synthetic strategy is based on the assembly of three main building blocks using a Sonogashira coupling reaction (blocks A and B) and Wittig olefination (block C) to provide the 22-carbon backbone of PDX. A key stereoselective reduction of enediyne leads to a central E,Z,E-trienic system of PDX and also gives access to its labeled versions (D and T).

An Improved Synthesis of Glucuronide Metabolites of Hindered Phenolic Xenoestrogens.

AIMS AND OBJECTIVE: The syntheses of glucuronide metabolites of phenolic xenoestrogens triclosan and 2-phenylphenol, namely triclosan-O-glucuronide (TCS-G; 1), and 2-phenylphenol-Oglucuronide (OPP-G; 2), were achieved for use as analytical standards. METHODS: Under classical conditions previously reported for glucuronide synthesis, the final basic hydrolysis of the peracylated ester intermediate leading to the free glucuronides is often a limiting step. Indeed, the presence of contaminating by-products resulting from ester elimination has often been observed during this step. This is particularly relevant when the sugar unit is close to a crowded environment as for triclosan and 2-phenylphenol. RESULTS: To circumvent these problems, we proposed mild conditions for the deprotection of peracetylated glucuronate intermediates. CONCLUSION: A new methodology using a key imidate following a two-step protocol for acetates and methyl ester hydrolysis was successfully applied to the preparation of TCS-d3 (1) and OPP-G (2) as well as deuterated isotopomers TCS-d3-G (1-d3) and OPP-d5-G (2-d5).

Total Synthesis of the Antidiabetic (Type 2) Lipid Mediator Protectin DX/PDX.

The first total synthesis of a lipid mediator derived from natural ω-3-fatty acid docosahexaenoic acid (DHA), 10 S,17 S-diHDHA (also referred to as protectin DX/PDX), was achieved in a convergent route (29 steps). The two chiral hydroxyl groups at C-10 and C-17 were derived from readily available ( S)-1,2,4-butanetriol and ( R)-glycidol, respectively. The two stereodefined E-double bonds were generated by a Takai olefination, and the skipped diene side chain was introduced with a stereocontrolled Wittig olefination. Importantly, the sensitive conjugated E, Z, E-triene intermediate was generated by a Boland reduction of the central triple bond of a E, E-dienyne. Overall, this synthetic strategy should allow the preparation of a larger quantity of PDX, which is inaccessible via previously reported biosynthetic approaches.

Effect of toremifene and ospemifene, compared to acolbifene, on estrogen-sensitive parameters in rat and human uterine tissues.

BACKGROUND: Although the first generation selective estrogen receptor modulator (SERM) tamoxifen (TAM) is well known for its uterotrophic activity, this study compares the stimulatory effect of the TAM derivatives toremifene (TORE) and ospemifene (OSPE) on estrogen-sensitive parameters in rat and human uterine tissues. MATERIAL AND METHODS: Ovariectomized female rats were treated daily orally for 10 days with 0.75 mg/rat of TORE, OSPE or acolbifene (ACOL, a pure estrogen antagonist in the uterus and mammary gland), which was used for comparison. Human endometrial carcinoma Ishikawa cells were incubated for 5 days with increasing doses of compounds, in the absence or presence of 1 nM estradiol (E2). RESULTS: TORE and OSPE revealed 52% and 56% increases, respectively, in uterine weight, whereas ACOL had no effect. Similar effects were observed on vaginal weight. Endometrial epithelial height increased from 15.82±0.20 to 48.94± 2.12 and 42.14±1.95 µm with TORE and OSPE, respectively, whereas ACOL had no effect. Alkaline phosphatase activity, an estrogen-sensitive parameter in Ishikawa cells, was increased by 144% and 135% with OH-TORE and OH-OSPE, respectively. Owing to their intrinsic estrogenic activity, at maximal concentrations, OH-TORE and OH-OSPE blocked the stimulatory effect of E2 by only 89% compared to 100% with ACOL. CONCLUSIONS: The present in vitro and in vivo data show similar stimulatory effects of 4-hydroxytoremifene (OH-TORE) and OH-OSPE on estrogen-sensitive parameters. ACOL, a third generation SERM, has no effect on any of these parameters. Such data add to the potential uterine safety limitations of triphenylethylene-derived SERMs for long-term use in humans.