The Direct C-H Difluoromethylation of Heteroarenes Based on the Photolysis of Hypervalent Iodine(III) Reagents That Contain Difluoroacetoxy Ligands.

In this letter, an efficient method for the photolytic generation of difluoromethyl radicals from [bis(difluoroacetoxy)iodo]benzene reagents is described. The present approach enables the introduction of difluoromethyl groups into various heteroarenes under mild conditions in the absence of any additional reagents or catalysts.

Identification of a selective inhibitor of transforming growth factor ß-activated kinase 1 by biosensor-based screening of focused libraries.

Transforming growth factor-ß activated kinase 1 (TAK1), a member of the mitogen-activated protein kinase kinase kinase family, plays an essential role in mediating signals from various pro-inflammatory cytokines and therefore may be a good target for developing anti-inflammation agents. Herein, we report our efforts to identify TAK1 inhibitors with a good selectivity profile with which to initiate medicinal chemistry. Instead of resorting to a high-throughput screening campaign, we performed biosensor-based biophysical screening for a limited number of compounds by taking advantage of existing knowledge on kinase inhibitors. Rather than focusing on one specific inhibition mode, we searched for three different types, Type I (ATP-competitive, DFG-in), Type II (DFG-out), and Type III binders (non-ATP competitive) in parallel, and succeeded in identifying candidates in all three categories efficiently and rapidly. Finally, the biosensor-based binding kinetics for the active and inactive forms of TAK1 were measured to prioritize the Type I and Type II inhibitors. The effort resulted in the identification of a new TAK1-selective Type I compound with a thienopyrimidine scaffold that served as a good starting point for medicinal chemistry.

Development of a Method for Converting a TAK1 Type I Inhibitor into a Type II or c-Helix-Out Inhibitor by Structure-Based Drug Design (SBDD).

We have developed a method for converting a transforming growth factor-ß-activated kinase 1 (TAK1) type I inhibitor into a type II or c-helix-out inhibitor by structure-based drug design (SBDD) to achieve an effective strategy for developing these different types of kinase inhibitor in parallel. TAK1 plays a key role in inflammatory and immune signaling, and is therefore considered to be an attractive molecular target for the treatment of human diseases (inflammatory disease, cancer, etc.). We have already reported novel type I TAK1 inhibitor, so we utilized its X-ray information to design a new chemical class type II and c-helix-out inhibitors. To develop the type II inhibitor, we superimposed the X-ray structure of our reported type I inhibitor onto a type II compound that inhibits multiple kinases, and used SBDD to design a new type II inhibitor. For the TAK1 c-helix-out inhibitor, we utilized the X-ray structure of a b-Raf c-helix-out inhibitor to design compounds, because TAK1 is located close to b-Raf in the Sugen kinase tree, so we considered that TAK1 would, similarly to b-Raf, form a c-helix-out conformation. The X-ray crystal structure of the inhibitors in complex with TAK1 confirmed the binding modes of the compounds we designed. This report is notable for being the first discovery of a c-helix-out inhibitor against TAK1.

Discovery of a potent and highly selective transforming growth factor ß receptor-associated kinase 1 (TAK1) inhibitor by structure based drug design (SBDD).

A novel thienopyrimidinone analog was discovered as a potent and highly selective TAK1 inhibitor using the SBDD approach. TAK1 plays a key role in inflammatory and immune signaling, so TAK1 is considered to be an attractive molecular target for the treatment of human diseases (inflammatory disease, cancer, etc.). After the hit compound had been obtained, our modifications successfully increased TAK1 inhibitory activity and solubility, but metabolic stability was still unsatisfactory. To improve metabolic stability, we conducted metabolic identification. Although the obtained metabolite was fortunately a potent TAK1 inhibitor, its kinase selectivity was low. Subsequently, to achieve high kinase selectivity, we used SBDD to follow two strategies: one targeting unique amino acid residues in TAK1, especially the combination of Ser111 and Asn114; the other decreasing the interaction with Tyr106 at the hinge position in TAK1. As expected, our designed compound showed an excellent kinase selectivity profile in both an in-house and a commercially available panel assay of over 420 kinases and also retained its potent TAK1 inhibitory activity (TAK1 IC50=11nM).

Efficient generation of perfluoroalkyl radicals from sodium perfluoroalkanesulfinates and a hypervalent iodine(iii) reagent: mild, metal-free synthesis of perfluoroalkylated organic molecules.

This article describes an efficient method for the introduction of perfluoroalkyl groups into N-acrylamides, 2-isocyanides, olefins, and other heterocycles using perfluoroalkyl radicals that were generated from the reaction between sodium perfluoroalkanesulfinates and a hypervalent iodine(iii) reagent. This approach represents a simple, scalable perfluoroalkylation method under mild and metal-free conditions.

Beneficial effect of D-allose for isolated islet culture prior to islet transplantation.

BACKGROUND: Pretransplant restoration of islets damaged during isolation remains to be solved. In this study, we examined the effect of D-allose on islets isolated from rat pancreata prior to islet transplantation. METHODS: Rat islets isolated from fresh pancreata were cultured overnight in Roswell Park Memorial Institute 1640 solution in the absence (group 1) or presence (group 2) of D-allose. Then we assessed stimulation index of insulin, and cure rate after islet transplantation to diabetic nude mice. We also measured malondialdehyde level and caspase 3 activity of islets after the overnight culture for assessment of the oxidative stress and the apoptosis. RESULTS: D-allose significantly improved insulin secretion of islets. The stimulation index in group 2 was significantly higher than in group 1. Cure rate after transplantation in group 2 was higher than in group 1 especially in the first week. The malondialdehyde level in group 2 was significantly lower than in group 1. But the caspase 3 activities in both groups did not differ. CONCLUSIONS: D-allose treatment of isolated islet culture prior to transplantation restored islet function and increased successful transplant rate. The results of this study suggested that D-allose improved function of damaged islets through its anti-oxidative activity.

A series of nonsecosteroidal vitamin D receptor agonists for osteoporosis therapy.

In an extension of our study on gamma hydroxy carboxylic acid analogs, we explored a series of nonsecosteroidal vitamin D receptor (VDR) agonists in which 1,3-diol of 1,25(OH)2D3 had been replaced by aryl acetic acid. These analogs showed very potent activity in vitro compared with 1,25(OH)2D3. An X-ray analysis of 8d showed that the inserted phenyl ring well mimicked the folded methylene linker of the gamma hydroxy carboxylic acid moiety but the carboxylic acid of 8d interacted with VDR in a different manner from gamma hydroxy carboxylic acids. Through our in vivo screening in an osteoporosis rat model using immature rats, we identified a potent active vitamin D3 analog, compound 7e. In mature rats of the same model, compound 7e also showed good PK profiling and excellent ability to prevent bone mineral density loss without severe hypercalcemia. Our nonsecosteroidal VDR agonist 7e (CH5036249) could be a possible new drug candidate for treating osteoporosis in human.

Effects of fluorines on nonsecosteroidal vitamin D receptor agonists.

From our research of nonsecosteroidal vitamin D(3) derivatives with gamma hydroxy carboxylic acid, we identified compound 6, with two CF(3) groups in the side chain, as a most potent vitamin D receptor (VDR) agonist that shows superagonistic activity in VDRE reporter gene assay, MG-63 osteocalcin production assay and HL-60 cell differentiation assay. Compound 6 demonstrated that fluorination is as effective in the case of our nonsecosteroidal scaffold as in the case of secosteroidal VD(3) analogs. X-ray analysis of the VDR with compound 6 revealed all of the six fluorine atoms of the hexafluoropropanol (HFP) moiety in the side chain effectively interacting with the VDR by both steric (van der Waals) and electrostatic (hydrogen bond, NH-F and CH-F) interactions. The HFP moiety of 6 effectively interacts with helix 12 (H12) of the VDR and stabilizes the position and the orientation of H12, which could result in stabilizing the coactivator and enhancing the VDR agonistic activity.

Extraperitoneal colostomy in laparoscopic abdominoperineal resection using a laparoscopic retractor.

Although extraperitoneal colostomy is often performed to prevent postoperative parastomal hernia formation following an open abdominoperineal resection of lower rectal cancer, it has not been widely employed laparoscopically because of the difficulty associated with the extraperitoneal route. This paper describes a laparoscopic extraperitoneal sigmoid colostomy using the Endo Retract™ Maxi instrument. This surgical technique is easy, and helps to prevent the development of parastomal hernias.

Systematic SAR study of the side chain of nonsecosteroidal vitamin D3 analogs.

A series of nonsecosteroidal vitamin D(3) analogs with carboxylic acid were explored. Through our systematic SAR studies on the side chain moiety, compound 6b was identified as the optimal compound showing excellent vitamin D receptor (VDR) agonistic activity. Compound 6b had the diethyl group in the terminal which was bound by (E)-olefin linker to the bisphenyl core. Calculating the volume of the side chain showed that the diethyl group in 6b filled the hydrophobic region of VDR with the ideal packing coefficient based on the 55% rule, and that this resulted in the most potent in vitro activity.

Novel nonsecosteroidal vitamin D3 carboxylic acid analogs for osteoporosis, and SAR analysis.

Novel vitamin D(3) analogs with carboxylic acid were explored, focusing on a nonsecosteroidal analog, LG190178, with a bisphenyl skeleton. From X-ray analysis of these analogs with vitamin D receptor (VDR), the carboxyl groups had very unique hydrogen bonding interactions in VDR and mimicked 1α-hydroxy group and/or 3ß-hydroxy group of 1α,25-dihydroxyvitamin D(3). A highly potent analog, 6a, with good in vitro activity and pharmacokinetic profiles was identified from an SAR study. Compound 6a showed significant prevention of bone loss in a rat osteoporosis model by oral administration.

Persisting ratio of total amylase output in drain fluid can predict postoperative clinical pancreatic fistula.

BACKGROUND/PURPOSE: A consistent predictor for pancreatic fistula (PF) development in the early period after pancreatic resection is still lacking. PATIENTS AND METHODS: A total of 54 consecutive patients undergoing pancreatic resection were enrolled between June 2007 and April 2010. Pancreaticoduodenectomy (PD) and distal pancreatectomy (DP) were performed in 38 and 16 patients, respectively. For the purpose of finding an early predictor for PF development, we investigated drain amylase levels (d-Amy, IU/mL), drain output volume (d-Vol, mL/day) and drain amylase output (Amy-V, IU/day) on postoperative days (POD) 1 and 3. Amy-V was calculated as the product of d-Amy and d-Vol, and was expressed as the sum of values obtained from all drains. In addition, the ratio of d-Amy or Amy-V on POD3 to that on POD1 was calculated as the persisting ratio in each patient. RESULTS: The overall incidence of clinical PF (International Study Group on Pancreatic Fistula Grade B and C) was 16.7%, occurring in 13.1% after PD and 25% after DP. All PF occurred in cases with a remnant pancreas of soft texture. There was no significant difference in d-Amy, d-Vol, or Amy-V on POD1 and POD3 between patients with and without clinical PF. The persisting ratio of Amy-V was significantly lower in patients without clinical PF compared to those with clinical PF (p = 0.029). Furthermore, the persisting ratio of Amy-V was significantly lower in patients with Grade A PF compared to those with Grade B PF (p = 0.03). CONCLUSION: The persisting ratio of drain amylase output is a new significant predictive factor for clinical PF development.

Slow parenchymal flattening technique for distal pancreatectomy using an endopath stapler: simple and safe technical management.

BACKGROUNDS/AIMS: The appropriate closure of the pancreatic remnant after a distal pancreatectomy remains controversial. To describe a safer and simple distal pancreatectomy using an endopath stapler, with special emphasis on the slow parenchymal flattening technique. METHODOLOGY: The slow parenchymal flattening technique (SFT) for a distal pancreatectomy using an endopath stapler (Echelon 60) was applied to avoid a destruction of pancreas capsule and parenchyma for a soft friable pancreas. In this technique, the pancreas was gently compressed with an atraumatic intestinal clamp for a few minutes prior to the stapling dissection. Then, the closure jaw of endopath stapler was closed carefully and slowly taking more than 5 minutes at the fixed speed before dissection. RESULTS: SFT using the Echelon 60 was performed for 22 consecutive patients who required a distal pancreatectomy. Only one patient (4.5%) developed a symptomatic pancreatic fistula (ISGPF classification grade B). There were no mortalities or severe pancreatic fistula (ISGPF classification grade C) in this series. CONCLUSIONS: The SFT using the Echelon 60 can be performed easily, which enables surgeons to achieve confident pancreas stump without any tissue injury.

Detection of hepatocellular carcinoma using 11C-choline PET: comparison with 18F-FDG PET.

UNLABELLED: The purpose of this study was to retrospectively investigate the feasibility of 11C-choline PET, compared with 18F-FDG PET, for the detection of hepatocellular carcinoma (HCC). METHODS: A total of 16 HCC lesions in 12 patients were examined with both 11C-choline PET and 18F-FDG PET. Tumor lesions were identified as areas of focally increased uptake, exceeding that of surrounding noncancerous liver tissue. For semiquantitative analysis, the tumor-to-liver (T/L) ratio was calculated by dividing the maximal standardized uptake value (SUV) in HCC lesions by the mean SUV in noncancerous liver tissue. RESULTS: 11C-choline PET showed a slightly higher detection rate than did 18F-FDG PET for detection of HCC (63% vs. 50%, respectively), although this difference was not statistically significant. 11C-choline PET had a better detection rate for moderately differentiated HCC lesions but not for those poorly differentiated (75% vs. 25%, respectively). In contrast, 18F-FDG PET exhibited the opposite behavior, with corresponding detection rates of 42% and 75%, respectively. The mean 11C-choline SUV and T/L ratio in moderately differentiated HCC lesions were higher than those in poorly differentiated HCC lesions. In contrast, the mean 18F-FDG SUV and T/L ratio in poorly differentiated HCC were higher than those in moderately differentiated HCC. These differences, however, were also not statistically significant. CONCLUSION: 11C-choline PET had a better detection rate for moderately differentiated HCC lesions but not for poorly differentiated HCC lesions, whereas 18F-FDG PET produced the opposite result. 11C-choline is a potential tracer to complement 18F-FDG in detection of HCC lesions.

Systematic solution-phase parallel synthesis of active vitamin D3 analogs with elongated side chains and their cell differentiation activities.

Side-chain elongation of active vitamin D3 is acknowledged as a structural modification to enhance its cell differentiation activity; however, the comprehensive structure-activity relationship (SAR) as a result of this modification has not been reported. To clarify the SAR, we synthesized six analogs systematically elongated at the 24-position, 26,27-position, or both by methylene (normal A-ring series 1a-f) in a facile parallel solution-phase synthesis. Using parallel synthesis, we expanded the side chain-elongation study into two 19-exomethylene analog series: 19-nor-A-ring (4a-f) and 2-methylene-19-nor-A-ring (5a-f). In the 19-nor-A-ring analog series, the SAR induced by side-chain elongation was similar to the normal A-ring analog series, but in the 2-methylene-19-nor-A-ring series, the SAR was unique.

Discovery and structure-activity relationship of coumarin derivatives as TNF-alpha inhibitors.

The discovery and structure-activity relationship of a novel series of coumarin-based TNF-alpha inhibitors is described. Starting from the initial lead 1a, various derivatives were prepared surrounding the coumarin core structure to optimize the in vitro inhibitory activity of TNF-alpha production by human peripheral blood mononuclear cells (hPBMC), stimulated by bacterial lipopolysaccharide (LPS). Selected compounds also demonstrated in vivo inhibition of TNF-alpha production in rats.