A randomized,controlled, phase II clinical trial of β‐D‐mannuronic acid (M2000) in pre‐surgical breast cancer patients at early stage (T1‐T2)

Following the potent efficacy of β‐D‐Mannuronic acid in a breast cancer murine model, we evaluated the efficacy of this novel non‐steroidal anti‐inflammatory drug in breast cancer patients in the present clinical trial. The study was an 8‐week randomized, controlled, phase II clinical trial (IRCT: 2017012213739N7 (in 48 pre‐surgical breast cancer patients. Patients who had breast cancer at early stage, with invasive ductal carcinoma, were placed on a waiting‐list for surgery and were allocated to the study. β‐D‐Mannuronic was administrated at a dose of two capsules (1000 mg/d) orally during a period of 8 weeks. The end point of this study was when the patients were admitted for surgery. Moreover, the patients' well‐being status was followed up on for safety. There were no statistically significant differences between treatment and non‐treatment groups at baseline. β‐D‐Mannuronic acid therapy, from 20 patients, showed that in one patient (5%) tumour size was decreased; in five patients (25%) tumour growth was stopped; and in 14 patients (70%) the growth rate in the treatment group did not show significant change, compared to the non‐treatment group. Evaluation of two tumour markers (carcinoembryonic antigen and cancer antigen 15‐3) showed that there was no significant difference between before and after treatment. Although the use of some non‐steroidal anti‐inflammatory drugs in a long time period has shown a prophylactic effect in breast cancer, their therapeutic efficacy in a short time period is unknown, whereas treatment with β‐D‐Mannuronic acid during 8 weeks could show 30% therapeutic effects in pre‐surgical breast cancer patients.     

Synthesis of Novel Oxazolo[4,5‐b]pyridine‐2‐one based 1,2,3‐triazoles as Glycogen Synthase Kinase‐3β Inhibitors with Anti‐inflammatory Potential

A novel series of oxazolo[4,5‐b]pyridine‐2‐one based 1,2,3‐triazoles has been synthesized by click chemistry approach and evaluated for in vitro GSK‐3β inhibitory activity. Compound 4g showed maximum inhibition with IC₅₀ value of 0.19 μ m . Keeping in view the effect of GSK‐3β inhibition on inflammation, compounds 4g , 4d , 4f , 4i , 4n and 4q exhibiting significant GSK‐3β inhibition were examined for in vivo anti‐inflammatory activity in rat paw edema model. The compounds 4g , 4d , 4f and 4i showed pronounced in vivo anti‐inflammatory activity (76.36, 74.54, 72.72 and 70.90%, respectively, after 5h post‐carrageenan administration) and were further found to inhibit the pro‐inflammatory mediators, viz. NO, TNF‐ α , IL‐1 β , and IL‐6 substantially in comparison with indomethacin, an anti‐inflammatory drug as well as SB216763, a GSK‐3 β inhibitor, reported to exert a similar effect. Histopathology studies confirmed the tolerance of gastric mucosa to these compounds.     

New biological investigations on 3‐bromophenyl 6‐acetoxymethyl‐2‐oxo‐2H‐1‐benzopyran‐3‐carboxylate as anti‐angiogenic agent

The development of blood vessels inside tumors is required to provide the nutrients and oxygen needed for tumor growth and to allow the spread of cancer cells at a distance to form metastasis. Angiogenesis is also implicated in ocular diseases like age‐related macular degeneration. The present work describes the potential anti‐angiogenic properties of a coumarinic derivative, 3‐bromophenyl 6‐acetoxymethyl‐2‐oxo‐2H‐1‐benzopyran‐3‐carboxylate (IK9), previously described as a potent inhibitor of HT 1080 fibrosarcoma cell invasion in vitro and tumor growth in vivo. In vivo, ex vivo, and in vitro models were used to delineate the anti‐angiogenic properties of IK9. The anti‐angiogenic effect of IK9 was demonstrated in vivo in a choroidal neovascularization mice model and additionally ex vivo in a rat aortic ring assay where it was more active than the known matrix metalloproteinase inhibitor Ro 28‐2653. IK9 did not affect apoptosis, proliferation, or endothelial cell invasiveness in vitro. These findings suggest a complex mechanism of action of the compound via direct or indirect effects on endothelial cell properties. This study identifies IK9 as a new potent inhibitor of angiogenesis and suggests its potential use as a therapeutic agent. Drug Dev Res 71, 2010. © 2010 Wiley‐Liss, Inc.     

Synthesis of 3,7,8‐15N3‐N1‐(β‐D‐erythro‐pentofuranosyl)‐5‐guanidinohydantoin

3,7,8‐¹⁵N₃‐N¹‐(β‐D‐erythro‐pentofuranosyl)‐5‐guanidinohydantoin was synthesized from the oxidation of 1,7,NH₂‐¹⁵N₃‐8‐oxo‐7,8‐dihydro‐2′‐deoxyguanosine with 2 equivalents of Ir(IV) in pH 4.5 potassium phosphate buffer. The synthesis of 1,7,NH₂‐¹⁵N₃‐8‐oxo‐7,8‐dihydro‐2′‐deoxyguanosine started with bromination of 1,7,NH₂‐¹⁵N₃‐2′‐deoxyguanosine. The resulting 1,7,NH₂‐¹⁵N₃‐8‐bromo‐7,8‐dihydro‐2′‐deoxyguanosine reacted with sodium benzyloxide to afford 1,7,NH₂‐¹⁵N₃‐8‐benzyloxy‐7,8‐dihydro‐2′‐deoxyguanosine. Subsequent catalytic transfer hydrogenation of 1,7,NH₂‐¹⁵N₃‐8‐benzyloxy‐7,8‐dihydro‐2′‐deoxyguanosine with cyclohexene and 10% Pd/C yielded 1,7,NH₂‐¹⁵N₃‐8‐oxo‐7,8‐dihydro‐2′‐deoxyguanosine. Purification of 3,7,8‐¹⁵N₃‐N¹‐(β‐D‐erythro‐pentofuranosyl)‐5‐guanidinohydantoin was first carried out on a C18 column and the product was further purified on a graphite column. ESI‐MS was used to confirm the identity and to determine the isotopic purity of all the labeled compounds. The isotopic purity of 3,7,8‐¹⁵N₃‐N¹‐(β‐D‐erythro‐pentofuranosyl)‐5‐guanidinohydantoin was 99.4 atom% based on LC‐MS measurements. Copyright © 2003 John Wiley & Sons, Ltd.     

Preparation and preliminary biological evaluation of 177Lu‐labeled GluDTPA‐cyclo(RGDfK) for integrin ανβ3 receptor‐positive tumor targeting

Integrin α_νβ₃ is a receptor and is highly expressed on activated and proliferating endothelial cells during the growth and metastasis of solid tumors but not on resting endothelial cells and normal organs. Because RGD peptide binds to integrin α_νβ₃ receptor, a variety of radiolabeled RGD peptides have been evaluated for non‐invasive imaging of integrin α_νβ₃‐positive tumors. In an attempt to develop RGD‐based radiopharmaceuticals, a novel GluDTPA‐cyclo arginine‐glycine‐aspartic acid‐d ‐phenylalanine‐lysine (GluDTPA‐cycloRGDfK) was simply synthesized and radiolabeled with ¹⁷⁷Lu. Also, tumor targeting and retention of the radiolabeled complex were evaluated in U87MG glioma‐bearing mice. The ¹⁷⁷Lu‐labeled GluDTPA‐cyclo(RGDfK) was formulated with a high radiolabeling yield (>98%) under mild condition, and the radiochemical purity was sustained in both saline and serum for over 4 days at 37°C. The radiolabeled compounds were rapidly cleared from the blood pool and non‐target tissue. Tumor‐to‐blood ratio was 12.09 at 2 h post injection and increased to 134.67 at 24 h, while tumor to liver ratio was 2.01 at 24 h similar to that of 2 h. Though it is inappropriate for targeted therapy due to its low uptake in tumor (~ 1 %ID/g), the acceptable results on radiochemistry and biodistribution propose to take a further assessment for non‐invasive imaging and detection of integrin α_νβ₃‐positive tumors by applying diagnostic radionuclides. Copyright © 2011 John Wiley & Sons, Ltd.     

Synthesis and Evaluation of 3‐(furo[2,3‐b]pyridin‐3‐yl)‐4‐(1H‐indol‐3‐yl)‐maleimides as Novel GSK‐3β Inhibitors and Anti‐Ischemic Agents

A series of novel 3‐(furo[2,3‐b]pyridin‐3‐yl)‐4‐(1H‐indol‐3‐yl)‐maleimides were designed, synthesized, and biologically evaluated for their GSK‐3β inhibitory activities. Most compounds showed favorable inhibitory activities against GSK‐3β protein. Among them, compounds 5n , 5o , and 5p significantly reduced GSK‐3β substrate tau phosphorylation at Ser396 in primary neurons, indicating inhibition of cellular GSK‐3β activity. In the in vitro neuronal injury models, compounds 5n , 5o , and 5p prevented neuronal death against glutamate, oxygen–glucose deprivation, and nutrient serum deprivation which are closely associated with cerebral ischemic stroke. In the in vivo cerebral ischemia animal model, compound 5o reduced infarct size by 10% and improved the neurological deficit. The results may provide new insights into the development of novel GSK‐3β inhibitors with potential neuroprotective activity against brain ischemic stroke.     

Synthesis and in vitro evaluation of 2‐[11C]methoxyestradiol‐3,17β‐O,O‐bissulfamate for in vivo studies of angiogenesis

In the present study, 2‐methoxyestradiol‐3,17β‐O,O‐bissulfamate (1), a known angiogenesis inhibitor, was prepared in a radiolabeled form by ¹¹C‐methylation of 2‐hydroxyestradiol‐3,17β‐O,O‐bis(N‐trityl)sulfamate (6) followed by detritylation. Synthesis of precursor 6 required a rather long step because of the presence of two sulfamoyl groups. The decay‐corrected radiochemical yield of [¹¹C]1 was 19 ± 2% based on [¹¹C]CH₃I, and the specific activity was 34–39 GBq/µmol. Although 1 is known to significantly inhibit the proliferation of human umbilical vascular endothelial cells (HUVECs), its radiolabeled form, [¹¹C]1 was not avidly taken up by HUVECs, and the uptake increased slightly in a time‐dependent manner (156% at 60 min relative to a value of 100% at 5 min). These results suggest that further studies are warranted to determine the molecular target for [¹¹C]1. Copyright © 2011 John Wiley & Sons, Ltd.     

Discovery of Novel 2‐(piperidin‐4‐yl)‐1H‐benzo[d]imidazole Derivatives as Potential Anti‐Inflammatory Agents

A novel 2‐(piperidin‐4‐yl)‐1H‐benzo[d]imidazole derivative 5 with good anti‐inflammatory activity was identified from our in‐house library. Based on hit compound 5 , two series of 2‐(piperidin‐4‐yl)‐1H‐benzo[d]imidazole derivative 6a – g and 7a – h were designed and synthesized as novel anti‐inflammatory agents. Most of synthesized compounds exhibited good inhibitory activity on NO and TNF‐α production in LPS‐stimulated RAW 264.7 macrophages, in which the compound 6e showed most potent inhibitory activity on NO (IC₅₀ = 0.86 μm ) and TNF‐α (IC₅₀ = 1.87 μm ) production. Further evaluation revealed that compound 6e displayed more potent in vivo anti‐inflammatory activity than ibuprofen did on xylene‐induced ear oedema in mice. Additionally, Western blot analysis revealed that compound 6e could restore phosphorylation level of IκBα and protein expression of p65 NF‐κB in LPS‐stimulated RAW 264.7 macrophages.     

Chemopreventive efficacy zingerone (4‐[4‐hydroxy‐3‐methylphenyl] butan‐2‐one) in experimental colon carcinogenesis in Wistar rats

Colorectal cancer is one of the most common cancers worldwide. Development of naturally occurring inexpensive and safe alternatives can be effective in suppressing colon related proliferations. Zingerone (4‐[4‐hydroxy‐3‐methylphenyl] butan‐2‐one), a polyphenolic alkanone of ginger, has massive pharmacological properties and thus can be used as promising candidate against various ailments. In the current study, we aimed at demonstrating the protective effect of zingerone against experimental colon carcinogenesis and elucidating its possible mechanism by studying inflammatory and Nrf‐2 signaling cascade. Four groups of animals (I‐IV) were made with six animals each. Group I (control) was given normal saline orally. Group II was given 1,2‐dimethylhydrazine (DMH) at the dose rate of 20 mg/kg body weight. Group III and IV were treated with DMH at the dose rate of 20 mg/kg body weight and also received oral treatment of zingerone at a dose rate of 50 and 100 mg/kg body weight, respectively, for first 5 weeks and animals were euthanized after 16 weeks. Our results reveal that DMH treated rats exhibited elevated ROS and MDA levels, increased activity of cytochrome P450 2E1 and serum marker enzyme carcinoembreyonic antigen (CEA), increased no of aberrant crypts of foci (ACF), and elevated expression of inflammatory and proliferative proteins. Nrf‐2 was downregulated by DMH treatment. Treatment with zingerone to DMH treated rats, resulted in alterations in the activity of the cytochrome P450 2E1 and CEA. In addition, immunostaining of NF‐kB‐p65, COX‐2, iNOS, and PCNA, Ki‐67 was suppressed by zingerone. Furthermore, zingerone administration also attenuated the level of IL‐6 and TNF‐α and it also helps in preserving mucous layer. Thus, zingerone could be considered as a good chemopreventive agent in experimental model of colon carcinogenesis. Further studies are required to study other pathways involved in colon carcinogenesis and their modulation buy zingerone.     

Entrapping unusual folding characteristics of the β‐Ala residues in a model peptide: Boc‐β‐Ala‐Aib‐β‐Ala‐NHCH3

Abstract: Crystal structure analysis of a model peptide: Boc‐β‐Ala‐Aib‐β‐Ala‐NHCH₃ (β‐Ala: 3‐amino propionic acid; Aib: α‐aminoisobutyric acid) revealed distinct conformational preferences for folded [φ≈136°, µ ≈ ?62°, ψ ≈100°] and semifolded [φ ≈ 83°, µ ≈ ?177°, ψ ≈ ?117°] structures of the N‐ and C‐terminus β‐Ala residues, respectively. The overall folded conformation is stabilized by unusual N_i···H‐N_i+1 and nonconventional C–H···O intramolecular hydrogen bonding interactions.     

Natriuretic peptide clearance receptor ligand (C‐ANP4–23) attenuates angiogenesis in a murine sponge implant model

Natriuretic peptide receptor‐C activation by the synthetic ligand C‐ANP‐_4–23, a specific agonist for this receptor, has been shown to inhibit key events of the angiogenic cascade, such as migration, proliferation and vascular endothelial growth factor (VEGF) production. In the present study we investigated whether C‐ANP_4–23 could also inhibit angiogenesis in the sponge model in vivo. To this end, we evaluated the effects of C‐ANP_4–23 on inflammatory and angiogenic components of the fibrovascular tissue induced by polyether polyurethane sponge implants in mice. Measurements of the haemoglobin content (μg/mg wet tissue) and blood flow (laser Doppler perfusion imaging) of the implants, used as an index of vascularization, revealed that single (200 ng) or multiple (200 ng/day, 5 days) doses of C‐ANP_4–23 reduced angiogenesis in the implants relative to the phosphate‐buffered saline‐treated group. The peptide exerted an inhibitory effect on nitric oxide production (nitrite levels) and had a dual effect on VEGF levels, depending on the number of doses (i.e. stimulation at 4 days after one dose; inhibition at 7 days after five doses). Histological analysis corroborated the biochemical and functional parameters indicative of inhibition of neovascularization (decreased vessel number) by C‐ANP_4–23. The peptide failed to modulate inflammation in our system. The inhibitory effect of C‐ANP_4–23 on the angiogenic component of the fibrovascular tissue induced by the synthetic matrix extends the range of the its actions and may indicate its therapeutic potential in controlling angiogenesis in fibroproliferative diseases.     

Detection and metabolic investigations of a novel designer steroid: 3‐chloro‐17α‐methyl‐5α‐androstan‐17β‐ol

In 2012, seized capsules containing white powder were analyzed to show the presence of unknown steroid‐related compounds. Subsequent gas chromatography–mass spectrometry (GC‐MS) and nuclear magnetic resonance (NMR) investigations identified a mixture of 3α‐ and 3β‐ isomers of the novel compound; 3‐chloro‐17α‐methyl‐5α‐androstan‐17β‐ol. Synthesis of authentic reference materials followed by comparison of NMR, GC‐MS and gas chromatography‐tandem mass spectrometry (GC‐MS/MS) data confirmed the finding of a new ‘designer’ steroid. Furthermore, in vitro androgen bioassays showed potent activity highlighting the potential for doping using this steroid. Due to the potential toxicity of the halogenated steroid, in vitro metabolic investigations of 3α‐chloro‐17α‐methyl‐5α‐androstan‐17β‐ol using equine and human S9 liver fractions were performed. For equine, GC‐MS/MS analysis identified the diagnostic 3α‐chloro‐17α‐methyl‐5α‐androstane‐16α,17β‐diol metabolite. For human, the 17α‐methyl‐5α‐androstane‐3α,17β‐diol metabolite was found. Results from these studies were used to verify the ability of GC‐MS/MS precursor‐ion scanning techniques to support untargeted detection strategies for designer steroids in anti‐doping analyses. Copyright © 2015 John Wiley & Sons, Ltd.     

(αMe)Aun: a highly lipophilic,chiral, Cα‐tetrasubstituted α‐amino acid. Incorporation into model peptides and preferred conformation

Abstract: Using a chemo‐enzymatic approach we prepared the highly lipophilic, chiral, C^α‐methylated α‐amino acid (αMe)Aun. Two series of terminally protected model peptides containing either d ‐(αMe)Aun in combination with Aib or l ‐(αMe)Aun in combination with Gly were synthesized using solution methods and fully characterized. A detailed solution conformational analysis, based on FT‐IR absorption, ¹H NMR and CD techniques, allowed us to determine the preferred conformation of this amino acid and the relationship between chirality at its α‐carbon atom and screw sense of the helix that is formed. The results obtained strongly support the view that d ‐(αMe)Aun favors the formation of the left‐handed 3₁₀‐helical conformation.     

Chemoenzymatic n.c.a synthesis of the coenzyme UDP‐2‐deoxy‐2‐[18F]fluoro‐α‐D‐glucopyranose as substrate of glycosyltransferases

The development of ¹⁸F‐labelling methods adopted to proteins and bioactive peptides is of great interest in radiopharmaceutical sciences. In order to provide ¹⁸F‐labelled sugars as a polar prosthetic group for an enzymatic ¹⁸F‐labelling procedure, an appropriate nucleotide activated sugar is needed. Here, we present the radiosynthesis of n.c.a. UDP‐2‐deoxy‐2‐[¹⁸F]fluoro‐α‐D‐glucopyranose (UDP‐[¹⁸F]FDG) as a substrate for glycosyltransferases. The MacDonald synthesis of [¹⁸F]FDG‐1‐phosphate was successfully combined with an enzymatic activation to obtain UDP‐[¹⁸F]FDG directly in an aqueous medium located in the void volume of a solid phase cartridge. The radiochemical yield of UDP‐[¹⁸F]FDG was 20% (based on [¹⁸F]fluoride) after a total synthesis time of 110 min. Thus, an intermediate was provided for the enzymatic transfer of [¹⁸F]FDG using UDP‐[¹⁸F]FDG as glycosyl donor making use of a suitable glycosyltransferase. This would represent a highly selective and mild ¹⁸F‐labelling method for glycosylated biomolecules. Copyright © 2007 John Wiley & Sons, Ltd.     

Discovery of N‐(2‐(Benzylamino)‐2‐oxoethyl)benzamide analogs as a novel scaffold of pancreatic β‐cell protective agents against endoplasmic reticulum stress

Endoplasmic reticulum (ER) stress‐induced pancreatic β‐cell dysfunction and death play important roles in the development of diabetes. The 1,2,3‐triazole derivative 1 is one of only a few structures that have thus far been identified that protect β cells against ER stress. However, this compound has narrow activity range and limited aqueous solubility. To overcome these, we designed and synthesized a new scaffold in which the triazole pharmacophore was substituted with a glycine‐like amino acid. Structure–activity relationship studies on this scaffold identified a N‐(2‐(Benzylamino)‐2‐oxoethyl)benzamide analog WO5m that possesses β‐cell protective activity against ER stress with much improved potency (maximal activity at 100% with EC₅₀ at 0.1 ± 0.01 µm ) and water solubility. Identification of this novel β‐cell protective scaffold thus provides a new promising modality for the treatment of diabetes.     

Virtual screening,SAR, and discovery of 5‐(indole‐3‐yl)‐2‐[(2‐nitrophenyl)amino] [1,3,4]‐oxadiazole as a novel Bcl‐2 inhibitor

A new series of oxadiazoles were designed to act as inhibitors of the anti‐apoptotic Bcl‐2 protein. Virtual screening led to the discovery of new hits that interact with Bcl‐2 at the BH3 binding pocket. Further study of the structure–activity relationship of the most active compound of the first series, compound 1 , led to the discovery of a novel oxadiazole analogue, compound 16j , that was a more potent small‐molecule inhibitor of Bcl‐2. 16j had good in vitro inhibitory activity with submicromolar IC₅₀ values in a metastatic human breast cancer cell line (MDA‐MB‐231) and a human cervical cancer cell line (HeLa). The antitumour effect of 16j is concomitant with its ability to bind to Bcl‐2 protein as shown by an enzyme‐linked immunosorbent assay (IC₅₀ = 4.27 μm ). Compound 16j has a great potential to develop into highly active anticancer agent.     

Simplified synthesis of N‐(3‐[18F]fluoropropyl)‐2β‐carbomethoxy‐3β‐(4‐fluorophenyl)nortropane ([18F]β‐CFT‐FP) using [18F]fluoropropyl tosylate as the labelling reagent

A synthesis method has been developed for the labelling of N‐(3‐[¹⁸F]fluoropropyl)‐2β‐carbomethoxy‐3β‐(4‐fluorophenyl)nortropane ([¹⁸F]β‐CFT‐FP), a potential radioligand for visualization of the dopamine transporters by positron emission tomography. The two‐step synthesis includes preparation of [¹⁸F]fluoropropyl tosylate and its use without purification in the fluoroalkylation of 2β‐carbomethoxy‐3β‐(4‐fluorophenyl)nortropane (nor‐β‐CFT). The final product is purified by HPLC. Optimization of the two synthesis steps resulted in a greater than 30% radiochemical yield of [¹⁸F]β‐CFT‐FP (decay corrected to end of bombardment). The synthesis time including HPLC‐purification was approximately 90 min. The radiochemical purity of the final product was higher than 99% and the specific radioactivity at the end of synthesis was typically 20 GBq/µmol. In comparison to alkylation by [¹⁸F]fluoropropyl bromide, the procedure described here results in an improved overall radiochemical yield of [¹⁸F]β‐CFT‐FP in a shorter time. Copyright © 2005 John Wiley & Sons, Ltd.     

Identification of Fmoc‐β‐Ala‐OH and Fmoc‐β‐Ala‐amino acid‐OH as new impurities in Fmoc‐protected amino acid derivatives*

Abstract: During the manufacture of a proprietary peptide drug substance a new impurity appeared unexpectedly. Investigation of its chemical structure established the impurity as a β‐Ala insertion mutant of the mother peptide. The source of the β‐Ala was identified as contamination of the Fmoc‐Ala‐OH raw material with Fmoc‐β‐Ala‐Ala‐OH. Further studies also demonstrated the presence of β‐Ala in other Fmoc‐amino acids, particularly in Fmoc‐Arg(Pbf)‐OH. In this case, it was due to the presence of both Fmoc‐β‐Ala‐OH and Fmoc‐β‐Ala‐Arg(Pbf)‐OH. It is concluded that β‐Ala contamination of Fmoc‐amino acid derivatives is a general and hitherto unrecognized problem to suppliers of Fmoc‐amino acid derivatives. The β‐Ala is often present as Fmoc‐β‐Ala‐OH and/or as a dipeptide, Fmoc‐β‐Ala‐amino acid‐OH. In collaboration with the suppliers, new specifications were introduced, recognizing the presence of β‐Ala‐related impurities in the raw materials and limiting them to acceptable levels. The implementation of these measures has essentially eliminated β‐Ala contamination as a problem in the manufacture of the drug substance.