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1.
J Am Chem Soc ; 141(3): 1201-1206, 2019 01 23.
Article in English | MEDLINE | ID: mdl-30601002

ABSTRACT

The alkylation of amines with either alcohols or carboxylic acids represents a mild and safe alternative to the use of genotoxic alkyl halides and sulfonate esters. Here we report two complementary one-pot systems in which the reductive aminase (RedAm) from Aspergillus oryzae is combined with either (i) a 1° alcohol/alcohol oxidase (AO) or (ii) carboxylic acid/carboxylic acid reductase (CAR) to affect N-alkylation reactions. The application of both approaches has been exemplified with respect to substrate scope and also preparative scale synthesis. These new biocatalytic methods address issues facing alternative traditional synthetic protocols such as harsh conditions, overalkylation and complicated workup procedures.


Subject(s)
Alcohols/chemistry , Amines/chemical synthesis , Carboxylic Acids/chemistry , Oxidoreductases Acting on CH-NH2 Group Donors/chemistry , Alcohol Oxidoreductases/chemistry , Alkylation , Aspergillus oryzae/enzymology , Biocatalysis , Molecular Structure , Oxidoreductases/chemistry
2.
J Med Chem ; 61(9): 3823-3841, 2018 05 10.
Article in English | MEDLINE | ID: mdl-29683659

ABSTRACT

ATM inhibitors, such as 7, have demonstrated the antitumor potential of ATM inhibition when combined with DNA double-strand break-inducing agents in mouse xenograft models. However, the properties of 7 result in a relatively high predicted clinically efficacious dose. In an attempt to minimize attrition during clinical development, we sought to identify ATM inhibitors with a low predicted clinical dose (<50 mg) and focused on strategies to increase both ATM potency and predicted human pharmacokinetic half-life (predominantly through the increase of volume of distribution). These efforts resulted in the discovery of 64 (AZD0156), an exceptionally potent and selective inhibitor of ATM based on an imidazo[4,5- c]quinolin-2-one core. 64 has good preclinical phamacokinetics, a low predicted clinical dose, and a high maximum absorbable dose. 64 has been shown to potentiate the efficacy of the approved drugs irinotecan and olaparib in disease relevant mouse models and is currently undergoing clinical evaluation with these agents.


Subject(s)
Ataxia Telangiectasia Mutated Proteins/antagonists & inhibitors , Drug Design , Pyridines/pharmacokinetics , Quinolines/pharmacokinetics , Quinolones/pharmacology , Quinolones/pharmacokinetics , Administration, Oral , Ataxia Telangiectasia Mutated Proteins/chemistry , Ataxia Telangiectasia Mutated Proteins/metabolism , Biological Availability , Humans , Inhibitory Concentration 50 , Models, Molecular , Protein Conformation , Protein Kinase Inhibitors , Pyridines/administration & dosage , Pyridines/chemistry , Quinolines/administration & dosage , Quinolines/chemistry , Quinolones/administration & dosage , Quinolones/chemistry , Structure-Activity Relationship , Substrate Specificity
3.
Org Biomol Chem ; 14(1): 105-12, 2016 Jan 07.
Article in English | MEDLINE | ID: mdl-26537532

ABSTRACT

The catalysis of reactions involving fluoropyruvate as donor by N-acetyl neuraminic acid lyase (NAL) variants was investigated. Under kinetic control, the wild-type enzyme catalysed the reaction between fluoropyruvate and N-acetyl mannosamine to give a 90 : 10 ratio of the (3R,4R)- and (3S,4R)-configured products; after extended reaction times, equilibration occurred to give a 30 : 70 mixture of these products. The efficiency and stereoselectivity of reactions of a range of substrates catalysed by the E192N, E192N/T167V/S208V and E192N/T167G NAL variants were also studied. Using fluoropyruvate and (2R,3S)- or (2S,3R)-2,3-dihydroxy-4-oxo-N,N-dipropylbutanamide as substrates, it was possible to obtain three of the four possible diastereomeric products; for each product, the ratio of anomeric and pyranose/furanose forms was determined. The crystal structure of S. aureus NAL in complex with fluoropyruvate was determined, assisting rationalisation of the stereochemical outcome of C-C bond formation.


Subject(s)
Biocatalysis , Imino Furanoses/metabolism , Imino Pyranoses/metabolism , Oxo-Acid-Lyases/metabolism , Pyruvates/metabolism , Imino Furanoses/chemistry , Imino Pyranoses/chemistry , Molecular Conformation , Pyruvates/chemistry , Stereoisomerism
4.
ChemCatChem ; 7(4): 579-583, 2015 Feb.
Article in English | MEDLINE | ID: mdl-27547270

ABSTRACT

Although the range of biocatalysts available for the synthesis of enantiomerically pure chiral amines continues to expand, few existing methods provide access to secondary amines. To address this shortcoming, we have over-expressed the gene for an (R)-imine reductase [(R)-IRED] from Streptomyces sp. GF3587 in Escherichia coli to create a recombinant whole-cell biocatalyst for the asymmetric reduction of prochiral imines. The (R)-IRED was screened against a panel of cyclic imines and two iminium ions and was shown to possess high catalytic activity and enantioselectivity. Preparative-scale synthesis of the alkaloid (R)-coniine (90 % yield; 99 % ee) from the imine precursor was performed on a gram-scale. A homology model of the enzyme active site, based on the structure of a closely related (R)-IRED from Streptomyces kanamyceticus, was constructed and used to identify potential amino acids as targets for mutagenesis.

5.
BMJ Case Rep ; 20132013 Dec 13.
Article in English | MEDLINE | ID: mdl-24334522

ABSTRACT

The majority of ingested foreign bodies pass of their own accord without causing any adverse impact on the patient, while others present a greater management dilemma. We present a case of a 36-year-old man admitted to the hospital with a 10-day history of colicky abdominal pain following voluntary ingestion of multiple pairs of vinyl gloves. The plain-film abdominal X-ray confirmed small bowel obstruction and gastric bezoar. After failed conservative management he opted for endoscopic retrieval. Following exposure to stomach acid the gloves had lost their structural integrity becoming hard, sharp and brittle. As a result endoscopic removal was abandoned due to the risk of traumatic injury to the oesophagus. A midline laparotomy was performed and the gloves were retrieved via enterotomy. While many foreign bodies are suitable for endoscopic extraction this case demonstrates that the retrieval of vinyl gloves is unlikely to be successful due to significant chemical change.


Subject(s)
Bezoars/etiology , Foreign Bodies/etiology , Ileal Diseases/etiology , Intestinal Obstruction/etiology , Pica/complications , Adult , Bezoars/surgery , Conversion to Open Surgery , Foreign Bodies/surgery , Gastroscopy , Humans , Ileal Diseases/surgery , Intestinal Obstruction/surgery , Intestinal Perforation/etiology , Intestinal Perforation/surgery , Male , Treatment Outcome
6.
BMJ Case Rep ; 20132013 Aug 09.
Article in English | MEDLINE | ID: mdl-23933859

ABSTRACT

A 77-year-old edentulous man presented to the accident and emergency department with a sudden onset of sharp right-sided abdominal pain. The patient reported a change in his bowel habit with constipation over a 6 month period but did not report any significant choking event or ingestion of a foreign body in the preceding months. On examination the patient was maximally tender with guarding over McBurneys point. CT scan showed an abnormal segment of distal ileum with a 3 cm high attenuation focus which had penetrated the bowel wall. At laparotomy the patient was found to have a perforation of his distal ileum caused by an ingested toothpick. Patients wearing dental plates or dentures are at higher risk of toothpick ingestion due to impaired palatal sensation. CT scanning, in the appropriate setting, may aid diagnosis and lower operator risk of sharp related injury at the time of operation.


Subject(s)
Foreign Bodies/diagnostic imaging , Ileal Diseases/diagnostic imaging , Intestinal Perforation/diagnostic imaging , Aged , Eating , Foreign Bodies/complications , Humans , Ileal Diseases/etiology , Ileum/diagnostic imaging , Ileum/injuries , Intestinal Perforation/etiology , Male , Radiography
7.
Org Lett ; 13(20): 5456-9, 2011 Oct 21.
Article in English | MEDLINE | ID: mdl-21932768

ABSTRACT

A one-pot, two-step catalytic protocol has been developed. A regioselective Heck coupling between aryl bromides and allyl alcohol leads to the generation of arylated allyl alcohols that in situ isomerize to give aldehydes, which then undergo an acylation reaction with a second aryl bromide. A variety of aryl bromides can be employed in both the initial Heck reaction and the acylation, providing easy access to a wide variety of substituted dihydrochalcones.


Subject(s)
Chalcones/chemical synthesis , Hydrocarbons, Brominated/chemistry , Propanols/chemistry , Acylation , Catalysis , Chalcones/chemistry , Combinatorial Chemistry Techniques , Molecular Structure , Palladium/chemistry , Stereoisomerism
8.
Molecules ; 15(4): 2453-72, 2010 Apr 08.
Article in English | MEDLINE | ID: mdl-20428055

ABSTRACT

Chiral amines are one of the ubiquitous functional groups in fine chemical, pharmaceutical and agrochemical products, and the most convenient, economical, and eco-benign synthetic pathway to these amines is direct asymmetric reductive amination (DARA) of prochiral ketones. This paper shows that a wide range of aliphatic ketones can be directly aminated under hydrogenation conditions, affording chiral amines with good to excellent yields and with enantioselectivities up to 96% ee. The catalysis is effected by the cooperative action of a cationic Cp*Ir(III) complex and its phosphate counteranion.


Subject(s)
Amines/chemistry , Iridium/chemistry , Ketones/chemistry , Phosphates/chemistry , Catalysis , Hydrogenation
9.
BMJ Case Rep ; 20102010.
Article in English | MEDLINE | ID: mdl-22242063

ABSTRACT

A 76-year-old female patient with diabetes presented with pyrexia and a recurrent painful right sided loin swelling. One year previously she had undergone radiological drainage of a large right sided loin abscess. At index presentation she was investigated both radiologically and endoscopically and a source for the abscess was not found. On this presentation, a computed tomography scan confirmed a large retroperitoneal abscess pointing through the lateral abdominal wall musculature. Surgical drainage was undertaken whereby the abscess was drained and several large gallstones extruded through the incision. The patient subsequently recuperated and the wound has healed successfully by second intention. Five years previously the patient had undergone an "uncomplicated" laparoscopic cholecystectomy. This case highlights the catastrophic late effects of dropped gallstones during laparoscopic cholecystectomy.

10.
J Am Chem Soc ; 128(33): 10638-9, 2006 Aug 23.
Article in English | MEDLINE | ID: mdl-16910632

ABSTRACT

The synthesis of a triglycosylated helical foldamer based on a combination of cyclopentyl- and pyrrolidinyl-based amino acids is described. This structure is stable in water, maintaining as it does a series of carbohydrate units in proximity to one another, and represents the basis of a new approach to the study of carbohydrate-carbohydrate interactions.


Subject(s)
Carbohydrates/chemistry , Peptides/chemistry , Glycosylation , Models, Molecular , Molecular Structure , Protein Folding
11.
JOP ; 5(6): 498-501, 2004 Nov 10.
Article in English | MEDLINE | ID: mdl-15536290

ABSTRACT

CONTEXT: It is rare for ectopic pancreatic tissue to cause symptoms or require treatment, however diseases of normal pancreas may also occur in ectopic pancreas tissue. CASE REPORT: This report describes the clinical, endoscopic, radiologic and histologic features of a pseudocyst occurring in gastric ectopic pancreas in a 19-year-old man. The difficulty and implications of making an accurate pre-operative diagnosis are highlighted. CONCLUSION: Ectopic pancreatic tissue, although rare, should be considered in the differential diagnosis of a submucosal gastric mass.


Subject(s)
Choristoma/complications , Pancreas , Pancreatic Pseudocyst/etiology , Pancreatitis/etiology , Stomach Diseases/complications , Acute Disease , Adult , Choristoma/diagnosis , Choristoma/diagnostic imaging , Choristoma/surgery , Diagnosis, Differential , Dyspepsia/etiology , Gastroscopy , Hematemesis/etiology , Humans , Male , Pancreatic Pseudocyst/diagnosis , Pancreatic Pseudocyst/diagnostic imaging , Pancreatic Pseudocyst/surgery , Pancreatitis/diagnostic imaging , Pancreatitis/surgery , Stomach Diseases/diagnosis , Stomach Diseases/diagnostic imaging , Stomach Diseases/surgery , Tomography, Spiral Computed
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