Ketoreductase-Catalyzed Access to Axially Chiral 2,6-Disubstituted Spiro[3.3]heptane Derivatives

The desymmetrization of a prochiral 6-oxaspiro[3.3]heptane-2-carboxylic acid derivative via biocatalytic ketoreductase-mediated reduction has provided access to both enantiomers in high ee. The axially chiral alcohol was converted to the corresponding ester alcohol, amino acid, and amino alcohol building blocks while high enantiopurity was maintained.

Discovery of Novel, Orally Bioavailable Pyrimidine Ether-Based Inhibitors of ELOVL1

In our efforts to identify novel small molecule inhibitors for the treatment of adrenoleukodystrophy (ALD), we conducted a high-throughput radiometric screen for inhibitors of elongation of very long chain fatty acid 1 (ELOVL1) enzyme. We developed a series of highly potent, central nervous system (CNS)-penetrant pyrimidine ether-based compounds with favorable pharmacokinetics culminating in compound 22. Compound 22 is a selective inhibitor of ELOVL1, reducing C26:0 VLCFA synthesis in ALD patient fibroblasts and lymphocytes in vitro. Compound 22 reduced C26:0 lysophosphatidyl choline (LPC), a subtype of VLCFA, in the blood of ATP binding cassette transporter D1 (ABCD1) KO mice, a murine model of ALD to near wild-type levels. Compound 22 is a low-molecular-weight, potent ELOVL1 inhibitor that may serve as a useful tool for exploring therapeutic approaches to the treatment of ALD.

Discovery and Optimization of Pyrazole Amides as Inhibitors of ELOVL1

Accumulation of very long chain fatty acids (VLCFAs) due to defects in ATP binding cassette protein D1 (ABCD1) is thought to underlie the pathologies observed in adrenoleukodystrophy (ALD). Pursuing a substrate reduction approach based on the inhibition of elongation of very long chain fatty acid 1 enzyme (ELOVL1), we explored a series of thiazole amides that evolved into compound 27─a highly potent, central nervous system (CNS)-penetrant compound with favorable in vivo pharmacokinetics. Compound 27 selectively inhibits ELOVL1, reducing C26:0 VLCFA synthesis in ALD patient fibroblasts, lymphocytes, and microglia. In mouse models of ALD, compound 27 treatment reduced C26:0 VLCFA concentrations to near-wild-type levels in blood and up to 65% in the brain, a disease-relevant tissue. Preclinical safety findings in the skin, eye, and CNS precluded progression; the origin and relevance of these findings require further study. ELOVL1 inhibition is an effective approach for normalizing VLCFAs in models of ALD.

Design and Synthesis of a Novel Series of Orally Bioavailable, CNS-Penetrant, Isoform Selective Phosphoinositide 3-Kinase γ (PI3Kγ) Inhibitors with Potential for the Treatment of Multiple Sclerosis (MS)

The lipid kinase phosphoinositide 3-kinase γ (PI3Kγ) has attracted attention as a potential target to treat a variety of autoimmune disorders, including multiple sclerosis, due to its role in immune modulation and microglial activation. By minimizing the number of hydrogen bond donors while targeting a previously uncovered selectivity pocket adjacent to the ATP binding site of PI3Kγ, we discovered a series of azaisoindolinones as selective, brain penetrant inhibitors of PI3Kγ. This ultimately led to the discovery of 16, an orally bioavailable compound that showed efficacy in murine experimental autoimmune encephalomyelitis (EAE), a preclinical model of multiple sclerosis.

Second-generation antibacterial benzimidazole ureas: discovery of a preclinical candidate with reduced metabolic liability

Compound 3 is a potent aminobenzimidazole urea with broad-spectrum Gram-positive antibacterial activity resulting from dual inhibition of bacterial gyrase (GyrB) and topoisomerase IV (ParE), and it demonstrates efficacy in rodent models of bacterial infection. Preclinical in vitro and in vivo studies showed that compound 3 covalently labels liver proteins, presumably via formation of a reactive metabolite, and hence presented a potential safety liability. The urea moiety in compound 3 was identified as being potentially responsible for reactive metabolite formation, but its replacement resulted in loss of antibacterial activity and/or oral exposure due to poor physicochemical parameters. To identify second-generation aminobenzimidazole ureas devoid of reactive metabolite formation potential, we implemented a metabolic shift strategy, which focused on shifting metabolism away from the urea moiety by introducing metabolic soft spots elsewhere in the molecule. Aminobenzimidazole urea 34, identified through this strategy, exhibits similar antibacterial activity as that of 3 and did not label liver proteins in vivo, indicating reduced/no potential for reactive metabolite formation.

Comparison of adaptive pacing therapy, cognitive behaviour therapy, graded exercise therapy, and specialist medical care for chronic fatigue syndrome (PACE): a randomised trial

BACKGROUND

Trial findings show cognitive behaviour therapy (CBT) and graded exercise therapy (GET) can be effective treatments for chronic fatigue syndrome, but patients' organisations have reported that these treatments can be harmful and favour pacing and specialist health care. We aimed to assess effectiveness and safety of all four treatments.

METHODS

In our parallel-group randomised trial, patients meeting Oxford criteria for chronic fatigue syndrome were recruited from six secondary-care clinics in the UK and randomly allocated by computer-generated sequence to receive specialist medical care (SMC) alone or with adaptive pacing therapy (APT), CBT, or GET. Primary outcomes were fatigue (measured by Chalder fatigue questionnaire score) and physical function (measured by short form-36 subscale score) up to 52 weeks after randomisation, and safety was assessed primarily by recording all serious adverse events, including serious adverse reactions to trial treatments. Primary outcomes were rated by participants, who were necessarily unmasked to treatment assignment; the statistician was masked to treatment assignment for the analysis of primary outcomes. We used longitudinal regression models to compare SMC alone with other treatments, APT with CBT, and APT with GET. The final analysis included all participants for whom we had data for primary outcomes. This trial is registered at http://isrctn.org, number ISRCTN54285094.

FINDINGS

We recruited 641 eligible patients, of whom 160 were assigned to the APT group, 161 to the CBT group, 160 to the GET group, and 160 to the SMC-alone group. Compared with SMC alone, mean fatigue scores at 52 weeks were 3·4 (95% CI 1·8 to 5·0) points lower for CBT (p = 0·0001) and 3·2 (1·7 to 4·8) points lower for GET (p = 0·0003), but did not differ for APT (0·7 [-0·9 to 2·3] points lower; p = 0·38). Compared with SMC alone, mean physical function scores were 7·1 (2·0 to 12·1) points higher for CBT (p = 0·0068) and 9·4 (4·4 to 14·4) points higher for GET (p = 0·0005), but did not differ for APT (3·4 [-1·6 to 8·4] points lower; p=0·18). Compared with APT, CBT and GET were associated with less fatigue (CBT p = 0·0027; GET p = 0·0059) and better physical function (CBT p=0·0002; GET p<0·0001). Subgroup analysis of 427 participants meeting international criteria for chronic fatigue syndrome and 329 participants meeting London criteria for myalgic encephalomyelitis yielded equivalent results. Serious adverse reactions were recorded in two (1%) of 159 participants in the APT group, three (2%) of 161 in the CBT group, two (1%) of 160 in the GET group, and two (1%) of 160 in the SMC-alone group.

INTERPRETATION

CBT and GET can safely be added to SMC to moderately improve outcomes for chronic fatigue syndrome, but APT is not an effective addition.

FUNDING

UK Medical Research Council, Department of Health for England, Scottish Chief Scientist Office, Department for Work and Pensions.

Novel antibacterial azetidine lincosamides

The synthesis and evaluation of novel azetidine lincosamides 1 are described. Eleven new (3-trans-alkyl)azetidine-2-carboxylic acids were synthesized via alkylation of N-TBS-4-oxo-azetidine-2-carboxylic acid and subsequent elaboration then coupled to 7-chloro-1-methylthio-lincosamine. The resulting lincosamides differ from the drug clindamycin in both the size of the ring and the position/structure of the alkyl side-chain. SAR within the series was explored with attention to alkyl variants in positions 1 and 3 of the azetidine ring.

Cognitive behavioural therapy in chronic fatigue syndrome: a randomised controlled trial of an outpatient group programme

OBJECTIVES

To test the hypothesis that group cognitive behavioural therapy (CBT) will produce an effective and cost-effective management strategy for patients in primary care with chronic fatigue syndrome/myalgic encephalopathy (CFS/ME).

DESIGN

A double-blind, randomised controlled trial was adopted with three arms. Outcomes were assessed at baseline and 6 and 12 months after first assessment and results were analysed on an intention-to-treat basis.

SETTING

A health psychology department for the management of chronic illness in a general hospital in Bristol, UK.

PARTICIPANTS

Adults with a diagnosis of CFS/ME referred by their GP.

INTERVENTIONS

The three interventions were group CBT incorporating graded activity scheduling, education and support group (EAS) and standard medical care (SMC).

OUTCOME MEASURES

The primary outcome measure was the Short Form with 36 Items (SF-36) physical and mental health summary scales. Other outcome measures included the Chalder fatigue scale, Hospital Anxiety and Depression Scale, General Health Questionnaire, physical function (shuttles walked, walking speed and perceived fatigue), health utilities index and cognitive function (mood, recall and reaction times).

RESULTS

A total of 153 patients were recruited to the trial and 52 were randomised to receive CBT, 50 to EAS and 51 to SMC. Twelve patients failed to attend for the 12-month follow-up and 19 patients attended one follow-up, but not both. The sample was found to be representative of the patient group and the characteristics of the three groups were similar at baseline. Three outcome measures, SF-36 mental health score, Chalder fatigue scale and walking speed, showed statistically significant differences between the groups. Patients in the CBT group had significantly higher mental health scores [difference +4.35, 95% confidence interval (CI) +0.72 to +7.97, p = 0.019], less fatigue (difference -2.61, 95% CI -4.92 to -0.30, p = 0.027) and were able to walk faster (difference +2.83 shuttles, 95% CI +1.12 to +5.53, p = 0.0013) than patients in the SMC group. CBT patients also walked faster and were less fatigued than those randomised to EAS (walking speed: difference +1.77, 95% CI +0.025 to +3.51, p = 0.047; fatigue: difference -3.16, 95% CI -5.59 to -0.74, p = 0.011). Overall, no other statistically significant difference across the groups was found, although for many measures a trend towards an improved outcome with CBT was seen. Except for walking speed, which, on average, increased by +0.87 shuttles (95% CI +0.09 to +1.65, p = 0.029) between the 6- and 12-month follow-ups, the scores were similar at 6 and 12 months. At baseline, 30% of patients had an SF-36 physical score within the normal range and 52% had an SF-36 mental health score in the normal range. At 12 months, the physical score was in the normal range for 46% of the CBT group, 26% of the EAS group and 44% of SMC patients. For mental health score the percentages were CBT 74%, EAS 67% and SMC 70%. Of the CBT group, 32% showed at least a 15% increase in physical function and 64% achieved a similar improvement in their mental health. For the EAS and SMC groups, this improvement in physical and mental health was achieved for 40 and 60% (EAS) and 49 and 53% (SMC), respectively. The cost-effectiveness of the intervention proved very difficult to assess and did not yield reliable conclusions.

CONCLUSIONS

Group CBT did not achieve the expected change in the primary outcome measure as a significant number did not achieve scores within the normal range post-intervention. The treatment did not return a significant number of subjects to within the normal range on this domain; however, significant improvements were evident in some areas. Group CBT was effective in treating symptoms of fatigue, mood and physical fitness in CFS/ME. It was found to be as effective as trials using individual therapy in these domains. However, it did not bring about improvement in cognitive function or quality of life. There was also evidence of improvement in the EAS group, which indicates that there is limited value in the non-specific effects of therapy. Further research is needed to develop better outcome measures, assessments of the broader costs of the illness and a clearer picture of the characteristics best fitted to this type of intervention.

Conformationally restricted analogs of deoxynegamycin

Deoxynegamycin (1b) is a protein synthesis inhibitor with activity against Gram-negative (GN) bacteria. A series of conformationally restricted analogs were synthesized to probe its bioactive conformation. Indeed, some of the constrained analogs were found to be equal or better than deoxynegamycin in protein synthesis assay (1b, IC(50)=8.2 microM; 44, IC(50)=6.6 microM; 35e(2), IC(50)=1 microM). However, deoxynegamycin had the best in vitro whole cell antibacterial activity (Escherichia coli, MIC=4-16 microg/mL; Klebsiella pneumoniae, MIC=8 microg/mL) suggesting that other factors such as permeation may also be contributing to the overall whole cell activity. A new finding is that deoxynegamycin is efficacious in an E. coli murine septicemia model (ED(50)=4.8 mg/kg), providing further evidence of the favorable in vivo properties of this class of molecules.

N- and C-terminal modifications of negamycin

Negamycin 1 is a bactericidal antibiotic with activity against Gram-negative bacteria, and served as a template in an antibiotic discovery program. An orthogonally protected beta-amino acid derivative 3a was synthesized and used in parallel synthesis of negamycin derivatives on solid support. This advanced intermediate was also used for N- and C-terminal modifications using solution-phase methodologies. The N-terminal modifications have resulted in the identification of active analogues, whereas the C-terminal modifications resulted in complete loss of antibacterial activity. The N-methyl negamycin analogue, 19a, inhibits protein synthesis (IC(50)=2.3 microM), has antibacterial activity (Escherichia coli, MIC=16 microgram/mL), and is efficacious in an E. coli murine septicemia model (ED(50)=16.3mg/kg).

Antimalarial sulfide, sulfone, and sulfonamide trioxanes

A series of trioxanes featuring sulfide, sulfone, and sulfonamide substituents in diverse positions has been prepared. Structure-activity relationship (SAR) generalizations highlight two major factors controlling the antimalarial potency of these new chemical entities: (1) the proximity of the sulfur-containing substituent to the crucial peroxide bond and (2) the oxidation state of the sulfur-containing substituent. Generally, sulfones are more antimalarially potent than the corresponding sulfides.

Antimalarial, antiproliferative, and antitumor activities of artemisinin-derived, chemically robust, trioxane dimers

Nine C-10 non-acetal derivatives of the natural trioxane artemisinin (1) were prepared as dimers using some novel chemistry. As designed, each dimer was stable chemically. C-10 Olefinic dimers 7 and C-10 saturated dimers 8-13 all showed good to excellent antimalarial and antiproliferative activities in vitro. Dimers 8, 10, and 12 were especially potent and selective at inhibiting growth of some human cancer cell lines in the NCI in vitro 60-cell line assay.

Antimalarial cyclic peroxy ketals

Over 20 new, cyclic, peroxy ketals have been prepared via a two-step protocol starting with readily available aryl methyl ketones. Structure-activity correlations using in vitro antimalarial data as a guide for optimization of potency have led to the design and synthesis of seven new peroxides that have IC50 values of 31-85 nM (artemisinin IC50 = 8.4 nM). Some SAR generalizations are discussed.