Heart Failure With Preserved Ejection Fraction With CKD: A Narrative Review of a Multispecialty Disorder

Heart failure with preserved ejection fraction (HFpEF) is a heterogenous syndrome with varying phenotypic expression. The phenotype chronic kidney disease (CKD) associated HFpEF is increasing in prevalence globally and is associated with increased morbidity and mortality compared to other HFpEF variants. These 2 conditions share common risk factors, including obesity, diabetes, and metabolic syndrome, as well as similar pathophysiology, including systemic inflammation, oxidative stress, elevated neurohormones, mineralocorticoid-receptor activation, and venous congestion. Given the coexistence of CKD and HFpEF, the diagnosis of HFpEF can be difficult. Moreover, treatment options for HFpEF have remained limited despite the success seen in its counterpart, heart failure with reduced ejection fraction. HFpEF encompasses complex multisystem pathophysiological perturbations beyond neurohormones, it is unlikely that a single agent can have significant benefit in this population. Recent data on sodium-glucose cotransporter 2 (SGLT2) inhibitors in HFpEF and CKD, and on glucagon-like peptide-1 (GLP-1) agonists and mineralocorticoid-receptor antagonists in metabolic syndrome, which target multiple pathways simultaneously, have led to promising therapeutics for HFpEF and CKD. In this perspective, our goal is to increase awareness of HFpEF as a multisystem disorder that shares the same disease processes seen in CKD and to emphasize that its management in individuals with CKD warrants a collective and multidisciplinary approach.

Variation in methods used to determine national mean DMFT scores for 12-year-old children in European countries

Aim

The aim of this study was to investigate the methods used to identify national mean DMFT scores for 12-year-old children in all the Member States of the European Union and European Economic Area, and in 11 other European countries.

Methods

The most recent national mean DMFT scores were accessed from the World Health Organisation Oral Health CAPP and the Council of European Chief Dental Officers databanks. A literature search was then performed to access the reports of the studies that had produced these DMFT scores, cited on these databanks. The reports were then analysed to determine: the year in which the survey/study that produced the score took place, the year the results were published, the geographical area (national, regional or local) covered, the number of children examined, how many examiners took part, how they were trained and calibrated, and the criteria used for the detection of caries.

Results

Data and information from 43 European countries were accessed. The years when the studies were performed ranged from 1990 to 2014. There were doubts over the representativeness of some samples. A wide range of different methods were used. Examiner training and calibration were very variable both in terms of duration and reported inter and intra-examiner consistency. There were important variations in the criteria employed for the detection of caries.

Conclusions

These findings support the view that most of current national caries data for DMFT levels in 12-year-old children are not comparable across Europe.

Ultrastructural changes during wood decay by Antrodiella sp. RK1

Southern yellow pine (softwood) and maple (hardwood) wood decayed for 12 weeks by Antrodiella sp. RK1 had average weight losses of 20 and 19%, respectively, and approximately 34 to 35% lignin loss. The ratio of percentage lignin loss to glucose loss was 3.6 and 2.7 for softwood and hardwood, respectively. There was negligible loss of other wood sugars such as xylose, arabinose, galactose and mannose. Scanning electron microscopy revealed the presence of erosion troughs and bore holes in decayed samples of both softwood and hardwood. Secondary walls were void of lignin, middle lamella and cell corners were extensively decayed. Ca(2+) crystals were abundantly present in the areas of decay. Transmission electron micrographs revealed the presence of hyphal sheath and growth of hyphae directly through the cell corners.

Oral health-related quality of life in non-syndromic cleft lip and/or palate patients: a systematic review

THE OBJECTIVE

To evaluate oral health-related quality of life (OHRQoL) in non-syndromic patients with cleft lip and/or palate (CLP), in comparison to a general non-cleft population.

BASIC RESEARCH DESIGN

Systematic review. A literature search was conducted to identify papers reporting on OHRQoL in cleft samples. Only studies with suitable control groups were included. From each included paper were extracted the study and sample characteristics and results.

MAIN OUTCOME MEASURES

OHRQoL score.

RESULTS

Three papers were chosen according to the preset inclusion and exclusion criteria. All used an OHRQoL generic patient-reported questionnaire with evidence of a development and validation process, with responses recorded on a five-point scale. The results could not be combined for the purposes of meta-analysis due to lack of standardisation. In 2 of the 3 studies, the OHRQoL was found to be significantly lower in the cleft than in the non-cleft samples (in patients 8-18 or 18-65 years of age). The third study, based on a relatively small sample size, could not detect significant differences between cleft and non-cleft individuals.

CONCLUSIONS

Based on the results of the few studies included in the present systematic review, non-syndromic patients with CLP tend to have a lower OHRQoL than a general non-cleft population. This seems to hold true both for children and adults.

Growth and Polysaccharide Production by Methylocystis parvus OBBP on Methanol

Methylocystis parvus OBBP, an obligate methylotroph originally isolated as a methane-utilizing bacterium, was cultivated on methanol as a sole source of carbon. After adaptation to high methanol levels, this organism grew on methanol with a maximum specific growth rate of 0.65 h. The pH optimum for growth was between 7 and 9, and the temperature optimum was between 30 and 37 degrees C. Methanol concentrations higher than 5% (by weight) were toxic. Formaldehyde, at a concentration greater than 1 mM, inhibited growth. Formate was neither a substrate nor an inhibitor. An extracellular viscous heteropolysaccharide was produced during growth. The maximum production of the total biomass was 14.5 g (dry weight) per liter of broth. The dried biomass contained 22% (wt/wt) crude protein and 62% (wt/wt) polysaccharide. The main components of the polysaccharide were d-glucose (82%) and l-rhamnose (14%).

Microbial Oxidation of Hydrocarbons: Properties of a Soluble Methane Monooxygenase from a Facultative Methane-Utilizing Organism, Methylobacterium sp. Strain CRL-26

Methylobacterium sp. strain CRL-26 grown in a fermentor contained methane monooxygenase activity in soluble fractions. Soluble methane monooxygenase catalyzed the epoxidation/hydroxylation of a variety of hydrocarbons, including terminal alkenes, internal alkenes, substituted alkenes, branched-chain alkenes, alkanes (C(1) to C(8)), substituted alkanes, branched-chain alkanes, carbon monoxide, ethers, and cyclic and aromatic compounds. The optimum pH and temperature for the epoxidation of propylene by soluble methane monooxygenase were found to be 7.0 and 40 degrees C, respectively. Among various compounds tested, only NADH(2) or NADPH(2) could act as an electron donor. Formate and NAD (in the presence of formate dehydrogenase contained in the soluble fraction) or 2-butanol in the presence of NAD and secondary alcohol dehydrogenase generated the NADH(2) required for the methane monooxygenase. Epoxidation of propylene catalyzed by methane monooxygenase was not inhibited by a range of potential inhibitors, including metal-chelating compounds and potassium cyanide. Sulfhydryl agents and acriflavin inhibited monooxygenase activity. Soluble methane monooxygenase was resolved into three components by ion-exchange chromatography. All three compounds are required for the epoxidation and hydroxylation reactions.

Copper(II) complexes of tridentate N,N,N',N'',N''-pentamethyldiethylenetriamine: superoxide dismutase and inhibitory activity against bacteria and fungi

A series of ternary copper(II) complexes containing same coordination sphere but difference in the counter ions, viz., [Cu(PMDT)(OAc)]PF(6)(1); [Cu(PMDT)(OAc)]ClO(4)(2); [Cu(PMDT)(OAc)]BF(4)(3) and [Cu(PMDT)(OAc)]BPh(4)(4) where PMDT=N,N,N',N'',N''-pentamethyldiethylenetriamine, OAc=Acetate ion were synthesized and characterized by means of spectroscopic, magnetic and cyclic voltammetric measurements. In frozen solution e.p.r. spectra, an interesting relation g|| >g(perpendicular) has been observed which is atypical of the axially symmetric d(9) Cu(II) (S(Cu)=1/2) having an unpaired electron in a d (x2-y2) orbital. Single crystal X-ray analysis of (1) has revealed the presence of distorted square planar geometry. The influence of the counter ion on the complexes has been examined by performing some biological experiments like superoxide dismutase and anti-microbial activity.

Synthesis, characterization and biological activity of ternary copper(II) complexes containing polypyridyl ligands

Ternary copper(II) complexes involving polypyridyl ligands in the coordination sphere of composition [Cu(tpy)(phen)](ClO4)2 (1), [Cu(tpy)(bipy)](ClO4)2 (2), [Cu(tptz)(phen)](ClO4)2 (3) and [Cu(tptz)(bipy)](BF4)2 (4) where tpy = 2,2':6',2''-terpyridine, tptz = 2,4,6-tri(2-pyridyl)-1,3,5-triazine, phen = 1,10-phenanthroline and bipy = 2,2'-bipyridine have been synthesized and characterized by elemental analysis, magnetic susceptibility, X-band e.p.r. spectroscopy and electronic spectroscopy. Single crystal X-ray of (1) has revealed the presence of a distorted square pyramidal geometry in the complex. Magnetic susceptibility measurements at room temperature were in the range of 1.77-1.81 BM. SOD and antimicrobial activities of these complexes were also measured. Crystal data of (1): P-1, a = 9.3010(7) A, b = 9.7900(6) A, c = 16.4620(6) A, Vc = 1342.73(14) A3, Z = 4. The bond distance of CuN in square base is 2+/-0.04 A.

Characterization and biological activities of two copper(II) complexes with diethylenetriamine and 2,2'-bipyridine or 1,10-phenanthroline as ligands

Two new mixed ligand copper(II) complexes with diethylenetriamine, 2,2'-bipyridine and 1,10-phenanthroline have been synthesized. The crystal and molecular structures of [Cu(dien)(phen)](ClO(4))(2) and [Cu(dien)(bipy)](BF(4))(2) (dien=diethylenetriamine, phen=1,10-phenanthroline, bipy=2,2'-bipyridine) were determined by X-ray crystallography from single crystal data. These two complexes have similar structures. The EPR spectral data also suggest that these complexes have distorted square pyramidal geometry about copper(II). Anti-microbial and superoxide dismutase activities of these complexes have also been measured. They show the higher SOD activity than the corresponding simple Cu(II)-dien/Cu(II)-PMDT (PMDT=N,N,N',N',N''-pentamethyldiethylenetriamine) complexes because of a strong axial bond of one of the nitrogen atoms of the alpha-diimine. Both the complexes have been found to cleave plasmid DNA in the presence of co-reductants such as ascorbic acid and glutathione.

Synthesis, spectra and biomimetic properties of copper(II)-copper(II) and copper(II)-zinc(II) binuclear complexes with CuN5 chromophores

X-band electron spin resonance (ESR) and UV-vis spectra of a homobinuclear [(Bipy)2Cu-E-Im-Cu(Bipy)2](BF4)3 and a heterobinuclear [(Bipy)2Cu-E-Im-Zn(Bipy)2](BF4)3 complexes, E-Im=2-ethylimidazolate ion have been described as possible models for superoxide dismutase (SOD). Magnetic moment and ESR spectral measurements of the homobinuclear complex have shown an antiferromagnetic exchange interaction. From pH-dependent ESR and UV-vis spectral measurements studies, these complexes have been found to be stable over 8.5-10.5 pH range. These complexes catalyze the dismutation of superoxide (O2-) at biological pH. All the observations indicate that these complexes act as good possible models for superoxide dismutase.

E.S.R., magnetic, electronic and superoxide dismutase studies of imidazolate-bridged Cu(II)-Cu(II) complexes with ethylenediamine as capping ligand

X-band E.S.R., magnetic and electronic spectra of some imidazolate-bridged homometallic complexes [(en)2Cu-R-Im-Cu(en)2](ClO4)3 where en, ethylenediamine; R-ImH, R = H imidazole (ImH); if R = CH3, 2-methylimidazole (M-ImH) and if R = C2H5, 2-ethylimidazole (E-ImH), and mononuclear complexes [(en)Cu-dien](ClO4)2 and [(en)Cu-PMDT](ClO4)2 where dien, diethylenetriamine; PMDT, pentamethyldiethylenetriamine have been described. Superoxide dismutase (SOD) activity has also been measured and compared with earlier reported complexes. In frozen solution at 77 K, the spectra show axial symmetry with a d(x2-y2) ground state. Difference in lambda(max) between mononuclear and binuclear complexes was found to be approximately 65-75 nm. Magnetic susceptibility and E.S.R. spectral measurements for all these binuclear complexes revealed that the copper(II) ions are involved in antiferromagnetic exchange interactions propagated by the imidazolate bridge.

Chiral chromatographic separation of beta-blockers

A novel amide based chiral stationary phase m-[(+)-alpha-methyl benzyl carboxamide] XAD-4 has been synthesized by covalently linking R(+)-1-phenylethylamine to chloroformoyl Amberlite XAD-4 under weak alkaline conditions. The synthesized resin has been primarily characterized by m.p., elemental analysis and FT-IR and 13C NMR spectra. beta-Blockers viz. atenolol, metoprolol, and propranolol were successfully separated into their enantiomers using a mixture of sodium acetate-acetic acid buffer (pH 4.1):acetonitrile (4:6, v/v) solution using the synthesized resin. Hydrogen bonding and pi-pi interactions are supposed to be the major analyte-chiral stationary phase interactions.

Synthesis, structure and biomimetic properties of Cu(II)–Cu(II) and Cu(II)–Zn(II) binuclear complexes: possible models for the chemistry of Cu–Zn superoxide dismutase

Four imidazolate-bridged binuclear copper(II)-copper(II) and copper(II)-zinc(II) complexes viz., [(Bipy)(2)Cu-Im-Cu(Bipy)(2)](ClO(4))(3).CH(3)OH, [(Phen)(2)Cu-Im-Cu(Phen)(2)](BF(4))(3).2CH(3)OH, [(Bipy)(2)Cu-Im-Zn(Bipy)(2)](BF(4))(3), and [(Phen)(2)Cu-Im-Zn(Phen)(2)](BF(4))(3), (Bipy=2,2'-Bipyridyl, Phen=1-10-Phenanthroline and Im=imidazolate ion) were synthesized as a possible models for superoxide dismutase (SOD). Complex [(Bipy)(2)Cu-Im-Cu(Bipy)(2)](ClO(4))(3).CH(3)OH has been structurally characterized. This complex crystallizes in the triclinic space group P1, with the unit parameters a=8.88(5) A, b=13.79(17) A, c=20.18(18) A, alpha=76.424(8)(o), beta=85.888(6)(o), gamma=82.213(7). The metal-nitrogen bond length from 1.972-2.273 A and the distance Cu-Cu is 5.92 A. The five-coordinate geometry about the copper(II) ion is square pyramidal. Magnetic moment and electron paramagnetic resonance (e.p.r.) spectral measurements of the homobinuclear complexes have shown an antiferromagnetic exchange interaction. From the e.p.r. and UV-Vis spectral measurement studies, these complexes have been found to be stable (pH 8.5-10.5 for 1, 10.5 for 2,3 and 8.5 for 4). These complexes catalyse the dismutation of superoxide radical (O(2)(-)) at biological pH. All the observations indicate that these complexes act as good possible models for superoxide dismutase.

Novel copper(II)-dien-imidazole/imidazolate-bridged copper(II) complexes. Crystal structure of [Cu(dien)(Him)](ClO4)2 and of [(dien)Cu(mu-im)Cu(dien)](ClO4)3, a homobinuclear model for the copper(II) site of the CuZn-superoxide dismutase

The imidazolate-bridged binuclear copper(II)-copper(II) complex [(dien)Cu(mu-im)Cu(dien)](ClO(4))(3) and related mononuclear complexes [Cu(dien)(H(2)O)](ClO(4))(2), [Cu(dien)(Him)](ClO(4))(2) were synthesized with diethylenetriamine (dien) as capping ligand. The crystal structure of mononuclear [Cu(dien)(Him)](ClO(4))(2) and binuclear complex [(dien)Cu(mu-im)Cu(dien)](ClO(4))(3) have been determined by single crystal X-ray diffraction methods. The mononuclear complex [Cu(dien)(Him)](ClO(4))(2) crystallizes in the orthorhombic, Pca2(1) with a = 9.3420(9) A, b = 12.3750(9) A, c = 14.0830(9) A, beta = 90.000(7)(o) and Z = 4 and binuclear complex [(dien)Cu(mu-im)Cu(dien)](ClO(4))(3) crystallizes in the monoclinic space group P2(1)/a, with a = 15.017(7) A, b = 11.938(6) A, c = 15.386(6) A, beta = 110.30(4)(o) and Z = 4. The molecular structures show that copper(II) ions in an asymmetrically elongated octahedral coordination (type 4 + 1 + 1) and in binuclear complex Cu(1) atom has a asymmetrically elongated octahedral coordination (type type 4 + 1 + 1) and Cu(2) atom exhibits a square base pyramidal coordination (type 4 + 1). The bridging ligand (imidazolate ion, im) lies nearly on a straight line between two Cu(2+), which are separated by 5.812 A, slightly shorter than the value in copper-copper superoxide dismutase (Cu(2)-Cu(2)SOD). Magnetic measurements and electron spin resonance (ESR) spectroscopy of the binuclear complex have shown an antiferromagnetic exchange interaction. From pH-dependent cyclic voltametry (CV) and electronic spectroscopic studies the complex has been found to be stable over a wide pH range (7.75-12.50).

X-band electron paramagnetic resonance, optical spectra and some biological (SOD and antimicrobial activity) studies of the copper(II) complexes: a plausible model for superoxide dismutase

The synthesis and characterization of homobinuclear complex by 2-ethylimidazole is reported along with two mononuclear complexes. Magnetic measurements and electron parameter resonance (e.p.r.) spectroscopy of the homobinuclear complex have shown an antiferromagnetic exchange interaction. Superoxide dismutase and antimicrobial activities of these complexes have also been measured.

X-ray, spectral and biological (antimicrobial and superoxide dismutase) studies of oxalato bridged CuII–NiII and CuII–ZnII complexes with pentamethyldiethylenetriamine as capping ligand

X-band electron spin resonance (ESR) and electronic spectra of oxalatobridged heterodinuclear Cu-Ni and Cu-Zn complexes, viz., [(PMDT)Cu-Ox-Ni(PMDT)](BPh(4))(2).2CH(3)CN and [(PMDT)Cu-Ox-Zn(PMDT)](BPh(4))(2).2CH(3)CN, where PMDT=pentamethyldiethylenetriamine, Ox=oxalate ion have been described. Complex [(PMDT)Cu-Ox-Ni(PMDT)](BPh(4))(2).2CH(3)CN has been structurally characterized. This complex crystallizes in the monoclinic space group, C(2) (No. 5) with the unit parameters a=20.445(4) A, b=14.884(3) A, c=23.174(5) A, alpha=90 degrees, beta=102.693(4) degrees, gamma=90 degrees, V=6880(2) A(3) and Z=4. The structure refined to R=0.0354 and R(w)=0.0853 for 21,109 reflections with I>2 sigma(I) using 765 parameters, shows the presence of a MN(3)O(2) chromophore in a distorted trigonal-bipyramidal (TBP) heterometallic complex with oxalate dianion. Taking with an equatorial Cu-O=2.137(8) A and an axial Cu-O=1.961(6) A coordination site at Cu(II) ion and equatorial Ni-O=2.178(7) A and axial Ni-O=1.994 (9) A coordination site at Ni(II) ion. The Cu-Ni distance is 5.3532(9) A and Cu-C(2)O(4)-Ni unit is planar. The [(PMDT)Cu-Ox-Ni(PMDT)](2+) shows the ESR spectrum of the antiferromagnetic spin exchange with each dinuclear delocalization of the unpaired electron over the unit and spin-doublet ground state which demonstrates the Cu-Ox-Ni core. Antimicrobial and superoxide dismutase (SOD) activities of these complexes have also been measured.

E.s.r., magnetic, optical and biological (SOD and antimicrobial) studies of imidazolate bridged Cu(II)-Zn(II) and Cu(II)-Ni(II) complexes with tris(2-amino ethyl)amine as capping ligand: a plausible model for superoxide dismutase

X-band e.s.r. and optical absorption spectra of the imidazolate bridged heterobimetallic complexes [(tren)Cu-E-Im-Zn-(tren)](ClO(4))(3) and [(tren)Cu-E-Im-Ni-(tren)](ClO(4))(3), where trentris(2-aminoethyl)amine, E-Im=2-ethylimidazolate ion and the related mononuclear complexes [Cu(tren)](ClO(4))(2) and [(tren)Cu-E-ImH)](ClO(4))(2) have been described. Biological activities (superoxide dismutase and antimicrobial) have also been measured and compared with reported complexes.

Microbial/enzymatic synthesis of chiral drug intermediates

Biocatalytic processes were used to prepare chiral intermediates for pharmaceuticals. These include the following processes. Enzymatic synthesis of [4S-(4a,7a,10ab)]1-octahydro-5-oxo-4-[[(phenylmethoxy) carbonyl]amino]-7H-pyrido-[2,1-b] [1,3]thiazepine-7-carboxylic acid methyl ester (BMS-199541-01), a key chiral intermediate for synthesis of a new vasopeptidase inhibitor. Enzymatic oxidation of the epsilon-amino group of lysine in dipeptide dimer N2-[N[[(phenylmethoxy)carbonyl] L-homocysteinyl] L-lysine)1,1-disulfide (BMS-201391-01) to produce BMS-199541-01 using a novel L-lysine epsilon-aminotransferase from S. paucimobilis SC16113 was demonstrated. This enzyme was overexpressed in E. coli, and a process was developed using recombinant enzyme. The aminotransferase reaction required alpha-ketoglutarate as the amine acceptor. Glutamate formed during this reaction was recycled back to alpha-ketoglutarate by glutamate oxidase from S. noursei SC6007. Synthesis and enzymatic conversion of 2-keto-6-hydroxyhexanoic acid 5 to L-6-hydroxy norleucine 4 was demonstrated by reductive amination using beef liver glutamate dehydrogenase. To avoid the lengthy chemical synthesis of ketoacid 5, a second route was developed to prepare the ketoacid by treatment of racemic 6-hydroxy norleucine (readily available from hydrolysis of 5-(4-hydroxybutyl) hydantoin, 6) with D-amino acid oxidase from porcine kidney or T. variabilis followed by reductive amination to convert the mixture to L-6-hydroxynorleucine in 98% yield and 99% enantiomeric excess. Enzymatic synthesis of (S)-2-amino-5-(1,3-dioxolan-2-yl)-pentanoic acid (allysine ethylene acetal, 7), one of three building blocks used for synthesis of a vasopeptidase inhibitor, was demonstrated using phenylalanine dehydrogenase from T. intermedius. The reaction requires ammonia and NADH. NAD produced during the reaction was recycled to NADH by oxidation of formate to CO2 using formate dehydrogenase. Efficient synthesis of chiral intermediates required for total chemical synthesis of a beta 3 receptor agonist was demonstrated. These include: (a) microbial reduction of 4-benzyloxy-3-methanesulfonylamino-2'-bromoacetophenone 9 to corresponding (R)-alcohol 10 by S. paucimobilis SC16113, (b) enzymatic resolution of racemic alpha-methyl phenylalanine amide 11 and alpha-methyl-4-hydroxyphenylalanine amide 13 by amidase from M. neoaurum ATCC 25795 to prepare corresponding (S)-amino acids 12 and 14, and (c) asymmetric hydrolysis of methyl-(4-methoxyphenyl)-propanedioic acid ethyl diester 15 to corresponding (S)-monoester 16 by pig liver esterase. (S)[1-(acetoxyl)-4-(3-phenyl)butyl]phosphonic acid diethyl ester 21, a key chiral intermediate required for total chemical synthesis of BMS-188494 (an anticholesterol drug) was prepared by stereoselective acetylation of racemic [1-(hydroxy)-4-(3-phenyl)butyl]phosphonic acid diethyl ester 22 using G. candidum lipase. Lipase-catalyzed stereoselective acetylation of racemic 7-[N,N'-bis-(benzyloxy-carbonyl)N-(guanidinoheptanoyl)]-alpha-hydroxy-glycine 24 to corresponding S-(-)-acetate 25 was demonstrated. S-(-)-acetate 25 is a key intermediate for total chemical synthesis of (-)-15-deoxyspergualin 23, an immunosuppressive agent and antitumor antibiotic. Stereoselective microbial reduction of (1S)[3-chloro-2-oxo-1-(phenyl-methyl)propyl] carbamic acid, 1,1-dimethyl-ethyl ester 26 to corresponding chiral alcohol 27a (a key chiral intermediate for HIV protease inhibitors) was also demonstrated. Stereospecific enzymatic hydrolysis of racemic epoxide RS-1-[2',3'-dihydro benzo[b]furan-4'-yl]-1,2-oxirane 29 the corresponding R-diol 30 and unreacted chiral S-epoxide 28 was demonstrated using R. glutinis and A. niger. Dynamic resolution of racemic diol RS-1-[2',3'-dihydrobenzo[b]furan-4'-yl]-ethane-1,2-diol 32 to corresponding S-diol S-1-[2',3'-dihydrobenzo[b]furan-4'-yl]-ethane-1,2-diol 31 was demonstrated using C. boidinii and P. methanolica. Chiral (S)-epoxide 28 and (S)-diol 31 are key intermediates for a new prospective circadian modulator drug. Enzymatic resolution of racemic 2-pentanol and 2-heptanol by lipase B from Candida antarctica was demonstrated. S-(+)-2-pentanol is a key chiral intermediate required for synthesis of anti-Alzheimer's drugs.

Magnetic, epr and SOD studies of some Cu(II)-Cu(II), Cu(II)-Ni(II) and Cu(II)-Zn(II) imidazolate bridged complexes

Magnetic, spectroscopic and superoxide dismutase activity of imidazolate bridged [(Salala)Cu-Im-Cu(Salala)]Na, [(Salala)Cu-Im-Zn(Salala)]Na and [(Salala)Cu-Im-Ni(Salala)]Na (Salala=Salicyledenealiniate, Im=Imdiazolate) are described. The epr and electronic spectra of related mononuclear complexes, viz., [(Salala)Cu-OH(2)] and [(Salala)Cu-ImH] also described. Appearance of a half-field signal in polycrystalline and decrease in mu(eff) per copper(II) ion indicate super exchange coupling between copper(II) ion in [(Salala)Cu-Im-Cu(Salala)]Na binuclear complex. A pH-dependent epr and UV-vis study of 50% aqueous DMSO solution of binuclear complexes suggest that the complexes are stable in narrow pH range.

Paramagnetic resonance in imidazolate-bridged homobinuclear (copper-copper) and heterobinuclear (copper-zinc) complexes

Bridged homobinuclear (copper-copper) and heterobinuclear (copper-zinc) complexes of diethylenetriamine have been prepared with 2-methyl-imidazole as bridging ligand. EPR spectra of the polycrystalline complexes have been studied at room temperature and also at liquid nitrogen temperature. Low temperature EPR and electronic spectroscopic studies of 50% aqueous DMSO of [(dien)Cu-(Melm)-Zn(dien)]3+ solutions show the imidazolate bridged complex to exist mainly over the pH range approximately 7.0 < pH < 10.0. At low pH the 2-MelmH+ ion and mononuclear copper and zinc complexes are formed. Above pH > 10.0 hydroxide ion splits the imidazolate bridge.

E.s.r., visible and SOD studies of imidazolate bridged Cu(2)(II,II), Cu(II)Zn(II) and Cu(II)Ni(II) complexes with pentamethyldiethylenetriamine as capping ligand: a plausible model for superoxide dismutase

X-band e.s.r. and electronic spectra of imidazolate bridged homobinuclear Cu-Cu complex, [(PMDT)Cu-Im-Cu(PMDT)](ClO(4))(3) and heterobinuclear Cu-Zn and Cu-Ni complexes, viz. [(PMDT)Cu-Im-Zn(PMDT)](ClO(4))(3), [(PMDT)Cu-Im-Ni(PMDT)] (ClO(4))(3), where PMDT=pentamethyldiethylenetriamine, Im=Imidazolate ion and related mononuclear complexes, [(PMDT)Cu(OH(2))](2+) and [(PMDT)Cu(ImH)](2+) have been described. Superoxide dismutase activities of these complexes have also been measured.

Biocatalytic synthesis of intermediates for the synthesis of chiral drug substances

There has been an increasing awareness of the enormous potential of microorganisms and enzymes for the transformation of synthetic chemicals with high chemo-, regio- and enantioselectivity. Chiral intermediates and fine chemicals are in high demand, both from the pharmaceutical and agrochemical industries, for the preparation of bulk drug substances and agricultural products. Biocatalytic processes have been described for the synthesis of chiral intermediates for beta3- and beta2-receptor agonists, antihypertensive drugs, antiviral agents, melatonin receptor agonists, anticholesterol and anticancer drugs, and drugs to treat Alzheimer's disease.

Enzymatic synthesis of chiral intermediates for Omapatrilat, an antihypertensive drug

Biocatalytic processes were used to prepare chiral intermediates required for the synthesis of Omapatrilat 1 by three different routes. The synthesis and enzymatic conversion of 2-keto-6-hydroxyhexanoic acid 3 to L-6-hydroxynorleucine 2 was demonstrated by reductive amination using beef liver glutamate dehydrogenase. To avoid the lengthy chemical synthesis of the ketoacid 3, a second route was developed to prepare the ketoacid by treatment of racemic 6-hydroxy norleucine [readily available from hydrolysis of 5-(4-hydroxybutyl) hydantoin 4] with D-amino acid oxidase from porcine kidney or Trigonopsis variabilis followed by reductive amination to convert the mixture completely to L-6-hydroxynorleucine in 98% yield and 99% enantiomeric excess (e.e.). The enzymatic synthesis of (S)-2-amino-5-(1,3-dioxolan-2-yl)-pentanoic acid (allysine ethylene acetal, 5) was demonstrated using phenylalanine dehydrogenase (PDH) from T. intermedius. Phenylalanine dehydrogenase was cloned and overexpressed in Escherichia coli and Pichia pastoris. Using PDH from E. coli or P. pastoris, the enzymatic process was scale-up to prepare kg quantity of allysine ethylene acetal 5. The reaction yields of >94% and e.e. of >98% were obtained for allysine ethylene acetal 5. An enzymatic process was developed for the synthesis of [4S-(4a,7a,10ab)]1-octahydro-5-oxo-4 [[(phenylmethoxy)carbonyl]amino]-7H-pyrido-[2,1-b] [1,3]thiazepine-7-carboxylic acid [BMS-199541-01]. The enzymatic oxidation of the epsilon-amino group of lysine in the dipeptide dimer N(2)-[N[[(phenyl-methoxy)carbonyl] L-homocysteinyl] L-lysine)-1,1-disulphide [BMS-201391-01] to produce BMS-199541-01 using a novel L-lysine epsilon-aminotransferase (LAT) from Sphingomonas paucimobilis SC 16113 was demonstrated. This enzyme was overexpressed in E. coli and a process was developed using the recombinant enzyme.

Microbial reduction of alpha-chloroketone to alpha-chlorohydrin

Microbial reduction of alpha-chloroketone to alpha-chlorohydrin was studied as one of the approaches for construction of the chiral center of the corresponding epoxide. About 100 microorganisms covering many species of Candida, Pichia, Hansenula, Geotrichum, Rhodococcus and Aureobasidium were screened to reduce the alpha-chloroketone stereospecifically. Many strains provided the R-alpha-chlorohydrin with 100% enantiomeric excess (ee), e.g., Candida sonorensis SC 16117, Geotrichum candidum SC 5469, Rhodotorula glutinis SC 16293, Sphingomonas paucimobilis SC 16113, Pichia silvicola SC 16159 and Rhodococcus equi SC 15835. Few microorganisms showed preferential formation of S-alpha-chlorohydrin after reduction. Among them, Pichia pinus SC 13864 and two Pichia methanolica strains SC 16116 and SC 13860 were the best, providing the S-alpha-chlorohydrin with ee of 88%, 79% and 78%, respectively. The enantiospecificity of the reduction by these Pichia species can be modified by changing the pH or prior heat treatment of the cells and S-alpha-chlorohydrin with > or =95% ee was obtained by appropriate modification of reaction conditions.

Paramagnetic resonance and visible spectroscopic properties of binuclear Cu-Cu and Cu-Zn imidazolate-bridged complexes: effective model for active site of superoxide dismutase

Syntheses of the imidazolate-bridged heterometallic binuclear copper-zinc complex [(glyala)Cu-im Zn(g-lyala)]Na, where H2glyala = glycylalanine, and im = imidazolate ion, has been achieved. X-band e.p.r and visible absorption spectra of the complex [(glyala)Cu-im-Zn(glyala)]Na at different pH values in frozen solution (50% aqueous DMSO, 77K) show that the imidazolate-bridged complex is stable in the pH range 7.15-10.50.

Regioselective enzymatic aminoacylation of lobucavir to give an intermediate for lobucavir prodrug

Synthesis of lobucavir prodrug, L-valine, [(1S,2R,3R)-3-(2-amino-1,6-dihydro-6-oxo-9H-purin-9-yl)-2-(hydroxymethyl) cyclobutyl]methyl ester monohydrochloride (BMS 233866), requires regioselective coupling of one of the two hydroxyl groups of lobucavir (BMS 180194) with valine. Either hydroxyl group of lobucavir could be selectively aminoacylated with valine by using enzymatic reactions. N-[(Phenylmethoxy)carbonyl]-L-valine, [(1R,2R,4S)-2-(2-amino-6-oxo-1H-purin-9-yl)-4-(hydroxymethyl)cyclobutyl]methyl ester (3, 82.5% yield), was obtained by selective hydrolysis of N,N'-bis[(phenylmethoxy)carbonyl]bis[L-valine], O,O'-[(1S,2R,3R)-3-(2-amino-6-oxo-1H-purin-9-yl)cyclobuta-1,2-diyl]methyl ester (1) with lipase M, and L-valine, [(1R,2R,4S)-2-(2-amino-1,6-dihydro-6-oxo-9H-purin-9-yl)-4-(hydroxymethyl)cyclobutyl]methyl ester monohydrochloride (4, 87% yield) was obtained by hydrolysis of bis[L-valine], O,O'-[(1S,2R,3R)-3-(2-amino-6-oxo-1H-purin-9-yl)cyclobuta-1,2-diyl]methyl ester, dihydrochloride (2), with lipase from Candida cylindracea. The final intermediate for lobucavir prodrug, N-[(phenylmethoxy)carbonyl]-L-valine, [(1S,2R,4R)-3-(2-amino-6-oxo-1H-purin-9-yl)-2-(hydroxymethyl)cyclobutyl]methyl ester (5), could be obtained by transesterification of lobucavir using ChiroCLEC BL (61% yield), or more selectively by using immobilized lipase from Pseudomonas cepacia (84% yield).

Biocatalytic preparation of a chiral synthon for a vasopeptidase inhibitor: enzymatic conversion of N(2)-

[4S-(4I,7I,10aJ)]1-Octahydro-5-oxo-4-[phenylmethoxy)carbonyl]amino]-7H-pyrido-[2,1-b] [1,3]thiazepine-7-carboxylic acid methyl ester (BMS-199541-01) is a key chiral intermediate for the synthesis of Omapatrilat (BMS-186716), a new vasopeptidease inhibitor under development. By using a selective enrichment culture technique we have isolated a strain of Sphingomonas paucimobilis SC 16113, which contains a novel L-lysine epsilon-aminotransferase. This enzyme catalyzed the oxidation of the epsilon-amino group of lysine in the dipeptide dimer N(2)-[N[phenyl-methoxy)-carbonyl] L-homocysteinyl] L-lysine)1,1-disulphide (BMS-201391-01) to produce BMS-199541-01. The aminotransferase reaction required alpha-ketoglutarate as the amino acceptor. Glutamate formed during this reaction was recycled back to alpha-ketoglutarate by glutamate oxidase from Streptomyces noursei SC 6007. Fermentation processes were developed for growth of S. paucimobilis SC 16113 and S. noursei SC 6007 for the production of L-lysine epsilon-amino transferase and glutamate oxidase, respectively. L-lysine epsilon-aminotransferase was purified to homogeneity and N-terminal and internal peptides sequences of the purified protein were determined. The mol wt of L-lysine epsilon-aminotransferase is 81 000 Da and subunit size is 40 000 Da. L-lysine epsilon-aminotransferase gene (lat gene) from S. paucimobilis SC 16113 was cloned and overexpressed in Escherichia coli. Glutamate oxidase was purified to homogeneity from S. noursei SC 6003. The mol wt of glutamate oxidase is 125 000 Da and subunit size is 60 000 Da. The glutamate oxiadase gene from S. noursei SC 6003 was cloned and expressed in Streptomyces lividans. The biotransformation process was developed for the conversion of BMS-201391-01 to BMS-199541-01 by using L-lysine epsilon-aminotransferase expressed in E. coli. In the biotransformation process, for conversion of BMS-201391-01 (CBZ protecting group) to BMS-199541-01, a reaction yield of 65-70 M% was obtained depending upon reaction conditions used in the process. Phenylacetyl or phenoxyacetyl protected analogues of BMS-201391-01 also served as substrates for L-lysine epsilon-aminotransferase giving reaction yields of 70 M% for the corresponding BMS-199541-01 analogs. Two other dipeptides N-[N[(phenylmethoxy)carbonyl]-L-methionyl]-L-lysine (BMS-203528) and N,2-[S-acetyl-N-[(phenylmethoxy)carbonyl]-L-homocysteinyl]-L-lysine (BMS-204556) were also substrates for L-lysine epsilon-aminotransferase. N-alpha-protected (CBZ or BOC)-L-lysine were also oxidized by L-lysine epsilon-aminotransferase.

Synthesis of allysine ethylene acetal using phenylalanine dehydrogenase from Thermoactinomyces intermedius

Allysine ethylene acetal [(S)-2-amino-5-(1,3-dioxolan-2-yl)-pentanoic acid (2)] was prepared from the corresponding keto acid by reductive amination using phenylalanine dehydrogenase (PDH) from Thermoactinomyces intermedius ATCC 33205. Glutamate, alanine, and leucine dehydrogenases, and PDH from Sporosarcina species (listed in order of increasing effectiveness) also gave the desired amino acid but were less effective. The reaction requires ammonia and NADH. NAD produced during the reaction was recyled to NADH by the oxidation of formate to CO(2) using formate dehydrogenase (FDH). PDH was produced by growth of T. intermedius ATCC 33205 or by growth of recombinant Escherichia coli or Pichia pastoris expressing the Thermoactinomyces enzyme. Using heat-dried T. intermedius as a source of PDH and heat-dried Candida boidinii SC13822 as a source of FDH,98%, but production of T. intermedius could not be scaled up. Using heat-dried recombinant E. coli as a source of PDH and heat-dried Candida boidinii 98%. In a third generation process, heat-dried methanol-grown P. pastoris expressing endogenous FDH and recombinant Thermoactinomyces98% ee.

Enzymatic synthesis of L-6-hydroxynorleucine

L-6-Hydroxynorleucine, a key chiral intermediate used for synthesis of a vasopeptidase inhibitor, was prepared in 89% yield and > 99% optical purity by reductive amination of 2-keto-6-hydroxyhexanoic acid using glutamate dehydrogenase from beef liver. In an alternate process, racemic 6-hydroxynorleucine produced by hydrolysis of 5-(4-hydroxybutyl)hydantoin was treated with D-amino acid oxidase to prepare a mixture containing 2-keto-6-hydroxyhexanoic acid and L-6-hydroxynorleucine followed by the reductive amination procedure to convert the mixture entirely to L-6-hydroxynorleucine, with yields of 91 to 97% and optical purities of > 99%.

A novel mechanism of action of chemically modified tetracyclines: inhibition of COX-2-mediated prostaglandin E2 production

Tetracyclines (doxycycline and minocycline) inhibit inducible NO synthase expression and augment cyclooxygenase (COX)-2 expression and PGE2 production. In contrast, chemically modified tetracyclines (CMTs), such as CMT-3 and -8 (but not CMT-1, -2, and -5), that lack antimicrobial activity, inhibit both NO and PGE2 production in LPS-stimulated murine macrophages, bovine chondrocytes, and human osteoarthritis-affected cartilage, which spontaneously produces NO and PGE2 in ex vivo conditions. Furthermore, CMT-3 augments COX-2 protein expression but inhibits net PGE2 accumulation. This coincides with the ability of CMT-3 and -8 to inhibit COX-2 enzyme activity in vitro. The action of CMTs is distinct from that observed with tetracyclines because 1) CMT-3-mediated inhibition of PGE2 production coincides with modification of COX-2 protein, which is distinct from the nonglycosylated COX-2 protein generated in the presence of tunicamycin, as observed by Western blot analysis and 2) CMT-3 and -8 have no significant effect on COX-2 mRNA accumulation. In contrast, CMT-3 and -8 do not inhibit COX-1 expression in A549 human epithelial cells at the level of protein and mRNA accumulation or modification of COX-1 protein. CMT-3 and -8 inhibit the sp. act. of COX-2 (but not COX-1) in cell-free extracts. These results demonstrate differential action of CMT-3 (Metastat) on COX-1 and -2 expression, which is distinct from other tetracyclines.

Tetracycline up-regulates COX-2 expression and prostaglandin E2 production independent of its effect on nitric oxide

Tetracyclines (doxycycline and minocycline) augmented (one- to twofold) the PGE2 production in human osteoarthritis-affected cartilage (in the presence or absence of cytokines and endotoxin) in ex vivo conditions. Similarly, bovine chondrocytes stimulated with LPS showed (one- to fivefold) an increase in PGE2 accumulation in the presence of doxycycline. This effect was observed at drug concentrations that did not affect nitric oxide (NO) production. In murine macrophages (RAW 264.7) stimulated with LPS, tetracyclines inhibited NO release and increased PGE2 production. Tetracycline(s) and L-N-monomethylarginine (L-NMMA) (NO synthase inhibitor) showed an additive effect on inhibition of NO and PGE2 accumulation, thereby uncoupling the effects of tetracyclines on NO and PGE2 production. The enhancement of PGE2 production in RAW 264.7 cells by tetracyclines was accompanied by the accumulation of both cyclooxygenase (COX)-2 mRNA and cytosolic COX-2 protein. In contrast to tetracyclines, L-NMMA at low concentrations (< or = 100 microM) inhibited the spontaneous release of No in osteoarthritis-affected explants and LPS-stimulated macrophages but had no significant effect on the PGE2 production. At higher concentrations, L-NMMA (500 microM) inhibited NO release but augmented PGE2 production. This study indicates a novel mechanism of action of tetracyclines to augment the expression of COX-2 and PGE2 production, an effect that is independent of endogenous concentration of NO.

Tour de paclitaxel: biocatalysis for semisynthesis

In collaboration with the National Cancer Institute, Bristol-Myers Squibb has developed paclitaxel for treatment of various cancers; it has been approved by the Food and Drug Administration for the treatment of ovarian and metastatic breast cancer. Originally paclitaxel was isolated and purified from the bark of Pacific yew trees. This source of paclitaxel was considered to be economically and ecologically unsuitable as it required the destruction of the yew trees. This review article describes alternate methods for the production of paclitaxel, specifically, a semisynthetic approach and the application of biocatalysis in enabling the semisynthesis of paclitaxel. Three novel enzymes were discovered in our laboratory that converted the variety of taxanes to a single molecule, namely 10-deacetylbaccatin III (paclitaxel without C-13 side chain and C-10 acetate), a precursor for paclitaxel semisynthesis. These enzymes are C-13 taxolase (catalyzes the cleavage of C-13 side chain of various taxanes), C-10 deacetylase (catalyzes the cleavage of C-10 acetate of various taxanes), and C-7 xylosidase (catalyzes the cleavage of C-7 xylose from various xylosyltaxanes). Using a biocatalytic approach, paclitaxel and a variety of taxane in extracts of a variety of Taxus cultivars were converted to a 10-deacetylbaccatin III. The concentration of 10-deacetylbaccatin III was increased by 5.5- to 24-fold in the extracts treated with the enzymes, depending upon the type of Taxus cultivars used. Biocatalytic processes have also been described for the preparation of C-13 paclitaxel side chain synthons. The chemical coupling of 10-deacetylbaccatin III or baccatin III to C-13 paclitaxel side chain has been summarized to prepare paclitaxel by semisynthesis.

TNF-alpha convertase enzyme from human arthritis-affected cartilage: isolation of cDNA by differential display, expression of the active enzyme, and regulation of TNF-alpha

A snake venom-like protease isolated by a differential display screen between normal and osteoarthritis (OA)-affected cartilage (designated as cSVP) has a cDNA sequence identical to TNF-alpha convertase enzyme (TACE). TACE shows the presence of an unknown prodomain, a cysteine switch, a catalytic domain, a zinc binding region, a disintegrin region, an EGF-like domain, a transmembrane domain, and a unique cytoplasmic region. A TACE construct harboring the signal + prodomain + catalytic region (TACE-SPCdeltaDETCy), expressed in baculovirus could cleave preferentially (approximately 12-fold) the TNF-specific peptide over the matrix metalloproteases peptide in vitro. This recombinant protein also cleaved the natural substrate GST-ProTNF-alpha to TNF-alpha (17 kDa) in vitro. The mRNA for TACE, which is broadly distributed and differentially expressed in a variety of human tissues, is up-regulated in arthritis-affected cartilage, but not normal cartilage. OA-affected cartilage also expressed TNF-alpha mRNA that was not detected in normal cartilage. The OA-affected cartilage (in explant assays) spontaneously released TNF-alpha and IL-8 in ex vivo conditions. Addition of TNF-alphaR fused to IgG Fc fragment (TNF-alphaR:Fc) in the presence or absence of soluble IL-1R (with which it acted additively) significantly attenuated the spontaneous/autocrine release of articular IL-8 in this assay. These experiments demonstrate a functional paracrine/autocrine role of TNF-alpha in OA-affected cartilage that may depend, in part, on up-regulated levels of chondrocyte-derived TACE.

Autocrine production of IL-1 beta by human osteoarthritis-affected cartilage and differential regulation of endogenous nitric oxide, IL-6, prostaglandin E2, and IL-8

Interleukin-1 beta (IL-1 beta) plays a central role in the pathophysiology of cartilage damage and degradation in arthritis. In noninflammatory arthropathies such as osteoarthritis (OA), the synovial-derived IL-1 beta has been implicated in the disease process. In this study, we report that human OA-affected cartilage demonstrates upregulated IL-1 beta mRNA not seen in normal cartilage. The OA-affected cartilage in ex vivo conditions spontaneously releases detectable amounts of autocrine IL-1 beta, nitric oxide (NO), and prostaglandin E2 (PGE2), known to be involved in cartilage damage and inflammation, that cannot be detected in normal cartilage. The autocrine IL-1 beta released by the OA-affected cartilage (for at least 72 hr in ex vivo conditions) is present in sufficient quantities to modulate NO and PGE2 production because addition of recombinant soluble IL-1 beta receptor (but not soluble tumor necrosis factor-alpha receptor) and cytokine-suppressive antiinflammatory drugs (CSAIDs) significantly attenuates the spontaneous release of NO and PGE2. Furthermore, OA-affected cartilage releases significant amounts of IL-6 and IL-8 in ex vivo conditions. Addition of CSAIDs to OA-affected cartilage differentially regulates IL-6 and IL-8 production by inhibiting the spontaneous release of IL-6 but not IL-8 in ex vivo conditions. These experiments demonstrate that the human OA-affected cartilage itself releases sufficient amounts of functionally active autocrine IL-1 beta that can modulate endogenous NO, PGE2, and IL-6, but not IL-8, all of which are known to be stimulated by IL-1 beta in vitro. These IL-1 beta induced pleotropic inflammatory mediators in OA-affected cartilage may be sufficient to facilitate or augment cartilage degradation and inhibit cartilage repair, and therefore lead the cartilage into an autodestructive pathway in osteoarthritis.

Post-transcriptional regulation of inducible nitric oxide synthase mRNA in murine macrophages by doxycycline and chemically modified tetracyclines

Chemically modified tetracyclines [CMT-3 (IC50 approximately 6-13 microM = approximately 2.5-5 microg/ml) and CMT-8 (IC50 approximately 26 microM = 10 microg/ml), but not CMT-1, -2 or -5], which lack anti-microbial activity, inhibited nitrite production in LPS-stimulated macrophages. Unlike competitive inhibitors of L-arginine which inhibited the specific activity of inducible nitric oxide synthase (iNOS) in cell-free extracts, CMTs exerted no such direct effect on the enzyme. CMTs could, however, be shown to inhibit both iNOS mRNA accumulation and protein expression in LPS-stimulated cells. Tetracyclines (doxycycline and CMT-3) unlike hydrocortisone had no significant effect on murine macrophages transfected with iNOS promoter (tagged to a luciferase reporter gene) in the presence of LPS. However, doxycycline and CMT-3 augmented iNOS mRNA degradation, in LPS-stimulated murine macrophages. These studies show a novel mechanism of action of tetracyclines which harbours properties to increase iNOS mRNA degradation and decrease iNOS protein expression and nitric oxide production in macrophages. This property of tetracyclines may have beneficial effects in the treatment of various diseases where excess nitric oxide has been implicated in the pathophysiology of these diseases.

Interleukin-17 up-regulation of nitric oxide production in human osteoarthritis cartilage

OBJECTIVE

To examine the effect of human interleukin-17 (IL-17) on nitric oxide (NO) production in human osteoarthritis (OA) cartilage under ex vivo conditions.

METHODS

OA cartilage from patients undergoing knee replacement surgery was used in explant assays to assess the effect of IL-17. NO production was measured by estimating the stable NO metabolite, nitrite, in conditioned medium.

RESULTS

IL-17 augmented the spontaneous production of nitric oxide. This augmentation was sensitive to cycloheximide and pyrrolidine dithiocarbamate, but not to dexamethasone or soluble IL-1 receptor.

CONCLUSION

IL-17 augments nitric oxide production in OA cartilage via nuclear factor kappaB activation, but independently of IL-1beta signaling.

Superinduction of cyclooxygenase-2 activity in human osteoarthritis-affected cartilage. Influence of nitric oxide

Cartilage specimens from osteoarthritis (OA)-affected patients spontaneously released PGE2 at 48 h in ex vivo culture at levels at least 50-fold higher than in normal cartilage and 18-fold higher than in normal cartilage + cytokines + endotoxin. The superinduction of PGE2 production coincides with the upregulation of cyclooxygenase-2 (COX-2) in OA-affected cartilage. Production of both nitric oxide (NO) and PGE2 by OA cartilage explants is regulated at the level of transcription and translation. Dexamethasone inhibited only the spontaneously released PGE2 production, and not NO, in OA-affected cartilage. The NO synthase inhibitor HN(G)-monomethyl-L-arginine monoacetate inhibited OA cartilage NO production by > 90%, but augmented significantly (twofold) the spontaneous production of PGE2 in the same explants. Similarly, addition of exogenous NO donors to OA cartilage significantly inhibited PGE2 production. Cytokine + endotoxin stimulation of OA explants increased PGE2 production above the spontaneous release. Addition of L-NMMA further augmented cytokine-induced PGE2 production by at least fourfold. Inhibition of PGE2 by COX-2 inhibitors (dexamethasone or indomethacin) or addition of exogenous PGE2 did not significantly affect the spontaneous NO production. These data indicate that human OA-affected cartilage in ex vivo conditions shows (a) superinduction of PGE2 due to upregulation of COX-2, and (b) spontaneous release of NO that acts as an autacoid to attenuate the production of the COX-2 products such as PGE2. These studies, together with others, also suggest that PGE2 may be differentially regulated in normal and OA-affected chondrocytes.

A novel mechanism of action of tetracyclines: effects on nitric oxide synthases

Tetracyclines have recently been shown to have "chondroprotective" effects in inflammatory arthritides in animal models. Since nitric oxide (NO) is spontaneously released from human cartilage affected by osteoarthritis (OA) or rheumatoid arthritis in quantities sufficient to cause cartilage damage, we evaluated the effect of tetracyclines on the expression and function of human OA-affected nitric oxide synthase (OA-NOS) and rodent inducible NOS (iNOS). Among the tetracycline group of compounds, doxycycline > minocycline blocked and reversed both spontaneous and interleukin 1 beta-induced OA-NOS activity in ex vivo conditions. Similarly, minocycline > or = doxycycline inhibited both lipopolysaccharide- and interferon-gamma-stimulated iNOS in RAW 264.7 cells in vitro, as assessed by nitrite accumulation. Although both these enzyme isoforms could be inhibited by doxycycline and minocycline, their susceptibility to each of these drugs was distinct. Unlike acetylating agents or competitive inhibitors of L-arginine that directly inhibit the specific activity of NOS, doxycycline or minocycline has no significant effect on the specific activity of iNOS in cell-free extracts. The mechanism of action of these drugs on murine iNOS expression was found to be, at least in part, at the level of RNA expression and translation of the enzyme, which would account for the decreased iNOS protein and activity of the enzyme. Tetracyclines had no significant effect on the levels of mRNA for beta-actin and glyceraldehyde-3-phosphate dehydrogenase nor on levels of protein of beta-actin and cyclooxygenase 2 expression. These studies indicate that a novel mechanism of action of tetracyclines is to inhibit the expression of NOS. Since the overproduction of NO has been implicated in the pathogenesis of arthritis, as well as other inflammatory diseases, these observations suggest that tetracyclines should be evaluated as potential therapeutic modulators of NO for various pathological conditions.

Carcinoma of the penis in a HIV positive patient

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Site-specific enzymatic hydrolysis of taxanes at C-10 and C-13

The production of large amounts of paclitaxel for use as an anticancer treatment has been a challenging problem because of the low concentration of the compound in yew trees and its occurrence as part of a mixture of other taxanes. Two novel enzymes were isolated to facilitate the production of 10-deacetylbaccatin III, a precursor used for semisynthesis of paclitaxel and analogs. A strain of Nocardioides albus (SC13911) was isolated from soil and found to produce an extracellular enzyme that specifically removed the C-13 side chain from paclitaxel, cephalomannine, 7-beta-xylosyltaxol, 7-beta-xylosyl-10-deacetyltaxol, and 10-deacetyltaxol. The enzyme was purified to near homogeneity to give a polypeptide with 47,000 M(r) on a sodium dodecyl sulfate gel. A strain of Nocardioides luteus (SC13912) isolated from soil was found to produce an intracellular 10-deacetylase that removed the 10-acetate from baccatin III and paclitaxel. The 10-deacetylase was purified to give a polypeptide with 40,000 M(r) on a sodium dodecyl sulfate gel. Treatment of extracts prepared from a variety of yew cultivars with the C-13-deacylase and C-10-deacetylase converted a complex mixture of taxanes primarily to 10-deacetylbaccatin III and increased the amount of this key precursor by 4-24 times.

Enzymic preparation of (3R-cis)-3-(acetyloxy)-4-phenyl-2-azetidinone: a taxol side-chain synthon

A key chiral intermediate [(3R-cis)-3-(acetyloxy)-4-phenyl-2-azetidinone (2)] for the semi-synthesis of paclitaxel (taxol; 5), an anti-cancer compound, was prepared by an enzymic process. The stereoselective enzymic hydrolysis of cis-3-(acetyloxy)-4-phenyl-2-azetidinone (1) to the corresponding (S)-(-)-alcohol (3) was carried out using various lipases. Lipase PS-30 (Pseudomonas cepacia) and BMS (Bristol-Myers Squibb) lipase (Pseudomonas sp. SC13856) catalysed hydrolysis of the undesired enantiomer of racemic compound 1, producing the (S)-(-)-alcohol (3) and the desired (R)-(+)-acetate (2). Reaction yields of > 96% and optical purities of > 99.5% were obtained. For a very efficient enzyme source (BMS lipase), a lipase fermentation using Pseudomonas sp. SC13856 was developed. In a fed-batch process using soybean oil, the fermentation resulted in 1500 units of extracellular lipase activity/ml. Crude BMS lipase (1.7 kg, containing 140,000 units/g) was recovered from the filtrate by ethanol precipitation. BMS lipase and commercially available lipase PS-30 were independently immobilized on Accurel polypropylene. These immobilized lipases were re-used (ten cycles) without loss of enzyme activity, productivity or optical purity of the product. The enzymic reaction process was scaled up to 75 and 150 litres using immobilized BMS lipase and lipase PS-30 respectively. From the reaction mixture, compound 2 was isolated in 88-90 mol% yield and 99.5% optical purity. A purity of 99.9 (area %) was demonstrated by g.c. for isolated compound 2.

Stereoselective epoxidation of 2,2-dimethyl-2H-1-benzopyran-6-carbonitrile

The chiral intermediate (3S,4R)-trans-3,4-dihydro-3,4-dihydroxy-2,2-dimethyl- 2H-1-benzopyran-6-carbonitrile [(+)-trans diol 3] was made by the stereoselective microbial epoxidation of 2,2-dimethyl-2H-1-benzopyran-6-carbonitrile 1. This compound is a potential intermediate for the total synthesis of potassium-channel openers. Several microbial cultures were found which catalyzed the transformation of 1 to the corresponding (3S,4S)-epoxide 2 and (+)-trans diol 3. The two best cultures, Corynebacterium sp. SC 13876 and Mortierella ramanniana SC 13840 gave reaction yields of 32 M% and 67.5 M% and optical purities of 88 and 96%, respectively, for (+)-trans diol 3. A single-stage process (fermentation-epoxidation) for the biotransformation of 1 was developed using Corynebacterium sp. SC 13876 and M. ramanniana SC 13840. In a 25-L fermentor, the (+)-trans diol 3 was obtained in 38.6 M% yield with an optical purity of 90% using Corynebacterium SC 13876. The reaction yield of 60.7 M% and optical purity of 92.5% were obtained for (+)-trans diol 3 using M. ramanniana SC 13840. A two-stage process for the preparation of (+)-trans diol 3 was also developed using a 3 L cell-suspension (10% w/v, wet cells) of M. ramanniana SC 13840. The reaction was carried out in a 5-L Bioflo fermentor. The concentration of substrate 1 was 2 g L-1 with glucose present at 10 g L-1. After 48 h, (+)-trans diol 3 was obtained in 76 M% yield with an optical purity of 96%.(ABSTRACT TRUNCATED AT 250 WORDS)

Microbial reduction of 1-(4-fluorophenyl)-4-[4-(5-fluoro-2-pyrimidinyl)-1- piperazinyl]butan-1-one

Among various micro-organisms screened for the stereoselective reduction of 4-chloro-1-(4-fluorophenyl)butan-1-one (1), Hansenula polymorpha [American Type Culture Collection (A.T.C.C.) 26012 and 86014], Nocardia salmonicolor [Squibb Culture (S.C.) 6370], Arthobacter simplex (A.T.C.C. 6949), Mycobacterium vaccae (A.T.C.C. 29678), Candida boidinii (A.T.C.C. 13821) and Saccharomyces cerevisiae (A.T.C.C. 13792) reduced compound 1 to the corresponding (R)-(+)-alcohol (2). In contrast, Lactobacillus kefir (A.T.C.C. 35411), Pullularia pullulans (A.T.C.C. 16623), Trigonopsis variabilis (A.T.C.C. 10679) and Cunninghamella echinulata (A.T.C.C. 26269) reduced compound 1 to the (S)-(-)-alcohol (2). When 1-(4-fluorophenyl)-4-(1-piperazinyl)butan-1-one (3) was used as substrate for the reduction, only Nocardia globerula (A.T.C.C. 12505) and Saccharomyces cerevisiae (A.T.C.C. 13792) converted compound 3 into the corresponding (R)-(+)-alcohol (4). Organisms which reduced compound 1 were inactive for the reduction of compound 3. 1-(4-Fluorophenyl)-4-[4-(5-fluoro-2- pyrimidinyl)butan-1-one (5) was reduced to the corresponding (R)-(+)-alcohol (6) by Mortierella ramanniana (A.T.C.C. 38191) and to the (S)-(-)-alcohol (6) by Pullularia pullulans (A.T.C.C. 16623). (R)-(+)-compound 2 and compound 4 are key chiral intermediates in the total chemical synthesis of (R)-(+)-compound 6, an effective antipsychotic agent under development at Bristol-Myers Squibb. A single-stage (fermentation/biotransformation) process and two-stage (fermentation and subsequent biotransformation by cell suspensions) process were developed for the stereoselective reduction of compound 5 to (R)-(+)-compound 6 by Mortierella ramanniana (A.T.C.C. 38191). In both processes, the reaction yield of 98% and the optical purity of 99.4% were obtained for (R)-(+)-compound 6. The enzyme which catalysed the reduction of compound 5 to (R)-(+)-compound 6 was purified to homogeneity. The purified protein consisted of a single polypeptide of 29 kDa.

Transformation of N?-CBZ-l-lysine to CBZ-l-oxylysine using l-amino acid oxidase from Providencia alcalifaciens and l-2-hydroxy-isocaproate dehydrogenase from Lactobacillus confusus

Biotransformations were developed to oxidize N epsilon-carbobenzoxy(CBZ)-L-lysine and to reduce the product keto acid to L-CBZ-oxylysine. Lysyl oxidase (L-lysine: O2 oxidoreductase, EC 1.4.3.14) from Trichoderma viride was relatively specific for L-lysine and had very low activity with N epsilon-substituted derivatives. L-Amino acid oxidase (L-amino acid: O2 oxidoreductase [deaminating], EC 1.4.3.2) from Crotalus adamanteus venom had low activity with L-lysine but high activity with N epsilon-formyl-, t-butyoxycarbonyl(BOC)-, acetyl-, trifluoroacetyl-, or CBZ-L-lysine. L-2-Hydroxyisocaproate dehydrogenase (EC 1.1.1.-) from Lactobacillus confusus catalyzed the reduction by NADH of the keto acids from N epsilon-acetyl-, trifluoroacetyl-, formyl- and CBZ-L-lysine but was inactive with the products from oxidation of L-lysine, L-lysine methyl ester, L-lysine ethyl ester or N epsilon-t-BOC-L-lysine. Providencia alcalifaciens (SC9036, ATCC 13159) was a good microbial substitute for the snake venom oxidase and also provided catalase (H2O2:H2O2 oxidoreductase EC 1.11.1.6). N epsilon-CBZ-L-Lysine was converted to CBZ-L-oxylysine in 95% yield with 98.5% optical purity by oxidation using P. alcalifaciens cells followed by reduction of the keto acid using L-2-hydroxyisocaproate dehydrogenase. NADH was regenerated using formate dehydrogenase (formate: NAD oxidoreductase, EC 1.2.1.2) from Candida boidinii. The Providencia oxidase was localized in the particulate fraction and catalase activity was predominantly in the soluble fraction of sonicated cells. The pH optima and kinetic constants were determined for the reactions.

X-band electron paramagnetic resonance spectra of bovine serum albumin-copper(II) and bovine serum albumin-copper(II)-aminoacid systems

X-band electron paramagnetic resonance (epr) spectra of the binary systems, BSA-copper(II) (1:1 and 2:1), and the ternary systems, BSA-Cu(II)-aminoacid (1:1:1), are described. In the binary system, two distinct epr features have been observed. One of the features (towards the low pH), showing broad and overlapping epr signals, has been attributed to non-specific bonding of copper(II) to the albumin and other feature (towards higher pH), showing sharp intense epr signals, has been attributed to the specific bonding. The change from non-specific to specific binding is favoured by increase in pH as well as by increase in protein concentration. Specific binding of copper(II) in BSA-Cu(II) has been suggested to be similar to that in HSA-Cu(II). Spectra of BSA-Cu(II)-aminoacid (1:1:1) show simultaneous presence of binary BSA-Cu(II) and ternary BSA-Cu(II)-aminoacid.