The 2-(2-arylphenyl)benzoxazole moiety has been found to be a new and selective ligand for the enzyme cyclooxygenase-2 (COX-2). The 2-(2-arylphenyl)benzoxazoles 3a−m have been synthesized by Suzuki reaction of 2-(2-bromophenyl)benzoxazole. Further synthetic manipulation of 3f and 3i led to 3o and 3n, respectively. The compounds 3g, 3n, and 3o selectively inhibited COX-2 with selectivity index of 3n much better than that of the COX-2 selective NSAID celecoxib. The in vivo anti-inflammatory potency of 3g and 3n is comparable to that of celecoxib and the nonselective NSAID diclofenac at two different doses, and 3o showed better potency compared to these clinically used NSAIDs. KEYWORDS: 2-(2-Arylphenyl)benzoxazoles, novel anti-inflammatory scaffold, 3D QSAR, cyclooxygenase-2 selective, in vivo potency I nflammation is the natural defense mechanism of the body to deal with infection and tissue damage. However, uncontrolled inflammatory cascades is responsible for various diseases such as chronic asthma, rheumatoid and osteo-arthritis, multiple sclerosis, inflammatory bowl diseases and psoriasis, 1 diabetic nephropathy, 2 tumor initiation, and malignant progression.3 Pain is the most prevalent inflammatory symptom needing medical attention with an estimated amount of 105 million of affected people in the US amounting to the financial burden of US$ 100 billion per annum to the health care expenditure. 4 Rheumatoid arthritis (RA) and osteoarthritis (OA) are the sever forms of inflammatory pain with a decade span of the disease shortening the life expectancy. 5,6 The major complication of RA is its association with acceleration of cardiovascular diseases (CVDs). 7 The nonsteroidal antiinflammatory drugs (NSAIDs) are used worldwide for therapeutic intervention of pain and inflammation. These exert their anti-inflammatory activity by inhibition of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) enzymes. 8 The side effects such as gastric ulcer and gastrointestinal bleeding associated with the traditional NSAIDs (nonselective inhibitors of COX-1 and COX-2) led to the development of selective COX-2 inhibitors as a new class of NSAIDs generally recognized as coxibs. 9 The recent withdrawal of COX-2 selective inhibitors rofecoxib and valdecoxib due to adverse cardiovascular side effects 10 fuelled a debate about the increased cardiovascular risk associated with existing COX-2 inhibitors 11 pressing the need for novel anti-inflammatory scaffold. The additional findings on therapeutic benefit of

Immobilized cells of a recombinant Escherichia coli expressing nitrilase from Pseudomonas putida were used to catalyze the hydrolysis of mandelonitrile (2-hydroxy-2-phenylacetonitrile) to ( R )-(−)-mandelic acid. The cells had been immobilized by entrapment in an alginate matrix. Conditions for the hydrolysis reaction were optimized in shake flasks and in a packed bed reactor. In shake flasks the best conditions for the reaction were a temperature of 40 °C, pH 8, biocatalyst bead diameter of 4.3 mm, sodium alginate concentration in the gel matrix of 2 % (w/v, g/100 mL), a cell dry mass concentration in the bead matrix of 20 mg/mL, an initial substrate concentration of 50 mM and a reaction time of 60 min. Under these conditions, the conversion of mandelonitrile was nearly 95 %. In the packed bed reactor, a feed flow rate of 20 mL/h at a substrate concentration of 200 mM proved to be the best at 40 °C, pH 8, using 4.3 mm beads (2 % w/v sodium alginate in the gel matrix, 20 mg dry cell concentration per mL of gel matrix). This feed flow rate corresponded to a residence time of 0.975 h in the packed bed.

Aims:  To evaluate the effect of different physicochemical parameters such as agitation, aeration and pH on the growth and nitrile hydratase production by Rhodococcus erythropolis MTCC 1526 in a stirred tank reactor. Methods and Results:  Rhodococcus erythropolis MTCC 1526 was grown in 7‐l reactor at different agitation, aeration and controlled pH. The optimum conditions for batch cultivation in the reactor were an agitation rate of 200 rev min−1, aeration 0·5 v/v/m at controlled pH 8. In this condition, the increase in nitrile hydratase activity was almost threefold compared to that in the shake flask. Conclusion:  Agitation and aeration rate affected the dissolved‐oxygen concentration in the reactor which in turn affected the growth and enzyme production. Significance and Impact of the Study:  Cultivation of R. erythropolis MTCC 1526 in the reactor was found to have significant effect on the growth and nitrile hydratase production when compared to the shake flask.

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The intracellular cobalt-type nitrile hydratase was purified from the bacterium Rhodococcuserythropolis. The pure enzyme consisted of two subunits of 29 and 30 kDa. The molecular weight of the native enzyme was estimated to be 65 kDa. At 25 °C the enzyme had a half-life of 25 h. The Michaelis–Menten constants Km and vmax for the enzyme were 0.624 mM and 5.12 μmol/min/mg, respectively, using 3-cyanopyridine as the substrate. The enzyme-containing freely-suspended bacterial cells and the cells immobilized within alginate beads were evaluated for converting the various nitriles to amides. In a packed bed reactor, alginate beads (2 % alginate; 3 mm bead diameter) containing 200 mg/mL of cells, achieved a conversion of >90 % for benzonitrile and 4-cyanopyridine in 38 h (25 °C, pH 7.0) at a feed substrate concentration of 100 mM. The beads could be reused for up to six reaction cycles.