Norberto Manjarrez

Evaluation of guanabana (Annona muricata) seed meal as a source of (S)-oxynitrilase

Guanabana seed meal is a source of (S)-oxynitrilase which biocatalyzes the enantioselective addition of HCN to aromatic, heteroaromatic and α,β-unsaturated aldehydes to produce cyanohydrins.

(S)-Naproxen® as a derivatizing agent to determine enantiomeric excess of cyanohydrins by HPLC

An easy, inexpensive and accurate method to determine enantiomeric excess of cyanohydrins is described. The method consists in derivatization of cyanohydrins with (S)-naproxen® chloride and the products analyzed by HPLC. The results of enantiomeric excess so determined are similar to those obtained with (Eu(hfc)3), as a chiral shift reagent, and analysis by 1H-NMR of the cyanohydrins.

New sources of (R)-oxynitrilase: capulin (Prunnus capuli) and mamey (Mammea americana)

Abstract(R)-Cyanohydrins were prepared from aldehydes and HCN in diisopropyl ether with high enantiomeric purity (89–98 %ee) by using the defatted meal from capulin (Prunnus capuli) or mamey (Mammea americana) as sources of (R)-oxynitrilase.

Resolution of methylarylmethanols via oxidation with Nocardia corallina

Abstract Ten different racemates of methylarylmethanols were subjected to whole cells of Nocardia corallina B-276 to give, via enantioselective oxidations, the corresponding ketone and the enantiomerically enriched secondary alcohol in moderate yields and excellent e.e.s. The configuration of the resulting alcohol is ( R ). This procedure permits a very good separation of the racemates of meta - and para -monosubstituted methylarylmethanols.

Nitrile hydratase activity of Nocardia corallina B-276

The nitrile hydratase activity of Nocardia corallina B-276 is described, and the only detected product during the biocatalyzed hydrolysis of selected nitriles was the corresponding amide. The best results were obtained using a suspension of cells in a phosphate buffer (pH= 7.0), with conversion percentages ranging from 31% to > 99%.

Enantioselective oxidation of diaryl carbinols by Nocardia corallina B-276

Abstract Whole cells of Nocardia corallina B-276 oxidized diaryl carbinols enantioselectively to give ketones in moderate yields, and some of the unreacted alcohols showed high ees. This asymmetric oxidation is a simple and efficient method for preparing meta- and para- monosubstituted optically active diaryl carbinols from the racemates. The para- substituted chiral alcohols have an R configuration.

Oxidation of substituted benzyl alcohols to carboxylic acids by Nocardia corallina B-276

Whole cells of Nocardia corallina B-276, oxidized 21 substituted benzyl alcohols, at 1 mM scale, to carboxylic acids at 28-30°C, giving yields of products from 5 to 77%.

Hydrolysis of Ibuprofen Nitrile and Ibuprofen Amide and Deracemisation of Ibuprofen Using Nocardia corallina B-276

A novel application of whole cells of Nocardia corallina B-276 for the deracemisation of ibuprofen is reported. This microorganism successfully hydrolysed ibuprofen nitrile to ibuprofen amide, and ibuprofen amide to ibuprofen, using a suspension of cells in a potassium phosphate buffer solution (0.1 M, pH = 7.0). These results can be explained by the presence of NHase and amidase enzymes, but the reactions are not enantioselective and low ee values were obtained. However, (R)-ibuprofen was isolated with >99% ee by a deracemisation process catalysed by N.corallina B-276. This is the first report of this kind of catalysis with this microorganism.

A Facile One-Pot Synthesis of 4-Hydroxy-3-methoxycarbonyl-2-methyl-2h-1,2-benzothiazine 1,1-Dioxide, a Key Intermediate in the Synthesis of Oxicam Anti-Inflammatory Agents

Abstract 4-Hydroxy-3-methoxycarbonyl-2-methyl-2H-1,2-benzothiazine 1,1-dioxide (8) was synthesized by a one-pot procedure, starting from the readily available saccharine. The synthesis involves 4 transformations with an overall yield equivalent to that from the stepwise process.

Anxiolytic-Like and Antinociceptive Effects of 2(S)-Neoponcirin in Mice

Study aims: 2(S)-neopincirin (NEO) is a constituent from of Clinopodium mexicanum, which is used in traditional Mexican herbal medicine for its tranquilizing and analgesic properties. This study investigated the anxiolytic-like, sedative and antinociceptive effects of NEO in several mice models. Material and methods: The anxiolytic-like effect was evaluated in the hole-board (HBT) and Open Field Tests (OFT); sedative effect was evaluated in sleeping time induced by sodium pentobarbital, and its antinociceptive actions were measured in the hot plate test. To evaluate if the GABA receptor could be involved in the anxiolytic-like effect produced by NEO, in independent experiments, the effects produced by co-administration of NEO plus muscimol (MUS) and NEO plus Pitrotoxin (PTX) were evaluated in the HBT. Results: NEO was isolated from Clinopodium mexicanum leaves. The NMR, MS and optic rotation data helped establish its identity as (2S)-5-hydroxy-4′-methoxyflavanone-7-O-{β-glucopyranosyl-(1→6)-β-rhamnoside}. NEO showed an anxiolytic-like effect and was able to counter the nociception induced by a thermal stimulus in a dose-dependent manner. PTX blocked the anxiolytic-like effect of NEO, while MUS was able to enhance it. Conclusions: The findings of present work demonstrated that NEO possesses anxiolytic-like and antinociceptive effects in mice. Such effects are not associated with changes in the locomotor activity. These results supported the notion that anxiolytic-like effect of NEO involves the participation of GABAergic system.