Assessment and determination of LC50 of carvacrol and salicylic acid analogues with acaricide activity in larvae and adult ticks of Rhipicephalus (Boophilus) microplus.

Rhipicephalus (Boophilus) microplus is a tick that causes huge economic losses in cattle. The indiscriminate use of acaricides has generated resistance to most compounds present on the market. Carvacrol and salicylic acid have been widely studied for their biological activities and have been evaluated in different strains of Rhipicephalus. In this research the analogues carvacrol and salicylic acid were evaluated in larvae of R. (B.) microplus with data obtained in larval packet test (LPT) and larval immersion test (LIT). A lethal concentration 50 (LC50) was assessed. The most potent compounds were evaluated in the adult ticks since there are no reports of evaluation in the life state of the parasite. From all the tested compounds, the ethyl 2-methoxybenzoate (91.82 ± 1.66%, 0.91 µmol/mL) and ethyl 2,5-dihydroxybenzoate (89.14 ± 1.61%, 2.04 µmol/mL) showed the highest percentage of mortality and the lowest LC50. They were found to be the best candidates for a study in vivo.

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-{ß-glucopyranosyl-(1→6)-ß-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.

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.

Hydroxynitrile lyases from prunus seeds in the preparation of cyanohydrins.

The hydroxynitrile lyase (HNL) activity of nine defatted Prunus seeds was compared for catalyzing the addition of HCN to aromatic, heteroaromatic and α,ß-unsaturated aldehydes. Although the conversion and enantiomeric excess (ee) of the corresponding cyanohydrins were both influenced by the HNL source and the chemical structure of the aldehyde, Prunus HNLs were all suitable for the enantioselective preparation of cyanohydrins.

Biocatalytic oxidative kinetic resolution of (±)-4-(chlorophenyl)phenylmethanol by Nocardia corallina B-276

Chiral diarylmethanols are versatile building blocks for the preparation of biologically active substances, but they are difficult to obtain in enantiopure form. We used Nocardia corallina B-276 for the oxidative kinetic resolution of (+/-)-4-(chlorophenyl)phenylmethanol, 1. Two experimental methods were used: 1) Suspension of cells in a phosphate buffer solution and 2) Cells in the culture media, in a 3-L bioreactor. After 36 hrs using the first method, the ketone/alcohol ratio was 56/44 and the unoxidized alcohol had an enantiomeric ratio of 93/7, predominating the R-alcohol.