Forced degradation study and characterization of main impurities of ibuprofen soft gelatin capsules by LC-MS-QTOF.

Ibuprofen soft gelatin capsules were subjected to degradation under acidic, basic, oxidation, photolytic, thermal, humidity, and metal ions conditions. To analyse the degradation products, a reversed-phase liquid chromatography (RP-LC) indicative stability method was successfully developed. Chromatographic separation was achieved using a Poroshell HPH-C18 150 x 4.6 mm, 4 µm, column at 25 °C, with a mobile phase constituted by 0.1% phosphoric acid and acetonitrile in gradient at a flow rate of 1.0 mL• min -1 , using ultraviolet detection at 220 nm and injection volume of 20 µL. In total, eight unknown impurities were found. The peaks RRt 0.49, RRt 0.75, and RRt 0.95 were above 0.17%, corresponding to the identification threshold. Those were identified and characterized by LC-MS-QTOF, with the same chromatographic conditions, except for the exchange of 0.1% phosphoric acid for 0.1% formic acid. The impurities originated from the interaction of ibuprofen with excipients: esterification with PEG, with sorbitol/sorbitan, and with glycerol by-products, which has not yet been reported in the literature. The developed method can be used in several pharmaceutical areas as quality control of impurities, studies of forced degradation, and for the development of future formulations.

A metal-free blue chromophore derived from plant pigments.

Blue natural pigments are rare, especially among plants. However, flowering species that evolved to attract Hymenoptera pollinators are colored by blue anthocyanin-metal complexes. Plants lacking anthocyanins are pigmented by betalains but are unable to produce blue hues. By extending the π-system of betalains, we designed a photostable and metal-free blue dye named BeetBlue that did not show toxicity to human hepatic and retinal pigment epithelial cells and does not affect zebrafish embryonal development. This chiral dye can be conveniently synthesized from betalamic acid obtained from hydrolyzed red beetroot juice or by enzymatic oxidation of l-dopa. BeetBlue is blue in the solid form and in solution of acidified polar molecular solvents, including water. Its capacity to dye natural matrices makes BeetBlue the prototype of a new class of low-cost bioinspired chromophores suitable for a myriad of applications requiring a blue hue.

A metal-free blue chromophore derived from plant pigments

Blue natural pigments are rare, especially among plants. However, flowering species that evolved to attract Hymenoptera pollinators are colored by blue anthocyanin-metal complexes. Plants lacking anthocyanins are pigmented by betalains but are unable to produce blue hues. By extending the p-system of betalains, we designed a photostable and metal-free blue dye named BeetBlue that did not show toxicity to human hepatic and retinal pigment epithelial cells and does not affect zebrafish embryonal development. This chiral dye can be conveniently synthesized from betalamic acid obtained from hydrolyzed red beetroot juice or by enzymatic oxidation of L-dopa. BeetBlue is blue in the solid form and in solution of acidified polar molecular solvents, including water. Its capacity to dye natural matrices makes BeetBlue the prototype of a new class of low-cost bioinspired chromophores suitable for a myriad of applications requiring a blue hue.

Potential antiproliferative activity of polyphenol metabolites against human breast cancer cells and their urine excretion pattern in healthy subjects following acute intake of a polyphenol-rich juice of grumixama (Eugenia brasiliensis Lam.).

The bioavailability and metabolism of anthocyanins and ellagitannins following acute intake of grumixama fruit, native Brazilian cherry, by humans, and its in vitro antiproliferative activity against breast cancer cells (MDA-MB-231) were investigated. A single dose of grumixama juice was administered to healthy women (n = 10) and polyphenol metabolites were analyzed in urine and plasma samples collected over 24 h. The majority of the metabolites circulating and excreted in urine were phenolic acids and urolithin conjugates, the gut microbiota catabolites of both classes of polyphenols, respectively. According to pharmacokinetic parameters, the subjects were divided into two distinct groups, high and low urinary metabolite excretors. The pool of polyphenol metabolites found in urine samples showed a significant inhibition of cell proliferation and G2/M cell cycle arrest in MDA-MB-231 cells. Our findings demonstrate the large interindividual variability concerning the polyphenol metabolism, which possibly could reflect in health promotion.

Perspectives of digestive pest control with proteinase inhibitors that mainly affect the trypsin-like activity of Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae).

The present study describes the main characteristics of the proteolytic activities of the velvetbean caterpillar, Anticarsia gemmatalis Hübner, and their sensitivity to proteinase inhibitors and activators. Midguts of last instar larvae reared on an artificial diet were homogenized in 0.15 M NaCl and centrifuged at 14,000 g for 10 min at 4 degrees C and the supernatants were used in enzymatic assays at 30 degrees C, pH 10.0. Basal total proteolytic activity (azocasein hydrolysis) was 1.14 +/- 0.15 absorbance variation min(-1) mg protein(-1), at 420 nm; basal trypsin-like activity (N-benzoyl-L-arginine-p-nitroanilide, BApNA, hydrolysis) was 0.217 +/- 0.02 mmol p-nitroaniline min(-1) mg protein(-1). The maximum proteolytic activities were observed at pH 10.5 using azocasein and at pH 10.0 using BApNA, this pH being identical to the midgut pH of 10.0. The maximum trypsin-like activity occurred at 50 degrees C, a temperature that reduces enzyme stability to 80 and 60% of the original, when pre-incubated for 5 and 30 min, respectively. Phenylmethylsulfonyl fluoride inhibited the proteolytic activities with an IC50 of 0.39 mM for azocasein hydrolysis and of 1.35 mM for BApNA hydrolysis. Benzamidine inhibited the hydrolysis with an IC50 of 0.69 and 0.076 mM for azocasein and BApNA, respectively. The absence of cysteine-proteinases is indicated by the fact that 2-mercaptoethanol and L-cysteine did not increase the rate of azocasein hydrolysis. These results demonstrate the presence of serine-proteinases and the predominance of trypsin-like activity in the midgut of Lepidoptera insects, now also detected in A. gemmatalis, and suggest this enzyme as a major target for pest control based on disruption of protein metabolism using proteinase inhibitors.

Perspectives of digestive pest control with proteinase inhibitors that mainly affect the trypsin-like activity of Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae)

The present study describes the main characteristics of the proteolytic activities of the velvetbean caterpillar, Anticarsia gemmatalis Hübner, and their sensitivity to proteinase inhibitors and activators. Midguts of last instar larvae reared on an artificial diet were homogenized in 0.15 M NaCl and centrifuged at 14,000 g for 10 min at 4°C and the supernatants were used in enzymatic assays at 30°C, pH 10.0. Basal total proteolytic activity (azocasein hydrolysis) was 1.14 ± 0.15 absorbance variation min-1 mg protein-1, at 420 nm; basal trypsin-like activity (N-benzoyl-L-arginine-p-nitroanilide, BApNA, hydrolysis) was 0.217 ± 0.02 mmol p-nitroaniline min-1 mg protein-1. The maximum proteolytic activities were observed at pH 10.5 using azocasein and at pH 10.0 using BApNA, this pH being identical to the midgut pH of 10.0. The maximum trypsin-like activity occurred at 50°C, a temperature that reduces enzyme stability to 80 and 60 percent of the original, when pre-incubated for 5 and 30 min, respectively. Phenylmethylsulfonyl fluoride inhibited the proteolytic activities with an IC50 of 0.39 mM for azocasein hydrolysis and of 1.35 mM for BApNA hydrolysis. Benzamidine inhibited the hydrolysis with an IC50 of 0.69 and 0.076 mM for azocasein and BApNA, respectively. The absence of cysteine-proteinases is indicated by the fact that 2-mercaptoethanol and L-cysteine did not increase the rate of azocasein hydrolysis. These results demonstrate the presence of serine-proteinases and the predominance of trypsin-like activity in the midgut of Lepidoptera insects, now also detected in A. gemmatalis, and suggest this enzyme as a major target for pest control based on disruption of protein metabolism using proteinase inhibitors.