Pharmacokinetics, Dose-Proportionality, and Tolerability of Intravenous Tanespimycin (17-AAG) in Single and Multiple Doses in Dogs: A Potential Novel Treatment for Canine Visceral Leishmaniasis.

In the New World, dogs are considered the main reservoir of visceral leishmaniasis (VL). Due to inefficacies in existing treatments and the lack of an efficient vaccine, dog culling is one of the main strategies used to control disease, making the development of new therapeutic interventions mandatory. We previously showed that Tanespimycin (17-AAG), a Hsp90 inhibitor, demonstrated potential for use in leishmaniasis treatment. The present study aimed to test the safety of 17-AAG in dogs by evaluating plasma pharmacokinetics, dose-proportionality, and the tolerability of 17-AAG in response to a dose-escalation protocol and multiple administrations at a single dose in healthy dogs. Two protocols were used: Study A: four dogs received variable intravenous (IV) doses (50, 100, 150, 200, or 250 mg/m2) of 17-AAG or a placebo (n = 4/dose level), using a cross-over design with a 7-day "wash-out" period; Study B: nine dogs received three IV doses of 150 mg/m2 of 17-AAG administered at 48 h intervals. 17-AAG concentrations were determined by a validated high-performance liquid chromatographic (HPLC) method: linearity (R2 = 0.9964), intra-day precision with a coefficient of variation (CV) ≤ 8%, inter-day precision (CV ≤ 20%), and detection and quantification limits of 12.5 and 25 ng/mL, respectively. In Study A, 17-AAG was generally well tolerated. However, increased levels of liver enzymes-alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transferase (GGT)-and bloody diarrhea were observed in all four dogs receiving the highest dosage of 250 mg/m2. After single doses of 17-AAG (50-250 mg/m2), maximum plasma concentrations (Cmax) ranged between 1405 ± 686 and 9439 ± 991 ng/mL, and the area under the curve (AUC) plotting plasma concentration against time ranged between 1483 ± 694 and 11,902 ± 1962 AUC 0-8 h µg/mL × h, respectively. Cmax and AUC parameters were dose-proportionate between the 50 and 200 mg/m2 doses. Regarding Study B, 17-AAG was found to be well tolerated at multiple doses of 150 mg/m2. Increased levels of liver enzymes-ALT (28.57 ± 4.29 to 173.33 ± 49.56 U/L), AST (27.85 ± 3.80 to 248.20 ± 85.80 U/L), and GGT (1.60 ± 0.06 to 12.70 ± 0.50 U/L)-and bloody diarrhea were observed in only 3/9 of these dogs. After the administration of multiple doses, Cmax and AUC 0-48 h were 5254 ± 2784 µg/mL and 6850 ± 469 µg/mL × h in plasma and 736 ± 294 µg/mL and 7382 ± 1357 µg/mL × h in tissue transudate, respectively. In conclusion, our results demonstrate the potential of 17-AAG in the treatment of CVL, using a regimen of three doses at 150 mg/m2, since it presents the maintenance of high concentrations in subcutaneous interstitial fluid, low toxicity, and reversible hepatotoxicity.

Biotransformation of progesterone by endophytic fungal cells immobilized on electrospun nanofibrous membrane.

Biotransformation of steroids by fungi has been raised as a successful, eco-friendly, and cost-effective biotechnological alternative for chemical derivatization. Endophytic fungi live inside vegetal tissues without causing damage to the host plant, making available unique enzymes that carry out uncommon reactions. Moreover, using nanofibrous membranes as support for immobilizing fungal cells is a powerful strategy to improve their performance by enabling the combined action of adsorption and transformation processes, along with increasing the stability of the fungal cell. In the present study, we report the use of polyacrylonitrile nanofibrous membrane (PAN NFM) produced by electrospinning as supporting material for immobilizing the endophytic fungus Penicillium citrinum H7 aiming the biotransformation of progesterone. The PAN@H7 NFM displayed a high progesterone transformation efficiency (above 90%). The investigation of the biotransformation pathway of progesterone allowed the putative structural characterization of its main fungal metabolite by GC-MS analysis. The oxidative potential of P. citrinum H7 was selective for the C-17 position of the steroidal nucleus.

Extraction of Antioxidant Compounds from Brazilian Green Propolis Using Ultrasound-Assisted Associated with Low- and High-Pressure Extraction Methods.

The demand for bee products has been growing, especially regarding their application in complementary medicine. Apis mellifera bees using Baccharis dracunculifolia D.C. (Asteraceae) as substrate produce green propolis. Among the examples of bioactivity of this matrix are antioxidant, antimicrobial, and antiviral actions. This work aimed to verify the impact of the experimental conditions applied in low- and high-pressure extractions of green propolis, using sonication (60 kHz) as pretreatment to determine the antioxidant profile in the extracts. Total flavonoid content (18.82 ± 1.15-50.47 ± 0.77 mgQE·g-1), total phenolic compounds (194.12 ± 3.40-439.05 ± 0.90 mgGAE·g-1) and antioxidant capacity by DPPH (33.86 ± 1.99-201.29 ± 0.31 µg·mL-1) of the twelve green propolis extracts were determined. By means of HPLC-DAD, it was possible to quantify nine of the fifteen compounds analyzed. The results highlighted formononetin (4.76 ± 0.16-14.80 ± 0.02 mg·g-1) and p-coumaric acid (

Oxidative potential of two Brazilian endophytic fungi from Handroanthus impetiginosus towards progesterone.

Biotransformation has been successfully employed to conduct uncommon reactions, which would hardly be carried out by chemical synthesis. A wide diversity of compounds may be metabolized by fungi, leading to chemical derivatives through selective reactions that work under ecofriendly conditions. Endophytic fungi live inside vegetal tissues without causing damage to the host plant, making available unique enzymes for interesting chemical derivatization. Biotransformation of steroids by endophytic fungi may provide new derivatives as these microorganisms came from uncommon and underexplored habitats. In this study, endophytic strains isolated from Handroanthus impetiginosus leaves were assayed for biotransformation of progesterone, and its derivatives were identified through GC-EI-MS analysis. The endophyte Talaromyces sp. H4 was capable of transforming the steroidal nucleus selectively into four products through selective ene-reduction of the C4-C5 double bond and C-17 oxidation. The best conversion rate of progesterone (>90 %) was reached with Penicillium citrinum H7 endophytic strain that transformed the substrate into one derivative. The results highlight endophytic fungi's potential to obtain new and interesting steroidal derivatizations.

Development and Characterization of Powdered Antioxidant Compounds Made from Shiraz (Vitis vinifera L.) Grape Peels and Arrowroot (Maranta arundinacea L.).

Grapevine (Vitis vinifera L.) is a plant containing many phenolic compounds, mostly distributed in the peel, pulp, and seeds. This study evaluates the centesimal composition and bioactive compounds in Shiraz grape (Vitis vinifera) peels using spectrophotometric and UHPLC techniques and develops different formulations of compound powders from the peels and arrowroot using conventional drying technology. The results demonstrate that Shiraz grape skin contains significant amounts of insoluble fiber (15.3%), phenolics (157.09 ± 6.96-149.11 ± 9.27 mg GAE g-1), and flavonoids (0.75 ± 0.50-2.00 ± 0.50 mg QE g-1), with excellent antioxidant capacity observed in the alcoholic extracts. The phenolic content in the developed powdered compounds ranged from 128.32 to 139.70 mg GAE g-1. In general, the compounds showed good antioxidant capacity (IC50 = 0.17 to 0.19 µg mL-1). According to the chromatographic evaluation, it was possible to quantify gallic acid, catechin, and epicatechin, the latter of which was found in the largest quantities in the six formulations. The EV5 formulation was the most efficient in terms of phenolic compounds and protein amounts. This formulation's composition and low cost could make it viable for use in the food industry.

A Simple Method for Evaluating the Bioactive Phenolic Compounds' Presence in Brazilian Craft Beers.

There are a significant number of analytical methodologies employing different techniques to determine phenolic compounds in beverages. However, these methods employ long sample preparation processes and great time consumption. The aim of this paper was the development of a simple method for evaluating the phenolic compounds' presence in Brazilian craft beers without a previous extraction step. Catechin, caffeic acid, epicatechin, p-coumaric acid, hydrated rutin, trans-ferulic acid, quercetin, kaempferol, and formononetin were analyzed in fifteen different craft beers. The method showed good linearity (R2 ≥ 0.9966). The limit of detection ranged from 0.08 to 0.83 mg L-1, and limits of quantification were between 0.27 and 2.78 mg L-1. The method showed a satisfactory precision (RSD ≤ 16.2%). A good accuracy was obtained by the proposed method for all phenolic compounds in craft beer (68.6% ˂ accuracy ˂ 112%). Catechin showed higher concentrations (up to 124.8 mg L-1) in the samples, followed by epicatechin (up to 51.1 mg L-1) and caffeic acid (up to 8.13 mg L-1). Rutin and formononetin were observed in all analyzed samples (0.52 mg L-1 to 2.40 mg L-1), and kaempferol was less present in the samples. The presence of plant origin products was determinant for the occurrence of the highest concentrations of phenolic compounds in Brazilian craft beers.

Determination of ethyl carbamate in cachaça produced from copper stills by HPLC.

Ethyl carbamate (EC) is a common substance in fermented foods and drinks, and its quantification is important because of its carcinogenic nature and its usually presence in alcoholic beverages. The present work involved the development and validation of an analytical method for the evaluation of EC in cachaça by HPLC-FLD after previous derivatization with xanthydrol. The method presented a mean recovery of 94.88%, an intra-day precision of 4.19% (30.0 µgL(-1)) and 3.32% (75.0 µgL(-1)), a coefficient of determination (r(2)) equal to 0.9985, and limits of detection and quantification equal to 6.39 and 21.32 µgL(-1), respectively. The results show that the analytical method is accurate, reproducible and linear over the concentration range from 5.0 to 160 µg of EC per litre. The method was applied to the analysis of EC in cachaça, the analyses being rapid and efficient.