The solvent effect in obtaining of acid–base multicomponent systems: thermal,structural and luminescence study

Journal of Thermal Analysis and Calorimetry - Acid–base multicomponent systems based on active pharmaceutical ingredients 2-chloro-5-nitrobenzoic acid (2Cl5NBH) and monoethanolamine were...     

Evaluation of hydrophobic‐interaction chromatography resins for purification of antibody‐drug conjugates using a mimetic model with adjustable hydrophobicity

Antibody drug conjugates are cytotoxic pharmaceuticals, designed to destroy malignant cells. A cytotoxic molecule is attached to an antibody that binds specific to a cancer‐cell surface. Given the high toxicity of the drugs, strict safety standards have to be kept. For this reason, an antibody drug conjugates model was developed with fluorescein 5‐isothiocyanate as the nontoxic payload surrogate. Due to the similar hydrophobicity, this model is used to establish a suitable purification process and characterization method for antibody drug conjugates. Because of the pH dependent solubility of fluorescein, the hydrophobicity of conjugates can be modulated by the pH value. Based on the complex heterogeneity and hydrophobicity of the conjugates a chromatographic purification is challenging. Hydrophobic interaction chromatography is used for analytical as well as for preparative separation. Because of the increased hydrophobicity of the conjugates compared to native antibody, hydrophobic interaction chromatography often suffer from resolution and recovery problems. Conjugates were separated differing on the number of payloads attached to the antibody. For this matter, the drug–antibody ratio is determined and used as a quantitative term. The conjugates are purified at high recoveries and resolution by step gradients using suitable resins, allowing the separation of the target drug–antibody ratio.     

Antioxidant Potential and Enhancement of Bioactive Metabolite Production in In Vitro Cultures of Scutellaria lateriflora L. by Biotechnological Methods

Studies carried out using three different in vitro assays and a biological setting (Escherichia coil) demonstrated the antioxidant activity of Scutellaria lateriflora microshoot extract. Moreover, the extract exhibited no toxicity in a brine shrimp lethality bioassay. These results indicated that microshoots are a rich, safe source of antioxidants, which encouraged us to enhance their production in vitro. In agar and agitated cultures, two biotechnological strategies were applied: feeding the cultures with the biogenetic precursors of the phenolics—phenylalanine and tyrosine, and eliciting them with methyl jasmonate. Specific Scutellaria flavonoids and verbascoside were analysed by HPLC. Feeding with precursors (1 g/L) in agar cultures decreased the production of the metabolites. In agitated cultures, different concentrations of precursors (1.0–2.5 g/L) and the elicitor (10; 50; 100 µM) were tested. Additionally, parallel feeding with the precursor and elicitor in a concentration of 50 µM were applied. The best strategy for total flavonoid and verbascoside production was phenylalanine feeding (1.5 g/L), max. 3765 and 475 mg/100 g DW, respectively, after 7 days. This is the first report documenting the high antioxidant production in S. lateriflora microshoots after feeding with phenylalanine. Moreover, for the first time, bioreactor cultures were successfully maintained, obtaining attractive results (max. total flavonoid content 2348 and verbascoside 485 mg/100 g DW).     

First report of the nutritional profile and antioxidant potential of Holothuria arguinensis,a new resource for aquaculture in Europe

This work reports for the first time the nutritional profile and antioxidant potential of the edible sea cucumber Holothuria arguinensis from the North-eastern Atlantic. H. arguinensis has high levels of protein, with the amino acids profile dominated by alanine, glycine and proline and low lysine/arginine ratios. Its carbohydrate and energetic contents are also low as well as the total lipid levels, although its lipid profile is rich in polyunsaturated fatty acids (PUFA), especially arachidonic, eicosapentaenoic and docosahexaenoic acids. In addition, H. arguinensis has high levels of calcium. The water and ethanol extracts show ability to scavenge free radicals and to chelate copper and iron ions. Our results indicate that H. arguinensis has a balanced nutritional quality suitable for human consumption. In addition, it contains compounds with antioxidant potential; thus its intake can contribute for a healthy and well-balanced diet.     

L‐lysine and EDTA polymer mimics as resins for the quantitative and reversible removal of heavy metal ion water pollutants

Traditional precipitation methods for inorganic micropollutant removal from waters are increasingly being replaced by sorption methods based on both natural and synthetic materials. In this context, two novel effective heavy metal ions absorbers are presented. These resins, LYMA and LMT85, were crosslinked poly(amidoamine)s carrying amine and carboxyl groups in their repeating units. In particular, the LYMA‐repeating unit contains one carboxyl and two amine groups and is a mimic of L ‐lysine, whereas LMT85 contains two amine and five carboxyl groups and is a mimic of EDTA. Both resins were prepared at moderate cost by simple eco‐friendly procedures. The heavy metal ion set adopted as benchmark was Cu²⁺, Cd²⁺, Pb²⁺, Zn²⁺, Ni²⁺, and Co²⁺. LYMA proved selective for Cu²⁺ and Ni²⁺, the other ions tested being negligibly absorbed, whereas LMT85 proved capable of rapidly and quantitatively absorbing all the ions tested either singly or in mixed solution. The absorption process was reversible, and the resins were easily regenerated by acidification. The absorption of several metal ions imparted intense coloring to the resins, a feature possibly exploitable for analytical purposes. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Potential of magnetic resonance spectroscopy to detect metastasis in axillary lymph nodes in breast cancer

Focused pathological evaluation of axillary lymph nodes in breast cancer is gaining importance. Nuclear magnetic resonance (NMR) spectroscopy that assesses the whole of the specimen has the potential in evaluating micrometastases. The biochemical changes associated with breast cancer metastases in axillary nodes by in vitro NMR and its use in the detection of axillary metastases in a clinical setting in comparison with conventional histopathology is presented in this study. Eighty-eight lymph nodes obtained from 30 patients with breast cancer were investigated. Histopathology revealed metastases in 20 nodes from 11 patients, while in vitro NMR spectroscopy revealed metastases in 22 nodes. Out of these 22 nodes, 16 were the same, which showed metastases on histopathology, while 6 nodes have shown metastases only on in vitro magnetic resonance spectroscopy (MRS). These 6 nodes with suspicion of metastases on MRS were subjected to reevaluation with serial sectioning and immunohistochemistry, but no additional metastases were revealed. Forty metabolites could be identified from the MR spectrum of lymph nodes. The levels of the glycerophosphocholine-phosphocholine (GPC-PC), choline, lactate, alanine and uridine diphosphoglucose were elevated significantly in nodes with metastases. In addition, the intensity ratio of GPC-PC/threonine (Thr) was higher in nodes with metastases, and using this as marker, MRS detected the axillary metastases with a sensitivity, specificity and accuracy of 80%, 91% and 88%, respectively. Neoadjuvant chemotherapy (NACT) lowered the concentrations of GPC-PC and GPC-PC/Thr ratio. The accuracy of MRS in detecting metastases was 75% in patients who received NACT (n=9) as compared to 96% in those who did not (n=21). Our results demonstrate the potential of in vitro MRS in characterizing the metabolite profile of the axillary nodes with breast cancer metastases. It detected axillary metastases with reasonable accuracy and can be complementary to histopathological evaluation and immunohistochemistry.     

1-ethynylpyrene-modified guanine and cytosine as optical labels for DNA hybridization

1-ethynylpyrene shows remarkable absorption changes upon DNA hybridization when it is covalently attached to the 8-position of guanine. An absorption band at approximately 420 nm is only present in the duplex, exhibits thermal melting behaviour and provides the basis for a molecular beacon together with 1-ethynylpyrene-modified cytosine.