Stingless Bee-Collected Pollen (Bee Bread): Chemical and Microbiology Properties and Health Benefits

Stingless bee-collected pollen (bee bread) is a mixture of bee pollen, bee salivary enzymes, and regurgitated honey, fermented by indigenous microbes during storage in the cerumen pot. Current literature data for bee bread is overshadowed by bee pollen, particularly of honeybee Apis. In regions such as South America, Australia, and Southeast Asia, information on stingless bee bee bread is mainly sought to promote the meliponiculture industry for socioeconomic development. This review aims to highlight the physicochemical properties and health benefits of bee bread from the stingless bee. In addition, it describes the current progress on identification of beneficial microbes associated with bee bread and its relation to the bee gut. This review provides the basis for promoting research on stingless bee bee bread, its nutrients, and microbes for application in the food and pharmaceutical industries.     

Novel Copper(II) Thiodibenzoic Acid Coordination Polymers by in situ Extrusion of Sulfur from 2,2′‐Dithiodibenzoic Acid and the Unique Oxidation of Disulfide to Sulfate

Slow diffusion reaction of 2,2′‐dithiodibenzoic acid (dtdb) with CuCl₂ in the presence of N‐donor ligands results in the formation of different coordination polymers where both S–S and C–S scission and oxidation of S is observed. X‐ray diffraction analysis of [Cu(tdb)(phen)(H₂O)]₂ · 2H₂O.2DMF] ( 1 ), [Cu(tdb)(py)₂(H₂O)]₂ ( 3 ), and [Cu(tdb)(bipy)(H₂O)]₂ · 0.5H₂O ( 4 ) (tdb = thiodibenzoic acid, phen = phenanthroline, py = pyridine, bipy = 2,2′‐bipyridine) show that the metal ions are coordinated to the carboxylate oxygen atoms of the in situ generated tdb ligand in a monodenate fashion. In [Cu(phen)(SO₄)₂(H₂O)₂]_n ( 2 ) and [Cu(bipy)(SO₄)₂(H₂O)₂]_n ( 5 ), the sulfur is oxidized to sulfate ions prior to coordination with the metal. Complex 1 has a dimeric structure with π–π interactions between the phen ligands, whereas 3 and 4 form 1D polymeric chains.     

A versatile high-performance thin-layer chromatographic method for the simultaneous determination of five antihypertensive drugs: method validation and application to different pharmaceutical formulations

JPC – Journal of Planar Chromatography – Modern TLC - A selective high-performance thin-layer chromatography (HPTLC) densitometric method has been developed for the simultaneous...     

Speciation of arsenic in coarse and fine urban aerosols using sequential extraction combined with liquid chromatography and atomic fluorescence detection

An analytical procedure for speciation of As in urban aerosol samples was developed. The aerosols were collected by sequential filtration through membrane filters. Part of each filter was investigated by INAA for the total amount of As. Another part of the filters was treated by a sequential extraction procedure to differentiate between water-extractable, phosphate-extractable and refractory chemical forms. Water-extractable forms were further differentiated into anionic As species by HPLC-HGAFS. Extractability of As into water exhibited a clear dependency on the aerosol size fraction (12% in coarse fraction and 50% in fine fraction). Dependency of the phosphate extractable As on the aerosol size fraction seems not to be significant (10–15% in both size fractions). The remaining amount, i.e., about 78% of the coarse As and about 40% of the fine As was considered to be refractory or environmentally immobile As. Water-extractable As forms could only be attributed to arsenate.     

Anti-Tumor Effects of Queen Bee Acid (10-Hydroxy-2-Decenoic Acid) Alone and in Combination with Cyclophosphamide and Its Cellular Mechanisms against Ehrlich Solid Tumor in Mice

Queen bee acid or 10-hydroxy-2-decenoic acid (10-HDA) is one of the main and unique lipid components (fatty acids) in royal jelly. Previous studies have demonstrated that 10-HDA has various pharmacological and biological activities. The present study aims to evaluate the anti-tumor effects of 10-HDA alone and combined with cyclophosphamide (CP), as an alkylating agent which widely used for the treatment of neoplastic cancers, against the Ehrlich solid tumors (EST) in mice. Methods: A total of 72 female Swiss albino mice were divided into eight groups. EST mice were treated with 10-HDA (2.5 and 5 mg/kg) alone and combined with CP (25 mg/kg) orally once a day for 2 weeks. Tumor growth inhibition, body weight, the serum level of alpha-fetoprotein (AFP) and carcinoembryonic antigen tumor (CAE), liver and kidney enzymes, tumor lipid peroxidation (LPO) and nitric oxide (NO), antioxidant enzymes (e.g. glutathione reductase (GR), glutathione peroxidase (GPx), catalase enzyme (CAT)), tumor necrosis factor alpha level (TNF-α), and the apoptosis-regulatory genes expression were assessed in tested mice. Results: the findings exhibited that treatment of EST-suffering mice with 10-HDA at the doses of 2.5 and 5 mg/kg especially in combination with CP significantly (p < 0.001) decreased the tumor volume and inhibition rate, tumor markers (AFP and CEA), serum level of liver and kidney, LPO and NO, TNF-α level, as well as the expression level of Bcl-2 in comparison with the mice in the C2 group; while 10-HDA at the doses of 2.5 and 5 mg/kg especially in combination with CP significantly (p < 0.001) improved the level of antioxidant enzymes of GPx, CAT, and SOD and the expression level of caspase-3 and Bax genes. Conclusions: According to the results of the present investigations, 10-HDA at the doses of 2.5 and 5 mg/kg especially in combination with CP showed promising antitumor effects against EST in mice and can be recommended as a new or alternative anticancer agent against tumor; nevertheless, further investigations, particularly in clinical setting, are required to confirm these results.     

Can restrictions on redemption timing boost profitability of loyalty programs in competitive environments?

Computational Management Science - This research investigates whether it is beneficial for competing firms offering loyalty programs (LPs) to restrict the reward redemption time. We develop a...     

A Baer-Krull Theorem for Quasi-Ordered Groups

We give group analogs of two important theorems of real algebra concerning convex valuations, one of which is the Baer-Krull theorem. We do this by using quasi-orders, which gives a uniform approach to valued and ordered groups. We also recover the classical Baer-Krull theorem from its group analog.     

Binding Free Energy (BFE) Calculations and Quantitative Structure–Activity Relationship (QSAR) Analysis of Schistosoma mansoni Histone Deacetylase 8 (smHDAC8) Inhibitors

Histone-modifying proteins have been identified as promising targets to treat several diseases including cancer and parasitic ailments. In silico methods have been incorporated within a variety of drug discovery programs to facilitate the identification and development of novel lead compounds. In this study, we explore the binding modes of a series of benzhydroxamates derivatives developed as histone deacetylase inhibitors of Schistosoma mansoni histone deacetylase (smHDAC) using molecular docking and binding free energy (BFE) calculations. The developed docking protocol was able to correctly reproduce the experimentally established binding modes of resolved smHDAC8–inhibitor complexes. However, as has been reported in former studies, the obtained docking scores weakly correlate with the experimentally determined activity of the studied inhibitors. Thus, the obtained docking poses were refined and rescored using the Amber software. From the computed protein–inhibitor BFE, different quantitative structure–activity relationship (QSAR) models could be developed and validated using several cross-validation techniques. Some of the generated QSAR models with good correlation could explain up to ~73% variance in activity within the studied training set molecules. The best performing models were subsequently tested on an external test set of newly designed and synthesized analogs. In vitro testing showed a good correlation between the predicted and experimentally observed IC₅₀ values. Thus, the generated models can be considered as interesting tools for the identification of novel smHDAC8 inhibitors.     

Synthesis of biosourced polyether-amides from 1,4-3,6-dianhydrohexitols: Characterization by NMR and MALDI–ToF mass spectrometry

New series of polyether-amides were prepared by polycondensation in solution of three diamines based on 1,4-3,6-dianhydrohexitols with two types of diacyl chlorides (sebacoyl and isophtaloyl). Unprecedented diamines based on isomannide and isoidide were elaborated. The corresponding polyether-amides (PeA) were obtained with high yields. They were characterized by different analytical techniques (NMR, MALDI–ToF MS, DSC). The combination of MALDI–ToF MS with NMR spectroscopy allowed us to confirm structure types. DSC measurements revealed an amorphous character for the isophtaloyl family with a high T_g value. The sebacoyl series proved to be semi-crystalline with a high T_m value. Isosorbide-based PeAs demonstrated interesting properties (T_g above 210 °C and T_m above 240 °C) and high viscosity (0.32).