In Vitro Regeneration of Tea (Camellia sinensis (L). O. Kuntze) By Somatic Embryogenesis from Immature Cotyledon Tissues

Tea (Camellia sinensis) is the world's most popular beverage plant, as well as an important plantation crop with high commercial value. It has been maintained for centuries through conventional vegetative propagation. Tea clonal propagation in vitro has the advantage of producing a large number of elite plants. If an efficient in vitro regeneration technology is available, this technique could be exploited for selection of tea plants for desired trait. The selected plants could be later on multiplied through in vitro or ex vitro techniques. The study aimed to induced somatic embryogenesis from immature embryo explants to genetic variaton. Different concentrations of phenylboronic acid with benzyladenine and phenylboronic acid with kinetin were tested in MS medium with 30 g/L sucrose and 8 g/L agar. MS medium without any plant growth regulators was used as control group. Considering the embryo survival rate, 1.5 mg/ L-1 phenylboronic acid + 1 mg/ L-1 kinetin produced highest result as 87.3% while lowest was in control group as 36.7%. The highest plant regeneration rate was found in 1,5 mg/ L-1 phenylboronic acid + 1 mg/ L-1 kinetin and 1.5 mg/ L-1 phenylboronic acid + 1 mg/ L-1 benzyladenine medium respectively as 58.3% and 55.6%. Kinetin treatment with increasing phenylboronic acid concentrations gave the best results in terms of somatic embryo survival rate. Also, kinetin treatment produced better results when compared to benzyladenine concentrations.

Ultrasensitive dynamic light scattering immunosensing platform for NT-proBNP detection using boronate affinity amplification

Herein, we reported a new dynamic light scattering (DLS) immunosensing technology for the rapid and sensitive detection of glycoprotein N-terminal pro-brain natriuretic peptide (NT-proBNP). In this design, the boronate affinity recognition based on the interaction of boronic acid ligands and cis-diols was introduced to amplify the nanoparticle aggregation to enable highly sensitive DLS transduction, thereby lowering the limit of detection (LOD) of the methodology. After covalently coupling with antibodies, magnetic nanoparticles (MNPs) were employed as the nanoprobes to selectively capture trace amount of NT-proBNP from complex samples and facilitate DLS signal transduction. Meanwhile, silica nanoparticles modified with phenylboronic acid (SiO2@PBA) were designed as the crosslinking agent to bridge the aggregation of MNPs in the presence of target NT-proBNP. Owing to the multivalent and fast affinity recognition between NT-proBNP containing cis-diols and SiO2@PBA, the developed DLS immunosensor exhibited charming advantages over traditional immunoassays, including ultrahigh sensitivity with an LOD of 7.4 fg mL−1, fast response time (< 20 min), and small sample consumption (1 μL). The DLS immunosensor was further characterized with good selectivity, accuracy, precision, reproducibility, and practicability. Collectively, this work demonstrated the promising application of the designed boronate affinity amplified-DLS immunosensor for field or point-of-care testing of cis-diol-containing molecules. Graphical Abstract

Determination of 3-Monochloropropanediol and Glycidol in Food Products

Due to the increasing globalization of food markets, there are evolving new challenges for maintaing food safety. The current problem is the development of analytical methods for 3-monochloropropanediol ester and glycidol ester, which are food contaminants of concern for the scientific community. The levels of 3-monochloropropanediol ester and glycidol ester in certain food products are controlled by the European legislation. However, the maximum allowed concentrations and uptake limits for various food products are permanently revised. Therefore, we aimed to determine 3-monochloropropanediol ester and glycidol ester in various food products, which may contain vegetable oils. We analyzed food samples obtained from local food shops, predominantly low-priced products, which are more likely to contain vegetable oils, and adulterated milk fat. The levels of 3-monochloropropanediol ester and glycidol ester were determined indirectly by analyzing free 3-monochloropropanediol and glycidol ester obtained by hydrolysis and derivatized with phenylboronic acid. Samples were analyzed by GC-MS/MS on a triple-quad mass spectrometer.

Phospholipid polymer hydrogels with rapid dissociation for reversible cell immobilization

Reversible and cytocompatible cell immobilization polymer matrix with rapid dissociation rate was prepared by using with a zwitterionic phospholipid polymer bearing phenylboronic acid and poly(vinyl alcohol)(PVA). A reversible and spontaneously...

Rapid Bacterial Recognition over a Wide pH Range by Boronic Acid-Based Ditopic Dendrimer Probes for Gram-Positive Bacteria

We have developed a convenient and selective method for the detection of Gram-positive bacteria using a ditopic poly(amidoamine) (PAMAM) dendrimer probe. The dendrimer that was modified with dipicolylamine (dpa) and phenylboronic acid groups showed selectivity toward Staphylococcus aureus. The ditopic dendrimer system had higher sensitivity and better pH tolerance than the monotopic PAMAM dendrimer probe. We also investigated the mechanisms of various ditopic PAMAM dendrimer probes and found that the selectivity toward Gram-positive bacteria was dependent on a variety of interactions. Supramolecular interactions, such as electrostatic interaction and hydrophobic interaction, per se, did not contribute to the bacterial recognition ability, nor did they improve the selectivity of the ditopic dendrimer system. In contrast, the ditopic PAMAM dendrimer probe that had a phosphate-sensing dpa group and formed a chelate with metal ions showed improved selectivity toward S. aureus. The results suggested that the targeted ditopic PAMAM dendrimer probe showed selectivity toward Gram-positive bacteria. This study is expected to contribute to the elucidation of the interaction between synthetic molecules and bacterial surface. Moreover, our novel method showed potential for the rapid and species-specific recognition of various bacteria.

Mono- and Bimetallic Nanoparticles Stabilized by an Aromatic Polymeric Network for a Suzuki Cross-Coupling Reaction

This work addresses the Suzuki cross-coupling between 4-bromoanisole (BrAn) and phenylboronic acid (PBA) in an environmentally benign ethanol–water solvent catalysed by mono- (Pd) and bimetallic (PdAu, PdCu, PdZn) nanoparticles (NPs) stabilised within hyper-cross-linked polystyrene (HPS) bearing tertiary amino groups. Small Pd NPs of about 2 nm in diameters were formed and stabilized by HPS independently in the presence of other metals. High catalytic activity and complete conversion of BrAn was attained at low Pd loading. Introduction of Zn to the catalyst composition resulted in the formation of Pd/Zn/ZnO NPs, which demonstrated nearly double activity as compared to Pd/HPS. Bimetallic core-shell PdAu/HPS samples were 3-fold more active as compared to Pd/HPS. Both Pd/HPS and PdAu/HPS samples revealed promising stability confirmed by catalyst recycling in repeated reaction runs.

INFLUENCE OF HALOGEN NATURE ON THE ADSORPTION ABILITY OF ARYL HALIDES ON PALLADIUM CLUSTERS

В данной работе методом теории функционала плотности проведен расчет энергий адсорбции бензольного кольца на маленьких кластерах Pd (состоящих из четырех или девяти атомов). Показано, что адсорбция бензола на кластерах палладия ведет к заметному выигрышу системы в энергии: -146 кДж/моль в случае Pd и -117 кДж/моль в случае Pd. Кроме того, для системы Pd * CH рассчитаны энергии адсорбции хлор-, бром- и йоданизола. Показано, что адсорбция йоданизола, характеризующаяся наибольшим выигрышем системы в энергии (-278 кДж/моль), происходит диссоциативно и безактивационно, что принципиально отличает его от хлор- и броманизола. Полученные данные могут использоваться для объяснения различий в поведении катализаторов на основе сверхсшитого полистирола в реакциях кросс-сочетания различных арилгалогенидов c фенилбороновой кислотой, а также того факта, что арилйодиды могут провоцировать образование гомогенных форм палладия. In this paper, the density functional theory calculations were carried out in order to find the adsorption energies of a benzene ring on small Pd clusters consisting of four or nine atoms. The adsorption of benzene on palladium clusters was found to result in a noticeable energy gain of the system: -146 kJ/mol in the case of Pd, and -117 kJ/mol in the case of Pd. The adsorption energies of chloro-, bromo- and iodoanisole on Pd * CH were also calculated. The adsorption of iodoanisole was characterized by the highest energy gain of the system (-278 kJ/mol) and occurred dissociatively without activation, that fundamentally distinguished it from chloro- and bromoanisole. The data obtained can be used to explain the differences in the behavior of catalysts based on hypercross-linked polystyrene in cross-coupling reactions of various aryl halides and phenylboronic acid, and also the fact that aryl iodides can favor the formation of homogeneous forms of palladium.