The Use of Bromfenac Ophthalmic Solution in Clinical Practice (Literature Review)

To this date nonsteroidal anti-inflammatory drugs play a huge role in the treatment of inflammatory eye diseases. Ophthalmologists face the question of choosing between glucocorticoid drugs (GCS) and nonsteroidal anti-inflammatory drugs (NSAIDs) for the treatment of any inflammatory process. At the same time, these groups can be used both in combinations and in monotherapy mode. Glucocorticoids are widely and effectively used in ophthalmology, but it should be remembered about a number of serious side effects of this group of drugs. When using these drugs, it is possible to increase ophthalmotonus, decrease the immune response and reparative processes, also GCS have cataractogenic and ulcerogenic effects, and therefore it careful use is necessary. NSAIDs are inferior to glucocorticoids in anti-inflammatory activity. Its mechanism of action is associated with blocking cyclooxygenase, inhibition of prostaglandin synthesis from arachidonic acid. In this regard, NSAIDs are the preferred group in the treatment of inflammatory eye diseases. The use of NSAIDs gives a good analgesic effect, this class of drugs is effective for the prevention of macular edema of various etiologies and reducing the risk of inflammation in the postoperative period. One of the most effective and most modern NSAIDs for topical use is a derivative of phenylacetic acid — Bromophenac, which in its formula has a bromine atom, which increases its lipophilicity, penetrating ability into the tissues of the eye, as well as analgesic and anti-inflammatory activity. Bromfenac is effective for relieving pain and all signs of inflammation caused by disease or surgery, suppressing the development of macular edema of various etiologies, has an antimiotic effect. Also, this group can be used after refractive surgery to reduce pain and photophobia, to relieve itching in allergic conjunctivitis. Double use of this drug during the day, the absence of discomfort and minimal side effects contribute to improving the patient’s compliance.

Ecological and Pharmacological Activities of Polybrominated Diphenyl Ethers (PBDEs) from the Indonesian Marine Sponge Lamellodysidea herbacea

Two known Polybrominated Diphenyl Ethers (PBDEs), 3,4,5-tribromo-2-(2′,4′-dibromophenoxy)phenol (1d) and 3,4,5,6-tetrabromo-2-(2′,4′-dibromophenoxy)phenol (2b), were isolated from the Indonesian marine sponge Lamellodysidea herbacea. The structure was confirmed using 13C chemical shift average deviation and was compared to the predicted structures and recorded chemical shifts in previous studies. We found a wide range of bioactivities from the organic crude extract, such as (1) a strong deterrence against the generalist pufferfish Canthigaster solandri, (2) potent inhibition against environmental and human pathogenic bacterial and fungal strains, and (3) the inhibition of the Hepatitis C Virus (HCV). The addition of a bromine atom into the A-ring of compound 2b resulted in higher fish feeding deterrence compared to compound 1d. On the contrary, compound 2b showed only more potent inhibition against the Gram-negative bacteria Rhodotorula glutinis (MIC 2.1 μg/mL), while compound 1d showed more powerful inhibition against the other human pathogenic bacteria and fungi. The first report of a chemical defense by compounds 1d and 2b against fish feeding and environmental relevant bacteria, especially pathogenic bacteria, might be one reason for the widespread occurrence of the shallow water sponge Lamellodysidea herbacea in Indonesia and the Indo-Pacific.

BROMINATION OF NR WITH N-BROMOSUCCINIMIDE

ABSTRACT The mechanism of bromination of NR was studied by solution-state 1H-NMR spectroscopy. The bromination of NR was carried out at 20–50 °C with N-bromosuccinimide as the brominating agent, and the kinetic study of bromination was conducted under nitrogen atmosphere at 30–50 °C for various reaction times. The influence of bromine atom substituent on the bromination rate constant (k) also was investigated. Bromine atom content was found to be dependent upon the reaction time, indicating first-order kinetics. The activation energy of bromination of NR, calculated from the reaction rate constants, was 19.3, 5.5, and 5.8 kJ mol−1 for bromine atom linked to carbon atom with methylene proton and methylene protons, respectively.

Oxidation of α,β-Unsaturated Ketones by Organophotocatalysis Using Rhodamine 6G Under Visible Light Irradiation: Insight into Reaction Mechanism

The oxidative transformation of α,β-unsaturated ketones was investigated under the visible light-induced photocatalytic conditions using rhodamine 6G as an organophotocatalyst. In this organocatalysis, a mild co-oxidant BrCCl3 acts not only as a quencher toward the activated photocatalyst species having reductant property but also as a brominating reagent for the intermediate radicals. This study shows that the bromine atom-transfer to intermediate radicals from BrCCl3 is a key step in the reaction mechanism of our oxidation method.

Spin-Crossover in Iron(II) Complexes of N,N′-Disubstituted 2,6-Bis(Pyrazol-3-yl)Pyridines: An Effect of a Distal Substituent in the 2,6-Dibromophenyl Group

A series of new bis(pyrazol-3-yl)pyridines (LR) N,N′-disubstituted by 4-functionalized 2,6-dibromophenyl groups have been synthesized to study the effect of a distal substituent on the spin-crossover (SCO) behaviour of the iron(II) complexes [Fe(LR)2](ClO4)2 by variable-temperature magnetometry, NMR spectroscopy, and X-ray diffraction. The SCO-assisting tendency of the substituents with different electronic and steric properties (i.e., the bromine atom and the methyl group) in the para-position of the 2,6-dibromophenyl group is discussed. Together with earlier reported SCO-active iron(II) complexes with N,N′-disubstituted bis(pyrazol-3-yl)pyridines, these new complexes open the way for this family of SCO compounds to emerge as an effective ‘tool’ in revealing structure–function relations, a prerequisite for successful molecular design of switchable materials for future breakthrough applications in sensing, switching, and memory devices.

Selectivity of a bromoacridine-containing fluorophore for triplex DNA

Fluorophore 1,8-naphthilamide was linked to 2-bromoacridine through an ethylenediamine spacer using a succinct synthetic route to give a bromoacridine-linked, bifunctional fluorophore conjugate for the detection of triplex DNA. Acridine is well known to intercalate into duplex DNA whereas introduction of a bulky bromine atom at position C2 redirects specificity for triplex over duplex DNA. In this work, photoelectron transfer assay was used to demonstrate that the synthesised 2-bromoacridine-linked fluorophore conjugate had good selectivity for the representative triplex DNA target sequence d(T*A.T)20 compared with double-stranded d(T.A)20, single-stranded dT20 or d(G/A)19 DNA sequences. Graphic abstract

Halogen…π Interactions in the Complexes of Fluorenonophane With Haloforms

The study of two complexes of fluorenonophane with CHCl3 and CHBr3 molecules has revealed that they differ mainly by the halogen bonds between host and guest molecules. The experimental and theoretical quantum chemical study has shown that the strength of a halogen bond depends on the nature of a halogen atom as well as its orientation to the π-system. The more positive electrostatic potential was revealed at the bromine atom indicating the stronger halogen bond with its participation that was confirmed by the interaction energies calculated for corresponding dimers and the evaluation of the true energy of a halogen bond. The orientation of the chlorine atom at the carbon aromatic atom instead of the center of the benzene ring leads to the shortest Hal…C distance that points out the stronger interaction according to the geometrical characteristics. The EDA analysis of the fluorenonophane complexes with CHCl3 and CHBr3 and their analogs with one halogen atom replaced by the hydrogen atom allows us to presume that the nature of halogen bonding is rather dispersive than electrostatic.

Rearrangement of spiroderivatives of 1,3-benzo(naphtho)dioxin-4(1)-ones as a new method of synthesis of xanthene bromo derivatives

We have proposed a method for the synthesis of previously unknown bromo xanthenes using the reagent PBr3/DMF as a rearrangement initiator. Bromo derivatives of xanthenes in the form of organic perchlorates were prepared by reacting the corresponding benzo(naphtho)dioxin-4(1)-ones with a three-fold excess of Vilsmeier-Haack PBr3/DMF reagent at 1100C for 2 hours, followed by the addition of sodium perchlorate. The conditions for the synthesis of formyl derivatives of xanthenes under conditions of acid hydrolysis were selected. The structure of the compounds was confirmed by 1H and 13C NMR spectral data and mass spectrometry. Preliminary studies showed that it is possible to selectively replace the dimethylamino group and the bromine atom with various nucleophiles in bromo derivatives of xanthenes, which opens up wide possibilities for the synthesis of low-molecular building blocks and dyes.

Reactivity of substrates with multiple competitive reactive sites toward NBS under neat reaction conditions promoted by visible light

Regioselectivity of visible-light-induced transformations of a range of (hetero)aryl alkyl-substituted ketones bearing several competitive reactive sites (α-carbonyl, benzyl and aromatic ring) with N-bromosuccinimide (NBS) was studied under solvent-free reaction conditions (SFRC) and in the absence of inert-gas atmosphere, radical initiators and catalysts. An 8-W energy-saving household lamp was used for irradiation. Heterogeneous reaction conditions were dealt with throughout the study. All substrates were mono- or dibrominated at the α-carbonyl position, and additionally, some benzylic or aromatic bromination was observed in substrates with benzylic carbon atoms or electron-donating methoxy groups, respectively. Surprisingly, ipso-substitution of the acyl group with a bromine atom took place with (4-methoxynaphthyl) alkyl ketones. While the addition of the radical scavenger TEMPO (2,2,6,6-tetramethylpiperidin-1-yloxy) decreased the extent of α- and ring bromination, it completely suppressed the benzylic bromination and α,α-dibromination with NBS under SFRC.

A Combined Experimental and Computational Study of Halogen and Hydrogen Bonding in Molecular Salts of 5-Bromocytosine

Although natural or artificial modified pyrimidine nucleobases represent important molecules with valuable properties as constituents of DNA and RNA, no systematic analyses of the structural aspects of bromo derivatives of cytosine have appeared so far in the literature. In view of the biochemical and pharmaceutical relevance of these compounds, six different crystals containing proton-transfer derivatives of 5-bromocytosine are prepared and analyzed in the solid-state by single crystal X-ray diffraction. All six compounds are organic salts, with proton transfer occurring to the Nimino atom of the pyridine ring. Experimental results are then complemented with Hirshfeld surface analysis to quantitively evaluate the contribution of different intermolecular interactions in the crystal packing. Furthermore, theoretical calculations, based on different arrangements of molecules extracted from the crystal structure determinations, are carried out to analyze the formation mechanism of halogen bonds (XBs) in these compounds and provide insights into the nature and strength of the observed interactions. The results show that the supramolecular architectures of the six molecular salts involve extensive classical intermolecular hydrogen bonds. However, in all but one proton-transfer adducts, weak to moderate XBs are revealed by C–Br…O short contacts between the bromine atom in the fifth position, which acts as XB donor (electron acceptor). Moreover, the lone pair electrons of the oxygen atom of adjacent pyrimidine nucleobases and/or counterions or water molecules, which acts as XB acceptor (electron donor).