New Insights into the Mechanism of Visible Light Photocatalysis

ABSTRACT: In recent years, the area of developing visible-lightactive photocatalysts based on titanium dioxide has been enormously investigated due to its wide range of applications in energy and environment related fields. Various strategies have been designed to efficiently utilize the solar radiation and to enhance the efficiency of photocatalytic processes. Building on the fundamental strategies to improve the visible light activity of TiO2-based photocatalysts, this Perspective aims to give an insight into many contemporary developments in the field of visible-light-active photocatalysis. Various examples of advanced TiO2 composites have been discussed in relation to their visible light induced photoconversion efficiency, dynamics of electron− hole separation, and decomposition of organic and inorganic pollutants, which suggest the critical need for further development of these types of materials for energy conversion and environmental remediation purposes

Human adenovirus infection causes cellular E3 ubiquitin ligase MKRN1 degradation involving the viral core protein pVII.

Human adenoviruses (HAdVs) are common human pathogens encoding a highly abundant histone-like core protein, VII, which is involved in nuclear delivery and protection of viral DNA as well as in sequestering immune danger signals in infected cells. The molecular details of how protein VII acts as a multifunctional protein have remained to a large extent enigmatic. Here we report the identification of several cellular proteins interacting with the precursor pVII protein. We show that the cellular E3 ubiquitin ligase MKRN1 is a novel precursor pVII-interacting protein in HAdV-C5-infected cells. Surprisingly, the endogenous MKRN1 protein underwent proteasomal degradation during the late phase of HAdV-C5 infection in various human cell lines. MKRN1 protein degradation occurred independently of the HAdV E1B55K and E4orf6 proteins. We provide experimental evidence that the precursor pVII protein binding enhances MKRN1 self-ubiquitination, whereas the processed mature VII protein is deficient in this function. Based on these data, we propose that the pVII protein binding promotes MKRN1 self-ubiquitination, followed by proteasomal degradation of the MKRN1 protein, in HAdV-C5-infected cells. In addition, we show that measles virus and vesicular stomatitis virus infections reduce the MKRN1 protein accumulation in the recipient cells. Taken together, our results expand the functional repertoire of the HAdV-C5 precursor pVII protein in lytic virus infection and highlight MKRN1 as a potential common target during different virus infections. IMPORTANCE Human adenoviruses (HAdVs) are common pathogens causing a wide range of diseases. To achieve pathogenicity, HAdVs have to counteract a variety of host cell antiviral defense systems, which would otherwise hamper virus replication. In this study, we show that the HAdV-C5 histone-like core protein pVII binds to and promotes self-ubiquitination of a cellular E3 ubiquitin ligase named MKRN1. This mutual interaction between the pVII and MKRN1 proteins may prime MKRN1 for proteasomal degradation, because the MKRN1 protein is efficiently degraded during the late phase of HAdV-C5 infection. Since MKRN1 protein accumulation is also reduced in measles virus-and vesicular stomatitis virus-infected cells, our results signify the general strategy of viruses to target MKRN1

Research Journal of Pharmaceutical, Biological and Chemical Sciences Development and Validation of RP-HPLC Method for Content Analysis and Dissolution Studies Of Sitagliptin Phosphate Monohydratein Pharmaceutical Dosage Forms

ABSTRACT A simple and accurate reverse phase high performance liquid chromatography (RP-HPLC) method for the validative determination of assay and dissolution of Sitagliptin Phosphate Monohydrate 100mg was developed and validated as per USP 1225 and ICH guidelines Q2(R1).The suitable chromatographic conditions were optimizedat a flow rate of 1.0ml/min along with the detection wavelength of 257nm.The method shows the linearity in the range of 50-150mg/mL with correlation coefficient of 0.9993.The assay value was obtained between 98%-101%. Precision shows relative standard deviation not more than 2%.The satisfactory conditions for the validation of dissolution were 900mL of distilled water at 37°C±0.5°C, basket apparatus with 100rpm stirring speed. The cumulative percentage drug release was found to be higher than 95% within 45min under the validated conditions. The stability of drug was satisfied up to 24hr at room temperature and at refrigeration and does not show any variations in the percentage drug release. The method was simple and free of sophisticate expenditure as it involves the usage of most commonly available reagents, medium and buffer. Hence, it was concluded that the proposed method was cost effective and sensitive for regular dissolution and content analysis determination of Sitagliptin Phosphate Monohydrate

N′-[(1E)-4-Hydroxy-3-Methoxybenzylidene]isonicotinohydrazide Monohydrate

In the title hydrate, C\sb 14H\sb 13N\sb 3O\sb 3⋅H\sb 2O, the dihedral angle between the pyridine and benzene rings is 2.52(9)\circ. Intra\-molecular O—-H⋅sO hydrogen bonds occur. In the crystal, O—-H⋅sO, O—-H⋅sN, N—-H⋅sO and C—-H⋅sO hydrogen bonds link the components into a three-dimensional network. π—π inter\-actions are also observed

2-Methoxy-4-[3-(3-nitrophenyl)-4,5-dihydro-1H-pyrazol-5-yl]phenol

In the title compound, C16H15N3O4, the pyrazole ring has an envelope conformation, with the C atom substituted by the 2-methoxyphenol ring as the flap. Its mean plane makes dihedral angles of 56.78 (9) and 9.7 (1)° with the 2-methoxyphenol and 3-nitrophenyl rings, respectively. The benzene rings are inclined to one another by 49.37 (8)°. In the crystal, molecules are linked by pairs of O—H...N hydrogen bonds, forming inversion dimers with an R22(16) ring motif. The dimers are linked by C—H...O hydrogen bonds, forming slabs parallel to the ac plane. There are slipped parallel π–π interactions present within the slabs, involving inversion-related 2-methoxyphenol rings [intercentroid distance = 3.729 (1) Å] and inversion-related 3-nitrophenyl rings [intercentroid distance = 3.831 (1) Å]