Chemical Profiles and Pharmacological Properties with in Silico Studies on Elatostema papillosum Wedd

The current study attempted, for the first time, to qualitatively and quantitatively determine the phytochemical components of Elatostema papillosum methanol extract and their biological activities. The present study represents an effort to correlate our previously reported biological activities with a computational study, including molecular docking, and ADME/T (absorption, distribution, metabolism, and excretion/toxicity) analyses, to identify the phytochemicals that are potentially responsible for the antioxidant, antidepressant, anxiolytic, analgesic, and anti-inflammatory activities of this plant. In the gas chromatography-mass spectroscopy analysis, a total of 24 compounds were identified, seven of which were documented as being bioactive based on their binding affinities. These seven were subjected to molecular docking studies that were correlated with the pharmacological outcomes. Additionally, the ADME/T properties of these compounds were evaluated to determine their drug-like properties and toxicity levels. The seven selected, isolated compounds displayed favorable binding affinities to potassium channels, human serotonin receptor, cyclooxygenase-1 (COX-1), COX-2, nuclear factor (NF)-κB, and human peroxiredoxin 5 receptor proteins. Phytol acetate, and terpene compounds identified in E. papillosum displayed strong predictive binding affinities towards the human serotonin receptor. Furthermore, 3-trifluoroacetoxypentadecane showed a significant binding affinity for the KcsA potassium channel. Eicosanal showed the highest predicted binding affinity towards the human peroxiredoxin 5 receptor. All of these findings support the observed in vivo antidepressant and anxiolytic effects and the in vitro antioxidant effects observed for this extract. The identified compounds from E. papillosum showed the lowest binding affinities towards COX-1, COX-2, and NF-κB receptors, which indicated the inconsequential impacts of this extract against the activities of these three proteins. Overall, E. papillosum appears to be bioactive and could represent a potential source for the development of alternative medicines; however, further analytical experiments remain necessary.     

Novel Semi-Synthetic Cu (II)–Cardamonin Complex Exerts Potent Anticancer Activity against Triple-Negative Breast and Pancreatic Cancer Cells via Inhibition of the Akt Signaling Pathway

Cardamonin is a polyphenolic natural product that has been shown to possess cytotoxic activity against a variety of cancer cell lines. We previously reported the semi-synthesis of a novel Cu (II)–cardamonin complex (19) that demonstrated potent antitumour activity. In this study, we further investigated the bioactivity of 19 against MDA-MB-468 and PANC-1 cancer cells in an attempt to discover an effective treatment for triple-negative breast cancer (TNBC) and pancreatic cancer, respectively. Results revealed that 19 abolished the formation of MDA-MB-468 and PANC-1 colonies, exerted growth-inhibitory activity, and inhibited cancer cell migration. Further mechanistic studies showed that 19 induced DNA damage resulting in gap 2 (G2)/mitosis (M) phase arrest and microtubule network disruption. Moreover, 19 generated reactive oxygen species (ROS) that may contribute to induction of apoptosis, corroborated by activation of caspase-3/7, PARP cleavage, and downregulation of Mcl-1. Complex 19 also decreased the expression levels of p-Akt and p-4EBP1, which indicates that the compound exerts its activity, at least in part, via inhibition of Akt signalling. Furthermore, 19 decreased the expression of c-Myc in PANC-1 cells only, which suggests that it may exert its bioactivity via multiple mechanisms of action. These results demonstrate the potential of 19 as a therapeutic agent for TNBC and pancreatic cancer.     

Syntheses of pyridine C-nucleosides as analogues of the natural nucleosides dC and dU

The syntheses of four pyrimidine C-nucleosides are described. These derivatives are designed as mimics of dC and dU, and in that respect, each can form two hydrogen bonds with complementary dG or dA residues. The minor groove O2 carbonyl in each derivative is replaced by a fluorine or a methyl group. The key carbon-carbon bond connecting the heterocycle to the carbohydrate is formed using a Heck-type palladium-mediated coupling reaction.     

Power-law behavior in complex organizational communication networks during crisis

Communication networks can be described as patterns of contacts which are created due to the flow of messages and information shared among participating actors. Contemporary organizations are now commonly viewed as dynamic systems of adaptation and evolution containing several parts, which interact with one another both in internal and in external environment. Although there is limited consensus among researchers on the precise definition of organizational crisis, there is evidence of shared meaning: crisis produces individual crisis, crisis can be associated with positive or negative conditions, crises can be situations having been precipitated quickly or suddenly or situations that have developed over time and are predictable etc. In this research, we study the power-law behavior of an organizational email communication network during crisis from complexity perspective. Power law simply describes that, the probability that a randomly selected node has k links (i.e. degree k) follows P(k)∼k^−γ, where γ is the degree exponent. We used social network analysis tools and techniques to analyze the email communication dataset. We tested two propositions: (1) as organization goes through crisis, a few actors, who are prominent or more active, will become central, and (2) the daily communication network as well as the actors in the communication network exhibit power-law behavior. Our preliminary results support these two propositions. The outcome of this study may provide significant advancement in exploring organizational communication network behavior during crisis.     

Exploring communication networks to understand organizational crisis using exponential random graph models

In recent social network studies, exponential random graph (ERG) models have been used comprehensively to model global social network structure as a function of their local features. In this study, we describe the ERG models and demonstrate its use in modelling the changing communication network structure at Enron Corporation during the period of its disintegration. We illustrate the modelling on communication networks, and provide a new way of classifying networks and their performance based on the occurrence of their local features. Among several micro-level structures of ERG models, we find significant variation in the appearance of A2P (Alternating k-two-paths) network structure in the communication network during crisis period and non-crisis period. We also notice that the attribute of hierarchical positions of actors (i.e., high rank versus low rank staff) have impact on the evolution process of networks during crisis. These findings could be used in analyzing communication networks of dynamic project groups and their adaptation process during crisis which could lead to an improved understanding how communications network evolve and adapt during crisis.     

Particles dispersion on fluid-liquid interfaces

This paper is concerned with the dispersion of particles on the fluid-liquid interface. In a previous study we have shown that when small particles, e.g., flour, pollen, glass beads, etc., contact an air-liquid interface, they disperse rapidly as if they were in an explosion. The rapid dispersion is due to the fact that the capillary force pulls particles into the interface causing them to accelerate to a large velocity. In this paper we show that motion of particles normal to the interface is inertia domin...     

Core-substituted naphthalene bisimides: new fluorophors with tunable emission wavelength for FRET studies

Highly colored and photoluminescent naphthalene bisimide dyes have been synthesized from 2,6-dichloronaphthalene bisanhydride 1 by means of a stepwise nucleophilic displacement of the two chlorine atoms by alkoxides and/or alkyl amines. The alkoxy-substituted derivatives are yellow dyes with green emission and low photoluminescence quantum yields, whereas the amine-substituted derivatives exhibit a color range from red to blue with strong photoluminescence up to 76%. Structure-property relationships for this class of two-dimensional chromophores were evaluated based on a single-crystal X-ray analysis for dye 5a, the observed solvatochromism, and quantum-chemical calculations. Owing to the simple tuning of the absorption properties over the whole visible range by the respective substituents, the pronounced brilliancy, and the intense photoluminescence, this class of dyes is considered to be highly suited for numerous applications such as fluorescent labeling of biomacromolecules and light-harvesting in supramolecular assemblies. As an important step towards such applications efficient FRET (fluorescence resonance energy transfer) has been demonstrated for a covalently tethered bichromophoric compound that contains a red and a blue naphthalene bisimide dye.     

Radioactivity in coral skeletons and marine sediments collected from the St. Martin’s Island of Bangladesh

Journal of Radioanalytical and Nuclear Chemistry - Although the coral island ‘St. Martin’s’ serves as the most attractive place for leisure and tourism, but no data on...