Herbicidal activity of pure compound isolated from rhizosphere inhabiting Aspergillus flavus

In the quest for bioactive natural products of fungal origin, Aspergillus flavus was isolated from rhizosphere of Mentha piperita using Potato Dextrose Agar (PDA) and Czapec Yeast Broth (CYB) nutrient media for metabolites production. In total, three different metabolites were purified using HPLC/LCMS and the structures were established using 500 Varian NMR experiments. Further the isolated metabolites in different concentrations (10, 100, 1000 μg/mL) were tested for herbicidal activity using Completely Randomized design (CRD) against the seeds of Silybum marianum and Avena fatua which are major threats to wheat crop in Pakistan. Among the isolated metabolites, one compound was found active against the test weed species whose activity is reported in the present work. The chemical name of the compound is 2-(1, 4-dihydroxybutan-2-yl)-1, 3-dihydroxy-6, 8-dimethoxyanthracene-9, 10(4aH, 9aH)-dione with mass of 388. Results showed that all seeds germinated in control treatment; however, with the metabolite treated, the growth was retarded to different levels in all parts of the weeds. At a dose of 1000 μg/mL of the pure compound, 100% seeds of S. marianum and 60% seeds of A. fatua were inhibited. Interestingly, the pure compound exhibited less inhibition of 10% towards the seeds of common wheat (Triticum aestivum).     

Synthesis and characterization of a photoaffinity labelling probe based on the structure of the cystic fibrosis drug ivacaftor

Cystic Fibrosis (CF) is a genetic disorder caused by loss-of-function mutations to the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein. Ivacaftor (1) was the first therapeutic approved for the treatment of CF that is able to restore gating activity to certain CFTR variants although the mechanism of action is poorly understood. Herein we describe the synthesis of a photoaffinity labelling (PAL) probe (2) based on the structure of ivacaftor incorporating a photoreactive diazirine moiety for use in labelling studies designed to identify the binding site for ivacaftor on mutant CFTR. The PAL probe 2 retained potentiation activity, with a potency similar to 1, using a Fluorescent Imaging Plate Reader (FLIPR^®) assay measuring ion conductance potentiation of wild type (Wt)-CFTR. Photolabelling experiments with human serum albumin (HSA) as a model protein have shown that probe 2 can label HSA in a manner consistent with observed and predicted binding.     

Eco-friendly synthesis of pyrimidines and its derivatives: A review on broad spectrum bioactive moiety with huge therapeutic profile

Among all heterocyclic compounds, pyrimidine is of prime interest, exhibit broad spectrum of biological activities, because of its occurrence in deoxyribonucleic acid bases. The bioactive moiety pyrimidine has a voluminous therapeutic profile as it is a vital component of a series of natural composites and chemotherapeutic drugs. Since from last 50–60 years, this motif has been used commendably against bacterial, tuberculosis viral, malarial, fungal, and cancerous contagions. Recently, numerous pyrimidine derivatives were synthesized and discussed here, fused with other heterocyclic moieties, pyrazole, coumarine, triazole, alkenyloxindole, hydrazine and others, were also investigated for their bioactivities. Amid all recently reported compounds, several exhibit potentials against breast cancer cell lines. Intensive research has been performed and is going ahead with distinctive emphasis on antineoplastic potential of pyrimidine. These widespread medicinal attributes impulse scientists to synthesize more and more biologically active pyrimidine composites by following simple and eco-friendly routes.     

Rovibrational spectroscopy and intramolecular dynamics of 1,2-trans-d(2)-ethene in the first C-H stretch overtone region

The first overtone region of the C-H stretching vibration of 1,2-trans-d(2)-ethene (HDC=CDH) was monitored via jet-cooled action spectroscopy and room temperature photoacoustic spectroscopy. The spectra include a strong band, which we assigned as the nu(1)+nu(9) C-H stretch vibration, and five additional bands related to transitions to coupled states. The spectral features were modeled in terms of a six-state deperturbation analysis, revealing the energies of the zero-order states and the relatively strong couplings between the initially excited nu(1)+nu(9) state and the doorway states. Considering these energies and the fundamental frequencies of 1,2-trans-d(2)-ethene and presuming that only low-order resonances are involved in the couplings enabled the assignment of the states. The analysis also allowed obtaining insight on energy flow and to find out that the energy oscillations between the C-H stretch state and the doorway states occur on a subpicosecond time scale.     

Efficient Intersystem Crossing and Long-lived Charge-Separated State Induced by Through-Space Intramolecular Charge Transfer in a Parallel Geometry Carbazole-Bodipy Dyad

The design of efficient heavy atom-free triplet photosensitizers (PSs) based on through bond charge transfer (TBCT) features is a formidable challenge due to the criteria of orthogonal donor-acceptor geometry. Herein, we propose using parallel (face-to-face) conformation carbazole-bodipy donor-acceptor dyads (BCZ-1 and BCZ-2) featuring through space intramolecular charge transfer (TSCT) process as efficient triplet PS. Efficient intersystem crossing (Φ_Δ=61 %) and long-lived triplet excited state (τ_T=186 μs) were observed in the TSCT dyad BCZ-1 compared to BCZ-3 (Φ_Δ=0.4 %), the dyad involving TBCT, demonstrating the superiority of the TSCT approach over conventional donor-acceptor system. Moreover, the transient absorption study revealed that TSCT dyads have a faster charge separation and slower intersystem crossing process induced by charge recombination compared to TBCT dyad. A long-lived charge-separated state (CSS) was observed in the BCZ-1 (τ_CSS=24 ns). For the first time, the TSCT dyad was explored for the triplet-triplet annihilation upconversion, and a high upconversion quantum yield of 11 % was observed. Our results demonstrate a new avenue for designing efficient PSs and open up exciting opportunities for future research in this field.     

Physico-Chemical Properties of Magnetic Dicationic Ionic Liquids with Tetrahaloferrate Anions

A series of imidazolium-based symmetrical and asymmetrical dicationic ionic liquids (DcILs) with alkyl spacers of different length and with [FeCl₃Br]⁻ as counter ion have been synthesized. The synthesized DcILs are characterized by using FTIR and Raman spectroscopy as well as mass spectrometry, along with single-crystal XRD analysis. Physicochemical properties such as solubility, thermal stability and magnetic susceptibility are also measured. These compounds show low melting points, good solubility in water and organic solvents, thermal stability, and paramagnetism. The products of molar susceptibility and temperature (χ_mol⋅T) for the synthesized DcILs have been found between 4.05 to 4.79 emu mol⁻¹ K Oe⁻¹ and effective magnetic moment values have also been determined to be compared to that expected from the spin-only approximation.     

Dynamic behavior and chaos control in a complex Riccati-type map

This paper is devoted to analyze the dynamic behavior of a Riccatitype map with complex variables and complex parameters. Fixed points and their asymptotic stability are studied. Lyapunov exponent is computed to indicate chaos. Bifurcation and chaos are discussed. Chaotic behavior of the map has been controlled by OGY feedback control method.     

Glutaric Acid Assisted Fabrication of CuO Nanostructures and their Application in Development of Highly Sensitive Electrochemical Sensor System for Carbamates

This work describes the fabrication of unique arrow head shaped CuO nanostructures using simple hydrothermal treatment method. The highly attractive features were obtained by the application of glutaric acid utilised simultaneous as template and functionalising agent. The functionalised nanostructures were known to possess excellent potential towards the electro‐catalytic oxidation of carbofuran pesticide. The generated intense electrochemical signal with lower potential value enabled sensitive and selective determination of carbofuran up to 1×10^?3 µM with wide sensing window in range of 0.01 to 0.16 µM. The feasibility of the developed sensor system for the practical application was also studied by testing its potential in real sample extracts of various vegetables. The excellent recoveries demonstrated the analytical robustness of the developed sensor system. The sensor system utilises a new and simple approach towards sensitive determination of toxic pesticides reflecting its wide spectrum application in various fields.     

Development of agriculture biotechnology in Pakistan

Agriculture plays an important role in the national economy of Pakistan, where most of the rapidly increasing population resides in rural areas and depends on agriculture for subsistence. Biotechnology has considerable potential for promoting the efficiency of crop improvement, food production, and poverty reduction. Use of modern biotechnology started in Pakistan since 1985. Currently, there are 29 biotech centers/institutes in the country. However, few centers have appropriate physical facilities and trained manpower to develop genetically modified (GM) crops. Most of the activities have been on rice and cotton, which are among the top 5 crops of Pakistan. Biotic (virus/bacterial/insect) and abiotic (salt) resistant and quality (male sterility) genes have already been incorporated in some crop plants. Despite acquiring capacity to produce transgenic plants, no GM crops, either produced locally or imported, have been released in the country. Pakistan is signatory to the World Trade Organization, Convention on Biological Diversity, and Cartagena protocols. Several legislations under the Agreement on Trade-Related Aspects of Intellectual Property Rights have been promulgated in the country. National Biosafety Guidelines have been promulgated in April 2005. The Plant Breeders Rights Act, Amendment in Seed Act-1976, and Geographical Indication for Goods are still passing through discussion, evaluation, and analysis phases. Meanwhile, an illegal GM crop (cotton) has already sneaked into farmer's field. Concerted and coordinated efforts are needed among various ministries for implementation of regulation and capacity building for import/export and local handling of GM crops. Pakistan could easily benefit from the experience of Asian countries, especially China and India, where conditions are similar and the agriculture sector is almost like that of Pakistan. Thus, the exchange of information and experiences is important among these nations.     

Sage,Salvia officinalis L., Constituents,Hepatoprotective Activity,and Cytotoxicity Evaluations of the Essential Oils Obtained from Fresh and Differently Timed Dried Herbs: A Comparative Analysis

Sage, Salvia officinalis L., is used worldwide as an aromatic herb for culinary purposes as well as a traditional medicinal agent for various ailments. Current investigations exhibited the effects of extended dryings of the herb on the yields, composition, oil quality, and hepatoprotective as well as anti-cancer biological activities of the hydrodistillation-obtained essential oils from the aerial parts of the plant. The essential oils’ yields, compositions, and biological activities levels of the fresh and differently timed and room-temperature dried herbs differed significantly. The lowest yields of the essential oil were obtained from the fresh herbs (FH, 631 mg, 0.16%), while the highest yield was obtained from the two-week dried herbs (2WDH, 1102 mg, 0.28%). A notable decrease in monoterpenes, with increment in the sesquiterpene constituents, was observed for the FH-based essential oil as compared to all the other batches of the essential oils obtained from the different-timed dried herbs. Additionally, characteristic chemotypic constituents of sage, i.e., α-pinene, camphene, β-pinene, myrcene, 1, 8-cineole, α-thujone, and camphor, were present in significantly higher proportions in all the dried herbs’ essential oils as compared to the FH-based essential oil. The in vivo hepatoprotective activity demonstrated significant reductions in the levels of AST, ALT, and ALP, as well as a significant increase in the total protein (p < 0.05) contents level, as compared to the acetaminophen (AAP) administered experimental group of rats. A significant reduction (p < 0.05) in the ALT level was demonstrated by the 4WDH-based essential oil in comparison to the FH-based essential oil. The levels of creatinine, cholesterol, and triglycerides were reduced (p < 0.05) in the pre-treated rats by the essential oil batches, with non-significant differences found among them as a result of the herbs dryings based oils. A notable increase in the viability of the cells, and total antioxidant capacity (TAOxC) levels, together with the reduction in malondialdehyde (MDA) levels were observed by the essential oils obtained from all the batches as compared with the AAP-treated cell-lines, HepG-2, HeLa, and MCF-7, that indicated the in vitro hepatoprotective effects of the sage essential oils. However, significant improvements in the in vivo and in vitro hepatoprotective activities with the 4WDH-based oil, as compared to all other essential oil-batches and silymarin standard demonstrated the beneficial effects of the drying protocol for the herb for its medicinal purposes.