New chlorogenic acid derivatives and triterpenoids from Scorzonera aucheriana

Chromatographic separation ofn-hexane and ethyl acetate fraction of a crude methanol extract obtained from aerial parts of theScorzonera aucherianaDC collected from Sivas province of Turkey yielded nine natural compounds; two new 3-caffeoyl-quinic acid analogs (1-2), one new taraxasterol oleate (3), and six known triterpenoids taraxasterol (4), taraxasterol acetate (5), ptiloepoxide (6), lupeol (7), lupeol acetate (8), andβ-sitosterol (9) were characterized. The structures of the isolated compounds were elucidated on the basis of NMR (¹H,¹³C, COSY, HMBC, HSQC, and TOCSY), UV, FT-IR and LC-Q-TOF-MS spectrometric data.     

Cellulose based electrospun nanofilters: perspectives on tannery effluent waste water treatment

Cellulose - Development of nanofilters with the ability to remove toxic metal ions from effluent wastewater will be of immense help to the leather industry. In this study, fibrous nanofilter (FNF)...     

Nonlinear models: a case of the COVID-19 confirmed rates in top 8 worst affected countries

Nonlinear Dynamics - Over the last 9 months, the most prominent global health threat has been COVID-19. It first appeared in Wuhan, China, and then rapidly spread throughout the world. Since no...     

Ambipolar inverters with natural origin organic materials as gate dielectric and semiconducting layer

Thin film electronics fabricated with non‐toxic and abundant materials are enabling for emerging bioelectronic technologies. Herein complementary‐like inverters comprising transistors using 6,6′‐dichloroindigo as the semiconductor and trimethylsilyl‐cellulose (TMSC) films on anodized aluminum as bilayer dielectric layer are demonstrated. The inverters operate both in the first and third quadrant, exhibiting a maximum static gain of 22 and a noise margin of 58% at a supply voltage of 14 V. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)     

Conventional and microwave irradiated synthesis,biological activity evaluation and molecular docking studies of highly substituted piperazine-azole hybrids

Azole derivatives(3,6) obtained starting from 1-(2-methoxyphenyl) piperazine were converted to the corresponding Mannich bases containing β-lactame or flouroquinolone core via a one pot three component reaction.The synthesis of conazole analogues was carried out starting from triazoles by three steps.Reactions were carried out under conventional and microwave mediated conditions.All the newly synthesized compounds were screened for their antimicrobial,enzyme inhibition and antioxidant activity,and most of them displayed good-moderate activity.Binding affinities and non-covalent interactions between enzyme-ligand complexes were predicted with molecular docking method at molecular level.Docking results complemented well the experimental results on α-glucosidase and urease inhibitory effects of the compounds.Higher binding affinities and much more interaction networks were observed for active compounds in contrary to inactive ones.It was predicted with the docking studies that triazole and anisole moieties in the structure of the synthesized compounds contributed to the stabilization of corresponding enzymes through noncovalent interactions.     

Recent Developments in Conjugated Polymer Based Plastic Solar Cells

Summary.  Recent developments on photovoltaic elements based on solid state composites of conjugated, semiconducting polymers mixed with buckminsterfullerene are reviewed. The photoinduced charge transfer from donor-type semiconducting conjugated polymers onto acceptor-type conjugated polymers or acceptor molecules such as buckminsterfullerene is reversible, ultrafast (within 100 fs) with a quantum efficiency approaching unity, and the charge separated state is metastable (up to ms at 80 K). This phenomenon of photoinduced electron transfer leads to a number of potentially interesting applications which include, among others, sensitization of the photoconductivity, reverse saturable absorption (optical limiting), and photovoltaic phenomena. Recent studies on the realization of photovoltaic elements with 3% power conversion efficiency are reported. Received December 19, 2000. Accepted December 22, 2000     

A calixpyridinium-pyranine complex as a selective anion sensing assembly via the indicator displacement strategy

The recently reported calixpyridinium tetracation is shown to be very well-suited for anion sensing via the indicator displacement strategy. A very strong binding interaction between the positively charged receptor and the fluorescent pH indicator pyranine (8-hydroxy-1,3,6-pyrenetrisulfonate) requires an anionic guest of comparable negative charge for effective indicator displacement. Thus, selective and sensitive signalling of ATP is achieved in aqueous solutions.