Solid Phase Synthesis of Ethyl β-Substituted Indolepropionates

A facile solid phase synthesis of ethyl β-substituted indolepropionates is reported. Condensation between indole, polymer-supported cyclic malonic acid ester and aldehyde yielded the trimolecular adducts, which was cleaved by pyridine/EtOH to release the final products in good yield with high purity.     

Incorporation of a fluorous diazirine group into phosphatidylinositol 4,5-bisphosphate to illustrate its interaction with ADP-ribosylation factor 1

Phosphatidylinositides are one family of the most versatile signaling molecules in cells, yet how they interact with different proteins to regulate biological processes is not well understood. Towards a general strategy to identify phosphatidylinositide-protein interactions, a fluorous diazirine group has been incorporated into phosphatidylinositol 4,5-bisphosphate (PIP(2)). The modified PIP(2) was effectively cleaved by phospholipase C, one signaling protein that utilizes PIP(2) as its endogenous substrate. Upon light illumination, the PIP(2) probe effectively crosslinks with small GTPase ADP-ribosylation 1 to form a complex, suggesting that the probe might be suitable to identify PIP(2)-interacting proteins on the proteome level.     

Synthesis and Crystal Structure of a Novel Diorganotin（Ⅳ） Complex Containing 3,4-Difluorobenzohydroxamato Ligand

In recent years, there has been considerable interest in organotin(Ⅳ) compounds. One of the important reasons is that many organotin compounds are biologically active1-3. The diorganotin(Ⅳ) complex containing carboxylate ligand have been investigated fo…     

Polychloromethylation-Initiated Radical 1,2-Aryl Migration of α,α-Diarylallyl Alcohols via Visible-Light Photoredox Catalysis

A visible-light induced radical 1,2-aryl migration of α,α-diarylallyl alcohols was developed under mild and metal-free conditions. Commercially available CHCl₃ and CH₂Cl₂ were used as tri- and dichloromethyl radical precursors. Structurally diverse β-polochloromethylated ketones were obtained in good to moderate yields via neophyl-type rearrangement. Besides, the polychloromethyl group can be easily transformed into other useful functional groups.     

MULTIPLICATIVE GROUP AUTOMORPHISMS OF INVERTIBLE UPPER TRIANGULAR MATRICES OVER FIELDS

1 IntroductionWe assume throughout that F is a field of characteristic not 2 and n 2 2. Let F* bethe multiplicative group of F and T; (F) the multiplicative group of invertible upper triangularn x n matrices over F. We denote by STs(F) and ST:(F) the subgroups, of T;(F), {(ail) ET:(F)Iaii = 1, Vi} and {(ail) E T:(F)laii = 11, Vi} respectively.Recently some authors have characterized the algebra automorphisms of upper triangularn x n matrices over some rings(see [2]-[5]). The authors …     

Magnetic-controllable Janus fibrous membranes with wind-resistant floatability for airflow-enhanced solar evaporation

Interfacial solar evaporation has been widely regarded as a promising pathway to desalinate seawater without secondary pollution and additional carbon emission. However, one of the challenges rarely considered is the floating stability and remote controllability of the evaporator in the face of wind and waves at the seawater surface. Herein, we demonstrate magnetic Janus membranes (MJMs) with remotely magnetic controllability and wind-resistant floatation for enhanced interfacial solar evaporation in airflow condition. These membranes are fabricated by sequential electrospinning of a hydrophobic Fe₃O₄-embedded polyvinylidene fluoride (PVDF) layer and a hydrophilic polyacrylonitrile (PAN) layer. Due to the superparamagnetism of Fe₃O₄, our MJMs can be remotely manipulated by a magnet and can float in situ with the aid of a magnetic field, even facing the blast of airflow with a speed of 1.75 m/s. Moreover, the MJMs realize an enhanced vapor diffusion under airflow (v = 0.5 m/s) and show a water evaporation rate of 1.39 ± 0.06 kg∙m⁻²∙h⁻¹ under one sun, which is 40.4% higher than that in windless condition. This work provides a promising material solution with magnetic design for the practical offshore application of Janus membranes in interfacial solar evaporation.     

Discovery and Biomimetic Synthesis of a Phloroglucinol-Terpene Adduct Collection from Baeckea frutescens and Its Biogenetic Origin Insight

A phloroglucinol-terpene adduct (PTA) collection consisting of twenty-four molecules featuring three skeletons was discovered from Baeckea frutescens. Inspired by its biosynthetic hypothesis, we synthesized this PTA collection by reductive activation of stable phloroglucinol precursors into highly reactive ortho-quinone methide (o-QM) intermediates and subsequently Diels–Alder cycloaddition. We also demonstrated, for the first time, the generation process of the active o-QM by performing dynamic NMR and HPLC-MS monitoring experiments. Moreover, the PTA collection showed significant antifeedant effect toward the Plutella xylostella larvae.     

A new sesquiterpenoid glycoside from Saussurea involucrata

Abstract

Saussurea involucrata, known for the abundant bioactive components, is a precious traditional Chinese medicine. In this study, a novel guaiane sesquiterpenoid glycoside named (1R, 5R, 6R, 7R, 8S, 11S)-11, 13-dihydrodehydrocostuslactone-8-O-6'-2''(E)-butenoyl-β-D-glucopyranoside (1), together with seven known compounds (2–8) were isolated from the dried aerial part of S. involucrata. Their structures were elucidated by spectroscopic and physico-chemical analyses. The antioxidant and anti-inflammatory activities of compound 1 were investigated. And compound 1 showed weak radical scavenging activity and low inhibitory activity on nitric oxide (NO) production.     

Multiple solutions for sub-linear impulsive three-point boundary value problems

In this article we establish multiplicity results for impulsive three-point boundary value problems if we assume a sub-linear condition at infinity. The proof involves Leray–Schauder degree and the lower and upper solution method.     

Rate of Innovation for (Non-)Periodic Signals and Optimal Lower Stability Bound for Filtering

One of fundamental problems in sampling theory is to reconstruct (non-)periodic signals from their filtered signals in a stable way. In this paper, we obtain a universal upper bound to the rate of innovation for signals in a closed linear space, which can be stably reconstructed, via the optimal lower stability bound for filtering on that linear space.