Search

Fluorescent carbon quantum dots (CQDs) were synthesized from cucurbit[7]uril (Q[7]) and 2,2-bis(hydroxymethyl)propionic (DMPA) by a hydrothermal method. The Q[7]–DMPA complex was confirmed by X-ray crystallography. The CQDs showed blue fluorescence, photostability, and ionic strength stability. They were used to detect histamine with a low limit of 2.33 × 10−6 M. [ABSTRACT FROM AUTHOR]

Covering: March 2010 to December 2020. Previous review: Nat. Prod. Rep., 2011, 28, 705 This review summarizes the latest progress and perspectives on the structural classification, biological activities and mechanisms, metabolism and pharmacokinetic investigations, biosynthesis, chemical synthesis and structural modifications, as well as future research directions of the promising natural withanolides. The literature from March 2010 to December 2020 is reviewed, and 287 references are cited. [ABSTRACT FROM AUTHOR]

The binding interactions of cucurbit[8]uril (Q[8]) with L -valine, D -leucine, and D -methionine, both in aqueous solution and solid state, have been studied by 1H NMR spectroscopy and X-ray crystallography. 1H NMR data indicate that Q[8] can encapsulate these three kinds of amino acids in aqueous solution. X-ray crystallography reveals how the Q[8] binds with the amino acids to form inclusion complexes L -Val2@Q[8], D -Leu2@Q[8], and D -Met2@Q[8] through host-guest interactions. It was also found that the deformation degree of the Q[8] host is related to the molecular size of the encapsulated guests. [ABSTRACT FROM AUTHOR]

Q[8]-based honeycomb-like frameworks can be obtained in [AuCl4]−-free aqueous HNO3 solution and aqueous HCl and HNO3 solutions that contain [AuCl4]−. The outer surface interaction of Q[8] with planar inorganic anions [AuCl4]− and NO3− is the main driving force. These frameworks exhibit a high selectivity for imprisoning [AuCl4]− that could establish a process for gold recovery. [ABSTRACT FROM AUTHOR]

A multicomponent supramolecular nanoparticle composed of a polysaccharide–quantum dot conjugate was successfully constructed using a ligand-exchange method, which possessed low cellular cytotoxicity and showed controlled DNA condensation and targeted cellular imaging abilities toward cancer cells. [ABSTRACT FROM AUTHOR]

Withanolides are a group of naturally occurring C28 steroids built on an ergostane skeleton functionalized at carbons 1, 22 and 26, commonly known as the withanolide skeleton. Over the period of August 1996 to March 2010, 360 new naturally occurring withanolides were isolated and identified. This review provides a comprehensive summary of the structural classification and distribution of these new compounds. The diverse biological and pharmacological activities of natural withanolides are also discussed based on their structural features. A total of 211 references are cited in this review.