ABSTRACT
Chemical investigation of the mangrove endophytic fungus Cladosporium sp. SCNU-F0001 resulted in the isolation and identification of a new macrolide compound named thiocladospolide E (1) and a novel macrolide lactam named cladospamide A (2), along with the known cladospolide B (3). The structures were elucidated based on spectroscopic methods, and the absolute configurations were determined by X-ray diffraction and HPLC analysis after chemical derivatization. All compounds were tested for their antibacterial and cytotoxic activity.
Subject(s)
Anti-Bacterial Agents/pharmacology , Cladosporium/chemistry , Lactams/pharmacology , Macrolides/pharmacology , Rhizophoraceae/microbiology , Anti-Bacterial Agents/isolation & purification , Cell Line, Tumor , Humans , Lactams/isolation & purification , Macrolides/isolation & purification , Molecular StructureABSTRACT
A novel macrocyclic host has been synthesized for the determination of Ni (II) ions in aqueous solution (H2O-CH3CN, v/v = 1:1). Its molecular structure has been verified by 1H-NMR, 13C NMR and mass spectrometry (ESI).This probe shows selectivity towards the presence of Ni (II) ion among various alkali, alkaline earth, and transition metal ions. The formation of a new fluorescence band at 311 nm has been detected due to possible complex formation with increasing Ni2+ concentration in the range of 10-5-10-4 M. The detection limit is calculated to be 5.22 µM. To our knowledge, it will be the first case for bis(p-phenylene)-34-crown-10 based molecules to recognize Ni2+ ions.
ABSTRACT
Crown ether carboxylic acids constitute main building blocks for the synthesis of terbium containing covalent cross-linked luminescent materials. Both the complexes and the hybrid nanomaterials could exhibit remarkable green emissions in pure water. More importantly, they were found to have a profound effect on the luminescence responses to arginine compared with glutamic acid, histidine, tryptophan, threonine, tyrosine and phenylalanine in aqueous environment. The present study provided the possibility of using a host-guest mechanism as a way of signal transduction based on lanthanide supramolecular hybrid materials.
Subject(s)
Arginine/analysis , Carboxylic Acids/chemistry , Crown Ethers/chemistry , Terbium/chemistry , Amino Acids/analysis , Coordination Complexes/chemistry , Luminescent Measurements , Nanostructures/chemistry , Water/chemistryABSTRACT
In the crystal structure of the title compound, C(33)H(39)N(3)O(10)·C(3)H(6)O, the acetone mol-ecule is encapsulated into the cavity of the cryptand and fixed by two N-Hâ¯O and one C-Hâ¯O hydrogen bond. C-Hâ¯O and C-Hâ¯N inter-actions link neighbouring cryptands. The dihedral angles between the pyridine ring and the benzene rings are 86.47â (17) and 85.53â (13)°.
ABSTRACT
The mol-ecule of the title compound {systematic name: 17,35-bis-[(2-propyn-1-yl-oxy)meth-yl]-2,5,8,11,14,20,23,26,29,32-deca-oxatricyclo-[31.3.1.1(15,19)]octa-triaconta-1(37),15,17,19â (38),33,35-hex-a--ene}, C(36)H(48)O(12), has crystallographic inversion symmetry and adopts a chair-like conformation. The polyether bridges of the macrocycle adopt gauche conformations and the cavity of the macrocycle is collapsed. In the crystal structure, there are weak inter-molecular C-Hâ¯O hydrogen bonds driven in part by the elevated acidity of acetylenyl H atoms.
ABSTRACT
Two novel cryptand-based [2]rotaxanes were synthesized by a facile one-pot reaction from three neutral precursors: easily accessible cryptand host 1 and commercially available 4,4'-bipyridine and 3,5-di-tert-butylbenzyl bromide. Their structures were confirmed by (1)H NMR, 2D NMR, HRMS and X-ray analysis. Moreover, two [2]pseudorotaxanes based on the same cryptand hosts and dibenzyl viologen guest 3 were also demonstrated both in solution and in the solid state, which are different from previously reported [3]pseudorotaxane-like complexes formed by dimethyl viologen guest 2 and the cryptands.
ABSTRACT
Pyridine N-oxide derivatives are capable of formation of stable [2]pseudorotaxanes with diamide-based macrocycles in solution and in the solid state, and their dethreading/rethreading movements can be easily controlled by acid-base stimuli.
