The dissociation constant pKa defines the ionization degree of organic compounds. It is an important parameter that affects their toxicity and environmental behavior and fate. Among the present approaches to predict pKa values of organic chemicals, increment methods show a good performance but are limited by missing values of special groups. The purpose of this study is to develop models for pr...

A supramolecular platform based on self-assembled monolayers (SAMs) has been implemented in a microfluidic device. The system has been applied for the sensing of two different analyte types: biologically relevant phosphate anions and aromatic carboxylic acids, which are important for anthrax detection. A Eu(III)-EDTA complex was bound to β-cyclodextrin monolayers via orthogonal supramolecular h...

Many natural products contain unusual aromatic β-amino acids or moieties derived therefrom. The biosynthesis of these β-amino acids was first elucidated during a biosynthetic study of the enediyne antitumor antibiotic C-1027, when an enzyme, SgcC4, was discovered to convert L-tyrosine to (S)-β-tyrosine. SgcC4 is similar in sequence and structure to 4-methylideneimidazole-5-one (MIO)-containing ...

The spoilage yeast Saccharomyces cerevisiae degraded the food preservative sorbic acid (2,4-hexadienoic acid) to a volatile hydrocarbon, identified by gas chromatography mass spectrometry as 1,3-pentadiene. The gene responsible was identified as PAD1, previously associated with the decarboxylation of the aromatic carboxylic acids cinnamic acid, ferulic acid, and coumaric acid to styrene, 4-viny...

We describe a novel two-step approach for the synthesis of compounds with hydroxyl-amide group (hydroxamic acids), which are widely known their biological activity (histone deacetylase inhibitors, matrix metalloproteinases inhibitors and others). The first stage is N-substituted succinimide via reaction aromatic amine or carboxylic acid hydrazide succinic anhydride. second step involves imide r...

vilsmeier several diamide derivatives containing 2-chloroquinoline scaffolds were synthesized via ugi reaction of 2-chloroquinoline-3-carboxaldehydes, amines, carboxylic acids and isocyanides. the diversity of these quinolinyl ugi-adducts was increased by using 2-chloroquinoline-3-carboxylic acids as a source of acid. among them, compounds 2d, 2n, 2p, 4a, 4c and 4e displayed moderate to good an...

A total of eleven alkali-released, aromatic compounds were identified by HPLC, MS and NMR analyses in cell wall extracts from Arabidopsis thaliana roots. Nine of them together constituted the three complete series of 4-hydroxy-, 4-hydroxy-3-methoxy, and 4-hydroxy-3,5-dimethoxy-substituted benzaldehydes, benzoic acids and cinnamic acids. The other two were indolic metabolites: indole-3-carboxyli...

Selective esterification of aliphatic and aromatic carboxylic acids with various alcohols is studied using triphenylphosphine, I2, and a catalytic amount of Zn(OTf)2. Use of this catalyst allows the formation of esters at a faster rate with good to excellent yield by activating the in situ generated acyloxyphosphonium ion intermediate. During the esterification process, both their aromatic and ...