Synthesis and screening of N-acyl thiolated chitosans for antibacterial applications

Abstract

Low-molecular weight chitosan-thioglycolic acid has shown significant antibacterial properties against different microorganisms. In order to explore the potential and structure-activity relationships of newly synthesized alkyl thiomers, chitosan has been functionalized with a series of thio-acids with increasing alkyl chain length. All thiomers were characterized with special emphasis on the determination of their degree of deacetylation and substitution, as well as on their molecular weight and amount of thiol groups. The pre-screened chitosan-thiomers were further investigated with plate counting on Pseudomonas aeruginosa, Streptococcus sobrinus and Streptococcus mutans. Furthermore, LIVE/DEAD assays supported the efficiency of chitosan-thiomers against the above microorganisms. All fully characterized chitosan-thiomers showed comparable or enhanced antimicrobial activity compared to pristine chitosan. Our comprehensive approach paves the way to detailed explorations of much sought-after structure activity relationships in the complex chitosan parameter room, starting from correlations between alkyl chain length and antimicrobial activity.

Functionalization of poly(3‐hydroxybutyrate) with different thiol compounds inhibits MDM2–p53 interactions in MCF7 cells

“…1 H‐NMR of PIII displayed new additional peaks at 2.48–2.65 ppm due to the protons of the methyl group (SCH 2 CH 3 ) that interfered with the other methyl group of PHB and 2.76–2.81 ppm due to the C H 2 SC H 2 protons (f and g, Figure ) . The sulfur content of PIII was 0.91% (Table ).…”

Thiolated-Polymer-Based Nanoparticles as an Avant-Garde Approach for Anticancer Therapies—Reviewing Thiomers from Chitosan and Hyaluronic Acid

“…They began to be explored in 1999 [10], and have since been used in multiple biomedical and pharmaceutical applications due to the close interest in their study among the research community [11][12][13]. These applications are connected with the presence of their thiol groups and their capability of conducting thiol-disulfide exchange reactions and oxidizing to disulfide bridges: from soft-tissue engineering [14] as biomaterial support for cartilage repair [15] and 3D bioscaffolds for cell culture [16,17] to antibacterial activity [18][19][20][21]. They are also prominent candidates for the formulation of controlled delivery carriers of APIs, whether for topical use [22], as dry powder inhalers [23], or in oral administration [24], among others.…”

Preparation, physicochemical characterization and antimicrobial activities of novel two phenolic chitosan Schiff base derivatives

“…Several studies have reported the significant effect of antimicrobial biopolymers and chitosan itself to enhance the wound healing process through preventing the wound infections that result in tissue maceration 23 , 25 – 27 . It has been reported that chitosan modified diisocyanate (DIMC) 28 , O-quaternary ammonium N-acyl thiourea chitosan 29 , chitosan-thioglycolic acid 30 , kanamycin-chitosan nanoparticles 31 , crosslinked chitosan 32 and O-amine functionalized chitosan 33 exhibited better antibacterial activity degrees against Escherichia coli , Staphyloccocus aureus and other microorganisms. Likewise, chitosan Schiff base derivatives are considered one of the best choices for increasing antimicrobial activity of chitosan, since carbonyl groups of aldehyde or ketone can efficiently couple with NH 2 groups of chitosan to form the corresponding chitosan Schiff base with imine characteristic group (-RC=N-) 34 .…”