Acid-base behaviour of sanguinarine and dihydrosanguinarine

Abstract

Acid-base and optical properties of sanguinarine and dihydrosanguinarine were studied in the presence of HCl, HNO 3 , H 2 SO 4 , H 3 PO 4 , CAPSO and acetic acid (HAc) of different concentrations and their mixtures. The equilibrium constants pK R+ of the transition reaction between an iminium cation Q + of sanguinarine and its uncharged QOH (pseudo-base, 6-hydroxy-dihydroderivative) form were calculated. A numerical interpretation of the A-pH curves by a SQUAD-G computer program was used. Remarkable shifts of formation parts of absorbance-pH (A-pH) curves to alkaline medium were observed. The shifts depend on the type and concentration of inert electrolyte (the most remarkable for HNO 3 and HCl ). The corresponding pK R+ values ranged from 7.21 to 8.16 in the same manner (ΔpK R+ = 0.81 and 0.73 for HNO 3 and HCl, respectively). The priority effect of ionic species and ionic strength was confirmed in the presence of NaCl and KCl. The strength of interaction of SA with bioactive compounds (i.e. receptors, transport proteins, nucleic acids etc.) may be affected because of the observed influence of both cations and anions of the inert electrolytes. Warsaw and Springer-Verlag Berlin Heidelberg. © Versita

Influence of Solvent Polarity and DNA-Binding on Spectral Properties of Quaternary Benzo[c]phenanthridine Alkaloids

“…Previous studies of sanguinarine and chelerythrine showed that the fluorescence of QBAs comes from two distinct species–neutral alkanolamine and positively charged iminium [ 20 , 21 ]. In aqueous solution typical values of pK ROH for QBAs are between 7.7 (chelirubine) and 9 (chelerythrine) [ 30 ].…”

“…While the fluorescence of sanguinarine and chelerythrine is well described [ 20 – 23 ], knowledge of the fluorescence properties of other QBAs is limited. Fluorescence spectra in aqueous solution and their change upon binding to DNA has previously been reported [ 24 ] and their potential use as probes in fluorescence microscopy and flow cytometry was proposed [ 19 ].…”

Spectrophotometric study of time stability and acid-base characteristics of chelerythrine and dihydrochelerythrine

“…), as Amresco ® , Solon, Ohio, USA) and sodium hydroxide (reagent grade purity, Penta, Chrudim, Czech Republic) solutions were used for the pH adjustment in a pH interval pH = 2 -11 with steps ∆pH = 0.2 -0.5. All other experimental conditions were in accordance to previous paper [17].…”

“…The absorbance values of both alkaloids were measured three times at each pH and the mean values from these measurements were used to calculate of pK R+ . For more details see our previous paper [17].…”

Zwitterion-Modified MXene Quantum Dot as a Nanocarrier for Traditional Chinese Medicine Sanguinarine Delivery and Its Application for Photothermal-Chemotherapy Synergistic Antibacterial and Wound Healing

“…And the characteristic absorption peaks of SAN appeared at the wavelengths of 270 and 323 nm, further confirming the successful synthesis of SAN@AHEP@Ta 4 C 3 (Figure 1d). 37 Figure 1e shows the hydrated particle size diagram of Ta 4 C 3 , AHEP@Ta 4 C 3 , and SAN@AHEP@Ta 4 C 3 . It can be observed that the particle size of Ta 4 C 3 quantum dots is about 6−8 nm (consistent with Figure 1a), and the particle size of SAN@AHEP@Ta 4 C 3 is about 140−180 nm (consistent with Figure 1b), which is not much different from AHEP@Ta 4 C 3 , indicating that SAN is evenly loaded in the flower-shaped production.…”