Effects of Metal and the Phytyl Chain on Chlorophyll Derivatives: Physicochemical Evaluation for Photodynamic Inactivation of Microorganisms

Abstract

Chlorophyll compounds and their derivatives containing metal or phytyl chain can be used as photosensitizer in photodynamic inactivation of microorganisms (PDI). So, the physicochemical properties and antimicrobial effect of chlorophyll derivatives were investigated: Mg-chlorophyll (Mg-Chl), Zn-chlorophyll (Zn-Chl), Zn-chlorophyllide (Zn-Chlde), Cu-chlorophyll (Cu-Chl), pheophytin (Pheo) and pheophorbide (Pheid). The photobleaching experiments showed photostability according to Cu-Chl > Pheo ∼ Pheid ≫ Zn-Chl ∼ Zn-Chlde > Mg-Chl. This order was discussed in terms of metal and the phytyl chain presences. Pheid and Zn-Chl in aqueous Tween 80 solution exhibited highest singlet oxygen yield compared with the other derivatives. Chlorophyll derivatives (CD) with phytyl chain was limited by the self-aggregation phenomenon at high concentrations, even in micellar systems (Tween 80 and P-123). The antimicrobial effect of CD derivatives was investigated against Staphylococcus aureus, Escherichia coli, Candida albicans and Artemia salina. Pheid showed the best results against all organisms tested, Zn-Chlde was an excellent bactericide in the dark and Cu-Chl had no PDI effect. No correlation with CD uptake by microorganisms and darkness cytotoxicity was found. The physicochemical properties allied to bioassays results indicate that Mg-Chl, Pheo, Zn-Chl and Pheid are good candidates for PDI.

Phytoconstituents from Sidastrum micranthum (A. St.-Hil.) Fryxell (Malvaceae) and antimicrobial activity of pheophytin a

“…The results obtained are in agreement with the antimicrobial effect of some chlorophyll derivatives, including pheophorbide, as determined by Gerola et al (2011). Thus, the antimicrobial activity shown by these compounds may be evidence of their additional role protecting plants from microorganisms in their environment.…”

Formulation of Aluminum Chloride Phthalocyanine in Pluronic™ P‐123 and F‐127 Block Copolymer Micelles: Photophysical properties and Photodynamic Inactivation of Microorganisms

“…. This figure shows the decrease in the UA band at 293 nm and the appearance of intermediates at 315 nm . The arrow indicates the decrease in UA absorption under LASER irradiation.…”

“…The photobleaching reactions can occur simultaneously with the photodynamic applications and can lead to the decrease in photodynamic action due to decrease in PS concentration . During the irradiation of AlPcCl incorporated in P‐123 and F‐127 with Diode LASER, the electronic absorption spectra remained unchanged regarding the shape and the intensity of the bands (not shown).…”

“…The increase of k 1 values with the PS concentration (Table 2) is a consequence of the increase of N abs (34)(35)(36). The slope of the linear relationship between k 1 and N abs is related to the efficiency of formation of singlet oxygen (c), which is directly proportional to the Φ D value (22,31). For the determination of singlet oxygen quantum yield of AlPcCl in ethanol, zinc phthalocyanine (ZnPc) was used as standard (37).…”

Effects of Chlorophyll-Derived Efflux Pump Inhibitor Pheophorbideaand Pyropheophorbideaon Growth and Macrolide Antibiotic Resistance of Indicator and Anaerobic Swine Manure Bacteria

“…It is not an uncommon feature for an EPI from natural sources to possess a direct antibacterial effect [26,35]. For example, the aerobic MIC of php was found to vary between 4 g mL −1 (S. epidermidis) and 500 g mL −1 (S. aureus ATCC 29213) [52], and in another study the death percentage of S. aureus ATCC 26923 in 20 g php mL −1 was 32% [114]. It is conceivable that, as discussed above for S. aureus, pyp exerted its intrinsic effect on the manure microbiota through inhibition of a MDR efflux pump, such as LmrS, MdeA, and possibly NorA, as these and their homologues occur in B. subtilis, a major component of MicroSource S, and are widespread among other low mol percentage guanine-cytosine Gram-positive (phylum Firmicutes) bacteria [27,81,97,100,[115][116][117], the predominant culturable anaerobic microorganisms from swine manure [73,118,119].…”