TY - JOUR
T1 - Competing photochemical reactions of bis-naphthols and their photoinduced antiproliferative activity
AU - Sambol, Matija
AU - Ester, Katja
AU - Landgraf, Stephan
AU - Mihaljević, Branka
AU - Cindrić, Mario
AU - Kralj, Marijeta
AU - Basarić, Nikola
PY - 2019/1/1
Y1 - 2019/1/1
N2 - The photophysical properties and photochemical reactivities of a series of bis-naphthols 4a-4e and bis-anthrols 5a and 5e were investigated by preparative irradiation in CH 3 OH, fluorescence spectroscopy and laser flash photolysis (LFP). Methanolysis taking place via photodehydration (bis-naphthols: Φ R = 0.04-0.05) is in competition with symmetry breaking charge separation (SB-CS). The SB-CS gave rise to radical ions that were detected for 4a and 4e by LFP. Photodehydration gave quinone methides (QMs) that were also detected by LFP (λ max = 350 nm, τ ≈ 1-2 ms). In the aqueous solvent, excited state proton transfer (ESPT) competes with the abovementioned processes, giving rise to naphtholates, but the process is inefficient and can only be observed in the buffered aqueous solution at pH > 7. Since the dehydration of bis-naphthols delivers QMs, their potential antiproliferative activity was investigated by an MTT test on three human cancer cell lines (NCI-H1299, lung carcinoma; MCF-7, breast adenocarcinoma; and SUM159, pleomorphic breast carcinoma). Cells were treated with 4 or 5 with or without irradiation (350 nm). An enhancement of the activity (up to 10-fold) was observed upon irradiation, which may be associated with QM formation. However, these QMs do not cross-link DNA. The activity is most likely associated with the alkylation of proteins present in the cell cytoplasm, as evidenced by photoinduced alkylation of bovine and human serum albumins by 4a.
AB - The photophysical properties and photochemical reactivities of a series of bis-naphthols 4a-4e and bis-anthrols 5a and 5e were investigated by preparative irradiation in CH 3 OH, fluorescence spectroscopy and laser flash photolysis (LFP). Methanolysis taking place via photodehydration (bis-naphthols: Φ R = 0.04-0.05) is in competition with symmetry breaking charge separation (SB-CS). The SB-CS gave rise to radical ions that were detected for 4a and 4e by LFP. Photodehydration gave quinone methides (QMs) that were also detected by LFP (λ max = 350 nm, τ ≈ 1-2 ms). In the aqueous solvent, excited state proton transfer (ESPT) competes with the abovementioned processes, giving rise to naphtholates, but the process is inefficient and can only be observed in the buffered aqueous solution at pH > 7. Since the dehydration of bis-naphthols delivers QMs, their potential antiproliferative activity was investigated by an MTT test on three human cancer cell lines (NCI-H1299, lung carcinoma; MCF-7, breast adenocarcinoma; and SUM159, pleomorphic breast carcinoma). Cells were treated with 4 or 5 with or without irradiation (350 nm). An enhancement of the activity (up to 10-fold) was observed upon irradiation, which may be associated with QM formation. However, these QMs do not cross-link DNA. The activity is most likely associated with the alkylation of proteins present in the cell cytoplasm, as evidenced by photoinduced alkylation of bovine and human serum albumins by 4a.
UR - http://www.scopus.com/inward/record.url?scp=85065863897&partnerID=8YFLogxK
U2 - 10.1039/c8pp00532j
DO - 10.1039/c8pp00532j
M3 - Article
C2 - 30820496
AN - SCOPUS:85065863897
SN - 1474-905X
VL - 18
SP - 1197
EP - 1211
JO - Photochemical & Photobiological Sciences
JF - Photochemical & Photobiological Sciences
IS - 5
ER -