Piroxicam

Piroxicam (compound #6) and meloxicam (compound #7) were obtained from commercial sources: Sigma-Aldrich (St. Luis, MO, USA) and Alfa Aesar (Thermo Fisher Scientific, Waltham, MA, USA), respectively, and served as reference standards.
Novel oxicam analogues, denoted as compounds #1–5, were synthesized as previously described [31 (link),32 (link),33 (link)]. In short, 1,1-dioxo-1,2-benzothiazol-3-one was condensed in dimethylformamide and in the presence of triethylamine with one of the following: 2-bromoacetophenone (in case of compound #1), 2-bromo-4′-fluoroacetophenone (in case of compounds #2, #3 and #4), or 2-bromo-4′-chloroacetophenone (in case of compound #5). The resulting condensation products were subsequently rearranged in sodium ethoxide (2.3%) to the corresponding 1,2-benzothiazine ring. The final compounds were prepared by alkylation of corresponding 1,2-benzothiazine with: 1-(3-chloropropyl)-4-phenylpiperazine (in case of compounds #1 and #2) or 1-(3-chloropropyl)-4-(2-fluorophenyl)-piperazine (in case of compound #3) or with 1-(2-chloroacetyl)-4-(2-fluorophenyl)-piperazine (in case of compounds #4 and #5). The resulting products were separated and purified by crystallization from ethanol. Compounds’ structures, presented in Table 2, were confirmed by elemental (C, H, N) and spectral analyses (1H NMR, 13C NMR, FT-IR and MS).

Phospholipids: 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC), 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine (DMPC) and egg yolk phoshphatidylcholine (EYPC) were obtained from Merck Life Science (Darmstadt, Germany) and used as delivered without any purification.
Piroxicam was purchased from Thermo Scientific (Ward Hill, MA, USA).
Studied oxicam derivatives (1,2-benzothiazine derivatives) were synthesized at the Department of Medicinal Chemistry, Wroclaw Medical University, by Berenika Szczęśniak-Sięga. Their purity was confirmed by ¹H NMR, ¹³C NMR, FT-IR, HRMS and elemental analysis (C, H, N). The synthesis and analysis of these compounds were described previously elsewhere [26 (link),27 (link),28 (link)]. Chemical structures and symbols of studied compounds are shown in Table 1.
Fluorescent labels: 6-dodecanoyl-2-dimethylaminonaphthalene (Laurdan) and 6-propionyl-2-dimethylaminonaphthalene (Prodan) were purchased from Molecular Probes (Eugene, OR, USA). Fluorescent probes were dissolved in DMSO to obtain 1 mM stock solutions.
Since studied compounds were insoluble in water, their chloroform or DMSO solutions were used for experiments. All other chemicals used in this study were of analytical grade.

Piroxicam was purchased from Alfa Aesar (Massachusetts,
USA). Aspirin, chloramphenicol, chlorpropamide, indomethacin, ketoprofen, n-vinyl caprolactam, paracetamol, phenobarbital, and trifluoroacetic
acid were purchased from Merck (Massachusetts, USA). Hexane and acetone
were purchased from Thermo Fisher Scientific (Massachusetts, USA).
Famotidine was purchased from Tokyo Chemical Industry (Tokyo, Japan).
Flurbiprofen, furosemide, mebendazole, and simvastatin were purchased
from Fluorochem (Derbyshire, UK). All chemicals were used without
further purification.