Journal of Spectroscopy

Research Article

4-Hydroxycoumarin Derivative: N-(diphenylmethyl)-2-[(2-oxo-2H-chromen-4-yl)oxy]acetamide Interaction with Human Serum Albumin

Table 2

Fluorescence lifetime profiles of HSA and increasing concentration of coumarin derivatives at different excitation wavelengths.


Wavelength (nm)	α₁ ± (error × 10⁻³)	α₂ ± (error × 10⁻³)	α₃ ± (error × 10⁻³)	τ₁ (ns)	τ₂ (ns)	τ₃ (ns)	(ns)	χ²

Fluorescence decay-fitting parameters for free HSA
280	0.00098 ± 0.012	0.74 ± 5.13	0.00015 ± 0.02	2.12 ± 0.008	0.0097 ± 0.002	6.82 ± 0.006	1.13	0.5
290	0.017 ± 0.024	0.61 ± 5.60	0.00106 ± 0.05	2.12 ± 0.008	0.0097 ± 0.002	6.82 ± 0.006	2.55	1.03
300	0.037 ± 0.033	0.29 ± 5.34	0.0024 ± 0.07	2.12 ± 0.008	0.0097 ± 0.002	6.82 ± 0.006	2.84	1.42
310	0.037 ± 0.036	0.21 ± 5.13	0.0047 ± 0.086	2.12 ± 0.008	0.0097 ± 0.002	6.82 ± 0.006	3.40	1.19
320	0.037 ± 0.042	0.15 ± 5.31	0.010 ± 0.013	2.12 ± 0.008	0.0097 ± 0.002	6.82 ± 0.006	4.24	1.12
330	0.035 ± 0.046	0.093 ± 5.34	0.016 ± 0.013	2.12 ± 0.008	0.0097 ± 0.002	6.82 ± 0.006	4.89	1.09
340	0.032 ± 0.048	0.042 ± 5.24	0.020 ± 0.014	2.12 ± 0.008	0.0097 ± 0.002	6.82 ± 0.006	5.23	1.00
350	0.027 ± 0.05	0.027 ± 5.23	0.024 ± 0.015	2.12 ± 0.008	0.0097 ± 0.002	6.82 ± 0.006	5.56	1.00
360	0.026 ± 0.051	0.00054 ± 5.0	0.026 ± 0.016	2.12 ± 0.008	0.0097 ± 0.002	6.82 ± 0.006	5.69	1.05
370	0.024 ± 0.050	0.0018 ± 5.0	0.027 ± 0.016	2.12 ± 0.008	0.0097 ± 0.002	6.82 ± 0.006	5.79	0.96
380	0.023 ± 0.052	0.0061 ± 5.1	0.029 ± 0.016	2.12 ± 0.008	0.0097 ± 0.002	6.82 ± 0.006	5.87	1.00
390	0.022 ± 0.051	0.0031 ± 5.1	0.028 ± 0.016	2.12 ± 0.008	0.0097 ± 0.002	6.82 ± 0.006	5.91	0.91
400	0.022 ± 0.051	0.016 ± 5.0	0.029 ± 0.016	2.12 ± 0.008	0.0097 ± 0.002	6.82 ± 0.006	5.90	1.00
410	0.024 ± 0.051	0.007 ± 5.0	0.027 ± 0.016	2.12 ± 0.008	0.0097 ± 0.002	6.82 ± 0.006	5.81	1.00
420	0.028 ± 0.051	0.035 ± 5.0	0.026 ± 0.016	2.12 ± 0.008	0.0097 ± 0.002	6.82 ± 0.006	5.66	1.00
430	0.029 ± 0.053	0.029 ± 4.9	0.024 ± 0.015	2.12 ± 0.008	0.0097 ± 0.002	6.82 ± 0.006	5.53	1.00
440	0.030 ± 0.050	0.030 ± 4.9	0.023 ± 0.015	2.12 ± 0.008	0.0097 ± 0.002	6.82 ± 0.006	5.50	1.00
450	0.031 ± 0.050	0.038 ± 4.9	0.023 ± 0.015	2.12 ± 0.008	0.0097 ± 0.002	6.82 ± 0.006	5.47	0.99

Fluorescence decay-fitting parameters for the HSA-coumarin derivative complex
280	0.0015 ± 0.011	0.00004 ± 0.0013	0.815 ± 5.5	1.9 ± 0.0082	6.8 ± 0.0065	0.009 ± 0.002	0.65	0.34
290	0.0051 ± 0.016	0.00021 ± 0.0021	0.806 ± 5.9	1.9 ± 0.0082	6.8 ± 0.0065	0.009 ± 0.002	1.55	0.73
300	0.029 ± 0.030	0.0015 ± 0.0054	0.499 ± 6.0	1.9 ± 0.0082	6.8 ± 0.0065	0.009 ± 0.002	2.51	1.07
310	0.037 ± 0.037	0.0004 ± 0.0073	0.374 ± 6.1	1.9 ± 0.0082	6.8 ± 0.0065	0.009 ± 0.002	3.17	1.16
320	0.038 ± 0.042	0.0008 ± 0.0096	0.20 ± 5.9	1.9 ± 0.0082	6.8 ± 0.0065	0.009 ± 0.002	4.03	1.11
330	0.041 ± 0.049	0.015 ± 0.012	0.095 ± 5.9	1.9 ± 0.0082	6.8 ± 0.0065	0.009 ± 0.002	4.69	1.07
340	0.037 ± 0.050	0.019 ± 0.013	0.025 ± 5.6	1.9 ± 0.0082	6.8 ± 0.0065	0.009 ± 0.002	5.11	0.98
350	0.035 ± 0.053	0.024 ± 0.014	0.012 ± 5.6	1.9 ± 0.0082	6.8 ± 0.0065	0.009 ± 0.002	5.41	1.01
360	0.030 ± 0.053	0.025 ± 0.014	0.020 ± 5.4	1.9 ± 0.0082	6.8 ± 0.0065	0.009 ± 0.002	5.59	0.97
370	0.029 ± 0.055	0.029 ± 0.015	0.035 ± 5.5	1.9 ± 0.0082	6.8 ± 0.0065	0.009 ± 0.002	5.73	1.09
380	0.026 ± 0.054	0.029 ± 0.015	0.049 ± 5.3	1.9 ± 0.0082	6.8 ± 0.0065	0.009 ± 0.002	5.80	1.03
390	0.026 ± 0.055	0.030 ± 0.016	0.072 ± 5.2	1.9 ± 0.0082	6.8 ± 0.0065	0.009 ± 0.002	5.83	0.98
400	0.024 ± 0.054	0.029 ± 0.016	0.075 ± 5.0	1.9 ± 0.0082	6.8 ± 0.0065	0.009 ± 0.002	5.89	1.13
410	0.027 ± 0.055	0.031 ± 0.016	0.11 ± 5.0	1.9 ± 0.0082	6.8 ± 0.0065	0.009 ± 0.002	5.85	1.06
420	0.028 ± 0.054	0.028 ± 0.016	0.15 ± 4.7	1.9 ± 0.0082	6.8 ± 0.0065	0.009 ± 0.002	5.76	1.26
430	0.030 ± 0.054	0.027 ± 0.016	0.17 ± 4.5	1.9 ± 0.0082	6.8 ± 0.0065	0.009 ± 0.002	5.67	1.15
440	0.033 ± 0.054	0.026 ± 0.016	0.19 ± 4.4	1.9 ± 0.0082	6.8 ± 0.0065	0.009 ± 0.002	5.50	1.17
450	0.032 ± 0.053	0.025 ± 0.015	0.21 ± 4.2	1.9 ± 0.0082	6.8 ± 0.0065	0.009 ± 0.002	5.53	1.04