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  3. 4-Iodobenzonitrile as a fluorogenic derivatization reagent for chromatographic analysis of L-p-boronophenylalanine in whole blood samples using Suzuki coupling reaction

4-Iodobenzonitrile as a fluorogenic derivatization reagent for chromatographic analysis of L-p-boronophenylalanine in whole blood samples using Suzuki coupling reaction

  • Anal Chim Acta. 2024 Jul 18:1313:342700. doi: 10.1016/j.aca.2024.342700.
Takayuki Fukuda 1,  Naoya Kishikawa 1,  Mahmoud El-Maghrabey 2,  Saori Nakamura 3,  Yoshihito Ohba 3,  Shigeru Kawakami 4,  Mitsuhiro Wada 5,  Naotaka Kuroda 6
Affiliations

Affiliations

  • 1 Department of Analytical Chemistry for Pharmaceuticals, Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan.
  • 2 Department of Analytical Chemistry for Pharmaceuticals, Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan; Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Mansoura University, 35516, Mansoura, Egypt.
  • 3 Faculty of Pharmaceutical Sciences, Nagasaki International University, 2825-7 HuisTen Bosch Cho, Sasebo, Nagasaki, 859-3298, Japan.
  • 4 Department of Pharmaceutical Informatics, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki, 852-8588, Japan.
  • 5 Faculty of Pharmaceutical Sciences, Sanyo-Onoda City University, 1-1-1 Daigakudori, SanyoOnoda, Yamaguchi, 756-0884, Japan.
  • 6 Department of Analytical Chemistry for Pharmaceuticals, Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan. Electronic address: n-kuro@nagasaki-u.ac.jp.
PMID: 38862203 DOI: 10.1016/j.aca.2024.342700
Abstract

Background: L-p-Boronophehylalanine (BPA) is used in boron neutron capture therapy (BNCT), which is a novel selective Cancer radiotherapy technique. It is important to measure BPA levels in human blood for effective radiotherapy; a prompt gamma-ray spectrometer, ICP-AES, and ICP-MS have been used for this purpose. However, these methods require sophisticated and expensive apparatuses as well as experienced analysts. Herein, we propose an HPLC-FL method for the determination of BPA after precolumn derivatization. A new fluorogenic reagent for aryl boronic acid derivatives, namely, 4-iodobenzonitrile, was employed for the fluorogenic derivatization of BPA based on the Suzuki coupling reaction.

Results: After the fluorogenic derivatization, a fluorescent cyanobiphenyl derivative is formed with maximum fluorescence at 335 nm after excitation at 290 nm. The developed method showed good linearity (r2=0.997) over the concentration range of 0.5-1000 nmol/L, and the detection limit (S/N = 3) was 0.26 nmol/L. The proposed method is more sensitive than previously reported methods for the determination of BPA, including the ICP-MS. Finally, the proposed method was successively applied to the measurement of BPA in human whole blood samples with a good recovery rate (≥95.7 %) using only 10 μL of blood sample. The proposed method offers a simple and efficient solution for monitoring BPA levels in BNCT-treated patients.

Significance: 4-Iodobenzonitrile was investigated as a new fluorogenic reagent for BPA based on Suzuki coupling. A new HPLC-FL method for BPA in whole blood samples with ultrasensitivity was developed. The developed method is superior in sensitivity to all previously reported methods for BPA. The method requires only a very small sample volume, making it suitable for micro-blood analysis of BPA via fingerstick sampling.

Keywords

4-Iodobenszonitrile; Blood samples; Boron neutron capture therapy; Fluorogenic derivatization; L-p-Boronophehylalanine; Suzuki coupling reaction.

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