Sano Aiko, Inoue Yutaka, Higuchi Yuji, Akao Ken-Ichi, Suzuki Ryuichiro
Faculty of Pharmacy and Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado, Saitama, 3500295, Japan.
Applicative Solution Lab, JASCO Corporation, 2967-5 Ishikawa-machi, Hachioji, Tokyo, 1928537, Japan.
Anal Sci. 2025 Mar;41(3):311-316. doi: 10.1007/s44211-024-00699-0. Epub 2024 Dec 9.
Aqueous extracts of corn silk exhibit glycation-inhibitory activity. Lignin is the active component of these extracts. As corn silk is highly nutritious and has medicinal value, it can be used as a functional food and cosmetics. However, to achieve this goal, it is necessary to evaluate its quality. As lignin, which could be used as a marker compound for quality control, is a macromolecule, HPLC cannot be employed for the quality control of the aqueous extracts of corn silk. We here develop a method to evaluate the anti-glycation activity of the aqueous extracts of corn silk using attenuated total reflectance (ATR)-Fourier transform infrared (FTIR) spectroscopy along with multivariate statistical analysis. The inhibitory activity was evaluated using two multivariate calibrations: principal component regression (PCR) and partial least square regression (PLSR). The spectral areas of the PCR model were 633.5-880.3, 1191.8-1359.6, 1423.1-1492.6, and 2572.6-2974.7 cm. Its coefficient of correlation (R = 0.981) and root mean square error of cross validation (RMSECV = 2.356) were highly predictable. The spectral regions of 983.5-985.5 and 1021.1-1107.9 cm offered the best prediction models for the PLSR model. The R value for the correlation between the actual values and the FTIR-predicted values was 0.994, while the corresponding RMSECV was 1.325%. Hence, FTIR spectroscopy along with multivariate calibration is a useful method for evaluating active corn silk aqueous extracts.
玉米须水提取物具有抗糖化活性。木质素是这些提取物中的活性成分。由于玉米须营养丰富且具有药用价值，它可被用作功能性食品和化妆品。然而，要实现这一目标，有必要评估其质量。由于可用作质量控制标记化合物的木质素是一种大分子，因此不能采用高效液相色谱法对玉米须水提取物进行质量控制。我们在此开发了一种方法，使用衰减全反射（ATR）-傅里叶变换红外（FTIR）光谱结合多元统计分析来评估玉米须水提取物的抗糖化活性。使用主成分回归（PCR）和偏最小二乘回归（PLSR）两种多元校准方法评估抑制活性。PCR模型的光谱区域为633.5 - 880.3、1191.8 - 1359.6、1423.1 - 1492.6和2572.6 - 2974.7 cm。其相关系数（R = 0.981）和交叉验证均方根误差（RMSECV = 2.356）具有高度可预测性。983.5 - 985.5和1021.1 - 1107.9 cm的光谱区域为PLSR模型提供了最佳预测模型。实际值与FTIR预测值之间的相关R值为0.994，而相应的RMSECV为1.325%。因此，FTIR光谱结合多元校准是评估活性玉米须水提取物的一种有用方法。
