Department of Pharmaceutical Technology, University of North Bengal, Darjeeling, India.
Department of Tea Science, University of North Bengal, Darjeeling, India.
Phytochem Anal. 2022 Oct;33(7):1018-1027. doi: 10.1002/pca.3155. Epub 2022 Jun 21.
α-Amylase inhibitors from natural sources are of interest for new drug development for the treatment of diabetes mellitus (DM). High-performance thin-layer chromatography (HPTLC) coupled bioassay guided isolation of bioactive compounds has been improved within last few years.
A microchemical derivatised HPTLC-coupled attenuated total reflectance-Fourier-transform infrared (ATR-FTIR) and nuclear magnetic resonance (NMR) spectroscopy was employed for profiling α-amylase inhibitor from the aerial part of Asparagus racemosus Willd.
Asparagus racemosus Willd. aerial part extracted with different solvents (n-hexane, chloroform, ethyl acetate, and methanol) and assayed to detect free radical scavengers and α-amylase inhibitor by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and starch-iodine assay method, respectively. HPTLC-coupled ATR-FTIR and NMR spectroscopy was used to identify the α-amylase inhibitor.
Methanolic extract of A. racemosus showed highest antioxidant activity (21.99 μg GAE/μL) where n-hexane extract showed lowest antioxidant activity (5.87 μg GAE/μL). The α-amylase inhibition was recorded as highest and lowest in ethyl acetate extract (13.13 AE/μL) and n-hexane extract (3.92 AE/μL), respectively. The deep blue zone of α-amylase sprayed TLC plate of extracts with hR = 72 analysed for ATR-FTIR and NMR spectroscopy which revealed the presence of stigmasterol is responsible for α-amylase inhibition.
The present work establishes the α-amylase inhibiting properties of A. racemosus maintaining its use for the treatment of DM as a traditional medicine. Bioassay guided isolation through HPTLC-coupled ATR-FTIR and NMR spectroscopy offers an effective method for the exploration of bioactive compounds such as α-amylase inhibitor from complex plant extracts.
从天然来源中提取的α-淀粉酶抑制剂是治疗糖尿病（DM）新药开发的热点。近年来，高效薄层色谱（HPTLC）结合生物测定法对生物活性化合物的分离得到了改进。
采用微量衍生化 HPTLC 结合衰减全反射傅里叶变换红外（ATR-FTIR）和核磁共振（NMR）光谱法对来自天门冬科天门冬属植物的α-淀粉酶抑制剂进行分析。
用不同溶剂（正己烷、氯仿、乙酸乙酯和甲醇）提取天门冬属植物的地上部分，用 2,2-二苯基-1-苦基肼（DPPH）法和淀粉-碘法分别检测自由基清除剂和α-淀粉酶抑制剂。采用 HPTLC 结合 ATR-FTIR 和 NMR 光谱法鉴定α-淀粉酶抑制剂。
天门冬属植物的甲醇提取物表现出最高的抗氧化活性（21.99μg GAE/μL），而正己烷提取物表现出最低的抗氧化活性（5.87μg GAE/μL）。乙酸乙酯提取物的α-淀粉酶抑制率最高（13.13 AE/μL），正己烷提取物的α-淀粉酶抑制率最低（3.92 AE/μL）。用 hR = 72 对提取物的α-淀粉酶喷雾 TLC 板进行分析，得到深蓝色区域，用于 ATR-FTIR 和 NMR 光谱分析，结果表明存在麦角甾醇是其具有α-淀粉酶抑制作用的原因。
本研究确立了天门冬属植物的α-淀粉酶抑制作用，维持了其作为传统医学治疗 DM 的用途。通过 HPTLC 结合 ATR-FTIR 和 NMR 光谱法进行生物测定指导的分离，为从复杂植物提取物中探索生物活性化合物（如α-淀粉酶抑制剂）提供了一种有效方法。
