The wavelength for the detection of PNM and the active constituents in this plant was selected by the UV-Vis (200–400 nm) detector. Due to a full-scan experiment of PNM, its UV spectrum showed maximum adsorption at the wavelengths of 210, 273, and 326 nm. The chromatographs monitored at 210 and 273 nm revealed more peaks than at 326 nm within 15–20 min. However, due to the fact that some peaks were missing between 40 and 70 min and due to the presence of serious baseline noise, some peaks seen at 210 and 273 nm were not well separated. Meanwhile, signals response for flavones and flavonols is commonly referred to as band I (usually 300–380 nm) and band II (usually 240–280 nm). In order to detect more common peaks while achieving suitable detection of PNM and active constituents, 326 nm was selected as the most appropriate detection wavelength. The HPLC chromatograms of standards and PNM are shown in Figure 3.