| Abstract: | Pedicularis longiflora var. tubiformis (Orobanchaceae) is an abundant
parasitic herb mainly found in the Xiaopohu wetland of the Qinghai Lake Basin in
Northwestern China. The species has an important local medicinal value, and in
this study, we evaluated the chemical profile of its stems, leaves and seeds using
mass spectrometry. Dried samples of stems, leaves and seeds were grinded,
weighted, and used for a series of extractions with an ultrasonic device at room
temperature. The chemical profiles for each tissue were determined using Gas
Chromatography-Mass Spectrometry (GC-MS) and Liquid ChromatographyMass Spectrometry (LC-MS). Twenty-seven amino acids and organic acids were
identified and quantified from stems, leaves and seeds. The content of amino acids
detected in leaves and seeds was higher than the amount found in stems. Six flavonoids were also detected, including isoorientin, orientin, luteolin-7-O-glucoside, luteolin, apigenin and tricin. The concentrations of luteolin-7-O-glucoside,
luteolin and tricin were the highest and more concentrated in leaves, while that
of orientin was the lowest and mainly found in stems. Soluble monosaccharides
and oligosaccharides below tetramer were also examined, and our analyses
detected the presence of arabitol, fructose, galacturonic acid, glucose, glucuronic
acid, inositol, sucrose, and trehalose. This is the first study to identify and quantify
the main components of amino acids, organic acids, flavonoids and soluble sugars
from stems, leaves and seeds of P. longiflora var. tubiformis. Eight of the amino
acids detected are essential for humans, highlighting the medicinal importance of
this species. Results shown here can be used as a reference case to develop future
studies on the chemical constituents of Pedicularis herbs and other medicinal
plants from the Tibetan region. |
