Electrospray ionization mass spectrometry is a powerful tool for identification of biomolecules such as peptides, proteins, oligosaccharides and neurotransmitters. Recent development of the nanospray techniques, applied at ultralow flow-rates, allowed a sensitive analysis of compounds at femto/attomolar level. Here, we present application of a novel nanospray device for the analysis and fragmentation of peptides with high sensitivity on a sector instrument. The lowest applied flow-rate of the mobile phase was maintained at 50 nl/min with a sample load of 90 fmol. Nanospray also provided a complete analysis of 500 nl of the sample for over 10 min, including sequencing of as little as 40 pmol of a substance. Such analysis provides full structural information necessary to identify the molecules.
Decalepis hamiltonii Wight & Arn., is a plant species that is endemic to southern parts of India. The aim of this study is to explore the influence of habitat heterogeneity on total phenolics, flavonoids, flavor compound 2-hydroxy-4-methoxy benzaldehyde (2H4MB) and antioxidant potential of tubers. The flavor metabolite 2H4MB was quantified by HPLC using isocratic solvent system (methanol : acetonitrile : water : acetic acid 47 : 10 : 42 : 1) that indicates obvious difference in 2H4MB content of tubers with a maximum of 96.4 ±2.6 and 92.6 ±1.2 mg 100 g–1 dry weight basis (DW) in samples from B.R. Hills and Mysore area of Karnataka, followed by samples from Tirumalai Hills and Kurnool from Andhra Pradesh (89.02 ±0.9 mg 100 g–1 DW), Tamil Nadu (81.6 ±2.4 mg 100 g–1 DW) and Kerala (80.18 ±1.1 mg 100 g–1 DW) of tubers. There was variation in total phenolics, total flavonoids and 2H4MB content of root samples collected from different habitats. Also significant variation in free radical scavenging potential of methanol root extracts was noticed, which is directly proportional to the phenolics, and flavonoids content. Overall, there was 10–16% difference in content of 2H4MB in D. hamiltonii tubers that were collected from different natural habitats, and this habitat heterogeneity has to be considered vital, while using such tubers for edible purposes and food formulations.