Altitudinal variation of UV-absorbing compounds in Plantago asiatica

UV-absorbing compounds such as flavonoids and phenolic acids are important for plants to protect their vegetative organs from harmful UV radiation at higher altitude. Two chemotypes, i.e., acteoside mainly-containing (AM) type and plantamajoside mainly-containing (PM) type were found by qualitative HPLC analysis of the phenolics in the leaves of Plantago asiatica in Mt. Norikura, Japan. Though AM type was not detected in low altitude populations, it occurred in high altitude populations. Acteoside has been reported to be more effective antioxidant than plantamajoside. On the other hand, higher accumulations of UV-absorbing substances were seen in higher altitude populations by quantitative analyses. Besides, B-ring ortho-dihydroxylated flavonoids notably increased than mono-hydroxylated flavonoids with increasing altitude. These results demonstrate that P. asiatica has chemically acclimated to high altitudes, in which severe environmental conditions such as higher UV radiation exist.     

Chemical Profiling and Assessment of Antineurodegenerative and Antioxidant Properties of Veronica teucrium L. and Veronica jacquinii Baumg.

Neuroprotective potential of V. teucrium and V. jacquinii methanol extracts was analyzed. Chemical analysis of investigated extracts showed the presence of phenolic acid derivatives, flavonoids and one secoiridoid. The detected flavonoids derived from flavones (luteolin and isoscutellarein in V. jacquinii ; apigenin, isoscutellarein and luteolin in V. teucrium ) and flavonol (quercetin in V. jacquinii ). Acteoside was the dominant compound in V. jacquinii , while plantamajoside and isoscutellarein 7‐O ‐(6?‐O ‐acetyl)‐β ‐allosyl (1?→2?)‐β ‐glucoside were the major phenolics in V. teucrium . Additionally, the antineurodegenerative activity was tested at concentrations of 25, 50, and 100 μg/ml using acetylcholinesterase (AC hE) and tyrosinase (TYR ) assays. The inhibition of both enzymes was achieved with the investigated extracts, ranging from 22.78 to 35.40% for AC hE and from 9.57 to 16.38% for TYR . There was no statistical difference between the activities of the analyzed extracts. Our data indicate that V. teucrium and V. jacquinii may have beneficial effects against Alzheimer 's and Parkinson 's disease.