Altitudinal and seasonal changes of phenolic compounds in Buxus sempervirens leaves and cuticles

Metabolomics analysis reveals the metabolic and functional roles of flavonoids in light-sensitive tea leaves

“…Many phenylpropanoid [27] and anthocyanin [28] compounds are effective sunlight attenuators and protect photosynthetic organs (chloroplasts) faced with a superabundance of radiant energy. Flavonoids play a vital role in protecting plants to excess UV-B or sunlight irradiance [29–31]. Flavonoids such as quercetin and dihydroxy catechins also serve multiple functions in higher plants under distinct environmental conditions [26].…”

“…Chloroplast-located flavonoids [10, 26], phenylpropanoids [27] and anthocyanins [28] are effective sunlight attenuators which play vital roles in protecting chloroplasts when facing with a superabundant radiant energy. The key antioxidant function of flavonoids to excess ultraviolet radiation b (UV-B)/sunlight irradiance have been well documented [29–31]. These studies are further confirmed by the fact that flavonoids with an ortho-dihydroxy structure in the B-ring are preferentially accumulated, compared to flavonoids having a mono-hydroxy substitution [32, 33].…”

The higher the better? Differences in phenolics and cyanogenic glycosides in Sambucus nigra leaves, flowers and berries from different altitudes

“…Different climatic environments, duration of solar irradiation and plant phenophase at specific altitudes caused the discrepancy in the amounts of active compounds in elder leaves, flowers and berries. Consequently, a delay of flowering and ripening has been monitored at higher altitudes compared to lower elevation . Therefore, elderberry samples have to be collected at different periods (Table ) to ensure similar conditions.…”

“…HCA (particularly caffeic acid derivatives) increased with the rising altitude as a response of higher light intensity (especially UV radiation). It is known, that UV‐B irradiation negatively impacts the plant life at higher altitudes and increases the content of phenolics, which are accumulated in epidermal cells lessening the effects of UV‐irradiation on sensitive processes in mesophyll cells . Flavonols, particularly anthocyanins, quercetin and kaempferol derivatives act as photoprotective compounds and respond to increased UV‐B irradiation .…”

Localization of polysaccharides in isolated and intact cuticles of eucalypt, poplar and pear leaves by enzyme-gold labelling

“…From a chemical point of view, the cuticle is mainly composed of a cutin and/or cutan polymer matrix, waxes both embedded in (intracuticular) and deposited onto (epicuticular) the outer surface of such matrix, polysaccharides and phenolics [3,6].…”