Plasticity of crassulacean acid metabolism at subtropical latitudes: a pineapple case study.

Plants with the crassulacean acid metabolism (CAM) express high-metabolic plasticity, to adjust to environmental stresses. This article hypothesizes that irradiance and nocturnal temperatures are the major limitations for CAM at higher latitudes such as the Azores (37°45'N). Circadian CAM expression in Ananas comosus L.

HPLC-UV-ESI-MS analysis of phenolic compounds and antioxidant properties of Hypericum undulatum shoot cultures and wild-growing plants.

LC-UV and LC-MS analysis were used to study the phenolic composition of water extracts of Hypericum undulatum (HU) shoot cultures and wild-growing (WG) plants. Total phenolic content (TPC), determined using the Folin-Ciocalteu assay, and the antioxidant activity measured by two complementary methods were also performed for each sample. Mass spectrometry revealed several phenolics acids with quinic acid moieties, flavonols, mostly quercetin, luteolin and apigenin glycosides, flavan-3-ols (catechin and epicatechin) and the xanthonoid mangiferin.

Content of hypericins from plants and in vitro shoots of Hypericum undulatum Schousb. ex Willd.

This study reports the first quantification study of pseudohypericin (PsHyp) and hypericin (Hyp) in Hypericum undulatum Schousb. ex Willd in vitro cultures developed by a Portuguese company. Both compounds were quantified by high-performance liquid chromatography and their levels were compared with those in commercial samples of Hypericum perforatum.

Anti-acetylcholinesterase and antioxidant activity of essential oils from Hedychium gardnerianum Sheppard ex Ker-Gawl.

Acetylcholinesterase inhibition, antioxidant and cytotoxic activities of Hedychium gardnerianum leaf essential oils from S. Miguel Island were determined. All the oils inhibited acetylcholinesterase, with IC(50) values of approximately 1 mg/mL, showing no statistical differences between collection sites.

Molluscicidal activity of crude water and hexane extracts of Hypericum species to snails (Radix peregra).

In spite of intense research on both chemical constituency and biological activity of Hypericum species, potential applications of their active components for pest control have been less well investigated. In the present study, Hypericum androsaemum (tutsan), Hypericum foliosum (malfurada), and Hypericum undulatum (wavy St. John's wort) aqueous and hexane extracts were studied for their molluscicidal and ovicidal activities against Radix peregra.

Assessment of molluscicidal activity of essential oils from five Azorean plants against Radix peregra (Müller, 1774).

The molluscicidal activity of essential oils from two endemic (Juniperus brevifolia; Laurus azorica) and three introduced (Hedychium gardnerianum; Pittosporum undulatum; Psidium cattleianum) Azorean plants against the snail Radix peregra was studied under laboratory conditions. Essential oils from leaves of H. gardnerianum, L.

Comparison of the endemic Azorean Hypericum foliosum with other Hypericum species: antioxidant activity and phenolic profile.

Water extracts of Hypericum foliosum (HF) from five Azorean Islands were analysed for their antioxidant activity and total phenolic contents. The results were compared with those from medicinal Hypericum species (H. perforatum, H.