Yazar "Jakstas, Valdas" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim
    Öğe
    Chemical composition of Hypericum species from the Taeniocarpium and Drosanthe sections
    (Springer Wien, 2014) Camas, Necdet; Radusiene, Jolita; Ivanauskas, Liudas; Jakstas, Valdas; Kayikci, Samim; Cirak, Cuneyt
    The presence of several phytochemicals, namely naphthodianthrones hypericin and pseudohypericin, phloroglucinol derivatives hyperforin and adhyperforin, the phenolic acids as chlorogenic acid, neochlorogenic acid, caffeic acid and 2,4-dihydroxybenzoic acid, the flavonols, hyperoside, isoquercitrin, quercitrin, quercetin, avicularin, rutin, and flavanols (+)-catechin and (-)-epicatechin, as well as biflavonoid amentoflavone was investigated in seven Turkish species of Hypericum from Taeniocarpium and Drosanthe sections. Plants were harvested at flowering, dried at room temperature, dissected into different tissues and assayed for chemical contents by HPLC. All chemicals were detected at various levels depending on species and plant parts. Despite the observed quantitative variation in the chemical content of plant material, it was found that phytochemical profiles of the species from the same section were very similar. The present data could be helpful in selecting the future targets for phytochemical and biological studies as well as enriching our current chemical knowledge about Hypericum species. Such kind of data could also be useful for elucidation of the chemotaxonomical relationships among the sections of Hypericum genus.
  • Küçük Resim
    Öğe
    Secondary metabolites in Hypericum species and their distribution in different plant parts
    (Lithuanian Research Centre Agriculture & Forestry, 2016) Odabas, Mehmet Serhat; Radusiene, Jolita; Ivanauskas, Liudas; Jakstas, Valdas; Camas, Necdet; Kayikci, Samim
    The genus Hypericum (Hypericaceae) has attracted remarkable scientific interest as its members accumulate significant amounts of various bioactive compounds. In the current study, we investigated accumulation of several bioactive compounds in various parts of Hypericum hircinum L. subsp. majus (Ainton) N. Robson, H. pallens Banks et Sol., H. russeggeri (Fenzl) R. Keller and H. lanuginosum Lam. The plant materials were harvested at flowering, dissected into different tissues and subsequently subjected to high performance liquid chromatography (HPLC) analyses. Accumulation level of the investigated compounds varied greatly depending on species and plant parts. Among different plant tissues, flowers were found to be superior to leaves with respect to accumulation of the chemicals tested except for neochlorogenic, caffeic and 2,4-dihydroxybenzoic acids which were accumulated mainly in leaves. H. hircinum did not produce quercitrin or avicularin, H. lanuginosum did not accumulate hyperforins and caffeic acid, rutin was detected only in H. pallens. For the first time, chemical profiles of these Turkish species of Hypericum were reported and the results are discussed from a phytochemical point of view. The present data could be helpful in selecting the future targets for phytochemical and biological studies on Hypericum genus as well as enriching our current knowledge about Hypericum chemistry.