Secondary metabolites in Hypericum perfoliatum: variation among plant parts and phenological stages

Abstract

Ç ırak C., Radušienė J., Janulis V. and Ivanauskas L. 2007. Secondary metabolites in Hypericum perfoliatum: variation among plant parts and phenological stages. Bot. Helv. 117: 29 -36.The genus Hypericum is a source of biologically active compounds, notably hypericin and various phenolics. The concentrations of these compounds in plant tissues vary among plant parts and during the growing season. To determine this variation for Hypericum perfoliatum, a widespread species in Northern Turkey, wildgrowing plants were harvested at five phenological stages: vegetative, floral budding, full flowering, fresh fruiting and mature fruiting. Whole shoots as well as individual parts (stems, leaves and reproductive tissues) were assayed for bioactive compounds by HPLC. In whole shoots, concentrations of secondary metabolites increased during shoot development. The highest concentrations of chlorogenic acid, hyperoside, quercitrin, quercetin and hypericin were reached when plants flowered, whereas rutin and apigenin-7-O-glucoside reached highest levels during fruit development. Of the individual plant parts, leaves did not contain any rutin, apigenin-7-O-glucoside and quercetin, and stems contained no hypericin. Reproductive parts had the highest levels of rutin, apigenin-7-O-glucoside, quercitrin, quercetin and hypericin, whereas leaves produced more chlorogenic acid and hyperoside. Compared to H. perforatum, a widely used medicinal plant, the tissues of H. perfoliatum contained similar concentrations of hypericin, less rutin, quercitrin and quercetin, and more chlorogenic acid and hyperoside. The presence of apigenin-7-O-glucoside had not been reported previously in the genus Hypericum.

Secondary Metabolites ofHypericum leptophyllumHochst., an Endemic Turkish Species

“…The differences in chemical composition between leaves and flowers found in the present study for the H. leptophyllum largely correspond to those described for H. perforatum , whose flowers accumulated larger amounts of quercetin and quercitrin and whose leaves had the highest level of hyperoside [19]. In other species of Hypericum, similarly, quercitrine and quercetine were accumulated mainly in floral parts while leaves produced higher amounts of chlorogenic acid and hyperoside in H. origanifolium [20], H. perfoliatum [21], and H. maculatum [18]. …”

<b>Effect of environmental and phenological factors on the antimicrobial activity of <i>Cochlospermum regium</i> (Schrank) Pilg. roots

“…In plants, bioactive metabolites vary depending on the phenological stage (Sartorelli, Marquioreto, Amaral, Lima, & Moreno, 2007;Çιrak, Radušienė, Janulis, & Ivanauskas, 2007;Ebrahimi, Hadian, Mirjalili, Sonboli, Yousefzadi, 2008). In the case of C. regium roots, as a whole or in parts ( Figure 1A and B), the phenological stage did not elicit a standard response for the specimens collected in different geographical locations.…”

Seed polyphenols in a diverse tropical plant community

“…A remarkable bias in the current literature on macroevolutionary patterns of plant defences is the strong focus on leaf defences in adult plants. Although investment in defences can vary with ontogeny (Boege & Marquis, ; Elger, Lemoine, Fenner, & Hanley, ; Kariñho‐Betancourt, Agrawal, Halitschke, & Núñez‐Farfán, ) and between different plant parts (Beckman, ; Çιrak, Radušienė, Janulis, & Ivanauskas, ; McKey, ; Tuominen, Toivonen, Mutikainen, & Salminen, ) and the impact of enemies on the evolution of plant defences might differ between different stages of the plant life cycle (Boege & Marquis, ; Janzen, ), multi‐species studies assessing the distribution of defensive traits in plants of different age cohorts and in nonfoliar plant tissues are scarce. Collating and analysing data on community‐level patterns of defence expression in the early stages of the plant life cycle could yield new insights into the role of plant defences in ecological processes of key importance.…”