Hypericum spp. volatile profiling and the potential significance in the quality control of new valuable raw material

he genus Hypericum (Guttiferae) is one of the most representative species in temperate zones and Turkey is one of the most important Mediterranean sites. Due to the increasing commercial value of Hyperici herba (Hypericum perforatum), many wild Turkish Hypericum species have received currently a considerable renewed interest as potential substitutes of the well-established H. perforatum crops for their similar content in the standardization bioactives (hypericins, hyperforins, and flavonoids). The present paper reported the volatile fingerprints of three selected wild Turkish Hypericum species recently characterized as H. perforatum bioactive-like profiles but lacking of the requested well-established usage in the EU market. In this context, the volatile constituents of the three-selected Hypericum spp. were investigated as additional discriminating markers to enhance the likelihood that this adulterating plant raw material will be detected before it is incorporated into finished H. perforatum products

Models of estimation on the content of secondary metabolites in some Hypericum species

In the present study, models for estimation of the content of main secondary metabolites, namely hypericin, pseudohypericin and hyperforin were developed for Hypericum originafolium Willd, Hypericum perfoliatum L. and Hypericum montbretii Spach. growing in Northern Turkey. Wild growing plants were harvested at vegetative, floral budding, full flowering, fresh fruiting, mature fruiting stages and dissected into stem, leaf and reproductive tissues. Actual secondary metabolite contents of plant materials were measured by High Performance Liquid Chromatography method. Multiple regression analysis with Excel 2003 computer package program was performed for each species and chemicals separately to develop multiple regression models. The produced equation for predicting the content of secondary metabolites in different tissues of the species was formulized as: SMC= [a + (b1 x S) + (b2 x L) + (b3 x RP) + (b4 x S²) + (b5 x (1/RP))] where SMC is whole plant secondary metabolite content, S is stem secondary metabolite content, L is leaf secondary metabolite content, RP is secondary metabolite content of reproductive parts and a, b1, b2, b3, b4, and b5 are coefficients?. The R2 coefficient values between predicted and observed contents of secondary metabolites were determined as 0.99 for H. originafolium, 0.95–0.98 for H. perfoliatum and 0.90–0.99 for H. montbretii. All R² values and standard errors were found to be significant at the P<0.05 level

Secondary Metabolites of Hypericum leptophyllum Hochst., an Endemic Turkish Species

In the present study, the presence of the phloroglucinol derivative hyperforin, the naphthodianthrones hypericin and pseudohypericin, the phenylpropane chlorogenic acid and the flavonoids rutin, hyperoside, kaempferol, isoquercetine, quercitrine, and quercetine was investigated in Hypericum leptophyllum Hochst., an endemic Turkish species for the first time. The aerial parts representing a total of 30 individuals were collected at full flowering and dissected into floral, leaf, and stem tissues. After being dried at room temperature, the plant materials were assayed for secondary metabolite concentrations by HPLC. Aerial plant parts accumulated chlorogenic acid, hyperoside, isoquercetine, quercitrine, and quercetine, but they did not accumulate hyperforin, hypericin, pseudohypericin, rutin, and kaempferol. Accumulation levels of the detected compounds varied with plant tissues. Such kind of data could be useful for elucidation of the chemotaxonomical significance of the corresponding compounds and phytochemical evaluation of this endemic species

Chemical and morphological diversity among wild populations of Hypericum aviculariifolium Jaub. et Spach subsp. depilatum (Freyn et Bornm.) N. Robson var. depilatum

In this study, the chemical and morphological diversity among eleven wild populations of Hypericum aviculariifolium Jaub. et Spach subsp. depilatum (Freyn et Bornm.) N. Robson var. depilatum, an endemic Turkish species was studied. These populations were investigated for their contents of hypericin, pseudohypericin, hyperforin, the chlorogenic, neochlorogenic, caffeic and 2,4-dihydroxybenzoic acids, hyperoside, quercitrin, isoquercitrin, avicularin, 13,118 biapigenin, (+)-catechin and (-)-epicatechin as well as for their morphological traits, including density of leaf light and dark glands, leaf area, leaf length/width ratio and plant height. The top two-thirds of the plants representing thirty individuals was harvested at full flowering from eleven sites and analyzed for the content of bioactive compounds by high-performance liquid chromatography after being dried at room temperature. Morphological characterization of the wild populations was performed on twenty randomly selected individuals from each plant-growing locality. The content of the tested compounds, except for caffeic acid and avicularin, and some morphological traits, namely, the density of leaf translucent glands and black nodules and leaf area varied significantly with the investigated populations. It was observed that hypericin and pseudohypericin contents were connected positively with leaf black nodule density, but negatively with leaf area and the contents of hyperforin, quercitrin and 13,118-biapigenin were correlated positively with leaf translucent gland density. Data presented here could be useful in determining future targets for further wide-ranging studies on this endemic species as well as in identifying superior germplasm in terms of high chemical content

Factors affecting the variation of bioactive compounds in Hypericum species

The genus Hypericum (Hypericaceae) consists of 484 species from 36 sections with worldwide distribution in different areas. Turkey is considered as hot spot for diversity of Hypericum genus. Despite numerous publications, Hypericum species still attracted considerable scientific interest due to pharmaceutically relevant secondary metabolites: naphthodianthrones, acylphloroglucinol derivatives, phenolic acids, flavonoid glycosides, biflavonoids, and some other valuable constituents. Phytochemical investigations carried out on different Hypericum species provided highly heterogeneous results. The content of bioactive compounds varies significantly due to many internal and external factors, including plant organs, phenological stage, genetic profile, environmental abiotic and biotic factors, such as growing site, light, temperature, radiation, soil drought and salinity, pathogens, and herbivores attack. The variations in content of bioactive compounds in plants are regarded as the main problem in the standardization of Hypericum-derived pharmaceuticals and dietary supplements. The review discusses the main factors contributing to the variations of bioactive compounds and what kind of modulations can increase quality of Hypericum raw material

The effects of salt and drought stress on phenolic accumulation in greenhouse-grown Hypericum pruinatum

Hypericum pruinatum is a medicinal herb containing several bioactive compounds with important pharmacological activity. In this study, we investigated the effects of the salt (0.03 - control, 1, 2.5, 4 and 8 dS m–1 of MgSO4, CaCl2 and NaCl salts) and drought stress (80, 100 and 120% of required water) on the content of phenolic compounds, namely chlorogenic acid, rutin, hyperoside, isoquercetine, quercitrine and quercetine in greenhouse grown plantlets. In general, the salt stress especially in elevating doses increased the levels of all of the compounds analysed, whereas drought stress did not cause a significant chance in chemical content of the plantlets. The present results indicated that abiotic stress factors, particularly salinity, have a marked influence on the content of phenolic constituents in H. pruinatum and it is a salt tolerant species. The results also indicated that phenolic compounds play significant physiological role in salinity tolerance