Molecular phylogeny of the genus<Emphasis Type="Italic">Hypericum</Emphasis> (Hypericaceae) from Korea and Japan: evidence from nuclear rDNA ITS sequence data

As part of our ongoing phylogenetic study of genusHypericum, nuclear ribosomal DNA internal transcribed spacer sequences were analyzed for 36 species ofHypericum as ingroup and two species ofThornea as outgroup. This sampling included most of the previously described species from both Korea and Japan. The ITS phylogeny suggested that the surveyedHypericum species belong to a monophyletic section,Trigynobrathys, and a polyphyletic section,Hypericum. In addition, two monotypic sections,Sampsonia andRoscyna, were identified. Members of sectionHypericum occur in four different lineages worldwide, which imply at least four independent origins. The Korean and Japanese species of sectionHypericum form a monophyletic group, except forH. vulcanicum. Instead, that particular species belongs to a distinct monophyletic group withH. scoreri andH. formosa from other geographic areas, and is a sister to sectionTrigynobrathys. The Korean and Japanese species of sectionTrigynobrathys show a monophyletic origin.H. sampsonii is now recognized as a distinct section rather than being a member of sectionsHypericum orDrosocarpium, as had been indicated previously. Our results differ somewhat from those of recent morphological and cytological studies. The phylogenetic relationships among Korean and Japanese species have now been mostly resolved via ITS phylogeny.     

Transactions of the Botanical Society of Edinburgh

Summary

Evidence is adduced that the ‘hypogynous bodies’ found in two unrelated sections of Hypericum are, at the same time, ‘new’ organs in Hypericum and yet homologous with sterile stamen facicles in other genera of the Guttiferae. Their reappearance is related to the development of specialised insect pollination.     

Variability of Hypericins and Hyperforin in Hypericum Species from the Sicilian Flora

Within Sicilian flora, the genus Hypericum (Guttiferae) includes 10 native species, the most popular of which is H. perforatum. Hypericum’s most investigated active compounds belong to naphtodianthrones (hypericin, pseudohypericin) and phloroglucinols (hyperforin, adhyperforin), and the commercial value of the drug is graded according to its total hypericin content. Ethnobotanical sources attribute the therapeutic properties recognized for H. perforatum, also to other Hypericum species. However, their smaller distribution inside the territory suggests that an industrial use of such species, when collected from the wild, would result in an unacceptable depletion of their natural stands. This study investigated about the potential pharmacological properties of 48 accessions from six native species of Hypericum, including H. perforatum and five ‘minor’ species, also comparing, when possible, wild and cultivated sources. The variability in the content of active metabolites was remarkably high, and the differences within the species were often comparable to the differences among species. No difference was enlightened between wild and cultivated plants. A carefully planned cultivation of Hypericum seems the best option to achieve high and steady biomass yields, but there is a need for phytochemical studies, aimed to identify for multiplication the genotypes with the highest content of the active metabolites.     

Hypericum sp.: essential oil composition and biological activities

Phytochemical composition of Hypericum genus has been investigated for many years. In the recent past, studies on the essential oils (EO) of this genus have been progressing and many of them have reported interesting biological activities. Variations in the EO composition of Hypericum species influenced by seasonal variation, geographic distribution, phenological cycle and type of the organ in which EO are produced and/or accumulated have also been reported. Although many reviews attributed to the characterization as well as biological activities of H. perforatum crude extracts have been published, no review has been published on the EO composition and biological activities of Hypericum species until recently (Crockett in Nat Prod Commun 5(9):1493–1506, 2010; Bertoli et al. in Global Sci Books 5:29–47, 2011). In this article, we summarize and update information regarding the composition and biological activities of Hypericum species EO. Based on experimental work carried out in our laboratory we also mention possible biotechnology approaches envisaging EO improvement of some species of the genus.     

A karyomorphological study of the genusHypericum (Hypericaceae) in Japan

Chromosome numbers were determined in 226 collections ofHypericum of Japan, representing nine species and one interspecific hybrid. These included the first cytological records forH. erectum var.caespitosum, H. samaniense, H. hakonense, H. sikokumontanum, H. kamtschaticum var.kamtschaticum, H. kamtschaticum var.hondoense, H. pseudopetiolatum, H. yojiroanum andH. tosaense. Counts of 2n=16 were made throughout for collections of six species, and those of 2n=18 forH. ascyron. Intraspecific polyploidy was found inH. samaniense (2x and 3x, x=8) andH. pseudopetiolatum (2x and 4x, x=8). Results of the karyotype analysis showed that three different karyotypes could be recognized, and they were parallel to the subdivision ofHypericum by Kimura (1951). The chromosomes were very small and mostly median centromeric. It was suggested that the role of polyploidy in the evolutionary differentiation ofHypericum in Japan might have been rather limited.     

Studies in the genus Hypericum L. (Clusiaceae). 1 Section 9. Hypericum sensu lato (part 3): Subsection 1. Hypericum series 2. Senanensia,subsection 2. Erecta and section 9b. Graveolentia

Abstract

Part 4(3) of this monographic series of papers on the genus Hypericum is prefaced by an introduction to the genus and a summary of the aims and methods of the project. This is followed by treatments of the remaining parts of sect. 9. Hypericum sensu stricto and the last segregate section from the original sect. Hypericum, sect. 9b. Graveolentia. Both hitherto untreated parts of the reduced sect. Hypericum are mainly Japanese, but some species extend in distribution as far as Kamchatka, eastern Siberia, central China, and Sabah (Mt. Kinabalu). Sect. Graveolentia is North and Central American. Sect. Hypericum subsect. Hypericum series Senanensia contains seven species from northern Japan and adjacent areas, including H. pibairense (Miyabe & Y. Kimura) N. Robson, stat. nov., H. nakaii subsp. miyabei (Y. Kimura) N. Robson, comb. et stat. nov., H. nakaii subsp. tatewakii (S. Watanabe) N. Robson, comb. et stat. nov. and H. senanense subsp. mutiloides (R. Keller) N. Robson, comb. et stat. nov. Sect. Hypericum subsect. Erecta contains 23 species and one hybrid from Japan, Korea, central China, Taiwan, Luzon, Sabah and Sumatera, including H. kawaranum N. Robson, stat. et nom. nov., H. watanabei N. Robson, stat. et nom. nov., H. kimurae N. Robson, stat. et nom. nov., H. pseudoerectum stat. et nom. nov., H. kitamense (Y. Kimura) N. Robson, stat. nov., H. kurodakeanum N. Robson, stat. et nom. nov., H. furusei N. Robson, sp. nov., H. nuporoense N. Robson, sp. nov. and H. ovalifolium subsp. hisauchii (Y. Kimura) N. Robson, stat. nov. Sect. Graveolentia contains nine species and one hybrid from southeastern Canada, the eastern half of the United States, Mexico and western Guatemala, including H. oaxacanum subsp. veracrucense N. Robson, subsp. nov. and H. macvaughii N. Robson, sp. nov.     

Rutin as Deoxyribonuclease I Inhibitor

DNase I inhibitory potential of water extract of nine Hypericum species (H. umbellatum, H. barbatum, H. rumeliacum, H. rochelii, H. perforatum, H. tetrapterum, H. olympicum, H. hirsutum, H. linarioides) and the most important Hypericum secondary metabolites (hypericin, hyperforin, quercetin, and rutin) was investigated. All examined Hypericum extracts inhibited DNase I with IC₅₀ below 800 μg/ml, whereby H. perforatum was the most potent (IC₅₀=391.26±68.40 μg/ml). Among the investigated Hypericum secondary metabolites, rutin inhibited bovine pancreatic DNase I in a non‐competitive manner with IC₅₀ value of 108.90±9.73 μm . DNase I inhibitory ability of rutin was further confirmed on DNase I in rat liver homogenate (IC₅₀=137.17±16.65 μm ). Due to the involvement of DNase I in apoptotic processes the results of this study indicate the importance of frequent rutin and H. perforatum consumption in daily human nutrition. Rutin is a dietary component that can contribute to male infertility prevention by showing dual mechanism of sperm DNA protection, DNase I inhibition and antioxidant activity.     

Lectotypifications of ten names of North American taxa in Clusiaceae, Elatinaceae, Ericaceae, Primulaceae, and Violaceae

Lectotypes are selected for 10 names inHypericum (Clusiaceae),Elatine (Elatinaceae),Arctostaphylos andVaccinium (Ericaceae),Androsace (Primulaceae), andViola (Violaceae).     

Interspecific variation in localization of hypericins and phloroglucinols in the genus Hypericum as revealed by desorption electrospray ionization mass spectrometry imaging

Plants of the genus Hypericum are widely known for their therapeutic properties. The most biologically active compounds of this genus are naphtodianthrones and phloroglucinols. Indirect desorption electrospray ionization mass spectrometry (DESI‐MS) imaging allows visualization and localization of secondary metabolites in different plant tissues. This study is focused on localization of major secondary compounds in the leaves of 17 different in vitro cultured Hypericum species classified in 11 sections. Generally, all identified naphtodianthrones, protohypericin, hypericin, protopseudohypericin and pseudohypericin were co‐localized in the dark glands of eight hypericin producing species at the site of their accumulation. The known phloroglucinols, hyperforin, adhyperforin, hyperfirin and some new phloroglucinols with m/z [M ? H]^? 495 and 569 were localized in the translucent and pale cavities within the leaf in the majority of studied species. The comparison of different Hypericum species revealed an interspecific variation in the distribution of the dark and translucent glands corresponding with the localization of hypericins and phloroglucinols. Moreover, similarities in the localization and composition of the phloroglucinols were observed in the species belonging to the same section. Adding to various quantitative studies focused on the detection of secondary metabolites, this work using indirect DESI‐MSI offers additional valuable information about localization of the above‐mentioned compounds.     

Host-specificity and virus-vector potential ofAphis chloris [Hemiptera: Aphididae], a biological control agent for St John's wort in Australia

Under laboratory conditionsAphis chloris Koch has been demonstrated to be specific to plants belonging to the genusHypericum. It can effect severe damage to its principal host,H. perforatum L., and shows good potential for contributing to the control of this noxious weed. Other species ofHypericum are less favoured hosts ofA. chloris and would not be endangered by it. A. chloris shows a high level of host-discrimination and does not transmit persistent viruses between non-host plants. Whereas in the laboratory it is capable of transmitting non-persistent viruses, it would contribute only marginally to the risk of virus transfer posed by the Australian aphid fauna as a whole, and its release would not necessitate changes to existing control practices, where these are required to reduce plant virus transmission. As a consequence,A. chloris is considered safe for release againstH. perforatum in Australia.