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Barrows Edward - One of the best experts on this subject based on the ideXlab platform.

Muraleedharan G. Nair - One of the best experts on this subject based on the ideXlab platform.

  • lipid peroxidation inhibitory compounds from daylily Hemerocallis fulva leaves
    Life Sciences, 2004
    Co-Authors: Yanjun Zhang, Robert H Cichewicz, Muraleedharan G. Nair
    Abstract:

    Daylilies (Hemerocallis spp.) have been used as food and in traditional medicine for thousands of years in eastern Asia. The leaves of the plant are used in the treatment of inflammation and jaundice. In studies of the aqueous methanol extracts of fresh Hemerocallis fulva leaves, 1′,2′,3′,4′-tetrahydro-5′-deoxy-pinnatanine (1), pinnatanine (2), roseoside (3), phlomuroside (4), lariciresinol (5), adenosine (6), quercetin 3-O-β-d-glucoside (7), quercetin 3,7-O-β-d-diglucopyranoside (8), quercetin 3-O-α-l-rhamnopyransol-(1→6)-β-d-glucopyranosol-7-O-β-d-glucopyranoside (9), isorhamnetin-3-O-β-d-6′-acetylglucopyranoside (10) and isorhamnetin-3-O-β-d-6′-acetylgalactopyranoside (11) were isolated. All of these compounds were tested for their in vitro lipid peroxidation inhibitory activities. Compounds 3–5 and 7–11 were found to possess strong antioxidant properties, inhibiting lipid oxidation by 86.4, 72.7, 90.1, 79.7, 82.4, 89.3, 82.2, and 93.2%, respectively at 50 μg/mL. Compound 1 is novel and compounds 3–6 and 8–11 described here in are isolated for the first time from daylily leaves.

  • kwanzoquinones a g and other constituents of Hemerocallis fulva kwanzo roots and their activity against the human pathogenic trematode schistosoma mansoni
    Tetrahedron, 2002
    Co-Authors: Robert H Cichewicz, Keechong Lim, James H Mckerrow, Muraleedharan G. Nair
    Abstract:

    Abstract Schistosomiasis is a debilitating disease caused by parasitic trematodes of the genus Schistosoma that afflicts 200 million people worldwide. Daylilies (Hemerocallis spp.) have been used in Asia for the treatment of schistosomiasis; however, the active principles have not been fully characterized. In our studies of Hemerocallis fulva ‘Kwanzo’ Kaempfer roots, we have isolated seven new anthraquinones, kwanzoquinones A ( 1 ), B ( 2 ), C ( 4 ), D ( 5 ), E ( 6 ), F ( 7 ), and G ( 9 ), two known anthraquinones, 2-hydroxychrysophanol ( 3 ) and rhein ( 8 ), one new naphthalene glycoside, 5-hydroxydianellin ( 11 ), one known naphthalene glycoside, dianellin ( 10 ), one known flavone, 6-methylluteolin ( 12 ), and α-tocopherol. The structures of the compounds were elucidated by spectroscopic and chemical methods. Compounds 1–11 and the monoacetates of kwanzoquinones A and B, 1a and 2a , respectively, were tested for their activity against multiple life-stages of Schistosoma mansoni. Compound 3 immobilized all cercariae within 15 s at 3.1 μg/mL. However, upon removal of the compound, 20% of the immobilized cercariae recovered after 24 h. In contrast, compound 6 immobilized cercariae within 12–14 min at 25 μg/mL. Following removal of the compound, all cercariae died within 24 h. The adult worms were also immobilized within 16 h by compounds 3 and 6 at 50 μg/mL. None of the compounds had an effect on the schistosomula stage.

  • isolation and characterization of stelladerol a new antioxidant naphthalene glycoside and other antioxidant glycosides from edible daylily Hemerocallis flowers
    Journal of Agricultural and Food Chemistry, 2002
    Co-Authors: Robert H Cichewicz, Muraleedharan G. Nair
    Abstract:

    Daylily (Hemerocallis spp.) flowers are utilized as an important ingredient in traditional Asian cuisine and are also valued for their reputed medicinal effects. In studies of the bioactive methanol and aqueous methanol extracts of lyophilized Hemerocallis cv. Stella de Oro flowers, kaempferol, quercetin, and isorhamnetin 3-O-glycosides (1−9), phenethyl β-d-glucopyranoside (10), orcinol β-d-glucopyranoside (11), phloretin 2‘-O-β-d-glucopyranoside (12), phloretin 2‘-O-β-d-xylopyranosyl-(1→6)-β-d-glucopyranoside (13), a new naphthalene glycoside, stelladerol (14), and an amino acid (longitubanine A) (15) have been isolated. All of these compounds were tested for their antioxidant and cyclooxygenase inhibitory activities. Stelladerol was found to possess strong antioxidant properties, inhibiting lipid oxidation by 94.6% ± 1.4 at 10 μM in an in vitro assay. Several of the flavonol 3-O-glycoside isolates also demonstrated modest antioxidant activities at 10 μM. None of the isolates inhibited cyclooxygenase act...

Michael S. Reid - One of the best experts on this subject based on the ideXlab platform.

  • Up-regulation of a cysteine protease accompanies the ethylene-insensitive
    2014
    Co-Authors: Short Communication, Victoriano Valpuesta, Nathan E. Lange, Consuelo Guerrero, Michael S. Reid
    Abstract:

    senescence of daylily (Hemerocallis) flower

  • analysis of the expression of two thiolprotease genes from daylily Hemerocallis spp during flower senescence
    Plant Molecular Biology, 1998
    Co-Authors: Consuelo Guerrero, Michael S. Reid, Mercedes De La Calle, Victoriano Valpuesta
    Abstract:

    A cDNA clone encoding a daylily (Hemerocallis spp.) thiolprotease (SEN11), whose expression is strongly upregulated in flower tepal senescence, has been isolated. The amino acid sequence, deduced from the nucleotide sequence, showed highest similarity to plant thiolproteases of Vigna mungo, Phaseolus vulgarisand Hemerocallis (SEN102), and contains a putative ER retention signal that has been described in Vigna mungo. SEN102 and SEN11 transcripts were not detectable in flower buds at the opening stage, but two peaks of transcripts were seen after 9 h and 19 h, in both petals and sepals, when wilting symptoms were apparent. The pattern of protease activity migrating on a 26.3 kDa protein was similar to the SEN102 and SEN11 transcript profiles. These two genes were also expressed in stamens and leaves, but their transcripts were undetectable in carpels and rhizomes. The expression of SEN102 was lower in the senescent leaf than in the green leaf. The pattern of expression of these genes suggests their involvement in the protein hydrolysis occurring in tepals at the late senescence stage, whereas in leaves they could be involved in the constitutive protein turnover machinery. Exogenous gibberellic acid application to cut flowers increased transcripts of both genes.

  • flower senescence in daylily Hemerocallis
    Physiologia Plantarum, 1992
    Co-Authors: Michael Layyee, Anthony D. Stead, Michael S. Reid
    Abstract:

    Daylily (Hemerocallis hybrid cv. Cradle Song) flower development and senescence was categorised into seven stages, each separated by one day. As the bud developed (Stages I to III) its fresh and dry weight increased, but during flower opening (Stages III to IV) only the fresh weight increased, reaching a maximum when the flower was fully open (Stage IV). Fresh and dry weight declined as the flower senesced (Stages V to VII), and the petal tissue became water-soaked. Flower respiration was relatively constant through Stages I to III, but during opening the CO2 production increased, then declined as the flowers senesced. Ethylene production was low throughout flower development, and there was a transient increase, up to 2.5 nl flower−1 h−1, as flowers senesced. Petal protein content per gram fresh weight decreased throughout flower development and senescence either on or off the plant. One-dimensional SDS-PAGE revealed a general gradual loss of protein bands during flower senescence and loss of some specific bands (e.g. at M, 30 000 and 40 000). Flowers, detached from the plant at Stage III, placed in deionised (DI) water for 7 h and then transferred to fresh DI water or actinomycin D (25 mg l−1), showed an increase in fresh weight up to a maximum at about 12 h after transfer, followed by a rapid decline. By 48 h the flowers had completely senesced, the tissue becoming watersoaked and free moisture appearing on the tips of collapsed petals. In contrast, senescence of flowers treated during opening with cycloheximide (1 mM) was greatly delayed, with little loss of fresh weight or reduction in flower diameter, even up to 181 h after transfer. When such flowers did finally senesce, they did not show the same pattern of senescence as seen with those in water or actinomycin D. Cycloheximide-treated flowers wilted gradually and showed no water-soaking and no free moisture at the petal tips. Cycloheximide treatment retarded the decline in protein content of the petals; and the protein population, as visualised by SDS-PAGE, was maintained for up to 204 h after transfer to cycloheximide.

Tetsukazu Yahara - One of the best experts on this subject based on the ideXlab platform.

  • Pollinator-Mediated Selection on Flower Color, Flower Scent and Flower Morphology of Hemerocallis: Evidence from Genotyping Individual Pollen Grains On the Stigma
    2016
    Co-Authors: Shun K Hirota, Kozue Nitta, Yoshihisa Suyama, Nobumitsu Kawakubo, Akiko A Yasumoto, Tetsukazu Yahara
    Abstract:

    To trace the fate of individual pollen grains through pollination processes, we determined genotypes of single pollen grains deposited on Hemerocallis stigmas in an experimental mixed-species array. Hemerocallis fulva, pollinated by butterflies, has diurnal, reddish and unscented flowers, and H. citrina, pollinated by hawkmoths, has nocturnal, yellowish and sweet scent flowers. We observed pollinator visits to an experimental array of 24 H. fulva and 12 F2 hybrids between the two species (H. fulva and H. citrina) and collected stigmas after every trip bout of swallowtail butterflies or hawkmoths. We then measured selection by swallowtail butterflies or hawkmoths through male and female components of pollination success as determined by single pollen genotyping. As expected, swallowtail butterflies imposed selection on reddish color and weak scent: the number of outcross pollen grains acquired is a quadratic function of flower color with the maximum at reddish color, and the combined pollination success was maximal at weak scent (almost unrecognizable for human). This explains why H. fulva, with reddish flowers and no recognizable scent, is mainly pollinated by swallowtail butterflies. However, we found no evidence of hawkmoths-mediated selection on flower color or scent. Our findings do not support a hypothesis that yellow flower color and strong scent intensity, the distinctive floral characteristics of H. citrina, having evolved in adaptations to hawkmoths. We suggest that the key trait that triggers the evolution of nocturnal flowers is flowering time rather than flower colo

  • J Plant Res (2006) 119:63–68 © The Botanical Society of Japan and Springer-Verlag Tokyo 2005 Digital Object Identifier (DOI) 10.1007/s10265-005-0241-3
    2014
    Co-Authors: Tetsukazu Yahara, Masahiro Hasegawa, Akiko Yasumoto, Mitsuru Hotta, T. Yahara, Blooming Speciation Sphingophily
    Abstract:

    Bimodal distribution of flowering time in a natural hybrid population of daylily (Hemerocallis fulva) and nightlily (Hemerocallis citrina

  • pollinator mediated selection on flower color flower scent and flower morphology of Hemerocallis evidence from genotyping individual pollen grains on the stigma
    PLOS ONE, 2013
    Co-Authors: Shun K Hirota, Kozue Nitta, Yoshihisa Suyama, Nobumitsu Kawakubo, Akiko A Yasumoto, Tetsukazu Yahara
    Abstract:

    To trace the fate of individual pollen grains through pollination processes, we determined genotypes of single pollen grains deposited on Hemerocallis stigmas in an experimental mixed-species array. Hemerocallis fulva, pollinated by butterflies, has diurnal, reddish and unscented flowers, and H. citrina, pollinated by hawkmoths, has nocturnal, yellowish and sweet scent flowers. We observed pollinator visits to an experimental array of 24 H. fulva and 12 F2 hybrids between the two species (H. fulva and H. citrina) and collected stigmas after every trip bout of swallowtail butterflies or hawkmoths. We then measured selection by swallowtail butterflies or hawkmoths through male and female components of pollination success as determined by single pollen genotyping. As expected, swallowtail butterflies imposed selection on reddish color and weak scent: the number of outcross pollen grains acquired is a quadratic function of flower color with the maximum at reddish color, and the combined pollination success was maximal at weak scent (almost unrecognizable for human). This explains why H. fulva, with reddish flowers and no recognizable scent, is mainly pollinated by swallowtail butterflies. However, we found no evidence of hawkmoths-mediated selection on flower color or scent. Our findings do not support a hypothesis that yellow flower color and strong scent intensity, the distinctive floral characteristics of H. citrina, having evolved in adaptations to hawkmoths. We suggest that the key trait that triggers the evolution of nocturnal flowers is flowering time rather than flower color and scent.

Robert H Cichewicz - One of the best experts on this subject based on the ideXlab platform.

  • lipid peroxidation inhibitory compounds from daylily Hemerocallis fulva leaves
    Life Sciences, 2004
    Co-Authors: Yanjun Zhang, Robert H Cichewicz, Muraleedharan G. Nair
    Abstract:

    Daylilies (Hemerocallis spp.) have been used as food and in traditional medicine for thousands of years in eastern Asia. The leaves of the plant are used in the treatment of inflammation and jaundice. In studies of the aqueous methanol extracts of fresh Hemerocallis fulva leaves, 1′,2′,3′,4′-tetrahydro-5′-deoxy-pinnatanine (1), pinnatanine (2), roseoside (3), phlomuroside (4), lariciresinol (5), adenosine (6), quercetin 3-O-β-d-glucoside (7), quercetin 3,7-O-β-d-diglucopyranoside (8), quercetin 3-O-α-l-rhamnopyransol-(1→6)-β-d-glucopyranosol-7-O-β-d-glucopyranoside (9), isorhamnetin-3-O-β-d-6′-acetylglucopyranoside (10) and isorhamnetin-3-O-β-d-6′-acetylgalactopyranoside (11) were isolated. All of these compounds were tested for their in vitro lipid peroxidation inhibitory activities. Compounds 3–5 and 7–11 were found to possess strong antioxidant properties, inhibiting lipid oxidation by 86.4, 72.7, 90.1, 79.7, 82.4, 89.3, 82.2, and 93.2%, respectively at 50 μg/mL. Compound 1 is novel and compounds 3–6 and 8–11 described here in are isolated for the first time from daylily leaves.

  • kwanzoquinones a g and other constituents of Hemerocallis fulva kwanzo roots and their activity against the human pathogenic trematode schistosoma mansoni
    Tetrahedron, 2002
    Co-Authors: Robert H Cichewicz, Keechong Lim, James H Mckerrow, Muraleedharan G. Nair
    Abstract:

    Abstract Schistosomiasis is a debilitating disease caused by parasitic trematodes of the genus Schistosoma that afflicts 200 million people worldwide. Daylilies (Hemerocallis spp.) have been used in Asia for the treatment of schistosomiasis; however, the active principles have not been fully characterized. In our studies of Hemerocallis fulva ‘Kwanzo’ Kaempfer roots, we have isolated seven new anthraquinones, kwanzoquinones A ( 1 ), B ( 2 ), C ( 4 ), D ( 5 ), E ( 6 ), F ( 7 ), and G ( 9 ), two known anthraquinones, 2-hydroxychrysophanol ( 3 ) and rhein ( 8 ), one new naphthalene glycoside, 5-hydroxydianellin ( 11 ), one known naphthalene glycoside, dianellin ( 10 ), one known flavone, 6-methylluteolin ( 12 ), and α-tocopherol. The structures of the compounds were elucidated by spectroscopic and chemical methods. Compounds 1–11 and the monoacetates of kwanzoquinones A and B, 1a and 2a , respectively, were tested for their activity against multiple life-stages of Schistosoma mansoni. Compound 3 immobilized all cercariae within 15 s at 3.1 μg/mL. However, upon removal of the compound, 20% of the immobilized cercariae recovered after 24 h. In contrast, compound 6 immobilized cercariae within 12–14 min at 25 μg/mL. Following removal of the compound, all cercariae died within 24 h. The adult worms were also immobilized within 16 h by compounds 3 and 6 at 50 μg/mL. None of the compounds had an effect on the schistosomula stage.

  • isolation and characterization of stelladerol a new antioxidant naphthalene glycoside and other antioxidant glycosides from edible daylily Hemerocallis flowers
    Journal of Agricultural and Food Chemistry, 2002
    Co-Authors: Robert H Cichewicz, Muraleedharan G. Nair
    Abstract:

    Daylily (Hemerocallis spp.) flowers are utilized as an important ingredient in traditional Asian cuisine and are also valued for their reputed medicinal effects. In studies of the bioactive methanol and aqueous methanol extracts of lyophilized Hemerocallis cv. Stella de Oro flowers, kaempferol, quercetin, and isorhamnetin 3-O-glycosides (1−9), phenethyl β-d-glucopyranoside (10), orcinol β-d-glucopyranoside (11), phloretin 2‘-O-β-d-glucopyranoside (12), phloretin 2‘-O-β-d-xylopyranosyl-(1→6)-β-d-glucopyranoside (13), a new naphthalene glycoside, stelladerol (14), and an amino acid (longitubanine A) (15) have been isolated. All of these compounds were tested for their antioxidant and cyclooxygenase inhibitory activities. Stelladerol was found to possess strong antioxidant properties, inhibiting lipid oxidation by 94.6% ± 1.4 at 10 μM in an in vitro assay. Several of the flavonol 3-O-glycoside isolates also demonstrated modest antioxidant activities at 10 μM. None of the isolates inhibited cyclooxygenase act...