The Experts below are selected from a list of 1065 Experts worldwide ranked by ideXlab platform

George Poinar - One of the best experts on this subject based on the ideXlab platform.

Fernando E Vega - One of the best experts on this subject based on the ideXlab platform.

Kenichi Kimura - One of the best experts on this subject based on the ideXlab platform.

  • yeast ca2 signal transduction inhibitors isolated from Dominican Amber prevent the degranulation of rbl 2h3 cells through the inhibition of ca2 influx
    Fitoterapia, 2016
    Co-Authors: Tomomi Abe, Miki Kobayashi, Yusuke Okawa, Tomoki Inui, Jun Yoshida, Hironori Higashio, Hisao Shinden, Shota Uesugi, Hiroyuki Koshino, Kenichi Kimura
    Abstract:

    A new norlabdane compound, named kujigAmberol has previously been isolated from Kuji Amber (but not from Baltic Amber) by activity guided fractionation. However, there has been no study of biological compounds in Dominican Amber. Biological activities were examined using the hypersensitive mutant yeast (zds1Δ erg3Δ pdr1Δ pdr3Δ) with respect to Ca(2+)-signal transduction, enzymes and rat basophilic leukemia (RBL)-2H3 cells. The structures were elucidated on the basis of spectral analysis including high resolution (HR)-EI-MS, 1D NMR and 2D NMR. Three diterpenoid compounds, 5(10)-halimen-15-oic acid (1), 3-cleroden-15-oic acid (2) and 8-labden-15-oic acid (3), which are different from the bioactive compounds in Kuji and Baltic Ambers, were isolated from Dominican Amber. They inhibited both calcineurin (CN) (IC50=40.0, 21.2 and 34.2μM) and glycogen synthase kinase-3β (GSK-3β) (IC50=48.9, 43.8 and 41.1μM) which are involved in the growth restored activity against the mutant yeast. The most abundant compound 2 showed inhibitory activity against both degranulation and Ca(2+)-influx in RBL-2H3 cells. The compounds having the growth restoring activity against the mutant yeast have potential as anti-allergic compounds.

  • yeast ca 2 signal transduction inhibitors isolated from Dominican Amber prevent the degranulation of rbl 2h3 cells through the inhibition of ca 2 influx
    Fitoterapia, 2016
    Co-Authors: Tomomi Abe, Miki Kobayashi, Yusuke Okawa, Tomoki Inui, Jun Yoshida, Hironori Higashio, Hisao Shinden, Shota Uesugi, Hiroyuki Koshino, Kenichi Kimura
    Abstract:

    A new norlabdane compound, named kujigAmberol has previously been isolated from Kuji Amber (but not from Baltic Amber) by activity guided fractionation. However, there has been no study of biological compounds in Dominican Amber. Biological activities were examined using the hypersensitive mutant yeast (zds1Δ erg3Δ pdr1Δ pdr3Δ) with respect to Ca(2+)-signal transduction, enzymes and rat basophilic leukemia (RBL)-2H3 cells. The structures were elucidated on the basis of spectral analysis including high resolution (HR)-EI-MS, 1D NMR and 2D NMR. Three diterpenoid compounds, 5(10)-halimen-15-oic acid (1), 3-cleroden-15-oic acid (2) and 8-labden-15-oic acid (3), which are different from the bioactive compounds in Kuji and Baltic Ambers, were isolated from Dominican Amber. They inhibited both calcineurin (CN) (IC50=40.0, 21.2 and 34.2μM) and glycogen synthase kinase-3β (GSK-3β) (IC50=48.9, 43.8 and 41.1μM) which are involved in the growth restored activity against the mutant yeast. The most abundant compound 2 showed inhibitory activity against both degranulation and Ca(2+)-influx in RBL-2H3 cells. The compounds having the growth restoring activity against the mutant yeast have potential as anti-allergic compounds.

Jochen Heinrichs - One of the best experts on this subject based on the ideXlab platform.

  • cheilolejeunea lamyi sp nov a fossil lejeuneaceae from miocene Dominican Amber
    Cryptogamie Bryologie, 2018
    Co-Authors: Jochen Heinrichs, Alfons Schaferverwimp, Matthew A M Renner, Kathrin Feldberg
    Abstract:

    An inclusion in Miocene Dominican Amber is described as Cheilolejeunea lamyi, sp. nov. The fossil resembles the extant Cheilolejeunea rigidula but differs in the partly subacute leaf lobes, often apiculate underleaf lobes, and the slightly more acute lobes of the bracteole. The two other Cheilolejeunea species in Dominican Amber, Cheilolejeunea antiqua and C. suzannensis, have entire rather than bifid underleaves.

  • the leafy liverwort genus lejeunea porellales jungermanniopsida in miocene Dominican Amber
    Review of Palaeobotany and Palynology, 2017
    Co-Authors: Alfons Schaferverwimp, Alexander R Schmidt, Matthew A M Renner, Gaik Ee Lee, Julia Bechteler, Laura Kolberg, Jochen Heinrichs
    Abstract:

    Lejeunea is a morphologically diverse subcosmopolitan genus of predominantly epiphytic leafy liverworts. We describe three Lejeunea fossils preserved in Miocene Dominican Amber, Lejeunea hamatiloba sp. nov., L. resinata sp. nov. and L. urbanioides sp. nov., thereby increasing the Lejeunea fossil record to four species. The overall similarity of the fossils and extant species suggests the conservation of the generic composition of Caribbean epiphyte communities since the early Miocene, a pattern that was also confirmed for mosses and ferns.

  • a caribbean epiphyte community preserved in miocene Dominican Amber
    Earth and Environmental Science Transactions of The Royal Society of Edinburgh, 2016
    Co-Authors: Ulla Kaasalainen, Jochen Heinrichs, Alfons Schaferverwimp, Matthew A M Renner, Gaik Ee Lee, Lars Hedenas, Michael S Ignatov, Jouko Rikkinen, Alexander R Schmidt
    Abstract:

    Fossil tree resins preserve a wide range of animals, plants, fungi and microorganisms in microscopic fidelity. Fossil organisms preserved in an individual piece of Amber lived at the same time in Earth history and mostly even in the same habitat, but they were not necessarily parts of the same interacting community. Here, we report on an in situ preserved corticolous community from a piece of Miocene Dominican Amber which is composed of a lichen, a moss and three species of leafy liverworts. The lichen is assigned to the extant genus Phyllopsora (Ramalinaceae, Lecanoromycetes) and is described as P. magna Kaasalainen, Rikkinen & A. R. Schmidt sp. nov. The moss, Aptychellites fossilis Schaf.-Verw., Hedenas, Ignatov & Heinrichs gen. & sp. nov., closely resembles the extant genus Aptychella of the family Pylaisiadelphaceae. The three leafy liverworts comprise the extinct Lejeuneaceae species Cheilolejeunea antiqua (Grolle) Ye & Zhu, 2010 and Lejeunea miocenica Heinrichs, Schaf.-Verw., M. A. M. Renner & G. E. Lee sp. nov. and the extinct Radulaceae species Radula intecta M. A. M. Renner, Schaf.-Verw. & Heinrichs sp. nov. The presence of five associated extinct cryptogam species, four of which belong to extant genera, further substantiates the notion of a stasis in morphotype diversity, but a certain turnover of species, in the Caribbean since the early Miocene.

  • microlejeunea miocenica sp nov porellales jungermanniopsida in Dominican Amber the first fossil of a subcosmopolitan genus of leafy liverworts
    Review of Palaeobotany and Palynology, 2015
    Co-Authors: Gaik Ee Lee, Alfons Schaferverwimp, Julia Bechteler, Jochen Heinrichs
    Abstract:

    Abstract We describe a lejeuneoid liverwort preserved in Miocene Dominican Amber. The plants creep on bark, have zig-zagged stems, entire-margined suberect leaves with large lobules with a curved apical tooth at the free margin, small, bifid underleaves with forward-directed lobes, and winged female bracts. They are assigned to the extant genus Microlejeunea and classified as Microlejeunea miocenica sp. nov., representing the first fossil of this genus. So far 17 extant genera of Lejeuneaceae have been recognized in Dominican Amber, pointing to generic stasis of the regional epiphytic diversity since the Miocene.

  • a new Dominican Amber fossil of the derived fern genus pleopeltis confirms generic stasis in the epiphytic fern diversity of the west indies
    Organisms Diversity & Evolution, 2015
    Co-Authors: Harald Schneider, Alexander R Schmidt, Paul C Nascimbene, Jochen Heinrichs
    Abstract:

    One of the grand objectives in the integration of fossils and phylogenetics is to obtain support for macroecological and macroevolutionary hypotheses. Here, we provide new evidence from Dominican Amber fossils, which supports a likely stasis in the generic composition of epiphytic plant communities in the West Indies for at least 16 million years. The proposed hypothesis is based on the discovery of the first fossil of the Neotropical fern genus Pleopeltis. The relationships of this specimen to extant genera are studied using a dated phylogenetic framework to reconstruct the evolution of the characters preserved in the fossil, as well as by exploring the phylomorphospace of Pleopeltis. The fossil corroborates divergence time estimates obtained independently and also suggests the conservation of the generic composition of epiphytic communities. We discovered evidence for conserved morphotypes in the genus Pleopeltis occurring from the mid-Miocene to the present. The innovative use of phylomorphospace reconstruction provided crucial information about the affinities of the fossil. Rather than relying on reconstructing the evolution of single characters, this analysis integrates the evolution of all informative characters observed to evaluate relationships of the fossilized morphotype to extant morphotypes.

Tomomi Abe - One of the best experts on this subject based on the ideXlab platform.

  • yeast ca2 signal transduction inhibitors isolated from Dominican Amber prevent the degranulation of rbl 2h3 cells through the inhibition of ca2 influx
    Fitoterapia, 2016
    Co-Authors: Tomomi Abe, Miki Kobayashi, Yusuke Okawa, Tomoki Inui, Jun Yoshida, Hironori Higashio, Hisao Shinden, Shota Uesugi, Hiroyuki Koshino, Kenichi Kimura
    Abstract:

    A new norlabdane compound, named kujigAmberol has previously been isolated from Kuji Amber (but not from Baltic Amber) by activity guided fractionation. However, there has been no study of biological compounds in Dominican Amber. Biological activities were examined using the hypersensitive mutant yeast (zds1Δ erg3Δ pdr1Δ pdr3Δ) with respect to Ca(2+)-signal transduction, enzymes and rat basophilic leukemia (RBL)-2H3 cells. The structures were elucidated on the basis of spectral analysis including high resolution (HR)-EI-MS, 1D NMR and 2D NMR. Three diterpenoid compounds, 5(10)-halimen-15-oic acid (1), 3-cleroden-15-oic acid (2) and 8-labden-15-oic acid (3), which are different from the bioactive compounds in Kuji and Baltic Ambers, were isolated from Dominican Amber. They inhibited both calcineurin (CN) (IC50=40.0, 21.2 and 34.2μM) and glycogen synthase kinase-3β (GSK-3β) (IC50=48.9, 43.8 and 41.1μM) which are involved in the growth restored activity against the mutant yeast. The most abundant compound 2 showed inhibitory activity against both degranulation and Ca(2+)-influx in RBL-2H3 cells. The compounds having the growth restoring activity against the mutant yeast have potential as anti-allergic compounds.

  • yeast ca 2 signal transduction inhibitors isolated from Dominican Amber prevent the degranulation of rbl 2h3 cells through the inhibition of ca 2 influx
    Fitoterapia, 2016
    Co-Authors: Tomomi Abe, Miki Kobayashi, Yusuke Okawa, Tomoki Inui, Jun Yoshida, Hironori Higashio, Hisao Shinden, Shota Uesugi, Hiroyuki Koshino, Kenichi Kimura
    Abstract:

    A new norlabdane compound, named kujigAmberol has previously been isolated from Kuji Amber (but not from Baltic Amber) by activity guided fractionation. However, there has been no study of biological compounds in Dominican Amber. Biological activities were examined using the hypersensitive mutant yeast (zds1Δ erg3Δ pdr1Δ pdr3Δ) with respect to Ca(2+)-signal transduction, enzymes and rat basophilic leukemia (RBL)-2H3 cells. The structures were elucidated on the basis of spectral analysis including high resolution (HR)-EI-MS, 1D NMR and 2D NMR. Three diterpenoid compounds, 5(10)-halimen-15-oic acid (1), 3-cleroden-15-oic acid (2) and 8-labden-15-oic acid (3), which are different from the bioactive compounds in Kuji and Baltic Ambers, were isolated from Dominican Amber. They inhibited both calcineurin (CN) (IC50=40.0, 21.2 and 34.2μM) and glycogen synthase kinase-3β (GSK-3β) (IC50=48.9, 43.8 and 41.1μM) which are involved in the growth restored activity against the mutant yeast. The most abundant compound 2 showed inhibitory activity against both degranulation and Ca(2+)-influx in RBL-2H3 cells. The compounds having the growth restoring activity against the mutant yeast have potential as anti-allergic compounds.