植物の屈性現象機構解明に関する生物有機化学的研究

科学研究費助成事業 研究成果報告書：基盤研究(C)2015-2017課題番号 : 15K0740

Structure-Activity Relationship of Acetylenes from Galls of Hedera rhombea as Plant Growth Inhibitors

The structure-activity relationship of 12 isolated acetylenes from galls of Hedera rhombea (Araliaceae) induced by Asphondylia sp. (Cecidomyiidae) and their derivatives has been studied for the inhibition of the shoot and root growth of rice, perennial ryegrass, cockscomb, lettuce, and cress. Almost all acetylenes generally showed growth inhibitory activity. The diacetylenes exhibited higher activity than the monoacetylenes, suggesting that a conjugated diyne segment is essential for the activity. On the other hand, the acetylenes with a nonoxidated methylene group at C-8 showed stronger activity comparing with those possessing hydroxy and acetoxy groups at C-8. Furthermore, it has been demonstrated that the acetylenes bearing a terminal olefinic group at C-16,C-17 enhanced the activity. It is thus clarified that important sites for the activity of the acetylenes from galls of H. rhombea are a conjugated diyne and a terminal olefinic group connecting to the aliphatic chain and that less oxidated compounds show more activity

Comparative transcriptional profiling-based identification of raphanusanin-inducible genes

<p>Abstract</p> <p>Background</p> <p>Raphanusanin (Ra) is a light-induced growth inhibitor involved in the inhibition of hypocotyl growth in response to unilateral blue-light illumination in radish seedlings. Knowledge of the roles of Ra still remains elusive. To understand the roles of Ra and its functional coupling to light signalling, we constructed the Ra-induced gene library using the Suppression Subtractive Hybridisation (SSH) technique and present a comparative investigation of gene regulation in radish seedlings in response to short-term Ra and blue-light exposure.</p> <p>Results</p> <p>The predicted gene ontology (GO) term revealed that 55% of the clones in the Ra-induced gene library were associated with genes involved in common defence mechanisms, including thirty four genes homologous to <it>Arabidopsis </it>genes implicated in R-gene-triggered resistance in the programmed cell death (PCD) pathway. Overall, the library was enriched with transporters, hydrolases, protein kinases, and signal transducers. The transcriptome analysis revealed that, among the fifty genes from various functional categories selected from 88 independent genes of the Ra-induced library, 44 genes were up-regulated and 4 were down-regulated. The comparative analysis showed that, among the transcriptional profiles of 33 highly Ra-inducible genes, 25 ESTs were commonly regulated by different intensities and duration of blue-light irradiation. The transcriptional profiles, coupled with the transcriptional regulation of early blue light, have provided the functional roles of many genes expected to be involved in the light-mediated defence mechanism.</p> <p>Conclusions</p> <p>This study is the first comprehensive survey of transcriptional regulation in response to Ra. The results described herein suggest a link between Ra and cellular defence and light signalling, and thereby contribute to further our understanding of how Ra is involved in light-mediated mechanisms of plant defence.</p

Inhibitory Activity on Amyloid Aggregation of Rosmarinic Acid and Its Substructures From Isodon japonicus

Nowadays, the incidence of Alzheimer’s disease (AD) and type 2 diabetes (T2D) is increasing at an alarming rate. More and more studies have been investigating the relationship between these two diseases and are trying to find an effective treatment. According to amyloid hypothesis, it is very necessary to find phenolic compounds with catechol moieties, which would inhibit the aggregation of amyloid β (Aβ) and human islet amyloid polypeptide (hIAPP), while also exhibiting antioxidant activity and protective effect. We isolated rosmarinic acid (RA) from the plant Isodon japonicus (Burm.f.) H. Hara. Thioflavin T assay and transmission electron microscopy observation were carried out to evaluate the inhibitory effect of RA, caffeic acid, and 3,4-dihydroxyphenyllactic acid, which are the substructures of RA, on both Aβ and hIAPP fibrillization. 2,2-Diphenyl-1-picrylhydrazyl assay was applied to test the antioxidant activity. RA showed inhibitory effect on both peptides and strong antioxidant activity. These results suggest that the existence of catechol units plays an important role on the inhibitory activity. Therefore, RA will be a promising strategy to prevent AD and T2D

Methanol and Butanol Extracts of Paeonia lutea

Squamous cell carcinoma (SCC) is one of the most common cancers of the head and neck region worldwide and is generally treated surgically in combination with radiotherapy and/or chemotherapy. However, anticancer agents have numerous serious side effects, and alternative, less toxic agents that are effective as chemotherapeutics for SCC are required. The Paeoniaceae family is widely used in traditional Chinese medicine. We examined methanol and butanol extracts of Paeonia lutea (P. lutea) leaves for their potential as an anticancer agent. Both extracts decreased the proliferation of SCC cells, induced apoptotic cell death, and modulated migration, adhesion, chemotaxis, and haptotaxis in an extracellular matrix- (ECM-) dependent manner due to altered expression of several integrin subunits. Subsequently, SCC cells were subcutaneously transplanted into athymic nude mice; the extracts reduced the metastasis of SCC cells but had little effect on the volume of the primary tumor or survival or body weight of the mice. The results suggest that the extracts may hold promise for preventing cancer metastasis

Electrochemical preparation of an electroactive polymer poly(dodecyloxy dibenzothiophene) (polyDDBTh) from hydroxyl dibenzothiophene (HDBTh) as a bioconverted monomer

A combination of biotechnological and electrochemical techniques is employed to synthesize an electroactive π-conjugated polymer. The monomer precursor bearing a hydroxyl group is obtained by the bioconversion of dibenzothiophene. An alkyl chain substituent is introduced by Williamson etherification with the aid of crown ether, and electrochemical polymerization is carried out by repeated potential scanning of the monomer in an electrolytic reaction solution. The polymer film thus prepared is shown to exhibit good electroactive characteristics

Isolation and identification of polar auxin transport inhibitors from Saussurea costus and Atractylodes japonica

An intensive survey of naturally-occurring regulators of polar auxin transport (PAT) was conducted in two oriental medicinal species from the Asteraceae, Saussurea costus and Atractylodes japonica, using the radish hypocotyl bioassay system and physicochemical analyses. Costunolide and santamarine were identified as well as dehydrocostus lactone from S. costus roots, and atractylenolide II and (+)-eudesma-4(14),7(11)-dien-8-one from Atractylodes japonica rhizomes as physiologically novel compounds possessing inhibitory activities of PAT. Costunolide and santamarine showed ca. 40% inhibition of PAT in the radish hypocotyl segments at a dose of 2.5 μg/plant and 1 μg/plant, respectively. Inhibitory effects of atractylenolide II and (+)-eudesma-4(14),7(11)-dien-8-one were ca. 10 times lower than those of costunolide and santamarine. Structure–activity relationships and possible mechanisms to inhibit PAT are also discussed

Zróżnicowany wpływ kwasu 1-N-naftyloftalamowego (NPA) i kwasu 2,3,5-trójjodobenzoesowego (TIBA) w relacji do auksyny na grubienie pędu Bryophyllum calycinum

The effects of N-1-naphthylphthalamic acid (NPA) and 2,3,5-triiodobenzoic acid (TIBA) on the swelling of the stem in intact and decapitated plants of Bryophyllum calycinum in relation to the interaction with auxin, indole-3-acetic acid (IAA), are described. NPA induced conspicuous local internode swelling only in the area of its application in intact plants and in the decapitated internode in the case of simultaneous application of IAA on the top of the internode. By contrast, TIBA applied to an internode of intact plants induced swelling along the entire internode above the treatment area, and similar results were obtained in the decapitated internode when TIBA was applied in the middle of the internode and IAA was applied onto the top of the internode. The differential effect of NPA and TIBA on stem swelling in B. calycinum is discussed in relation to their differential mode of action on auxin transport.W pracy przedstawiono zróżnicowany wpływ kwasu 1-N-naftyloftalamowego (NPA) i kwasu 2,3,5-trójjodobenzoesowego (TIBA) na grubienie łodygi w całych i dekapitowanych roślinach B. calycinum w relacji do interakcji z auksyną, kwasem indolilo-3-octowym (IAA). NPA silnie indukował miejscowe grubienie łodygi tylko w miejscu jego traktowania w roślinach całych i w dekapitowanych międzywęźlach w przypadku jednoczesnego podania IAA na wierzchołek międzywęźla. Z drugiej strony, TIBA podany na środek międzywęźla całych roślin indukował grubienie łodygi wzdłuż całego międzywęźla powyżej miejsca traktowania i podobne wyniki otrzymano w międzywęźlach dekapitowanych kiedy TIBA podano na środek międzywęźla i jednocześnie IAA nałożono na wierzchołek dekapitowanego międzywęźla. Zróżnicowany wpływ NPA i TIBA na grubienie łodygi B. calycinum jest dyskutowany w relacji z ich zróżnicowanym mechanizmem działania na transport auksyny

Suffruyabiosides A and B, Two New Monoterpene Diglycosides from Moutan Cortex

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