121007-18-9Relevant academic research and scientific papers
Dying-arm disease in grapevines: Diagnosis of infection with Eutypa lata by metabolite analysis
Mahoney, Noreen,Molyneux, Russell J.,Smith, Leverett R.,Schoch, Thomas K.,Rolshausen, Philippe E.,Gubler, W. Douglas
, p. 8148 - 8155 (2007/10/03)
Dying-arm disease in grapevines, produced by infection with the ascomycete Eutypa lata, is responsible for major production losses in vineyards. Dieback of the shoots and cordon is believed to be due to acetylenic phenol metabolites produced by the fungus. To identify specific metabolites that could potentially be used for diagnosis of infection, eight E. lata isolates were grown in vitro on hot water extracts from grape varieties with various degrees of tolerance to the foliar symptoms of E. lata dieback. HPLC analysis showed that eutypinol was consistently produced in large amounts, together with smaller amounts of methyleutypinol and eulatachromene; eutypine, the putative toxin, was produced solely on Sauvignon Blanc extract and then in only barely detectable amounts. When E. lata isolates from Cabernet Sauvignon and Merlot were grown on identical media, the amounts of metabolites produced differed significantly between isolates but the pattern of metabolites was quite similar, with eutypinol again predominating. The consistent production of eutypinol indicated that this was the most suitable metabolite for which to analyze in order to diagnose the presence of E. lata. Extraction and analysis of grapevine tissues exhibiting symptoms of dieback failed to show the presence of any metabolites. However, when infected cordon sections were placed in water and cultured for 5 days, eutypinol was readily detected in the aqueous solution; metabolites were not produced from uninfected tissue. This provides a method for detection of infected tissue and indicates that the toxic metabolites react at the point of production, disrupting the vascular structure and inhibiting transport of nutrients, rather than being translocated to tissues that exhibit symptoms.
Palladium-Catalyzed Arylation of Polar Organometallics Mediated by 9-Methoxy-9-Borabicyclononane: Suzuki Reactions of Extended Scope
Fuerstner, Alois,Seidel, Guenter
, p. 11165 - 11176 (2007/10/02)
An alternative way for performing Suzuki reactions is presented.The necessary borate is the actual nucleophile in these palladium catalyzed C-C-bond formations is prepared from 9-methoxy-9-borabicyclononane (9-OMe-9-BBN) and a polar organometallic reagent RM, and not as usually from a borane and a base.This approach allows cross couplings of aryl halides with e.g. alkynyl-, methyl-, or TMSCH2-groups, which were beyond the scope of the conventional Suzuki reaction.The method is highly chemoselective and turned out to be compatible with aldehyde-, amide-, ketone-, ester- and cyano functions as well as with basic nitrogen atoms in the substrates.It was applied to the synthesis of the acetylenic natural products junipal (9a) and eutypine methyl ether (10).Since 11B NMR studies revealed that the 9-OMe-9-BBN only serves as a shuttle for delivering the RM reagent but remains unchanged during the course of the reaction, it has been possible to device the first Suzuki-type reaction sub-stoichiometric in boron.This "catalytic" protocol was used to prepare compound 8 which is highly valuable for its chemoluminescence properties.
An Alternative Route to a Benzofuran Natural Product Dehydrotremetone
Hiroya, Kou,Hashimura, Kazuya,Ogasawara, Kunio
, p. 2463 - 2472 (2007/10/02)
Dehydrotremetone, a toxic ketone isolated from the weeds Eupatorium urticaefolium and Aplopappus heterophyllus, has been synthesized from isovanillin via palladium-mediated cross-coupling reaction and lithium chloride-mediated concurrent demethylation-ben
The Synthesis of Natural Acetylenic Compounds from Eutypa lata (Pers:F.) TUL.
Defranq, Eric,Zesiger, Thierry,Tabacchi, Raffaele
, p. 425 - 430 (2007/10/02)
The synthesis of a series of novel acetylenic compounds 1-7, isolated recently from the fungus Eutypa lata, is described.The crucial step is the coupling reaction between protected aryl halogenide and the acetylenic chain as a cuprous acetylide (Scheme I).A more efficient method using bis(triphenylphosphine)palladium dichloride () as catalyst was also carried out with success.
