- (Methylsulfanyl)alkanoate ester biosynthesis in Actinidia chinensis kiwifruit and changes during cold storage
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Four 3-(methylsulfanyl)propionate esters, ethyl 3-(methylsulfanyl)prop-2-enoate, two 2-(methylsulfanyl)acetate esters and their possible precursors 2-(methylsulfanyl)ethanol, 3-(methylsulfanyl)propanol and 3-(methylsulfanyl)propanal were quantified from the headspace of Actinidia chinensis 'Hort 16A' kiwifruit pulp by GC-MS-TOF analysis. The majority of these compounds were specific for eating-ripe fruit and their levels increased in parallel with the climacteric rise in ethylene, accumulating towards the very soft end of the eating firmness. No ethylene production could be observed after long-term storage (4-6 months) at 1.5 °C and the levels of all methylsulfanyl-volatiles, except methional, declined by 98-100% during that period. This depletion of (methylsulfanyl)alkanoate-esters after prolonged cold storage points towards little flavour impact of these compounds on commercial 'Hort 16A' kiwifruits. However, ethyl 3-(methylsulfanyl)propionate is suggested to be odour active in ripe 'Hort 16A' fruit that has not been stored. Gene expression measured by q-RT PCR of six ripening-specific alcohol acyltransferase (AAT) expressed sequence tags and (methylsulfanyl)alkanoate-ester production of cell-free extracts were also significantly decreased after prolonged cold storage. However, (methylsulfanyl)alkanoate-ester synthesis of cell-free extracts and AAT gene transcript levels could be recovered by ethylene treatment after five months at 1.5 °C indicating that the biosynthesis of (methylsulfanyl)alkanoate-esters in 'Hort 16A' kiwifruit is likely to depend on ethylene-regulated AAT-gene expression. That the composition but not the concentration of (methylsulfanyl)alkanoate-esters in fresh fruit could be restored after ethylene treatment suggests that substrate availability might also have an impact on the final levels of these volatiles.
- Günther, Catrin S.,Matich, Adam J.,Marsh, Ken B.,Nicolau, Laura
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experimental part
p. 742 - 750
(2010/07/02)
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- Pronounced catalytic effect of a micellar solution of sodium dodecyl sulfate (SDS) on the efficient C-S bond formation via an odorless thia-michael addition reaction through the in situ generation of S-alkylisothiouronium salts
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A pronounced catalytic effect of sodium dodecyl sulfate (SDS) was observed on the in situ production of 5-alkylisothiouronium salts via the reaction of primary, allyl and benzyl halides with thiourea in SDS droplets .Hydrolysis of the generated Salkylisot
- Firouzabadi, Habib,Iranpoor, Nasser,Abbasi, Mohammad
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experimental part
p. 755 - 766
(2009/11/30)
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- A facile generation of C-S bonds via one-pot, odourless and efficient thia-Michael addition reactions using alkyl, aryl or allyl halides, thiourea and electron-deficient alkenes in wet polyethylene glycol (PEG 200) under mild reaction conditions
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An efficient and odourless synthesis of thia-Michael adducts by the reaction of various organic halides (primary, secondary, tertiary, allylic, and benzylic), structurally diverse electron-deficient alkenes (ketones, esters, and acrylonitrile) and thioure
- Firouzabadi, Habib,Iranpoor, Nasser,Abbasi, Mohammad
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experimental part
p. 5293 - 5301
(2009/11/30)
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- Efficient synthesis of β-alkyl/arylsulfanyl carbonyl compounds by In-TMSCl-promoted cleavage of dialkyl/diaryl disulfides and subsequent Michael addition
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A convenient and efficient procedure for the synthesis of β-alkyl/arylsulfanyl carbonyl compounds has been developed by a simple one-pot reaction of dialkyl/diaryl sulfides with α,β-unsaturated aldehydes, ketones, carboxylic esters, and nitriles in presence of indium and trimethylsilyl chloride under sonication. Copyright Taylor & Francis Group, LLC.
- Ranu, Brindaban C.,Mandal, Tanmay
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p. 1517 - 1523
(2008/02/03)
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