01512nas a2200169 4500008004100000022001400041245015600055210006900211260000800280300001400288490000700302520082800309100002201137700003201159700002201191856012901213 2023 eng d a0022-326300aBi(III)-catalyzed synthesis of substituted furans from hydroxy-oxetanyl ketones: application to unified total synthesis of shikonofurans J, D, E, and C0 aBiIIIcatalyzed synthesis of substituted furans from hydroxyoxeta cMAY a7328-73460 v883 a

We report an improved synthetic protocol for hydroxymethyl-derivedpolysubstituted furans employing Bi-(III)-catalyzed dehydrative cycloisomerizationof alpha-hydroxy oxetanyl ketones. This procedure provides rapidaccess (within 5 min) to highly substituted furans with exceptionalfunctional group diversity, excellent yields, generality, scalability,and operationally simple reaction conditions. Further, it demonstratedthe utility of this method in the first enantioselective total synthesisof furyl-hydroquinone-derived biologically potent natural productsshikonofurans J, D, E, and C in seven linear steps, starting fromreadily available building blocks of 2,5-dihydroxy acetophenone and3-oxetanone employing chiral-phosphoric acid (TRIP)-catalyzed asymmetricprenylation as a key step to induce the chirality.

1 aKataria, Priyanka1 aSahoo, Shubhranshu, Shekhar1 aKontham, Ravindar uhttps://library.ncl.res.in/content/biiii-catalyzed-synthesis-substituted-furans-hydroxy-oxetanyl-ketones-application-unified02322nas a2200253 4500008004100000022001400041245014300055210006900198260000800267490000800275520140100283653001701684653003701701653001401738653002501752653001901777100002301796700003201819700002101851700002501872700002201897700002001919856012901939 2024 eng d a0965-174800aAminoacylase efficiently hydrolyses fatty acid amino acid conjugates of Helicoverpa armigera potentially to increase the pool of glutamine0 aAminoacylase efficiently hydrolyses fatty acid amino acid conjug cFEB0 v1653 a

One of the most prevalent bioactive molecules present in the oral secretion (OS) of lepidopteran insects is fatty acid amino acid conjugates (FACs). Insect dietary components have influence on the synthesis and retaining the pool of FACs in the OS. We noted differential and diet-specific accumulation of FACs in the OS of Helicoverpa armigera by using Liquid Chromatography-Quadrupole Time of Flight Mass Spectrometry. Interestingly, we identified FACs hydrolyzing enzyme aminoacylase (HaACY) in the OS of H. armigera through proteomic analysis. Next, we have cloned, expressed, and purified active recombinant HaACY in the bacterial system. Recombinant HaACY hydrolyzes all the six identified FACs in the OS of H. armigera larvae fed on host and non-host plants and releases respective fatty acid and glutamine. In these six FACs, fatty acid moieties vary while amino acid glutamine was common. Glutamine obtained upon hydrolysis of FACs by HaACY might serve as an amino acid pool for insect growth and development. To understand the substrate choices of HaACY, we chemically synthesized, purified, and characterized all the six FACs. Interestingly, rHaACY also shows hydrolysis of synthetic FACs into respective fatty acid and glutamine. Our results underline the importance of diet on accumulation of FACs and role of aminoacylase(s) in regulating the level of FACs and glutamine.

10aAminoacylase10aFatty acid amino acid conjugates10aGlutamine10aHelicoverpa armigera10aOral secretion1 aKallure, Gopal, S.1 aSahoo, Shubhranshu, Shekhar1 aKale, Rutuja, S.1 aBarvkar, Vitthal, T.1 aKontham, Ravindar1 aGiri, Ashok, P. uhttps://library.ncl.res.in/content/aminoacylase-efficiently-hydrolyses-fatty-acid-amino-acid-conjugates-helicoverpa-armigera02021nas a2200169 4500008004100000022001400041245012400055210006900179260000900248300001400257490000700271520137100278100003201649700002201681700002201703856012601725 2024 eng d a1477-052000aConcise and collective total syntheses of 2,4-disubstituted furan-derived natural products from hydroxyoxetanyl ketones0 aConcise and collective total syntheses of 24disubstituted furand cFEB  a1475-14830 v223 a

The furan moiety, prevalent in bioactive natural products and essential drugs, presents intriguing structural features that have spurred our exploration into streamlined chemical synthesis routes for related natural products. In this study, we demonstrate the concise total synthesis of eight 2,4-disubstituted furan-derived natural products (including methylfuroic acid, rabdoketones A and B, paleofurans A and B, tournefolin C, and shikonofurans A and B). Our methodology revolves around the utilization of hydroxyoxetanyl ketones as pivotal intermediates. The approach encompasses transformations such as selective organo-catalyzed cross-ketol addition, synthesis of hydroxymethyl-tethered furans through Bi(OTf)3 catalyzed dehydrative cycloisomerization of alpha-hydroxyoxetanyl ketones, and a hydrogen atom transfer (HAT)-mediated oxidation of primary alcohols into the corresponding acids. This comprehensive synthetic strategy highlights the versatility of hydroxyoxetanyl ketones as invaluable building blocks in the synthesis of furan-containing natural products. A unified total synthesis of eight 2,4-disubstituted furan-derived natural products has been achieved through Bi(iii)-catalyzed cascade cycloisomerization of alpha-hydroxyoxetanyl ketones and hydrogen atom transfer-mediated oxidation of primary alcohols as pivotal transformations.

1 aSahoo, Shubhranshu, Shekhar1 aKataria, Priyanka1 aKontham, Ravindar uhttps://library.ncl.res.in/content/concise-and-collective-total-syntheses-24-disubstituted-furan-derived-natural-products