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Armin Geyer - One of the best experts on this subject based on the ideXlab platform.
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scaling the amphiphilic character and antimicrobial activity of gramicidin s by dihydroxylation or ketal formation
Journal of Organic Chemistry, 2017Co-Authors: Christoph Priem, Marina Berditsch, Anne S. Ulrich, Andre Wuttke, Armin GeyerAbstract:The acid lability of Aliphatic ketals, which often serve as protection groups for 1,2-diols, is influenced by their local structural environment. The acetonide of the protected amino acid cis-dihydroxyproline (Dyp) is a typical protecting group cleavable by traces of TFA. The tricyclic acetonide of the dipeptide d-Hot═Tap is resistant to TFA and thus can serve as a bioorthogonal modification of bioactive peptides. With the aim of improving antimicrobial activity and hemolytic properties, we use these reactivity differences to scale the membrane affinity of the decapeptide Gramicidin S cyclo(d-Phe-Pro-Val-Orn-Leu-)2 (GS). The cis-dihydroxylated amino acids are used to increase the polarity of GS or obversely decrease the polarity by stereoselective ketal formation with an Aliphatic Ketone. While Dyp (GS mimetic 15) has only minimal influence on the biological properties of GS, d-Hot═Tap at the position of d-Phe1-Pro2 eradicates the biological activity (GS mimetic 16). The acid-stable ketals 17–19 are bioor...
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Scaling the Amphiphilic Character and Antimicrobial Activity of Gramicidin S by Dihydroxylation or Ketal Formation
2017Co-Authors: Christoph Priem, André Wuttke, Marina Berditsch, Anne S. Ulrich, Armin GeyerAbstract:The acid lability of Aliphatic ketals, which often serve as protection groups for 1,2-diols, is influenced by their local structural environment. The acetonide of the protected amino acid cis-dihydroxyproline (Dyp) is a typical protecting group cleavable by traces of TFA. The tricyclic acetonide of the dipeptide d-HotTap is resistant to TFA and thus can serve as a bioorthogonal modification of bioactive peptides. With the aim of improving antimicrobial activity and hemolytic properties, we use these reactivity differences to scale the membrane affinity of the decapeptide Gramicidin S cyclo(d-Phe-Pro-Val-Orn-Leu-)2 (GS). The cis-dihydroxylated amino acids are used to increase the polarity of GS or obversely decrease the polarity by stereoselective ketal formation with an Aliphatic Ketone. While Dyp (GS mimetic 15) has only minimal influence on the biological properties of GS, d-HotTap at the position of d-Phe1-Pro2 eradicates the biological activity (GS mimetic 16). The acid-stable ketals 17–19 are bioorthogonal modifications which reconstitute the biological activity of GS. We describe an improved synthesis of orthogonally protected Fmoc-Dyp-acetonide (9) and of several Fmoc-d-HotTap-ketals for solid-phase peptide synthesis
Christoph Priem - One of the best experts on this subject based on the ideXlab platform.
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scaling the amphiphilic character and antimicrobial activity of gramicidin s by dihydroxylation or ketal formation
Journal of Organic Chemistry, 2017Co-Authors: Christoph Priem, Marina Berditsch, Anne S. Ulrich, Andre Wuttke, Armin GeyerAbstract:The acid lability of Aliphatic ketals, which often serve as protection groups for 1,2-diols, is influenced by their local structural environment. The acetonide of the protected amino acid cis-dihydroxyproline (Dyp) is a typical protecting group cleavable by traces of TFA. The tricyclic acetonide of the dipeptide d-Hot═Tap is resistant to TFA and thus can serve as a bioorthogonal modification of bioactive peptides. With the aim of improving antimicrobial activity and hemolytic properties, we use these reactivity differences to scale the membrane affinity of the decapeptide Gramicidin S cyclo(d-Phe-Pro-Val-Orn-Leu-)2 (GS). The cis-dihydroxylated amino acids are used to increase the polarity of GS or obversely decrease the polarity by stereoselective ketal formation with an Aliphatic Ketone. While Dyp (GS mimetic 15) has only minimal influence on the biological properties of GS, d-Hot═Tap at the position of d-Phe1-Pro2 eradicates the biological activity (GS mimetic 16). The acid-stable ketals 17–19 are bioor...
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Scaling the Amphiphilic Character and Antimicrobial Activity of Gramicidin S by Dihydroxylation or Ketal Formation
2017Co-Authors: Christoph Priem, André Wuttke, Marina Berditsch, Anne S. Ulrich, Armin GeyerAbstract:The acid lability of Aliphatic ketals, which often serve as protection groups for 1,2-diols, is influenced by their local structural environment. The acetonide of the protected amino acid cis-dihydroxyproline (Dyp) is a typical protecting group cleavable by traces of TFA. The tricyclic acetonide of the dipeptide d-HotTap is resistant to TFA and thus can serve as a bioorthogonal modification of bioactive peptides. With the aim of improving antimicrobial activity and hemolytic properties, we use these reactivity differences to scale the membrane affinity of the decapeptide Gramicidin S cyclo(d-Phe-Pro-Val-Orn-Leu-)2 (GS). The cis-dihydroxylated amino acids are used to increase the polarity of GS or obversely decrease the polarity by stereoselective ketal formation with an Aliphatic Ketone. While Dyp (GS mimetic 15) has only minimal influence on the biological properties of GS, d-HotTap at the position of d-Phe1-Pro2 eradicates the biological activity (GS mimetic 16). The acid-stable ketals 17–19 are bioorthogonal modifications which reconstitute the biological activity of GS. We describe an improved synthesis of orthogonally protected Fmoc-Dyp-acetonide (9) and of several Fmoc-d-HotTap-ketals for solid-phase peptide synthesis
Madan M Gupta - One of the best experts on this subject based on the ideXlab platform.
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4α methyl 24β ethyl 5α cholesta 14 25 dien 3β ol and 24β ethylcholesta 5 9 11 22e trien 3β ol sterols from clerodendrum inerme
Phytochemistry, 2003Co-Authors: Richa Pandey, R K Verma, Subhash C Singh, Madan M GuptaAbstract:From the aerial parts of Clerodendrum inerme, two new sterols (4α-methyl-24β-ethyl-5α-cholesta-14, 25-dien-3β-ol and 24β-ethylcholesta-5, 9(11), 22E-trien-3β-ol) and a new Aliphatic Ketone (11-pentacosanone) were isolated together with another known Aliphatic Ketone (6-nonacosanone) and a diterpene (clerodermic acid). The structure elucidations were based on analyses of physical and spectroscopic data.
Anne S. Ulrich - One of the best experts on this subject based on the ideXlab platform.
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scaling the amphiphilic character and antimicrobial activity of gramicidin s by dihydroxylation or ketal formation
Journal of Organic Chemistry, 2017Co-Authors: Christoph Priem, Marina Berditsch, Anne S. Ulrich, Andre Wuttke, Armin GeyerAbstract:The acid lability of Aliphatic ketals, which often serve as protection groups for 1,2-diols, is influenced by their local structural environment. The acetonide of the protected amino acid cis-dihydroxyproline (Dyp) is a typical protecting group cleavable by traces of TFA. The tricyclic acetonide of the dipeptide d-Hot═Tap is resistant to TFA and thus can serve as a bioorthogonal modification of bioactive peptides. With the aim of improving antimicrobial activity and hemolytic properties, we use these reactivity differences to scale the membrane affinity of the decapeptide Gramicidin S cyclo(d-Phe-Pro-Val-Orn-Leu-)2 (GS). The cis-dihydroxylated amino acids are used to increase the polarity of GS or obversely decrease the polarity by stereoselective ketal formation with an Aliphatic Ketone. While Dyp (GS mimetic 15) has only minimal influence on the biological properties of GS, d-Hot═Tap at the position of d-Phe1-Pro2 eradicates the biological activity (GS mimetic 16). The acid-stable ketals 17–19 are bioor...
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Scaling the Amphiphilic Character and Antimicrobial Activity of Gramicidin S by Dihydroxylation or Ketal Formation
2017Co-Authors: Christoph Priem, André Wuttke, Marina Berditsch, Anne S. Ulrich, Armin GeyerAbstract:The acid lability of Aliphatic ketals, which often serve as protection groups for 1,2-diols, is influenced by their local structural environment. The acetonide of the protected amino acid cis-dihydroxyproline (Dyp) is a typical protecting group cleavable by traces of TFA. The tricyclic acetonide of the dipeptide d-HotTap is resistant to TFA and thus can serve as a bioorthogonal modification of bioactive peptides. With the aim of improving antimicrobial activity and hemolytic properties, we use these reactivity differences to scale the membrane affinity of the decapeptide Gramicidin S cyclo(d-Phe-Pro-Val-Orn-Leu-)2 (GS). The cis-dihydroxylated amino acids are used to increase the polarity of GS or obversely decrease the polarity by stereoselective ketal formation with an Aliphatic Ketone. While Dyp (GS mimetic 15) has only minimal influence on the biological properties of GS, d-HotTap at the position of d-Phe1-Pro2 eradicates the biological activity (GS mimetic 16). The acid-stable ketals 17–19 are bioorthogonal modifications which reconstitute the biological activity of GS. We describe an improved synthesis of orthogonally protected Fmoc-Dyp-acetonide (9) and of several Fmoc-d-HotTap-ketals for solid-phase peptide synthesis
Marina Berditsch - One of the best experts on this subject based on the ideXlab platform.
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scaling the amphiphilic character and antimicrobial activity of gramicidin s by dihydroxylation or ketal formation
Journal of Organic Chemistry, 2017Co-Authors: Christoph Priem, Marina Berditsch, Anne S. Ulrich, Andre Wuttke, Armin GeyerAbstract:The acid lability of Aliphatic ketals, which often serve as protection groups for 1,2-diols, is influenced by their local structural environment. The acetonide of the protected amino acid cis-dihydroxyproline (Dyp) is a typical protecting group cleavable by traces of TFA. The tricyclic acetonide of the dipeptide d-Hot═Tap is resistant to TFA and thus can serve as a bioorthogonal modification of bioactive peptides. With the aim of improving antimicrobial activity and hemolytic properties, we use these reactivity differences to scale the membrane affinity of the decapeptide Gramicidin S cyclo(d-Phe-Pro-Val-Orn-Leu-)2 (GS). The cis-dihydroxylated amino acids are used to increase the polarity of GS or obversely decrease the polarity by stereoselective ketal formation with an Aliphatic Ketone. While Dyp (GS mimetic 15) has only minimal influence on the biological properties of GS, d-Hot═Tap at the position of d-Phe1-Pro2 eradicates the biological activity (GS mimetic 16). The acid-stable ketals 17–19 are bioor...
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Scaling the Amphiphilic Character and Antimicrobial Activity of Gramicidin S by Dihydroxylation or Ketal Formation
2017Co-Authors: Christoph Priem, André Wuttke, Marina Berditsch, Anne S. Ulrich, Armin GeyerAbstract:The acid lability of Aliphatic ketals, which often serve as protection groups for 1,2-diols, is influenced by their local structural environment. The acetonide of the protected amino acid cis-dihydroxyproline (Dyp) is a typical protecting group cleavable by traces of TFA. The tricyclic acetonide of the dipeptide d-HotTap is resistant to TFA and thus can serve as a bioorthogonal modification of bioactive peptides. With the aim of improving antimicrobial activity and hemolytic properties, we use these reactivity differences to scale the membrane affinity of the decapeptide Gramicidin S cyclo(d-Phe-Pro-Val-Orn-Leu-)2 (GS). The cis-dihydroxylated amino acids are used to increase the polarity of GS or obversely decrease the polarity by stereoselective ketal formation with an Aliphatic Ketone. While Dyp (GS mimetic 15) has only minimal influence on the biological properties of GS, d-HotTap at the position of d-Phe1-Pro2 eradicates the biological activity (GS mimetic 16). The acid-stable ketals 17–19 are bioorthogonal modifications which reconstitute the biological activity of GS. We describe an improved synthesis of orthogonally protected Fmoc-Dyp-acetonide (9) and of several Fmoc-d-HotTap-ketals for solid-phase peptide synthesis