The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Garth L Wilkes - One of the best experts on this subject based on the ideXlab platform.
-
in situ photo cross linking of Cinnamate functionalized poly methyl methacrylate co 2 hydroxyethyl acrylate fibers during electrospinning
Macromolecules, 2004Co-Authors: Pankaj Gupta, Scott R. Trenor, Timothy E. Long, Garth L WilkesAbstract:A novel methodology for in situ cross-linking of polymeric fibers during electrospinning is described. The electrospinning apparatus was modified to facilitate UV irradiation of the electrospun fibers while in flight to the collector target. Three polymers with different mol % of the photoreactive Cinnamate functional group (4, 9, and 13 mol %) were synthesized and utilized for this study. Fibers of Cinnamate functionalized poly(methyl methacrylate-co-2-hydroxyethyl acrylate) were cross-linked in situ by UV irradiation during electrospinning. Subsequent FTIR measurements on irradiated and nonirradiated electrospun fibers indicated both [2π + 2π] cycloaddition of the vinylene CC and trans−cis photoisomerization of the Cinnamate group. Furthermore, the irradiated copolymers were observed to form insoluble gels which indicated that the photodimerization was the primary photoprocess during UV irradiation, leading to the formation of a cross-linked network. As expected, it was found that the gel fraction incre...
-
In situ photo-cross-linking of Cinnamate functionalized poly(methyl methacrylate-co-2-hydroxyethyl acrylate) fibers during electrospinning
Macromolecules, 2004Co-Authors: Pankaj Gupta, Scott R. Trenor, Timothy E. Long, Garth L WilkesAbstract:A novel methodology for in situ cross-linking of polymeric fibers during electrospinning is described. The electrospinning apparatus was modified to facilitate UV irradiation of the electrospun fibers while in flight to the collector target. Three polymers with different mol % of the photoreactive Cinnamate functional group (4, 9, and 13 mol %) were synthesized and utilized for this study. Fibers of Cinnamate functionalized poly(methyl methacrylate-co-2-hydroxyethyl acrylate) were cross-linked in situ by UV irradiation during electrospinning. Subsequent FTIR measurements on irradiated and nonirradiated electrospun fibers indicated both [2π + 2π] cycloaddition of the vinylene CC and trans?cis photoisomerization of the Cinnamate group. Furthermore, the irradiated copolymers were observed to form insoluble gels which indicated that the photodimerization was the primary photoprocess during UV irradiation, leading to the formation of a cross-linked network. As expected, it was found that the gel fraction increased with increasing mol % of the Cinnamate species. A novel methodology for in situ cross-linking of polymeric fibers during electrospinning is described. The electrospinning apparatus was modified to facilitate UV irradiation of the electrospun fibers while in flight to the collector target. Three polymers with different mol % of the photoreactive Cinnamate functional group (4, 9, and 13 mol %) were synthesized and utilized for this study. Fibers of Cinnamate functionalized poly(methyl methacrylate-co-2-hydroxyethyl acrylate) were cross-linked in situ by UV irradiation during electrospinning. Subsequent FTIR measurements on irradiated and nonirradiated electrospun fibers indicated both [2π + 2π] cycloaddition of the vinylene CC and trans?cis photoisomerization of the Cinnamate group. Furthermore, the irradiated copolymers were observed to form insoluble gels which indicated that the photodimerization was the primary photoprocess during UV irradiation, leading to the formation of a cross-linked network. As expected, it was found that the gel fraction increased with increasing mol % of the Cinnamate species.
Pankaj Gupta - One of the best experts on this subject based on the ideXlab platform.
-
in situ photo cross linking of Cinnamate functionalized poly methyl methacrylate co 2 hydroxyethyl acrylate fibers during electrospinning
Macromolecules, 2004Co-Authors: Pankaj Gupta, Scott R. Trenor, Timothy E. Long, Garth L WilkesAbstract:A novel methodology for in situ cross-linking of polymeric fibers during electrospinning is described. The electrospinning apparatus was modified to facilitate UV irradiation of the electrospun fibers while in flight to the collector target. Three polymers with different mol % of the photoreactive Cinnamate functional group (4, 9, and 13 mol %) were synthesized and utilized for this study. Fibers of Cinnamate functionalized poly(methyl methacrylate-co-2-hydroxyethyl acrylate) were cross-linked in situ by UV irradiation during electrospinning. Subsequent FTIR measurements on irradiated and nonirradiated electrospun fibers indicated both [2π + 2π] cycloaddition of the vinylene CC and trans−cis photoisomerization of the Cinnamate group. Furthermore, the irradiated copolymers were observed to form insoluble gels which indicated that the photodimerization was the primary photoprocess during UV irradiation, leading to the formation of a cross-linked network. As expected, it was found that the gel fraction incre...
-
In situ photo-cross-linking of Cinnamate functionalized poly(methyl methacrylate-co-2-hydroxyethyl acrylate) fibers during electrospinning
Macromolecules, 2004Co-Authors: Pankaj Gupta, Scott R. Trenor, Timothy E. Long, Garth L WilkesAbstract:A novel methodology for in situ cross-linking of polymeric fibers during electrospinning is described. The electrospinning apparatus was modified to facilitate UV irradiation of the electrospun fibers while in flight to the collector target. Three polymers with different mol % of the photoreactive Cinnamate functional group (4, 9, and 13 mol %) were synthesized and utilized for this study. Fibers of Cinnamate functionalized poly(methyl methacrylate-co-2-hydroxyethyl acrylate) were cross-linked in situ by UV irradiation during electrospinning. Subsequent FTIR measurements on irradiated and nonirradiated electrospun fibers indicated both [2π + 2π] cycloaddition of the vinylene CC and trans?cis photoisomerization of the Cinnamate group. Furthermore, the irradiated copolymers were observed to form insoluble gels which indicated that the photodimerization was the primary photoprocess during UV irradiation, leading to the formation of a cross-linked network. As expected, it was found that the gel fraction increased with increasing mol % of the Cinnamate species. A novel methodology for in situ cross-linking of polymeric fibers during electrospinning is described. The electrospinning apparatus was modified to facilitate UV irradiation of the electrospun fibers while in flight to the collector target. Three polymers with different mol % of the photoreactive Cinnamate functional group (4, 9, and 13 mol %) were synthesized and utilized for this study. Fibers of Cinnamate functionalized poly(methyl methacrylate-co-2-hydroxyethyl acrylate) were cross-linked in situ by UV irradiation during electrospinning. Subsequent FTIR measurements on irradiated and nonirradiated electrospun fibers indicated both [2π + 2π] cycloaddition of the vinylene CC and trans?cis photoisomerization of the Cinnamate group. Furthermore, the irradiated copolymers were observed to form insoluble gels which indicated that the photodimerization was the primary photoprocess during UV irradiation, leading to the formation of a cross-linked network. As expected, it was found that the gel fraction increased with increasing mol % of the Cinnamate species.
Timothy E. Long - One of the best experts on this subject based on the ideXlab platform.
-
in situ photo cross linking of Cinnamate functionalized poly methyl methacrylate co 2 hydroxyethyl acrylate fibers during electrospinning
Macromolecules, 2004Co-Authors: Pankaj Gupta, Scott R. Trenor, Timothy E. Long, Garth L WilkesAbstract:A novel methodology for in situ cross-linking of polymeric fibers during electrospinning is described. The electrospinning apparatus was modified to facilitate UV irradiation of the electrospun fibers while in flight to the collector target. Three polymers with different mol % of the photoreactive Cinnamate functional group (4, 9, and 13 mol %) were synthesized and utilized for this study. Fibers of Cinnamate functionalized poly(methyl methacrylate-co-2-hydroxyethyl acrylate) were cross-linked in situ by UV irradiation during electrospinning. Subsequent FTIR measurements on irradiated and nonirradiated electrospun fibers indicated both [2π + 2π] cycloaddition of the vinylene CC and trans−cis photoisomerization of the Cinnamate group. Furthermore, the irradiated copolymers were observed to form insoluble gels which indicated that the photodimerization was the primary photoprocess during UV irradiation, leading to the formation of a cross-linked network. As expected, it was found that the gel fraction incre...
-
In situ photo-cross-linking of Cinnamate functionalized poly(methyl methacrylate-co-2-hydroxyethyl acrylate) fibers during electrospinning
Macromolecules, 2004Co-Authors: Pankaj Gupta, Scott R. Trenor, Timothy E. Long, Garth L WilkesAbstract:A novel methodology for in situ cross-linking of polymeric fibers during electrospinning is described. The electrospinning apparatus was modified to facilitate UV irradiation of the electrospun fibers while in flight to the collector target. Three polymers with different mol % of the photoreactive Cinnamate functional group (4, 9, and 13 mol %) were synthesized and utilized for this study. Fibers of Cinnamate functionalized poly(methyl methacrylate-co-2-hydroxyethyl acrylate) were cross-linked in situ by UV irradiation during electrospinning. Subsequent FTIR measurements on irradiated and nonirradiated electrospun fibers indicated both [2π + 2π] cycloaddition of the vinylene CC and trans?cis photoisomerization of the Cinnamate group. Furthermore, the irradiated copolymers were observed to form insoluble gels which indicated that the photodimerization was the primary photoprocess during UV irradiation, leading to the formation of a cross-linked network. As expected, it was found that the gel fraction increased with increasing mol % of the Cinnamate species. A novel methodology for in situ cross-linking of polymeric fibers during electrospinning is described. The electrospinning apparatus was modified to facilitate UV irradiation of the electrospun fibers while in flight to the collector target. Three polymers with different mol % of the photoreactive Cinnamate functional group (4, 9, and 13 mol %) were synthesized and utilized for this study. Fibers of Cinnamate functionalized poly(methyl methacrylate-co-2-hydroxyethyl acrylate) were cross-linked in situ by UV irradiation during electrospinning. Subsequent FTIR measurements on irradiated and nonirradiated electrospun fibers indicated both [2π + 2π] cycloaddition of the vinylene CC and trans?cis photoisomerization of the Cinnamate group. Furthermore, the irradiated copolymers were observed to form insoluble gels which indicated that the photodimerization was the primary photoprocess during UV irradiation, leading to the formation of a cross-linked network. As expected, it was found that the gel fraction increased with increasing mol % of the Cinnamate species.
Scott R. Trenor - One of the best experts on this subject based on the ideXlab platform.
-
in situ photo cross linking of Cinnamate functionalized poly methyl methacrylate co 2 hydroxyethyl acrylate fibers during electrospinning
Macromolecules, 2004Co-Authors: Pankaj Gupta, Scott R. Trenor, Timothy E. Long, Garth L WilkesAbstract:A novel methodology for in situ cross-linking of polymeric fibers during electrospinning is described. The electrospinning apparatus was modified to facilitate UV irradiation of the electrospun fibers while in flight to the collector target. Three polymers with different mol % of the photoreactive Cinnamate functional group (4, 9, and 13 mol %) were synthesized and utilized for this study. Fibers of Cinnamate functionalized poly(methyl methacrylate-co-2-hydroxyethyl acrylate) were cross-linked in situ by UV irradiation during electrospinning. Subsequent FTIR measurements on irradiated and nonirradiated electrospun fibers indicated both [2π + 2π] cycloaddition of the vinylene CC and trans−cis photoisomerization of the Cinnamate group. Furthermore, the irradiated copolymers were observed to form insoluble gels which indicated that the photodimerization was the primary photoprocess during UV irradiation, leading to the formation of a cross-linked network. As expected, it was found that the gel fraction incre...
-
In situ photo-cross-linking of Cinnamate functionalized poly(methyl methacrylate-co-2-hydroxyethyl acrylate) fibers during electrospinning
Macromolecules, 2004Co-Authors: Pankaj Gupta, Scott R. Trenor, Timothy E. Long, Garth L WilkesAbstract:A novel methodology for in situ cross-linking of polymeric fibers during electrospinning is described. The electrospinning apparatus was modified to facilitate UV irradiation of the electrospun fibers while in flight to the collector target. Three polymers with different mol % of the photoreactive Cinnamate functional group (4, 9, and 13 mol %) were synthesized and utilized for this study. Fibers of Cinnamate functionalized poly(methyl methacrylate-co-2-hydroxyethyl acrylate) were cross-linked in situ by UV irradiation during electrospinning. Subsequent FTIR measurements on irradiated and nonirradiated electrospun fibers indicated both [2π + 2π] cycloaddition of the vinylene CC and trans?cis photoisomerization of the Cinnamate group. Furthermore, the irradiated copolymers were observed to form insoluble gels which indicated that the photodimerization was the primary photoprocess during UV irradiation, leading to the formation of a cross-linked network. As expected, it was found that the gel fraction increased with increasing mol % of the Cinnamate species. A novel methodology for in situ cross-linking of polymeric fibers during electrospinning is described. The electrospinning apparatus was modified to facilitate UV irradiation of the electrospun fibers while in flight to the collector target. Three polymers with different mol % of the photoreactive Cinnamate functional group (4, 9, and 13 mol %) were synthesized and utilized for this study. Fibers of Cinnamate functionalized poly(methyl methacrylate-co-2-hydroxyethyl acrylate) were cross-linked in situ by UV irradiation during electrospinning. Subsequent FTIR measurements on irradiated and nonirradiated electrospun fibers indicated both [2π + 2π] cycloaddition of the vinylene CC and trans?cis photoisomerization of the Cinnamate group. Furthermore, the irradiated copolymers were observed to form insoluble gels which indicated that the photodimerization was the primary photoprocess during UV irradiation, leading to the formation of a cross-linked network. As expected, it was found that the gel fraction increased with increasing mol % of the Cinnamate species.
Youngho Park - One of the best experts on this subject based on the ideXlab platform.
-
kojyl Cinnamate ester derivatives promote adiponectin production during adipogenesis in human adipose tissue derived mesenchymal stem cells
Bioorganic & Medicinal Chemistry Letters, 2014Co-Authors: Soo Hyun Hong, Jongho Park, Hyo Il Jung, Youngho Park, Song Seok ShinAbstract:Abstract The subcutaneous fat tissue mass gradually decreases with age, and its regulation is a strategy to develop anti-aging compounds to ameliorate the photo-aging of human skin. The adipogenesis of human adipose tissue-mesenchymal stem cells (hAT-MSCs) can be used as a model to discover novel anti-aging compounds. Cinnamomum cassia methanol extracts were identified as adipogenesis-promoting agents by natural product library screening. Cinnamates, the major chemical components of Cinnamomum cassia extracts, promoted adipogenesis in hAT-MSCs. We synthesized kojyl Cinnamate ester derivatives to improve the pharmacological activity of Cinnamates. Structure–activity studies of kojyl Cinnamate derivatives showed that both the α,β-unsaturated carbonyl ester group and the kojic acid moiety play core roles in promoting adiponectin production during adipogenesis in hAT-MSCs. We conclude that kojyl Cinnamate ester derivatives provide novel pharmacophores that can regulate adipogenesis in hAT-MSCs.
-
depigmenting activity of new kojic acid derivative obtained as a side product in the synthesis of Cinnamate of kojic acid
Bioorganic & Medicinal Chemistry Letters, 2012Co-Authors: Heung Soo Baek, Song Seok Shin, Yong Deog Hong, Jong Woo Cheon, Youngho ParkAbstract:Abstract We synthesized Cinnamate derivatives of kojic acid for use as depigmenting agents by various esterification methods. The Cinnamate of 5-position of kojic acid ( 6 ) was obtained by EDC coupling, DCC coupling, acid chloride, and mixed anhydride methods. To obtain the Cinnamate of the 2-position of kojic acid ( 7 ), we carried out the nucleophilic addition of the potassium salt of cinnamic acid to kojyl chloride. In this reaction, we discovered the occurrence of a side reaction and identified the structure of the side product thus formed. We evaluated the depigmenting activities of both the side product and the Cinnamate derivatives of kojic acid. Interestingly, the side product ( 11 ) showed more potent depigmenting activity (IC 50 = 23.51 μM) than compound 7 (IC 50 >100 μM) which is the mother compound of the side product. However, it has no tyrosinase inhibitory activity. Compound 6 , the Cinnamate of 5-position of kojic acid, also showed moderate depigmenting activity (IC 50 = 46.64 μM) without tyrosinase inhibitory activity. Production of this side product ( 11 ) may have originated from the proton exchange between the potassium salt of cinnamic acid and kojyl chloride. We then efficiently reduced the yield of the side product by controlling the equilibrium of the potassium salt of cinnamic acid. The addition of cinnamic acid greatly reduced the amount of the side product produced.