The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Peter Winterhalter - One of the best experts on this subject based on the ideXlab platform.
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Enzymatic carotenoid cleavage in star fruit (Averrhoa carambola).
Phytochemistry, 2003Co-Authors: Peter Fleischmann, Naoharu Watanabe, Peter WinterhalterAbstract:Abstract This paper presents the first description of an enzyme fraction exhibiting carotenoid cleavage activity isolated from fruit skin of Averrhoa carambola. Partial purification of the enzyme could be achieved by acetone precipitation, ultrafiltration (300 kDa, 50 kDa), isoelectric focusing (pH 3–10) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (7.5%). In this way, an enzymatically active protein fraction was obtained, consisting of four proteins in the molecular weight range of between 12 and 90 kDa. Using β-carotene as substrate, the enzyme activity was detected spectrophotometrically at 505 nm. The main reaction product, detected by GC analysis, was β-ionone. This proves that the isolated enzymes are closely related to aroma metabolism and release of star fruit. The time constant of the reaction was 16.6 min, the Michaelis Constant Km=3.6 μmol 1−1 and the maximum velocity Vmax=10.5×10−3 μmol l−1 s−1 mg(Protein)−1. The optimum temperature was 45 °C.
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The generation of norisoprenoid volatiles in starfruit (Averrhoa carambola L.): A review∗
Food Reviews International, 1995Co-Authors: Peter Winterhalter, Peter SchreierAbstract:Abstract This paper summarizes our studies on the formation of C13‐noriso‐prenoid aroma substances in starfruit (Averrhoa carambola L.). The finding that the majority of norisoprenoid volatiles in starfruit are derived from glycosidically bound progenitors stimulated more intense studies into the glycosidic fraction of the fruit. In this paper the isolation and structural elucidation of several novel C13‐ and C15‐norisoprenoid structures in starfruit is reported and the degradative pathways giving rise to the formation of potent starfruit aroma compounds are discussed. In the last part, attention is focused on possible pathways of carotenoid breakdown in starfruit, thus rationalizing the co‐occurrence of C13‐ and C15‐norisoprenoids with volatiles apparently derived from the central portion of the carotenoid chain.
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Dihydroabscisic alcohol from Averrhoa carambola fruit
Phytochemistry, 1994Co-Authors: Andrea Lutz, Peter WinterhalterAbstract:Abstract (1′ S ,4 E )-2,3-Dihydroabscisic alcohol has been identified in an ether extract of starfruit ( Averrhoa carambola ). After purification by multilayer coil countercurrent chromatography (MLCCC) and HPLC, the structure of the new ABA derivative was elucidated by 1 H and 13 C NMR spectroscopy.
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The Structure of a New Ionone Glucoside from Starfruit (Averrhoa carambola L.)
Natural Product Letters, 1993Co-Authors: Andrea Lutz, Peter Winterhalter, Peter SchreierAbstract:Abstract The 2-0-β-D-glucopyranoside of 4-(1′,4′-dihydroxy-2′,2′,6′-trimethylcyclohexyl)-but-3-en-2-ol 1a was isolated from the juice of Averrhoa carambola by XAD-2 adsorption and MeOH elution. After a preseparation of the crude glycosidic extract with multi-layer coil countercurrent chromatography the new natural product was peracetylated, purified by HPLC and characterized as its pentaacetate 1b.
Haihui Xie - One of the best experts on this subject based on the ideXlab platform.
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dihydrochalcone c glycosides from Averrhoa carambola leaves
Phytochemistry, 2020Co-Authors: Yue Yang, Haihui Xie, Xuchao Jia, Xiaoyi WeiAbstract:Abstract Ten undescribed dihydrochalcone C-glycosides, carambolasides R1‒R3, S1, S2, T1‒T3, 3-hydroxycarambolaside T1, and 3-hydroxycarambolaside P were isolated along with carambolasides I and P from the leaves of Averrhoa carambola L. (Oxalidaceae). Their structures were determined by spectroscopic and chemical methods. Among them, carambolasides P, T1, T2, and I with contents of 22.78, 14.39, 4.93, and 1.87 mg g−1 dry wt., respectively, were shown to be abundant in the leaves by HPLC analysis. All the compounds showed more potent ABTS radical cation scavenging activity than l -ascorbic acid. 3-Hydroxycarambolaside T1 and 3-hydroxycarambolaside P also demonstrated moderate DPPH radical scavenging activity. Further, carambolaside R3, 3-hydroxycarambolaside T1, and 3-hydroxycarambolaside P exhibited weak in vitro porcine pancreatic lipase inhibitory activity.
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carotenoid derived flavor precursors from Averrhoa carambola fresh fruit
Molecules, 2019Co-Authors: Xuchao Jia, Dan Yang, Yue Yang, Haihui XieAbstract:The fruit of Averrhoa carambola L. (Oxalidaceae), commonly known as star fruit or carambola, is popular in tropical and subtropical regions. Carotenoid-derived components, mainly C13- and C15-norisoprenoids, contribute greatly to the flavor of star fruit. Previously reported norisoprenoids were tentatively identified by GC-MS analysis after enzymatic hydrolysis. To gain accurate information about glycosidically bound flavor precursors in star fruit, a phytochemical study was conducted, which led to the isolation of 16 carotenoid derivatives—One new C13-norisoprenoid glucoside, (5R,6S,7E,9R)-5,6,9-trihydroxy-7-megastigmene 9-O-β-d-glucoside (1); one new C15-norisoprenoid, (6S,7E,10S)-Δ9,15-10-hydroxyabscisic alcohol (11); and 14 known ones, of which 12 were in glucoside form. The structures of the two new compounds were elucidated on the basis of extensive spectroscopic data analysis and chemical reaction. Compound 11 was a rare C15-norisoprenoid with a double bond between C-9 and C-15, and its possible biogenetic pathway was proposed. The known compounds were identified by comparison of their mass and nuclear magnetic resonance (NMR) data with those reported in the literature. The structure identification of one new (1) and seven known (3–7, 9, and 10) C13-norisoprenoid glucosides from the genus Averrhoa for the first time enriches the knowledge of carotenoid-derived flavor precursors in star fruit.
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Carotenoid-Derived Flavor Precursors from Averrhoa carambola Fresh Fruit
MDPI AG, 2019Co-Authors: Xuchao Jia, Dan Yang, Yue Yang, Haihui XieAbstract:The fruit of Averrhoa carambola L. (Oxalidaceae), commonly known as star fruit or carambola, is popular in tropical and subtropical regions. Carotenoid-derived components, mainly C13- and C15-norisoprenoids, contribute greatly to the flavor of star fruit. Previously reported norisoprenoids were tentatively identified by GC-MS analysis after enzymatic hydrolysis. To gain accurate information about glycosidically bound flavor precursors in star fruit, a phytochemical study was conducted, which led to the isolation of 16 carotenoid derivatives—One new C13-norisoprenoid glucoside, (5R,6S,7E,9R)-5,6,9-trihydroxy-7-megastigmene 9-O-β-d-glucoside (1); one new C15-norisoprenoid, (6S,7E,10S)-Δ9,15-10-hydroxyabscisic alcohol (11); and 14 known ones, of which 12 were in glucoside form. The structures of the two new compounds were elucidated on the basis of extensive spectroscopic data analysis and chemical reaction. Compound 11 was a rare C15-norisoprenoid with a double bond between C-9 and C-15, and its possible biogenetic pathway was proposed. The known compounds were identified by comparison of their mass and nuclear magnetic resonance (NMR) data with those reported in the literature. The structure identification of one new (1) and seven known (3–7, 9, and 10) C13-norisoprenoid glucosides from the genus Averrhoa for the first time enriches the knowledge of carotenoid-derived flavor precursors in star fruit
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Non-flavonoid phenolics from Averrhoa carambola fresh fruit
Journal of Functional Foods, 2017Co-Authors: Xuchao Jia, Dan Yang, Haihui Xie, Yueming Jiang, Xiaoyi WeiAbstract:Abstract The fruit of Averrhoa carambola L. (Oxalidaceae) is a commercially important fruit. Our study on the chemical constituents present in the fresh sweet fruit led to the isolation of eleven non-flavonoid phenolic compounds. Their structures were identified by analyses of spectroscopic data. They were two new alkyl phenol diglucosides, carambolasides K (1) and L (2), four phenylpropanoids, (+)-isolariciresinol 9-O-β- d -glucoside (3), (+)-lyoniresinol 9-O-β- d -glucoside (4), (−)-lyoniresinol 9-O-β- d -glucoside (5), and 1-O-feruloyl-β- d -glucose (6), three benzoic acids, protocatechuic acid (7), 1-O-vanilloyl-β- d -glucose (8), and tecomin (9), a simple phenol, koaburaside (10), and a naphthoquinone, (+)-cryptosporin (11). All of them were reported from A. carambola fruit for the first time. Compounds 1–8 and 10 showed 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical cation scavenging activity comparable to l -ascorbic acid, while compounds 3, 5, and 7 exhibited potent ferric reducing antioxidant power (FRAP). In addition, compounds 6 and 11 demonstrated weak porcine pancreatic lipase inhibitory activity.
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further dihydrochalcone c glycosides from the fruit of Averrhoa carambola
Lwt - Food Science and Technology, 2016Co-Authors: Dan Yang, Haihui Xie, Xuchao Jia, Xiaoyi WeiAbstract:Abstract Further study on the chemical constituents present in the fruit of Averrhoa carambola L. (Oxalidaceae), commonly called star fruit or carambola, led to the isolation of six new dihydrochalcone C -glycosides, carambolasides E∼J ( 1 ∼ 6 ). Their structures were determined by spectroscopic and chemical methods, including low temperature nuclear magnetic resonance (NMR). Compounds 1 ∼ 6 and two alkaline hydrolysates, 5a and 6a , exhibited more potent 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) radical cation (ABTS + ) scavenging activity with IC 50 values ranging from 4.52 to 2.54 μM than l -ascorbic acid (14.21 μM). However, they were inactive in scavenging 1,1-diphenyl-2-picrylhydrazyl radical (DPPH ) and in ferric reducing antioxidant power (FRAP).
Xiaoyi Wei - One of the best experts on this subject based on the ideXlab platform.
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dihydrochalcone c glycosides from Averrhoa carambola leaves
Phytochemistry, 2020Co-Authors: Yue Yang, Haihui Xie, Xuchao Jia, Xiaoyi WeiAbstract:Abstract Ten undescribed dihydrochalcone C-glycosides, carambolasides R1‒R3, S1, S2, T1‒T3, 3-hydroxycarambolaside T1, and 3-hydroxycarambolaside P were isolated along with carambolasides I and P from the leaves of Averrhoa carambola L. (Oxalidaceae). Their structures were determined by spectroscopic and chemical methods. Among them, carambolasides P, T1, T2, and I with contents of 22.78, 14.39, 4.93, and 1.87 mg g−1 dry wt., respectively, were shown to be abundant in the leaves by HPLC analysis. All the compounds showed more potent ABTS radical cation scavenging activity than l -ascorbic acid. 3-Hydroxycarambolaside T1 and 3-hydroxycarambolaside P also demonstrated moderate DPPH radical scavenging activity. Further, carambolaside R3, 3-hydroxycarambolaside T1, and 3-hydroxycarambolaside P exhibited weak in vitro porcine pancreatic lipase inhibitory activity.
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Non-flavonoid phenolics from Averrhoa carambola fresh fruit
Journal of Functional Foods, 2017Co-Authors: Xuchao Jia, Dan Yang, Haihui Xie, Yueming Jiang, Xiaoyi WeiAbstract:Abstract The fruit of Averrhoa carambola L. (Oxalidaceae) is a commercially important fruit. Our study on the chemical constituents present in the fresh sweet fruit led to the isolation of eleven non-flavonoid phenolic compounds. Their structures were identified by analyses of spectroscopic data. They were two new alkyl phenol diglucosides, carambolasides K (1) and L (2), four phenylpropanoids, (+)-isolariciresinol 9-O-β- d -glucoside (3), (+)-lyoniresinol 9-O-β- d -glucoside (4), (−)-lyoniresinol 9-O-β- d -glucoside (5), and 1-O-feruloyl-β- d -glucose (6), three benzoic acids, protocatechuic acid (7), 1-O-vanilloyl-β- d -glucose (8), and tecomin (9), a simple phenol, koaburaside (10), and a naphthoquinone, (+)-cryptosporin (11). All of them were reported from A. carambola fruit for the first time. Compounds 1–8 and 10 showed 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical cation scavenging activity comparable to l -ascorbic acid, while compounds 3, 5, and 7 exhibited potent ferric reducing antioxidant power (FRAP). In addition, compounds 6 and 11 demonstrated weak porcine pancreatic lipase inhibitory activity.
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further dihydrochalcone c glycosides from the fruit of Averrhoa carambola
Lwt - Food Science and Technology, 2016Co-Authors: Dan Yang, Haihui Xie, Xuchao Jia, Xiaoyi WeiAbstract:Abstract Further study on the chemical constituents present in the fruit of Averrhoa carambola L. (Oxalidaceae), commonly called star fruit or carambola, led to the isolation of six new dihydrochalcone C -glycosides, carambolasides E∼J ( 1 ∼ 6 ). Their structures were determined by spectroscopic and chemical methods, including low temperature nuclear magnetic resonance (NMR). Compounds 1 ∼ 6 and two alkaline hydrolysates, 5a and 6a , exhibited more potent 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) radical cation (ABTS + ) scavenging activity with IC 50 values ranging from 4.52 to 2.54 μM than l -ascorbic acid (14.21 μM). However, they were inactive in scavenging 1,1-diphenyl-2-picrylhydrazyl radical (DPPH ) and in ferric reducing antioxidant power (FRAP).
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Two tetrahydroisoquinoline alkaloids from the fruit of Averrhoa carambola
Phytochemistry Letters, 2014Co-Authors: Dan Yang, Haihui Xie, Bao Yang, Xiaoyi WeiAbstract:The fruit of Averrhoa carambola, commonly known as star fruit or carambola, is popular in Southeast Asia and China. Two new tetrahydroisoquinoline alkaloids, (1R*,3S*)-1-(5-hydroxymethylfuran-2-yl)-3-carboxy-6-hydroxy-8-methoxyl-1,2,3,4-tetrahydroisoquinoline (1) and (1S*,3S*)-1-methyl-3-carboxy-6-hydroxy-8-methyoxyl-1,2,3,4-tetrahydroisoquinoline (2), were isolated from the fruit, along with vanillic acid (3), ferulic acid (4), 8,9,10-trihydroxythymol (5), and arjunolic acid (6). Their structures were elucidated by spectroscopic method. Compounds 1, 2, and 5 showed weak ferric reducing antioxidant potency (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity.
Xuchao Jia - One of the best experts on this subject based on the ideXlab platform.
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dihydrochalcone c glycosides from Averrhoa carambola leaves
Phytochemistry, 2020Co-Authors: Yue Yang, Haihui Xie, Xuchao Jia, Xiaoyi WeiAbstract:Abstract Ten undescribed dihydrochalcone C-glycosides, carambolasides R1‒R3, S1, S2, T1‒T3, 3-hydroxycarambolaside T1, and 3-hydroxycarambolaside P were isolated along with carambolasides I and P from the leaves of Averrhoa carambola L. (Oxalidaceae). Their structures were determined by spectroscopic and chemical methods. Among them, carambolasides P, T1, T2, and I with contents of 22.78, 14.39, 4.93, and 1.87 mg g−1 dry wt., respectively, were shown to be abundant in the leaves by HPLC analysis. All the compounds showed more potent ABTS radical cation scavenging activity than l -ascorbic acid. 3-Hydroxycarambolaside T1 and 3-hydroxycarambolaside P also demonstrated moderate DPPH radical scavenging activity. Further, carambolaside R3, 3-hydroxycarambolaside T1, and 3-hydroxycarambolaside P exhibited weak in vitro porcine pancreatic lipase inhibitory activity.
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carotenoid derived flavor precursors from Averrhoa carambola fresh fruit
Molecules, 2019Co-Authors: Xuchao Jia, Dan Yang, Yue Yang, Haihui XieAbstract:The fruit of Averrhoa carambola L. (Oxalidaceae), commonly known as star fruit or carambola, is popular in tropical and subtropical regions. Carotenoid-derived components, mainly C13- and C15-norisoprenoids, contribute greatly to the flavor of star fruit. Previously reported norisoprenoids were tentatively identified by GC-MS analysis after enzymatic hydrolysis. To gain accurate information about glycosidically bound flavor precursors in star fruit, a phytochemical study was conducted, which led to the isolation of 16 carotenoid derivatives—One new C13-norisoprenoid glucoside, (5R,6S,7E,9R)-5,6,9-trihydroxy-7-megastigmene 9-O-β-d-glucoside (1); one new C15-norisoprenoid, (6S,7E,10S)-Δ9,15-10-hydroxyabscisic alcohol (11); and 14 known ones, of which 12 were in glucoside form. The structures of the two new compounds were elucidated on the basis of extensive spectroscopic data analysis and chemical reaction. Compound 11 was a rare C15-norisoprenoid with a double bond between C-9 and C-15, and its possible biogenetic pathway was proposed. The known compounds were identified by comparison of their mass and nuclear magnetic resonance (NMR) data with those reported in the literature. The structure identification of one new (1) and seven known (3–7, 9, and 10) C13-norisoprenoid glucosides from the genus Averrhoa for the first time enriches the knowledge of carotenoid-derived flavor precursors in star fruit.
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Carotenoid-Derived Flavor Precursors from Averrhoa carambola Fresh Fruit
MDPI AG, 2019Co-Authors: Xuchao Jia, Dan Yang, Yue Yang, Haihui XieAbstract:The fruit of Averrhoa carambola L. (Oxalidaceae), commonly known as star fruit or carambola, is popular in tropical and subtropical regions. Carotenoid-derived components, mainly C13- and C15-norisoprenoids, contribute greatly to the flavor of star fruit. Previously reported norisoprenoids were tentatively identified by GC-MS analysis after enzymatic hydrolysis. To gain accurate information about glycosidically bound flavor precursors in star fruit, a phytochemical study was conducted, which led to the isolation of 16 carotenoid derivatives—One new C13-norisoprenoid glucoside, (5R,6S,7E,9R)-5,6,9-trihydroxy-7-megastigmene 9-O-β-d-glucoside (1); one new C15-norisoprenoid, (6S,7E,10S)-Δ9,15-10-hydroxyabscisic alcohol (11); and 14 known ones, of which 12 were in glucoside form. The structures of the two new compounds were elucidated on the basis of extensive spectroscopic data analysis and chemical reaction. Compound 11 was a rare C15-norisoprenoid with a double bond between C-9 and C-15, and its possible biogenetic pathway was proposed. The known compounds were identified by comparison of their mass and nuclear magnetic resonance (NMR) data with those reported in the literature. The structure identification of one new (1) and seven known (3–7, 9, and 10) C13-norisoprenoid glucosides from the genus Averrhoa for the first time enriches the knowledge of carotenoid-derived flavor precursors in star fruit
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Non-flavonoid phenolics from Averrhoa carambola fresh fruit
Journal of Functional Foods, 2017Co-Authors: Xuchao Jia, Dan Yang, Haihui Xie, Yueming Jiang, Xiaoyi WeiAbstract:Abstract The fruit of Averrhoa carambola L. (Oxalidaceae) is a commercially important fruit. Our study on the chemical constituents present in the fresh sweet fruit led to the isolation of eleven non-flavonoid phenolic compounds. Their structures were identified by analyses of spectroscopic data. They were two new alkyl phenol diglucosides, carambolasides K (1) and L (2), four phenylpropanoids, (+)-isolariciresinol 9-O-β- d -glucoside (3), (+)-lyoniresinol 9-O-β- d -glucoside (4), (−)-lyoniresinol 9-O-β- d -glucoside (5), and 1-O-feruloyl-β- d -glucose (6), three benzoic acids, protocatechuic acid (7), 1-O-vanilloyl-β- d -glucose (8), and tecomin (9), a simple phenol, koaburaside (10), and a naphthoquinone, (+)-cryptosporin (11). All of them were reported from A. carambola fruit for the first time. Compounds 1–8 and 10 showed 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical cation scavenging activity comparable to l -ascorbic acid, while compounds 3, 5, and 7 exhibited potent ferric reducing antioxidant power (FRAP). In addition, compounds 6 and 11 demonstrated weak porcine pancreatic lipase inhibitory activity.
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further dihydrochalcone c glycosides from the fruit of Averrhoa carambola
Lwt - Food Science and Technology, 2016Co-Authors: Dan Yang, Haihui Xie, Xuchao Jia, Xiaoyi WeiAbstract:Abstract Further study on the chemical constituents present in the fruit of Averrhoa carambola L. (Oxalidaceae), commonly called star fruit or carambola, led to the isolation of six new dihydrochalcone C -glycosides, carambolasides E∼J ( 1 ∼ 6 ). Their structures were determined by spectroscopic and chemical methods, including low temperature nuclear magnetic resonance (NMR). Compounds 1 ∼ 6 and two alkaline hydrolysates, 5a and 6a , exhibited more potent 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) radical cation (ABTS + ) scavenging activity with IC 50 values ranging from 4.52 to 2.54 μM than l -ascorbic acid (14.21 μM). However, they were inactive in scavenging 1,1-diphenyl-2-picrylhydrazyl radical (DPPH ) and in ferric reducing antioxidant power (FRAP).
Dan Yang - One of the best experts on this subject based on the ideXlab platform.
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carotenoid derived flavor precursors from Averrhoa carambola fresh fruit
Molecules, 2019Co-Authors: Xuchao Jia, Dan Yang, Yue Yang, Haihui XieAbstract:The fruit of Averrhoa carambola L. (Oxalidaceae), commonly known as star fruit or carambola, is popular in tropical and subtropical regions. Carotenoid-derived components, mainly C13- and C15-norisoprenoids, contribute greatly to the flavor of star fruit. Previously reported norisoprenoids were tentatively identified by GC-MS analysis after enzymatic hydrolysis. To gain accurate information about glycosidically bound flavor precursors in star fruit, a phytochemical study was conducted, which led to the isolation of 16 carotenoid derivatives—One new C13-norisoprenoid glucoside, (5R,6S,7E,9R)-5,6,9-trihydroxy-7-megastigmene 9-O-β-d-glucoside (1); one new C15-norisoprenoid, (6S,7E,10S)-Δ9,15-10-hydroxyabscisic alcohol (11); and 14 known ones, of which 12 were in glucoside form. The structures of the two new compounds were elucidated on the basis of extensive spectroscopic data analysis and chemical reaction. Compound 11 was a rare C15-norisoprenoid with a double bond between C-9 and C-15, and its possible biogenetic pathway was proposed. The known compounds were identified by comparison of their mass and nuclear magnetic resonance (NMR) data with those reported in the literature. The structure identification of one new (1) and seven known (3–7, 9, and 10) C13-norisoprenoid glucosides from the genus Averrhoa for the first time enriches the knowledge of carotenoid-derived flavor precursors in star fruit.
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Carotenoid-Derived Flavor Precursors from Averrhoa carambola Fresh Fruit
MDPI AG, 2019Co-Authors: Xuchao Jia, Dan Yang, Yue Yang, Haihui XieAbstract:The fruit of Averrhoa carambola L. (Oxalidaceae), commonly known as star fruit or carambola, is popular in tropical and subtropical regions. Carotenoid-derived components, mainly C13- and C15-norisoprenoids, contribute greatly to the flavor of star fruit. Previously reported norisoprenoids were tentatively identified by GC-MS analysis after enzymatic hydrolysis. To gain accurate information about glycosidically bound flavor precursors in star fruit, a phytochemical study was conducted, which led to the isolation of 16 carotenoid derivatives—One new C13-norisoprenoid glucoside, (5R,6S,7E,9R)-5,6,9-trihydroxy-7-megastigmene 9-O-β-d-glucoside (1); one new C15-norisoprenoid, (6S,7E,10S)-Δ9,15-10-hydroxyabscisic alcohol (11); and 14 known ones, of which 12 were in glucoside form. The structures of the two new compounds were elucidated on the basis of extensive spectroscopic data analysis and chemical reaction. Compound 11 was a rare C15-norisoprenoid with a double bond between C-9 and C-15, and its possible biogenetic pathway was proposed. The known compounds were identified by comparison of their mass and nuclear magnetic resonance (NMR) data with those reported in the literature. The structure identification of one new (1) and seven known (3–7, 9, and 10) C13-norisoprenoid glucosides from the genus Averrhoa for the first time enriches the knowledge of carotenoid-derived flavor precursors in star fruit
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Non-flavonoid phenolics from Averrhoa carambola fresh fruit
Journal of Functional Foods, 2017Co-Authors: Xuchao Jia, Dan Yang, Haihui Xie, Yueming Jiang, Xiaoyi WeiAbstract:Abstract The fruit of Averrhoa carambola L. (Oxalidaceae) is a commercially important fruit. Our study on the chemical constituents present in the fresh sweet fruit led to the isolation of eleven non-flavonoid phenolic compounds. Their structures were identified by analyses of spectroscopic data. They were two new alkyl phenol diglucosides, carambolasides K (1) and L (2), four phenylpropanoids, (+)-isolariciresinol 9-O-β- d -glucoside (3), (+)-lyoniresinol 9-O-β- d -glucoside (4), (−)-lyoniresinol 9-O-β- d -glucoside (5), and 1-O-feruloyl-β- d -glucose (6), three benzoic acids, protocatechuic acid (7), 1-O-vanilloyl-β- d -glucose (8), and tecomin (9), a simple phenol, koaburaside (10), and a naphthoquinone, (+)-cryptosporin (11). All of them were reported from A. carambola fruit for the first time. Compounds 1–8 and 10 showed 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical cation scavenging activity comparable to l -ascorbic acid, while compounds 3, 5, and 7 exhibited potent ferric reducing antioxidant power (FRAP). In addition, compounds 6 and 11 demonstrated weak porcine pancreatic lipase inhibitory activity.
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further dihydrochalcone c glycosides from the fruit of Averrhoa carambola
Lwt - Food Science and Technology, 2016Co-Authors: Dan Yang, Haihui Xie, Xuchao Jia, Xiaoyi WeiAbstract:Abstract Further study on the chemical constituents present in the fruit of Averrhoa carambola L. (Oxalidaceae), commonly called star fruit or carambola, led to the isolation of six new dihydrochalcone C -glycosides, carambolasides E∼J ( 1 ∼ 6 ). Their structures were determined by spectroscopic and chemical methods, including low temperature nuclear magnetic resonance (NMR). Compounds 1 ∼ 6 and two alkaline hydrolysates, 5a and 6a , exhibited more potent 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) radical cation (ABTS + ) scavenging activity with IC 50 values ranging from 4.52 to 2.54 μM than l -ascorbic acid (14.21 μM). However, they were inactive in scavenging 1,1-diphenyl-2-picrylhydrazyl radical (DPPH ) and in ferric reducing antioxidant power (FRAP).
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Two tetrahydroisoquinoline alkaloids from the fruit of Averrhoa carambola
Phytochemistry Letters, 2014Co-Authors: Dan Yang, Haihui Xie, Bao Yang, Xiaoyi WeiAbstract:The fruit of Averrhoa carambola, commonly known as star fruit or carambola, is popular in Southeast Asia and China. Two new tetrahydroisoquinoline alkaloids, (1R*,3S*)-1-(5-hydroxymethylfuran-2-yl)-3-carboxy-6-hydroxy-8-methoxyl-1,2,3,4-tetrahydroisoquinoline (1) and (1S*,3S*)-1-methyl-3-carboxy-6-hydroxy-8-methyoxyl-1,2,3,4-tetrahydroisoquinoline (2), were isolated from the fruit, along with vanillic acid (3), ferulic acid (4), 8,9,10-trihydroxythymol (5), and arjunolic acid (6). Their structures were elucidated by spectroscopic method. Compounds 1, 2, and 5 showed weak ferric reducing antioxidant potency (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity.
