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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. [ABSTRACT FROM AUTHOR]

In order to improve the bioactivities of the polysaccharide from Enteromorpha prolifera (PE), crude PE (Mw 1400 kDa) was degraded to low molecular weight polysaccharide (44 kDa) in the presence of hydrogen peroxide/ascorbic acid, followed by carboxymethylation. The reaction conditions for carboxymethylation of degraded polysaccharide (DPE) were optimized by Response Surface Methodology. The carboxymethyled degraded polysaccharide (CDPE) obtained under optimized conditions, with a degree of carboxymethylation of 0.849, was characterized by FT-IR and 13 C NMR. The molecular weight of CDPE was measured to be 53.7 kDa. CDPE was evaluated for its antioxidant activity by determining the ability to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl and superoxide anion radicals, and by determining the ferric reducing power. The antioxidant activity of CDPE was found to be greatly improved in comparison with degraded polysaccharide (DPE) and crude polysaccharide from Enteromorpha prolifera (PE). [ABSTRACT FROM AUTHOR]

Star fruit (the fruit of Averrhoa carambola L., Oxalidaceae) is popular in tropical regions. Chemical study of the fruit yielded four new dihydrochalcone C -glycosides, carambolasides A ( 1 ), B ( 2 ), C ( 3 ), and D ( 4 ), in addition to hovertichoside C ( 5 ), isovitexin 2″- O -α- l -rhamnopyranoside ( 6 ), and carambolaflavone ( 7 ). Their structures were identified by spectroscopic and chemical methods, including electronic circular dichroism (ECD) calculation. Compounds 5 – 7 were reported from the fruit for the first time. Compounds 1 – 7 were evaluated for antioxidant activity using three assays. All of them exhibited 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical cation scavenging activity with IC 50 values ranging from 7.6 to 3.9 µM, which were more potent than l -ascorbic acid (IC 50  = 11.6 µM). However, they were inactive in scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and in ferric reducing antioxidant power (FRAP). [ABSTRACT FROM AUTHOR]

Highlights: [•] Six phenolics and two sesquiterpenes were isolated from litchi pericarp. [•] Their structures were identified by spectroscopic methods. [•] Five compounds were new and the others were reported from litchi for the first time. [•] Five phenolics showed antioxidant activity in FRAP and DPPH assays. [Copyright &y& Elsevier]

Highlights: [•] Six compounds including two new alkaloids were isolated from star fruit in China. [•] It is the first report of all the compounds except for ferulic acid from this species. [•] Two alkaloids and 8,9,10-trihydroxythymol showed weak antioxidant activity. [Copyright &y& Elsevier]

Highlights: [•] Thirteen phenolic compounds were isolated from the herb for the first time. [•] Their structures were identified by spectroscopic method. [•] Antioxidant and antibacterial activities of these compounds were evaluated. [•] Nine compounds were antioxidant and two compounds were antibacterial. [Copyright &y& Elsevier]

The fruit of Clausena lansium (wampee) is popular in southern China and warm areas of the world. Our chemical study on the fruit yielded three jasmonoid glucosides, 12-β- d -glucopyranosyloxy-6- epi -7-isocucurbic acid-1,6-lactone ( 1 ), 12-β- d -glucopyranosyloxyjasmonic acid ( 2 ) and 12-hydroxyjasmonic acid ( 3 ), two sesquiterpenes, (+)-curcumen-12-oic acid ( 4 ) and (+)-( E )-α-santalen-12-oic acid ( 5 ), two coumarins, xanthotoxol ( 6 ) and indicolactone ( 7 ), in addition to 3,4-dihydroxybenzoic acid ( 8 ), 5-hydroxymethylfuraldehyde ( 9 ), isopropyl β- d -glucopyranoside ( 10 ) and stigmasterol ( 11 ). Their structures were determined by spectroscopic methods. Compound 1 was a new metabolite and the others excluding 6 were reported from the species for the first time. Compounds 1 – 7 were evaluated for antioxidant and antibacterial activities. Among them, compound 6 showed antioxidant activity in ferric reducing antioxidant power (FRAP) and DPPH radical scavenging assays as well as antibacterial activity against Staphyloccocus aureus and Shigella dysenteriae , while compound 5 was active against Bacillus cereus . [ABSTRACT FROM AUTHOR]

Thirteen flavonoids were isolated from the fresh sweet fruit of Averrhoa carambola L. (Oxalidaceae), commonly known as star fruit, and their structures were determined by spectroscopic and chemical methods. 8-Carboxymethyl-(+)-epicatechin methyl ester, pinobanksin 3- O -β- d -glucoside, and carambolasides M–Q were undescribed structures. (+)-Epicatechin, aromadendrin 3- O -β- d -glucoside, helicioside A, taxifolin 3′- O -β- d -glucoside, galangin 3- O -rutinoside, and isorhamnetin 3- O -rutinoside were reported from this species for the first time. Pinobanksin 3- O -β- d -glucoside and carambolasides M–Q showed more potent 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical cation scavenging activity (IC 50  = 5.3–2.3 μM) than l -ascorbic acid (10.5 μM). Further, (+)-epicatechin, pinobanksin 3- O -β- d -glucoside, isorhamnetin 3- O -rutinoside, and carambolasides O–Q exhibited weak porcine pancreatic lipase inhibitory activity. [ABSTRACT FROM AUTHOR]

Three new phenolic glucosides, falandiosides A ( 1 ), B ( 2 ), and C ( 6 ) were isolated from strawberry ( Fragaria × ananassa Duch.) cv. Falandi fruit, together with three flavone glucuronides ( 3 – 5 ), eleven lignan glycosides ( 12 – 22 ), and five others. Their structures were determined by spectroscopic methods. All the known phenolics were reported from strawberry for the first time. They were evaluated for antioxidant and α-glucosidase inhibitory activities. Three new and fifteen known phenolics showed potent 2,2′-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical cation scavenging activity with IC 50 values of 22.50–4.28 μM in comparison to l -ascorbic acid (14.21 μM). Quercetin 3-(6-methylglucuronide) ( 4 ), (+)-isolariciresinol 9′-glucoside ( 12 ), and (−)-isolariciresinol 9′-glucoside ( 13 ) were active in scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. Moreover, compounds 12 and 13 had moderate ferric reducing antioxidant power (FRAP) values. Further, two new and seven known phenolics exhibited more potent α-glucosidase inhibitory activity with IC 50 values of 537.43–25.39 μM than acarbose (619.94 μM). [ABSTRACT FROM AUTHOR]

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). [ABSTRACT FROM AUTHOR]

Abstract: The experiments were performed to extract and purify substrates for polyphenol oxidase (PPO) from pericarp tissue of postharvest litchi fruit. Two purified PPO substrates were identified as (−)-epicatechin and procyanidin A2. The antioxidant properties of two PPO substrates were further evaluated in the present study. Variation in the content of the major substrate (−)-epicatechin of litchi fruit during storage at 25°C was analysed using the HPLC-UV method. The results showed that (−)-epicatechin exhibited stronger antioxidant capability than procyanidin A2, in terms of reducing power and scavenging activities of DPPH radical, hydroxyl radical and superoxide radical. Furthermore, (−)-epicatechin content in pericarp tissue tended to decrease with increasing skin browning index of litchi fruit during storage at 25°C. Thus, these two compounds can be used as potential antioxidants in litchi waste and the fresh pericarp tissue of litchi fruit exhibited a better utilisation value. [Copyright &y& Elsevier]

Abstract: Fruits of wampee [Clausena lansium (Lour.) Skeels] contain a significant amount of coumarins with many health benefits. The activity-guided separation of an ethyl acetate-soluble fraction on a polyamide column followed by silica gel column and high performance liquid chromatography (HPLC) preparation afforded a pure compound, which was identified to be 8-hydroxypsoralen based on the 1H, 13C NMR (nuclear magnetic resonance), and ESI-MS (electrospray ionisation mass spectrometric) analysis. This isolate exhibited good scavenging activities against DPPH radical and superoxide anion as well as significant reducing power. It also showed potent proliferation inhibitory activity against human hepatocellular liver carcinoma cell line (HepG2), human lung adenocarcinoma epithelial cell line (A549) and human cervical carcinoma cell line (HELA). This is the first report on the antioxidant and cytotoxic properties of C. lansium fruit extract. The food and pharmaceutical industry could be benefited by the usage of this extract containing this constituent. [Copyright &y& Elsevier]

Abstract: Longan fruit pericarp was extracted with 50% ethanol employing high pressure (500 MPa) and conventional extraction methods. Total phenolic contents of high pressure-assisted extract of longan (HPEL) and conventional extract of longan (CEL) were 20.8 and 14.6 mg gallic acid equivalents/g dry weight, respectively. Subsequently, the antioxidant activities of these extracts were analyzed employing various antioxidant model systems including 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, superoxide anion radical scavenging activity, total antioxidant capacity, and lipid peroxidation inhibitory activity. In addition, anticancer activity was also tested using HepG2, A549, and SGC 7901 cancer cell lines. HPEL showed excellent antioxidant and anticancer activities and were higher than CEL. Three phenolic compounds, namely gallic acid, corilagin, and ellagic acid, were identified and quantified by external standard methods. Compared with CEL, HPEL exhibited higher extraction effectiveness in terms of higher extraction yield, higher phenolic content, and higher antioxidant and anticancer activity with shorter extraction time. Industrial relevance: This study was focused to evaluate the antioxidant and anticancer activity of longan fruit pericarp by high-pressure treatment. The high-pressure treatment provided a better way of utilizing longan fruit pericarp as a readily accessible source of the natural anticancer and antioxidant in food and pharmaceutical industry. [Copyright &y& Elsevier]

Abstract: Five previously uncharacterised polyphenols, ethyl gallate (2), 1-β-O-galloyl-d-glucopyranose (3), methyl brevifolin carboxylate (4), brevifolin (5) and 4-O-α-l-rhamnopyranosyl-ellagic acid (8), and three previously identified polyphenols, gallic acid (1), corilagin (6) and ellagic acid (7), were isolated from longan seeds. Their structures were identified by spectroscopic and chemical methods including HRESIMS and NMR. Eight polyphenols exhibited scavenging activity towards DPPH radicals with SC50 values of 0.80–5.91μg/ml and towards superoxide radicals with SC50 values of 1.04–7.03μg/ml. The radical-scavenging activity of the newly characterised polyphenols was comparable to that of gallic acid, corilagin and ellagic acid. [Copyright &y& Elsevier]

Abstract: Iridoid glycosides, 2′,3′,6′-tri-O-acetyl-4′-O-trans-p-(O-β-d-glucopyranosyl)coumaroyl-7-ketologanin (1), 2′-O-caffeoylloganic acid (2), 2′-O-p-hydroxybenzoylloganic acid (3), 2′-O-trans-p-coumaroylloganic acid (4), and 2′-O-cis-p-coumaroylloganic acid (5), were isolated from whole plants of Gentiana loureirii along with six known iridoids, 7-ketologanin (6), loganin (7), loganic acid (8), sweroside, boonein, and isoboonein, and three other known compounds. Their structures were elucidated by spectroscopic means and chemical correlations. The isolated iridoids were evaluated for antibacterial and antioxidant activities, but were either inactive or very weakly active. [Copyright &y& Elsevier]

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. From Averrhoa carambola leaves, ten undescribed and two known dihydrochalcone C -glycosides were isolated, which showed potent antioxidant and weak pancreatic lipase inhibitory activities. The contents of five compounds were measured. Image 1 • Ten undescribed dihydrochalcone C -glycosides were isolated from A. carambola leaves. • The contents of five compounds were measured. • All the compounds showed potent ABTS radical cation scavenging activity. • Three compounds exhibited weak pancreatic lipase inhibitory activity. [ABSTRACT FROM AUTHOR]

Averrhoa carambola L. (Oxalidaceae) was widely cultivated for fruits (star fruit), whereas the value of leaves remains to be discovered. Our study on the leaves yielded five flavan-3-ols (1 – 5) and two 2-diglycosyloxybenzoates. Their structures were determined by spectroscopic and chemical methods. Epicatechin-(5,6-bc)-4β-(p -hydroxyphenyl)-dihydro-2(3 H)-pyranone (1) and benzyl 2-β- d -apiofuranosyl-(1 → 6)-β- d -glucopyranosyloxybenzoate (6) were new structures. 6-(S −2-Pyrrolidinone-5-yl)epicatechin (4) and 6-(R -2-pyrrolidinone-5-yl)epicatechin (5) were obtained as monomeric diastereomer for the first time and their absolute configurations were determined by electronic circular dichroism (ECD) computation. Epicatechin-(7,8-bc)-4α-(p -hydroxyphenyl)-dihydro-2(3 H)-pyranone (2), epicatechin-(7,8-bc)-4β-(p -hydroxyphenyl)-dihydro-2(3 H)-pyranone (3), and methyl 2-β- d -apiofuranosyl-(1 → 6)-β- d -glucopyranosyloxybenzoate (7) were not previously reported from the genus Averrhoa. Compounds 1 – 5 showed more potent 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical cation and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities and ferric reducing antioxidant power (FRAP) than l -ascorbic acid. Meanwhile 1 and 3 exhibited lipase and α-glucosidase inhibitory activities, respectively. The results clarified the structures of flavan-3-ols and 2-diglycosyloxybenzoates in the leaves and their antioxidant, lipase, and α-glucosidase inhibitory activities. Graphic abstract Unlabelled Image • New flavan-3-ol and 2-diglycosylxoybenzoate were isolated from A. carambola leaves • The absolute configurations of two diastereomers were determined by ECD computation • The isolates showed antioxidant, lipase, and α-glucosidase inhibitory activities [ABSTRACT FROM AUTHOR]