Search

The agri-food industry generates substantial waste, leading to significant environmental impacts. Lychee (Litchi chinensis Sonnerat), which is rich in bioactive compounds in its peel, pulp, and seeds, offers an opportunity for waste use. This study aimed to evaluate the effects of supplementing a high-carbohydrate diet with varying levels of lychee peel flour on lipid metabolism biomarkers and oxidative stress in a zebrafish (Danio rerio) model. A total of 225 zebrafish, approximately four months old, were divided into five groups: control, high-carbohydrate (HC), HC2%, HC4%, and HC6%. The study did not find significant differences in the growth performance of zebrafish in any group. However, the HC6% group exhibited a significant decrease in glucose and triglyceride levels compared with the HC group. Furthermore, this group showed enhanced activities of the antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD), along with reduced levels of malondialdehyde (MDA). Increased antioxidant activity was also evidenced by DPPH - , ABTS + , and β-carotene/Linoleic acid assays in the HC6% group. A positive correlation was identified between SOD/CAT activity and in vitro antioxidant assays. These findings suggest that dietary supplementation with 6% lychee peel flour can significantly modulate glucose homeostasis, lipid metabolism, and antioxidant activity in zebrafish., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

This work follows an ethnobotanical study that took place in the island of Mayotte (France), which pointed out the potential properties of Litchi chinensis Sonn. roots when used to enhance skin health and appearance. Through in vitro testing of a crude methanolic extract, high anti-tyrosinase (skin whitening effect) and antioxidant activities (skin soothing effect) could be measured. HPLC successive bio-guided fractionation steps allowed the purification of one of the compounds responsible for the biological activities. The isolated compound was characterized by UV, IR, MS and 2D-NMR, revealing, for the first time in Litchi chinensis Sonn. roots, an A-type proanthocyanidin and thus revealing a consensus among the traditional use shown by the ethnobotanical study, in vitro biological activities and chemical characterization.

Context: The study was carried out to evaluate the effect of the aqueous fruit pericarp extract of Litchi chinensis (APLC) on parameters which leads to diabetic cataractogenesis and retinopathy in the streptozotocin-induced diabetic rats., Objective: The objective of the study is to evaluate the APLC for in vivo antioxidant activity and its role in inhibiting the polyol pathway and formation of advanced glycation end products (AGEs)., Materials and Methods: The diabetic animals were treated with L. chinensis for a period of 12 weeks. At the end of 12 weeks, the animals were killed and the biochemical pathways involved in the pathogenesis of cataract such as oxidative stress by protein content, superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), and polyolpathway by aldose reductase (AR) in lens homogenates, alterations in protein carbonyl content (PCO) and AGEs in both serum and lens the APLC-treated diabetic rats were compared against diabetic control rats. Cataract progression due to hyperglycemia was monitored by slit lamp bio microscope and classified into four stages. Fundoscope test and retinal histopathology were done for assessing retinopathy., Results: Statistically significant reduction in glucose, and elevation of protein content, SOD, CAT, and GSH levels and decreased levels of AR and PCO in lens homogenate and significant reduction in AGEs serum and lens homogenate were observed. Slit lamp examination, fundoscope, and histopathology showed improvement in retinal changes in APLC-treated rats compared to diabetic control animals., Conclusion: The treatment with APLC found to delay the progression of diabetic cataractogenesis and retinopathy, which might be due to its antioxidant activity, because of the presence of active phytochemicals in APLC.

Copyright of Engenharia na Agricultura is the property of Engenharia na Agricultura and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Litchi chinensis Sonn seeds and pericarp are used in popular medicine as antioxidant, anticancer, antiviral, analgesic, antipyretic, immunomodulatory agent and others. However, literature on litchi leaves extract and the main compound procyanidin A2 (PA2) activities are scarce. Here, we investigated the anti-inflammatory activity of L. chinensis leaves extract and the main compound PA2 using in vitro and in vivo assays. We used the pleurisy and air-pouch model induced by carrageenan, substance P, histamine, bradykinin or lipopolysaccharide (LPS) in mice. The PA2 effects were also evaluated using carrageenan-induced pleurisy and LPS-induced air-pouch. In addition, LPS-induced NO2 - production and cytotoxicity were quantified using peritoneal neutrophils recruited by oyster glycogen previously treated with L. chinensis extract or PA2. Animals orally treated with L. chinensis leaves extract exhibited a reduction on carrageenan-induced paw edema. Furthermore, the extract reduced the leukocyte migration and the protein leakage in the pleurisy model induced by carrageenan, substance P, histamine and bradykinin. The main compound in the leaves extract, PA2 reduced the paw edema and cell migration into the carrageenan-inflamed tissue. The data obtained in the LPS-induced air pouch model show that the extract and PA2 inhibit the in vivo neutrophil migration. In addition, the leaves extract and PA2 did not affect the neutrophil viability and reduces NO2 - production. Taken together, the data herein obtained showed the modulatory actions of L. chinensis leaves extract on leukocyte migration to inflamed tissue, suggesting its therapeutic application to acute inflammatory process. In addition, it may be supposed that PA2 could be related with these actions, as it is the main compound of L. chinensis leaves extract. [ABSTRACT FROM AUTHOR]

The antioxidant and antibacterial activities of wood vinegar from Litchi chinensis, and its components have been studied. The chemical compositions of wood vinegar were analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 17 chemical compounds were identified, representing 83.96% of the compositions in the wood vinegar. Three major components, included 2,6-dimethoxyphenol (syringol, 29.54%), 2-methoxyphenol (guaiacol, 12.36%), and 3,5-dimethoxy-4-hydroxytoluene (11.07%), were found in the wood vinegar. Antioxidant activities of the acids were investigated from the aspects of 1,1-Diphyl-2-picrylhydrazyl (DPPH) free radicals scavenging capacity, superoxide anion radical scavenging capacity, and reducing power. The pyroligneous acid exhibited high antioxidant activity which was comparable to the reference standards (vitamin C and butylated hydroxyl toluene) at the same dose with IC50 values of 36.5 ppm calculated by the DPPH radical scavenging assay, 38.38 g Trolox equivalent/100 g DW by the trolox equivalent antioxidant capacity (TEAC) assay, and 67.9 by the reducing power analysis. Antibacterial activity was evaluated using the disc diffusion and microdilution methods against a group of clinically antibiotic resistant isolates. The major components exhibited broad spectrum inhibition against all the bacterial strains with a range of disc inhibition zoon between 15-19 mm. The minimum inhibition concentration and minimum bactericide concentration against the test strains was ranging in 0.95-3.80 μL/100 μL and 1.90-3.80 μL/100 μL, respectively. Most of the antibiotic resistant strains were more susceptible to the wood vinegar than the non-antibiotic resistant strain except the strain of ornithine resistant Staphylococcus aureus. Based on the chemical profile, it was considered that the strongest antioxidant and antibacterial activity of Litchi chinensis wood vinegar was due to its highly phenolic compositions. This study revealed that the Litchi chinensis wood vinegar is valuable to develop as alternative food antioxidant and antibiotics. [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance Litchi chinensis Sonn. (Sapindaceae) has been widely used in many cultures for the treatment of cough, flatulence, stomach ulcers, diabetes, obesity, testicular swelling, hernia-like conditions, and epigastric and neuralgic pains. The ethnopharmacologial history of L. chinensis indicated that it possesses hypoglycemic, anticancer, antibacterial, anti-hyperlipidemic, anti-platelet, anti-tussive, analgesic, antipyretic, hemostatic, diuretic, and antiviral activities. Aim of the review The aim of this review is to provide up-to-date information on the botanical characterization, distribution, traditional uses, and chemical constituents, as well as the pharmacological activities and toxicity of L. chinensis . Moreover, the focus of this review is the possible exploitation of this plant to treat different diseases and to suggest future investigations. Materials and methods To provide an overview of the ethnopharmacology, chemical constituents, and pharmacological activities of litchi, and to reveal their therapeutic potentials and being an evidence base for further research works, information on litchi was gathered from scientific journals, books, and worldwide accepted scientific databases via a library and electronic search (PubMed, Elsevier, Google Scholar, Springer, Scopus, Web of Science, Wiley online library, and pubs.acs.org/journal/jacsat). All abstracts and full-text articles were examined. The most relevant articles were selected for screening and inclusion in this review. Results A comprehensive analysis of the literature obtained through the above-mentioned sources confirmed that ethno-medical uses of L. chinensis have been recorded in China, India, Vietnam, Indonesia, and Philippines. Phytochemical investigation revealed that the major chemical constituents of litchi are flavonoids, sterols, triterpenens, phenolics, and other bioactive compounds. Crude extracts and pure compounds isolated from L. chinensis exhibited significant antioxidant, anti-cancer, anti-inflammatory, anti-microbial, anti-viral, anti-diabetic, anti-obesity, hepato-protective, and immunomodulatory activities. From the toxicological perspective, litchi fruit juice and extracts have been proven to be safe at a dose 1 g/kg. Conclusions Phytochemical investigations indicated that phenolics were the major bioactive components of L. chinensis with potential pharmacological activities. The ethnopharmacological relevance of L. chinensis is fully justified by the most recent findings indicating it is a useful medicinal and nutritional agent for treating a wide range of human disorders and aliments. Further investigations are needed to fully understand the mode of action of the active constituents and to fully exploit its preventive and therapeutic potentials. [ABSTRACT FROM AUTHOR]

The antioxidant activity and phytoconstituents of the hydromethanolic extract of Litchi chinensis (HELC) fruit was explored in the present study. The antioxidant potential of extract has been evaluated using several antioxidant models and results were compared to standards. Fruit extract showed effective reducing power and free radical scavenging activity in a dose-dependent manner. In case of in vitro studies, the IC50 values were found to be 100, 525, 550 and 1000 μg/ml respectively in DPPH, Superoxide, Hydroxyl radical and Nitric oxide scavenging assays. In case of in vivo studies, the levels of liver enzymatic [Serum glutamate oxalo-acetate (SGOT), serum glutamate pyruvate (SGPT), Alkaline phosphatase (ALP), Catalase (CAT), Superoxide dismutase (SOD)], non-enzymatic systems [Glutathione (GSH)] and Lipid peroxidation (LPO) level were restored toward the normal value in HELC-treated carbon tetrachloride-induced hepatotoxicity which suggest the hepatoprotective effect of Litchi chinensis in rats. The antioxidant activity of Litchi chinensis may be due to the presence of phenolic (pyrocatechol and gallic acid content is 5.7 and 2.81 μg/mg respectively), vitamin C (ascorbic acid content is 0.943 μg/mg) and flavonoid compounds (5.415 μg/mg) present in HELC. The results obtained in the present study indicate that the Litchi chinensis fruit is a potential source of natural antioxidant. [ABSTRACT FROM AUTHOR]

Two polysaccharides, LCP70S-1 and LCP70W, were isolated from the pulp tissues of Litchi chinensis by anion-exchange chromatography and gel-filtration chromatography, while the structure of LCP70S-1 was elucidated and its physico-chemical properties was analyzed. The results demonstrated that LCP70S-1 is composed of L-rhamnose, L-arabinose and D-galactose in the ratio of 1.06:6.39:4.21, and the main chain of the heteropolysaccharide possess (1→3,6)-linked galactopyranosyl branches at O-6. The three branches consist of (1→3)-linked rhamnopyranosyl residues, (1→3,6)-linked galactopyranosyl and (1→5)-linked arabinopyranosyl residues, and terminated with (1→)-linked arabinopyranosyl residues, respectively. The two polysaccharides were further evaluated with 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities and their reducing power in vitro. The results showed that LCP70W and LCP70S-1 possessed significant antioxidant activities, especially for LCP70S-1. As such, LCP70S-1 could potentially serve as an antioxidant and would value further study for human healthcare. [ABSTRACT FROM AUTHOR]

Litchi is known for its delicious taste and reddish pericarp colour. However, pericarp browning limits the postharvest life of litchi fruit with reduced fruit quality. Therefore, present study was conducted to investigate the influence of harvest location (Lahore and Haripur) as well as cultivar ('Gola' and 'Serai') on pericarp browning, changes in the biochemical quality attributes and enzymatic activities in litchi fruit. Fruit harvested from Lahore exhibited significantly higher pericarp browning index (3.99), weight loss (12.7%), ascorbic acid contents (48.9 mg 100 g-1) and activities of enzymes responsible for browning (peroxidase and polyphenol oxidase) as compared to Haripur. Moreover, fruit harvested from Lahore exhibited less SSC: TA ratio (105.3), total phenolic contents (187.35 mg GAE 100 g-1), total antioxidants (45.27%) and activity of superoxide dismutase enzyme (40.86 U mg-1 protein) than that of Haripur. On the other hand, 'Serai' fruit exhibited higher weight loss (12.86%), SSC (19.58oBrix), TA (0.24%), activities of peroxidase (35.81 U mg-1 protein) and polyphenol oxidase (25.22 U mg-1 protein) enzymes. Moreover, lower level of TPC (202.9 mg GAE 100 g-1), total antioxidants (50.2%), activities of superoxide dismutase (39.85 U mg-1 protein) and catalase (22.32 U mg-1 protein) enzymes were observed in 'Serai' than 'Gola' fruit. Results suggested that fruit harvested from Haripur exhibited better fruit quality characteristics and browning index than fruit harvested from Lahore. Cultivar 'Gola' showed better quality with less pericarp browning than 'Serai'. [ABSTRACT FROM AUTHOR]

Abstract: Gentisic acid and epicatechin are two major compounds in phenolic acids and flavonoids of litchi-flower-water extracts (LFWEs), respectively. Increased (p <0.05) serum lipids and liver size/lipid, damage/inflammatory indices, TBARS value, CRP level, MMP-9 activity, and decreased (p <0.05) liver GSH and TEAC levels, and SOD, CAT and GSH-Px activities were observed in high-fat-diet fed hamsters compared to normal-fat-dietary hamsters. Those biochemical values of high-fat-diet fed hamsters were significant improved (p <0.05) by drinking LFWEs. In addition, these improvements on liver damage induced by a high-fat diet were also evidenced in the histopathological examination of livers where less microvesicular steatosis and no necrotic/inflammatory cells were observed in high-fat-diet fed hamster drinking LFWEs. Therefore, protective effects of LFWEs on liver damage of high-fat-diet fed hamsters can be accounted for antioxidative properties and anti-inflammatory effects of LFWEs. [Copyright &y& Elsevier]

Abstract: Procyanidin oligomers from litchi pericarp (Litchi chinensis) were isolated and identified by online analysis. Accurate molecular weight (MW) distribution and composition of the procyanidin extracts were recorded on an Apex-Qe–FT–ICR mass spectrometer. The MW range of litchi procyanidins was from 289.07151 to 1439.30529 m/z and composed of A- and B-series oligomeric procyanidins. The variety of the main procyanidins (DP<5) was identified by HPLC and LC–ESI-MS analysis. There are more than 41.7% of A-series procyanidins in the oligomeric procyanidins, however, B-series procyanidins takes only 24.1% of the litchi pericarp extracts. In this study, we determined the effects of (−)-epicatechin, A-type procyanidin dimer (A2) and trimer, epicatechin-(4β→8, 2β→O→7)-epicatechin-(4β→8)-epicatechin from litchi pericarp on free radical scavenging. The results showed that A-type procyanidin dimer and trimer both had a strong scavenging ability on DPPH and OH, indicating that litchi is a new plant source of A-type procyanidins and natural antioxidant. [Copyright &y& Elsevier]

Context: Litchi chinensis Sonn. (Spindaceae) is an important economic fruit of Thailand. Therapeutic effects of the fruits are contributed by anti-inflammatory phenolics. Objective: To extract the litchi fruit pericarp in order to identify biologically actives substances with potential for cosmetic application. Materials and methods: The litchi pericarp was macerated by 70% ethanol (EtOH) and partitioned using n-hexane and ethyl acetate (EtOAc). In vitro antioxidant activities were assessed by 1, 1-diphenyl-2-picrylhydrazyl (DPPH), ABTS and ferric reducing ability of plasma (FRAP) assays including tyrosinase inhibitory effect. Cellular radical scavenging capacity was monitored in a normal human fibroblast cell culture (NHF). Total phenolic content was determined and characterized by HPLC. Results: The EtOAc fraction was a significant antioxidant, stronger than ascorbic acid ( p < 0.01), as assessed by ABTS (IC50 = 7.137 ± 0.021 μg/mL), DPPH (IC50 = 2.288 ± 0.063 μg/mL) and FRAP (EC1mMFeSO4 = 8013.183 ± 58.804 μg/mL) assays. It demonstrated an antityrosinase effect (IC50 = 197.860 ± 1.230 μg/mL) and showed no cytotoxic activity toward Vero and NHF cells, at a maximum tested concentration (50 μg/mL), with cellular antioxidant activity. Total phenolic content was highest in the most potent antioxidant fraction. Quercetin, rosmarinic and gallic acids were found. Total phenolic content is highly related to FRAP, antityrosinase, and ABTS activities. Discussion and conclusion: Pericarp from litchi fruit can be obtained abundantly from agricultural waste, and the strong antioxidant activity demonstrated in this report may have application in topical cosmetic products. This ecological antioxidant can be prepared using a feasible method resulting in less waste and increased agro-industrial profitability. [ABSTRACT FROM AUTHOR]

Abstract: Litchi (Litchi chinensis Sonn.) is widely accepted as a delicious fruit in China and its seeds have been commonly used in traditional Chinese medicine to relieve neuralgic pain. In the present study, chemical investigation of the 95% ethanol extract of Litchi chinensis seeds led to the isolation of four new compounds, 2α,3α-epoxy-5,7,3′,4′-tetrahydroxyflavan-(4β-8-catechin) (5), 2β,3β-epoxy-5,7,3′,4′-tetrahydroxyflavan-(4α-8-epicatechin) (7), litchiol A (9) and litchiol B (12), together with 11 known ones, 2,5-dihydroxy-hexanoic acid (1), soscopoletin (2), coumaric acid (3), protocatechuic acid (4), 2α,3α-epoxy-5,7,3′,4′-tetrahydroxyflavan-(4β−8)-epicatechin (6), pterodontriol d-6-O-β-d-glucopyranoside (8), Narirutin (10), naringin (11), dihydrocharcone-4′-O-β-d-glucopyranoside (13), pinocembrin-7-rutinoside (14), pinocembrin-7-neohesperidoside (15). Their structures were mainly elucidated on the basis of NMR, MS, IR, CD and UV spectral evidences. Antioxidant activities of 14 compounds were determined by DPPH radical-scavenging assay and Trolox equivalent antioxidant capacity assay, and the results showed that four compounds, protocatechuic acid (4), 2α,3α-epoxy-5,7,3′,4′-tetrahydroxyflavan-(4β-8-catechin (5), 2α,3α-epoxy-5,7,3′,4′-tetrahydroxyflavan-(4β−8)-epicatechin (6), 2β,3β-epoxy-5,7,3′,4′-tetrahydroxyflavan-(4α-8)-epicatechin (7), exhibited moderate antioxidant activities. [ABSTRACT FROM AUTHOR]

Abstract: In an earlier study, radiation treatment (0.5kGy) and low temperature (4°C) storage were found to extend the shelf life of litchi fruit var. ‘Shahi’ and ‘China’ from India up to 28days, while maintaining its physical, biochemical and organoleptic properties. The current study was aimed to elucidate the antioxidant and radioprotective properties of the litchi fruit, and the effect of radiation processing on these properties. The litchi fruit was found to be significantly rich in antioxidant and radioprotective properties, and the antioxidant parameters were found to be well correlated with the phenolic and flavonoid contents. A significant protection to pBR322 plasmid DNA and Escherichia coli cells from radiation induced damage was observed in the presence of litchi juice. Plasmid DNA was well protected even at the dose of 5kGy, whereas, bacterial cells could be protected up to 0.5kGy. Neither of these properties was found to be sensitive to radiation processing or low temperature storage. [ABSTRACT FROM AUTHOR]

Abstract: 3,12-Dihydroxy-cis-3,4-methylenedodecanoic acid 3-O-β-d-glucopyranoside, trivially named litchioside C (1), the first cyclopropyl-containing fatty acid glycoside, was isolated along with three previously uncharacterized galactosylacylglycerols from the seeds of Litchi chinensis. Its structure was established on the basis of spectroscopic analysis including HRESIMS and 2D NMR spectra. Its antioxidant and antibacterial activities were evaluated and its biogenetic pathway was discussed. [Copyright &y& Elsevier]

Abstract: Fruit stones and pericarps of Litchi chinensis, waste products of the food, were studied as a source of polymeric proanthocyanidins. The structures of the polymeric proanthocyanidins isolated from Litchi chinensis were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) coupled with high performance liquid chromatography electrospray ionization mass spectrometry (HPLC-ESI-MS) analysis. The spectra obtained through MALDI-TOF MS analysis revealed that the dominant A-type procyanidin polymers occurred in each polymer length with one or more A-type linkages. The polymeric proanthocyanidins of litchi fruit stones exhibited longer polymer length than those of fruit pericarps, with polymerization degrees up to 20 and 11 for fruit stones and pericarps, respectively. After depolymerization with toluene-α-thiol, HPLC-ESI-MS analysis showed that epicatechin and A-type dimer were the major constituent units, and the mean polymerization degrees were 15.4 and 5.8 for polymeric proanthocyanidins of fruit stones and pericarps, respectively. The antioxidant properties investigated using DPPH, ABTS and FRAP methods showed that the higher polymerization degree of polymeric proanthocyanidins from litchi fruit stones exhibited higher antioxidant activities than those from litchi pericarps. [Copyright &y& Elsevier]

Litchi (Litchi chinensis Sonn.) fruit pericarp (LFP) contains a high amount of flavonoids, which could be used as natural antioxidants. Some emerging novel technologies, such as ultrasonic extraction (UE) and high-pressure extraction (HPE), have exhibited great potential for flavonoid extraction. Experiments were conducted to comparatively investigate the effects of conventional extraction (CE), 40-KHz UE and 200- or 400-MPa HPE on the extraction efficiency of flavonoids from LFP. After 30 min of extraction, the extract yield, total phenolic content, 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and superoxide anion scavenging ability were examined. The crude extract yields by the UE, 400 HPE and CE were 24, 30 and 1.83%, respectively. However, there were no significant differences (P > 0.05) in the total phenolic content and antioxidant activity tested among these three different extractions at the same concentration. In addition, two flavonoids, namely epicatechin and epicatechin gallate, were identified and quantified as the major compounds, while catechin and procyanidin B2 were identified as the minor compounds. The total flavonoid content detected was 0.65, 0.75, 0.29 and 0.07 mg/g dry weight by HPE at 200 and 400 MPs, UE, and CE, respectively. Thus, the HPE technique showed a higher efficiency in extracting flavonoids from LFP, and the HPE could reduce the extraction time and increase the amount of the extracted phenolics. PRACTICAL APPLICATIONS Litchi ( Litchi chinensis Sonn.) is a subtropical fruit that originated in Southeast Asia. As litchi fruit is gradually accepted by consumers for its delicious taste and attractive red skin, litchi production has steadily increased in recent decades, with increasing exports to Europe and North America from both the southern and northern hemisphere production areas. Litchi fruit pericarp (LFP) accounts for approximately 16% by weight of the whole fresh fruit and is comprised of a significant amount of flavonoids. Therefore, LFP tissues may be considered an important source of dietary flavonoids. This work showed that HPE technique has a high efficiency in extracting flavonoids from LFP tissues, which may help the litchi industry develop new extraction methods to better utilize the flavonoids from LFP tissues. [ABSTRACT FROM AUTHOR]

Abstract: The antioxidant capacities of the acetone, methanol and water extracts of hot-air dried lychee (Litchi chinenesis Sonn.) flowers were estimated with Trolox equivalent antioxidant capacity (TEAC) assay, reducing power and 2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) radical-scavenging assay. The contents of antioxidant components in these extracts were also determined. Results showed that the highest and lowest contents of these components including phenols, flavonoids and condensed tannins were found in acetone and water extracts, respectively. The antioxidant activities of the lychee flower extracts for all assays were in the order: acetone extract>methanol extract>water extract. The contents of antioxidant components in these extracts were correlated with antioxidant activities. [Copyright &y& Elsevier]

As a promising technique, high-pressure extraction (HPE) method was used to extract bioactive compounds from litchi fruit pricarp. The study involved in different experimental factors such as solvent, ethanol concentration (35-95, v/v), material to solvent ratio (1:25-1:100, w/v), acidic medium, extraction pressure (200-500 MPa), time (2.5-30 min) and temperature (30-90 °C). The extraction yield, total phenolic contents, 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and superoxide anion scavenging capability of the HPE sample were examined and then compared with those of ultrasonic extraction and conventional extraction samples. The application of HPE obtained higher extraction yield compared to other extraction methods. However, there were no significant differences ( P > 0.05) in the total phenolic content and the antioxidant activities among these various extractions. Compared with some conventional extraction method, the HPE exhibited higher extraction efficiency in terms of higher extraction yield and extraction time. [ABSTRACT FROM AUTHOR]

Abstract: The main oligomeric procyanidins from litchi pericarp (Litchi chinensis) were isolated and identified. Complete assignment of epicatechin-(4β→8, 2β→O→7)-epicatechin-(4β→8)-epicatechin structure was obtained using CD, NMR and ESI-MS techniques. The known (−)-epicatechin and procyanidin A2 were also isolated from litchi pericarp. The effects of oligomeric procyanidins, A2 and epicatechin-(4β→8, 2β→O→7)-epicatechin-(4β→8)-epicatechin from litchi pericarp on free radical-scavenging were determined by using a chemiluminescent method. The results showed that all of them had a strong scavenging effect on OH, and the IC50 values were 2.60μg/ml, 1.75μg/ml and 1.65μg/ml for oligomeric procyanidins, A2 and the trimeric procyanidins, respectively. The antioxidant activities of A-type dimeric and trimeric procyanidins seemed to be related to the number of hydroxyls in their molecular structures. [Copyright &y& Elsevier]