Search

Backgroud The Lanzhou lily (Lilium davidii var. unicolor) is the only Lilium species that is used for both culinary and medicinal purposes in China. Its bulbs contain various bioactive substances, such as polysaccharides, saponins and colchicine. Lanzhou lily polysaccharides are known to have anti-immunity, anti-tumor and anti-oxidation functions. Results The present study used a Box-Behnken design to optimize the ultrasound-assisted extraction of Lanzhou lily polysaccharides. Compared to other enzymes, trypsin significantly increased the polysaccharide yields, whereas the protein content of polysaccharides extracted with trypsin was the lowest. Monosaccharide mainly includes glucose (> 50%) and mannose (> 10%). 1,1-Diphenyl-2-picrylhydrazyl radical scavenging activity, chelating activity, total antioxidant capacity and hydroxyl radical scavenging activity of Lanzhou lily polysaccharides extracted with trypsin were stronger than those extracted without enzymes (control). Structural characteristics of Lanzhou lily polysaccharides extracted with trypsin and extracted without enzymes were characterized by scanning electron microscopy and nuclear magnetic resonance spectroscopy. When water extracted polysaccharide and trypsin extracted polysaccharide concentrations were 200 μg mL-1 , Raw264.7 proliferation rates were 101.69% and 159.41%, respectively. Conclusion The Lanzhou lily polysaccharide was identified as α-(1 → 6)-d-glucan. Consequently, the effects of both potential antioxidant and proliferative activity of trypsin are significant. © 2020 Society of Chemical Industry.

Glycyrrhizae radix has been widely accepted as a functional food in Asia. Isoliquiritigenin is a characteristic bioactive chemical in this medicinal plant. In this work, the neuroprotective effect of isoliquiritigenin and the possible mechanisms were investigated. The results revealed that isoliquiritigenin exhibited better neuroprotective and antioxidant activities than quercetin, a commercial natural antioxidant. Isoliquiritigenin significantly inhibited the release of lactate dehydrogenase, and the generation of reactive oxygen species in H2O2-treated cells. The activities of superoxide dismutase, glutathione peroxidase and catalase were improved. The mRNA expression levels related to oxidative defense and cell apoptosis were reversed by isoliquiritigenin. Moreover, isoliquiritigenin might inhibit the cell apoptosis via ameliorating the loss of mitochondrial membrane potential and the change of nucleus morphology.

Banana is a fruit widely accepted by people over the world. Besides having delicious taste, it shows multiple health benefits. In this work, the major polysaccharide was isolated from banana and purified. It was identified to be α-(1 → 6)- d -glucan. The in vivo immunomodulatory activity assay indicated that α-(1 → 6)- d -glucan could improve the immune status by elevating T cell proliferation, phagocytic function of macrophage, CD3+ T cell level, CD4+/CD8+ ratio, IL-6, IgG, IgM, TNF-α and hemolysin antibody levels. The immunostimulatory activities of α-(1 → 6)- d -glucan were similar to β-(1 → 3)- d -glucan, a clinical immunostimulatory drug. This work revealed that α-(1 → 6)- d -glucan was an important bioactive chemical for the immunostimulatory activity of banana. It could be used as a nutraceuticals candidate.

Estrogen receptors (ERs) are transcription factors highly involved in physiological development and metabolism in the human body. They also play important roles in the treatment of cancer and metabolic diseases. Chemicals that interact with ERs can be used to treat diseases and maintain health. Phytoestrogens are natural chemicals that have been documented to possess significant ER modulatory activities. However, since phytoestrogens usually exist at low quantities in nature, heterologous biosynthesis techniques have quickly developed in recent years in order meet the demands for needed therapeutic amounts. In this review, the performance of phytoestrogens as ER modulators is described along with recent advances in biosynthesis techniques.

The peel of Citrus reticulate ‘Chachiennsis’ (Chachi) is widely accepted as a functional food. It is generally recognized that its health benefits are dependent on storage time. However, the chemicals responsible for this phenomonon remain unclear. As bioactive polysaccharides are dominant in Chachi, Chachi polysaccharides with various storage times (5–20 years) were prepared. The monosaccharide composition was analyzed by GC-MS. NMR data revealed that Chachi polysaccharides were mainly consisted of arabinogalacturonan and another pectin with side chain of →4)-β-D-Galp-(1 → . α-L-Araf-(1→, →5)-α-L-Araf-(1→, →4)-α-D-GalpA-(1→, →4)-α-D-GalpAMe-(1→, →4)-β-D-Galp-(1→ and →4)-β-D-Glcp-(1→ were detected. The molecular weight of Chachi polysaccharides decreased along with the extension of storage time. However, the basic structure characteristics remained stable. The immumomodulatory activities of Chachi polysaccharides were improved as the storage time extended. The change of molecular weight was responsible for the improved immunomodulatory activity. The results explained how polysaccharides contributed to the enhanced health benefits of Chachi during storage.

Background Neurodegenerative diseases are becoming increasingly prevalent over the world. Therefore, drug development in this field is urgently required. Neuron impairment leads to the pathogenesis of neurodegenerative diseases, while amelioration of oxidative stress can inhibit the impairment. As a traditional Chinese medicine, mulberry leaf exhibits various pharmacological properties, including neuroprotective activity. But the major components responsible for the neuroprotective activity of mulberry leaf remained unknown. Phytochemicals were potent candidates of neuroprotective drug. Prenylated phenolics are the leading phytochemicals present in mulberry leaf. Purpose The aim of this study was to investigate the neuroprotective activities and mechanisms of prenylated phenolics. Methods The chemical structure of isolated compounds were elucidated by MS and NMR. UPLC-MS/MS was used to determine the contents of prenylated phenolics in fresh mulberry leaf. Neurotoxicity was induced by erastin in HT22 cells. CCK-8 assay was performed to assess cell viability. ROS production, GSH level and iron release were monitored by using DCFH-DA, monobromobimane, and FeRhoNox™-1, respectively. qRT-PCR and Western blotting assays were performed to assess gene and protein expression, respectively. Results Four prenylated phenolics, including isobavachalcone, morachalcone B, moracin N and morachalcone A were isolated and identified from mulberry leaf. Their levels in fresh mulberry leaf were in a decreasing order, moracin N > morachalcone A > morachalcone B > isobavachalcone. Moreover, moracin N showed a good neuroprotective activity with an EC50 Conclusion The results confirmed that moracin N was a good ferroptosis inhibitor, which exerted neuroprotective activity through preventing from oxidative stress.

The physicochemical properties of starch in Chinese yam (Dioscorea opposita Thunb.) are highly dependent on the growth stage. However, relevant information available is limited. In this work, native starch and resistant starch (RS) were prepared from Chinese yam tuber at expansion stage and dormant stage, respectively. Their structural and physicochemical properties were determined. They presented A-type polymorphic structure. The starches from dormant stage had smaller granule sizes, lower amylose contents, less branching degrees of amylopectin, and higher proportions of double helix than those from expansion stage. Dormant stage induced starch to form a more compact structure with a higher crystallinity and larger amount of short-range ordering than expansion stage. Moreover, the starch paste from dormant stage had a high thermal stability. These results were helpful for further application of Chinese yam starch in food products.

The study explored the changes of a sulfated polysaccharide (SP) from Gracilaria Lemaneiformis during simulated human digestive system. The results showed SP was scarcely degraded without significant difference. Moreover, the results of fermentation in vitro indicated 53.7% of SP were utilized by gut microbiota with the molecular weight decreasing by 59.41% at 48 h. Meanwhile, 50.07 ± 2.82 mM of short chain fatty acids were produced in culture medium. Besides, in contrast with the regulation of galacto-oligosaccharide sacrificing diversity and richness of community, SP could regulate the composition of microbiota in a mild way. What’s more, Proteobacteria and Firmicutes were the most sensitive phyla responding to changes of pH values in this study. And Sutterella, Phascolarctobacterium, Parabacteroides, Lachnospiraceae_UCG-004, Desulfovibrio and Bacteroides were dominant genera for degrading and utilizing SP. Furthermore, the metagenomic function characteristics of microbes might be changed by SP. Thus, SP could be a potential prebiotic.

Ganoderma lucidum spore serves as a well-known immunomodulatory functional food in Asia. The polysaccharides in G. lucidum spore are responsible for the claimed immunomodulatory activity. However, the structural information of polysaccharides remains unclear. In this work, the leading water-soluble polysaccharide in G. lucidum spore (GLSP-I) with a molecular weight of 128.0 kDa was isolated and purified. The monosaccharide composition analysed by gas chromatography indicated that GLSP-I was a glucan. Three side chains, including Glc-(1 → 3)-Glc-(1 → 3)-Glc-(1 → 6)-Glc, Glc-(1 → 6)-Glc-(1 → 6)-Glc-(1 → 6)-Glc and Glc-(1 → 3)-Glc-(1 → 3)-Glc-(1 → 3)-Glc-(1 → 3)-Glc, were identified by UPLC-MS/MS. The structural characteristics were further identified by NMR spectra. The results indicated that the backbone of GLSP-I was (1 → 3)-β-D-glucan, with side chains linking at O-6. The proposed structure was drawn as below. The immunomodulatory activity assay indicated that GLSP-I could activate macrophages in a dose-dependent manner. Download : Download high-res image (29KB) Download : Download full-size image

Unlike common orange fruit, Citrus reticulata Blanco ‘Chachiensis’ (CRB) is usually served as traditional herbal medicine and function food. It is an abundant source of bioactive polysaccharides which contribute to the health benefits of CRB. However, the structure information of polysaccharides still remains unknown. In this work, the leading polysaccharide (CRBP) was purified from CRB peel. The structure was identified by nuclear magnetic resonnance spectroscopy. The backbone was (1 → 4)-α-D-galacturonan, while the branch was α-L-Araf-(1 → 5)-α-L-Araf-(1 → . The molecular weight was calculated to be 55.4 kDa. The proposed structure was drawed as below. The cell assays indicated that CRBP was not toxic to macrophage cells, and could promote the NO production significantly in a dose-dependent manner. These results demonstrated that CRBP was a good candidate for functional food development.

In order to evaluate the release of phenolics and the changes in antioxidant activities, fruits of Crataegus pinnatifida were subjected to in vitro digestion including simulated oral, gastric, small/large intestine digestion. Results showed that totally 37.41 ± 3.09 and 31.51 ± 2.35 mg GAE/g fruit, DW of phenolics were released for Shanlihong and Dajinxing, respectively, and the phenolics released were mainly flavonoids. Catechin, chlorogenic acid, procyanidine B2, epicatechin, paracoumaric acid, hyperoside and isoquercitrin were identified in the soluble fractions by high-performance liquid chromatography (HPLC). Results indicated that procyanidine B2, epicatechin, chlorogenic acid and catechin are four major released antioxidants. Oxygen radical absorption capacity and rapid peroxyl radical scavenging capacity were significantly positive-correlated with the release amount of total phenolics or flavonoids, demonstrating the major roles of phenolics and flavonoids in antioxidant activities. Our results implied that Shanlihong and Dajinxing could be considered as good sources of natural antioxidants.

Sour orange (Citrus aurantium) is a popular fruit with health benefits. Phenolics are the dominant bioactive compounds in this fruit. However, the full phenolics composition remains unclear. In this work, UHPLC-MS/MS was used to qualify and quantify the phenolics in sour orange fruits of cv. Morocco (MSO) and United (USO). Fifty-eight phenolics, including 26 flavonoid glycosides, 22 polymethoxylated flavonoids, 8 coumarins and 2 phenolic acids, were identified. Four limonoids were characterized. Flavonoid glycosides were the leading phenolics in MSO, while polymethoxylated flavonoids (including nobiletin, tangeritin and sinensetin) were dominant in USO. The phenolic extracts showed good antioxidant activities. USO extract had a significantly (p

In this study, Sargassum fusiforme polysaccharide was purified using a DEAE-Sepharose fast-flow column to obtain Sargassum fusiforme polysaccharides fraction (SFP-P1). As expected, the SFP-P1 contains mainly carbohydrates (87%) with less than 1% protein. Within the carbohydrate, it contains about 10% sulfate and 18% uronic acids. SFP-P1 consisted of l -fucose (13.17%), galactose (4.28%), glucose (1.95%), xylose (5.50%), and mannose (75.10%) with an average molecular weight of 113 kDa. Mannose and l -fucose were two predominant monosaccharides. In addition, (1 → )-linked or (1 → 6)-linked, (1 → 2)-linked or (1 → 4)-linked and (1 → 3)-linked glycosyl linkages accounted for 1.62%, 60.69% and 37.69% of all linkages in the molecule, respectively. The glycosidic linkage types of SFP-P1 were proven to be → 3,6)-α- d -Man p (1 →, → 4)-α- d -GalA p (1 →, → 4)-β- d -Xyl p (1 → and → 3,4)-α- d -GlcA p (1 →. The results indicated the SFP-P1 had cytoprotective activity against UVB-induced oxidative stress in HaCaT cells through stimulation of SOD, GSH-P X enzymes activities and ROS. Also SFP-P1 suppressed the UVB-induced expression of MMP-1 & MMP-9.

Flavonoids have been documented to have good antioxidant activities in vitro. However, reports on the cellular antioxidant activities of flavonoid C-glycosides are very limited. In this work, an apigenin C-glycoside was purified from Artocarpus heterophyllus by column chromatography and was identified to be 2″-O-β-D-xylosylvitexin by nuclear magnetic resonance spectroscopy. The cellular antioxidant activity and anticancer activity of 2″-O-β-D-xylosylvitexin were evaluated for the first time. The quantitative structure-activity relationship was analysed by molecular modeling. Apigenin presented an unexpected cellular antioxidation behaviour. It had an antioxidant activity at low concentration and a prooxidant activity at high concentration, whereas 2″-O-β-D-xylosylvitexin showed a dose-dependent cellular antioxidant activity. It indicated that C-glycosidation improved the cellular antioxidation performance of apigenin and eliminated the prooxidant effect. The ortho-dihydroxyl at C-3'/C-4' and C-3 hydroxyl in the flavonoid skeleton play important roles in the antioxidation behaviour. The cell proliferation assay revealed a low cytotoxicity of 2″-O-β-D-xylosylvitexin.

Polysaccharides from Gracilaria lemaneiformis possess various beneficial bioactive functions, but the immunomodulatory activity remains incompletely known. In the present study, a new low molecular-weight sulfated polysaccharide named as GLP-2 was isolated from G. lemaneiformis. The chemical composition and structural characteristics of GLP-2 were determined by high-performance gel permeation chromatography (HPGPC), gas chromatography (GC), infrared (IR) spectrum, methylation and nuclear magnetic resonance (NMR) analyses. In addition, the immunomodulatory activity and underlying mechanism of GLP-2 were examined using murine macrophage RAW264.7 cells. The results indicated GLP-2 could significantly improve the proliferation and pinocytic capability of RAW264.7 cells, and promote the production of reactive oxygen species (ROS), nitric oxide (NO), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) by activating iNOS, IL-6 and TNF-α gene expressions. These results suggested that GLP-2 could be developed as a potent immunomodulatory agent for use in functional foods and dietary supplements.

Methylated flavonoids are an important type of natural flavonoid derivative with potentially multiple health benefits; among other things, they have improved bioavailability compared with flavonoid precursors. Flavonoids have been documented to have broad bioactivities, such as anticancer, immunomodulation, and antioxidant activities, that can be elevated, to a certain extent, by methylation. Understanding the structure, bioactivity, and bioavailability of methylated flavonoids, therefore, is an interesting topic with broad potential applications. Though methylated flavonoids are widely present in plants, their levels are usually low. Because developing efficient techniques to produce these chemicals would likely be beneficial, we provide an overview of their chemical and biological synthesis.

In the present study, polysaccharides from Gracilaria lemaneiformis (GLP) were obtained by citric acid extraction, and had a low molecular weight (21.2 kDa) with a high amount of galactose. GLP showed effective inhibitory effects on α-amylase activity. After a six-week animal trial, GLP was found to combat streptozotocin (STZ)-induced diabetes and associated with oxidative stress, via its regulation of glucose and lipid metabolism, repair of pancreatic β-cells, protection of liver and kidney function, promotion of the activities of endogenous antioxidant enzymes, and suppression of lipid peroxidation. A dose-dependent manner was found in these examinations except for the glucokinase level, superoxide dismutase activity, and malondialdehyde content. GLP treatments were also more effective at regulating the insulin level, lipidemic parameters and blood urea nitrogen level than metformin treatment. Thus, GLP is more advantageous than metformin not only in the naturalness of GLP but also in the action of combating STZ-induced diabetes. Accordingly, GLP may be utilized as a potential functional food supplement for diabetes prevention in the future.

Banana is a delicious fruit with potent immunomodulatory function. In this study, α-D-(1→6)-glucan was purified from banana pulp. It could significantly promote pinocytic activity and production of nitric oxide (NO), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). The mRNA expression of nitric oxide synthase (iNOS), IL-6 and TNF-α was increased in RAW264.7 macrophages. α-D-(1→6)-glucan could not only increase the expression levels of p-p65 and p-IκBα, but also induce the translocation of nuclear factor-kappa B (NF-κB) p65 into the nucleus. Moreover, mitogen-activated protein kinases (MAPKs), including p-ERK, p-JNK and p-p38, were upregulated. These results suggested that NF-κB and MAPK signaling pathways were involved in the immunomodulatory mechanisms of α-D-(1→6)-glucan. The results revealed that α-D-(1→6)-glucan might be the critical component responsible for the health benefits of banana.

Banana as a typical climacteric fruit soften rapidly, resulting in a very short shelf life after harvest. Sodium dichloroisocyanurate (NaDCC) is reported to be an effectively antibacterial compound. Here, we investigated the effects of NaDCC on ripening and senescence of harvested banana fruit at physiological and molecular levels. Application of 200 mg L−1 NaDCC solution effectively inhibited the ripening and senescence of banana fruit after harvest. NaDCC treatment reduced greatly ethylene production rate and expressions of genes encoding 1-aminocyclopropane-1-carboxylate synthetase, 1-aminocyclopropane-1-carboxylate oxidase, ethylene-responsive transcription factor and EIN3-binding F-box protein. Meanwhile, NaDCC treatment down-regulated markedly the expressions of xyloglucan endotransglucosylase/hydrolase and pectinesterase genes. Furthermore, NaDCC treatment affected significantly the accumulation of ripening-related primary metabolites such as sugars and organic acids. Additionally, NaDCC treatment decreased the production of hydroxyl radical and increased 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, reducing power and hydroxyl radical scavenging activity. In conclusion, NaDCC delayed effectively the ripening and senescence of harvested banana fruit via the reduced ethylene effect and enhanced antioxidant activity. Electronic supplementary material The online version of this article (10.1186/s13065-018-0503-5) contains supplementary material, which is available to authorized users.

The phenolic contents, antioxidant, and antiproliferative activities of Malus doumeri were evaluated. Heyuanxiaoguo variety contained higher level of total phenolics (101.9 mg GAE/g fruit, DW), whereas Xinyishanzha variety exhibited the highest total flavonoids (85.35 mg CE/g fruit, DW), and highest cellular antioxidant and antiproliferative activities. Higher ORAC and PSC values were found in Limushan variety. Chlorogenic acid, phloretin-2′-xyloglucoside and ursolic acid were the predominant phenolics in M. doumeri , their contents were highest in Limushan (1850 mg/100g fruit, DW), Xinyishanzha (2212 mg/100g fruit, DW), and Heyuanxiaoguo variety (506.3 mg/100g fruit, DW), respectively. Among the 14 compounds identified, chlorogenic acid and phloretin glycosides accounted for 55.95% of the extracellular antioxidant capacity, while quercetin, luteolin, ursolic acid, and chlorogenic acid contributed significantly to the intracellular antioxidant activity. Furthermore, the intracellular antioxidant property of the Xinyishanzha extracts was related to the protection of endogenous antioxidant enzymes activities and inhibition of reactive oxygen species production.

Tremella fuciformis Berk, a popular nutritious mushroom in China, has attracted increasing attention due to its various bioactivities. In the present work, T. fuciformis polysaccharides (TP) were extracted with hot water. It mainly consisted of mannose, as well as 10.77% (w/w) uronic acid. In additional, the anti-photoaging effects of TP were evaluated using a 30-day UV-irradiated animal assay. TP could efficiently reduce the water and collagen losses of the skin, and inhibit the increase of glycosaminoglycans. Moreover, a histopathological study showed that, UV-induced skin structural alterations were alleviated as well as repairing endogenous collagen breakdown and maintaining the ratio of type I/III collagen, after oral treatment of TP. The activities of SOD, GSH-Px and CAT were increased compared to the irradiated control group without treatment. Accordingly, TP can be used as a potential functional food supplement for skin function protection.

Mulberry leaf is a vegetable used in daily diet. It can bring delicious taste and multiple health benefits. However, the chemicals responsible for these health benefits remain unveiled. In this work, two novel prenylated flavonoids were isolated from mulberry leaf. Their structures were identified and named as morachalcone D and morachalcone E. The protective effects of these two compounds were investigated, against endogenous oxidative damage (oxytosis/ferroptosis) induced by glutamate and erastin in HT22 cells. The results revealed that morachalcone D was much more potent in preventing from glutamate- and erastin-induced cell death than morachalcone E. The neuroprotective effect of morachalcone D was related to the prevention of ROS production, glutathione depletion, and iron accumulation. Morachalcone D upregulated the expression of genes involved in antioxidant defense, including GPx4, CAT, SOD2, Nrf2, HMOX1 and SLC7A11. These findings indicated that morachalcone D was responsible for the health benefits of mulberry leaf, and could be a potent neuroprotective agent for use in dietary supplements and functional foods.

Thermal treatment is an effective technique to modify the physiochemical properties of starch. However, investigation on the effect of repeated dry-heat treatment (RDHT) on the starch properties is limited. In this work, RDHT and continuous dry-heat treatment (CDHT) were conducted on normal maize starch. Both treatments increased pore no on the granule surface and facilitated the granule aggregation. The solubility and swelling power of normal maize starch were improved. The levels of slowly digestible starch (SDS) and resistant starch (RS) + SDS were increased. The structural characteristics, including crystallinity and short-range order, were impaired. The peak viscosity and thermal properties (To, Tp, Tc and ΔH) of starch paste were decreased. When comparing of CDHT samples with the same treating time, RDHT samples showed a lower crystallinity, a weaker thermal stability, a higher paste viscosity and a lower resistance to amylase. These results were useful for industrial application of thermal treatment on starch.

The degradation of cell wall polysaccharides is highly associated with the softening process of banana. In this work, banana was treated by morin to delay softening during storage. Water-soluble polysaccharides were extracted from banana pulp at four storage stages. Their levels increased when the banana was green, but decreased when turned to yellow. Three types of polysaccharides were identified by nuclear magnetic resonance spectroscopy, including starches, homogalacturonans and arabinogalactan proteins. (1 → 4)-α-D-galacturonan constructed the backbone of homogalacturonans, which was the leading water-soluble polysaccharide in the last stage. Starch was the dominant polysaccharide at all stages in morin-treated banana. Deassembly of insoluble starch granules and degradation of soluble starches were responsible for its high level in banana. Arabinogalactan proteins were only detected in late stages, and could be a marker for banana deterioration. The inhibited degradation of cell wall polysaccharides contributed to the preservative effect of morin.

Litchi (Litchi chinensis Sonn.) is a well-known traditional medicine since ancient times. The crude extract of litchi leaf exhibited good bioactivity against cancer cells. In this work, three sesquilignans, ehletianol C (1), sesquipinsapol B (2) and sesquimarocanol B (3), and one lignan glycoside schizandriside (4) were isolated from the ethyl acetate-soluble extract of litchi leaf by column chromatography. Their structures were further elucidated by ESI-MS and NMR spectral studies. Ehletianol C, sesquipinsapol B and sesquimarocanol B were detected from this species for the first time. Sesquipinsapol B (EC50 values less than 2.0 μg/mL) and sesquimarocanol B (EC50 values less than 2.4 μg/mL) showed very high cytotoxicities against nasopharynx carcinoma cells CNE1 and CNE2 cells, respectively. Thus, they could be utilized as good drug candidates against nasopharynx cancer. Moreover, three sesquilignans showed effective in vitro cytotoxicities against human cancer cells HepG2 and Hela. Four lignans showed better antioxidant activities than butylated hydroxytoluene (BHT).

Our previous work exhibited Aspergillus awamori fermentation of the litchi pericarp increased significantly antioxidant activity and DNA protection effect. In this present study, the litchi pericarp and its aqueous-organic extracted residues were fermented by A. awamori in order to elucidate the enhanced beneficial effects. The study identified that rutin which present in litchi pericarp could be deglycosylated to form quercetin and quercetin-3-glucoside after the fermentation. Application the standard compounds (rutin, quercetin 3-glucoside, quercetin, kaempferol-3-glucoside and kaempferol) further revealed the effective biotransformation by A. awamori fermentation. It was hypothesised that rutin was initially dehydroxylated to form kaempferol-3-rutinoside and then deglycosylated to form kaempferol-3-glucoside and kaempferol. To our best knowledge, it is the first report on dehydroxylated effect of polyphenols caused by A. awamori fermentation. Thus, A. awamori fermentation can provide an effective way to produce health benefiting value-added products from litchi pericarp in food industry.

Six flavonoids, namely luteolin (1), epicatechin (2), kaempferol 3-O-β-glucoside (3), kaempferol 3-O-α-rhamnoside (4), procyanidin A2 (5) and rutin (6) were purified from the EtOAc-soluble extract of litchi leaf by column chromatography. Their structures were elucidated by nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS) evidences. Luteolin and kaempferol 3-O-α-rhamnoside were found from this plant for the first time. Procyanidin A2 exhibited high anticancer activities against human hepatoma HepG2 and human cervical carcinoma Hela cells. However, it had poor anticancer activities against human lung cancer A549 and human breast cancer MCF-7 cells. Luteolin, epicatechin, procyanidin A2 and rutin showed good antioxidant activities than butylated hydroxytoluene (BHT). The antimicrobial activity assay indicated that luteolin possessed the strongest antimicrobial activity against Staphylococcus aureus, Escherichia coli, Shigella dysenteriae, Salmonella and Bacillus thuringiensis. Epicatechin, procyanidin A2 and rutin showed relatively weak antimicrobial activities.

Mulberry leaf is a newly accepted vegetable for daily diet. It tastes good and has multiple health benefits, including antioxidant and anti-inflammatory activities. However, the chemicals responsible for these health benefits remain unveiled. Prenylated phenolics are characteristic bioactive compounds in mulberry leaf, which are recognized as good antioxidants. In this work, moracin N was purified from mulberry leaf. It showed better antioxidant activities than resveratrol. The EC50 value of cellular antioxidant activity was 24.92 μM, and the IC50 value against DPPH radical was 40.00 μM. The prenyl group rendered the molecule more membrane affinity which improved the bioavailability. The furan ring was critical for the antioxidant behaviour. The cell viability test revealed that moracin N had a good safety. These results pointed out that moracin N contributed to the antioxidant activity of mulberry leaf.

Chinese olive (Canarium album (Lour.) Raeusch) is a subtropical fruit, which has been used in traditional Chinese medicine since ancient age. In the present work, the structural characteristics of oligosaccharides from C. album fruit (OCAF) fleshes were investigated. By gas chromatography analysis, both OCAF and free sugar fractions comprised fructose, glucose, and galactose, and the molar percentages varied between cultivars. Moreover, galactose was found to be the dominant monosaccharide in OCAF, while glucose was the dominant one in free sugar fraction. The glycosidic linkages of OCAF were →6)-Gal-(1→, →6)-Glu-(1→, →4)-Fru-(2→, and →1)-Gal. Hierarchical cluster dendrogram indicated that oligosaccharides of “XZ” and “HP” cultivars had a greater proximity than the others, while the oligosaccharides of “TS” cultivar had the most significant difference to the other cultivars. The growth-stimulating effect of OCAF on Lactobacillus bulgaricus and Streptococcus thermophilus was observed to vary in a dose-dependent manner.

This study was conducted to increase the bioactivity of litchi pericarp polysaccharides (LPPs) biotransformed byAspergillus awamori. Compared to the non-A. awamori-fermented LPP, the growth effects ofA. awamori-fermented LPP onLactobacillus bulgaricusandStreptococcus thermophiluswere four and two times higher after 3 days of fermentation, respectively. Increased 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and DNA protection activity of litchi pericarp polysaccharides were also achieved afterA. awamorifermentation. Moreover, the relative content of glucose and arabinose in LPP after fermentation decreased from 58.82% to 22.60% and from 18.82% to 10.09%, respectively, with a concomitant increase in the relative contents of galactose, rhamnose, xylose, and mannose. Furthermore, lower molecular weight polysaccharides were obtained afterA. awamorifermentation. It can be concluded thatA. awamoriwas effective in biotransforming LPP into a bioactive mixture with lower molecular weight polysaccharides and higher antioxidant activity and relative galactose content.

Litchi (Litchi chinensis Sonn.) is a delicious fruit widely accepted by consumers all over the world. In this work, phytochemical investigation of litchi pericarp methanol extracts led to the isolation of a novel phenolic, 2-(2-hydroxyl-5-(methoxycarbonyl) phenoxy) benzoic acid, together with kaempferol, isolariciresinol, stigmasterol, butylated hydroxytoluene, 3,4-dihydroxyl benzoate, methyl shikimate and ethyl shikimate. Most were found in litchi pericarp for the first time. Their structures were mainly elucidated by NMR and MS evidences. Antioxidant activities of the eight compounds were determined by a DPPH radical scavenging assay and the results showed that 2-(2-hydroxy-5-(methoxycarbonyl) phenoxy)benzoic acid, kaempferol, isolariciresinol, butylated hydroxytoluene and 3,4-dihydroxy benzoate exhibited good antioxidant activities. An interesting finding was that butylated hydroxytoluene was detected as a natural antioxidant in this work, which was usually taken as a synthesized antioxidant. Furthermore, the novel compound exhibited no inhibitory effects against tyrosinase and α-glucosidase activities.

The cytotoxicity and antiproliferative effect of phytochemicals presenting in the fruits of Chinese hawthorn (Crataegus pinnatifida) were evaluated. Shanlihong (Crataegus pinnatifida Bge. var. major N.E.Br.) variety possessed significant levels of flavonoids and triterpenoids, and showed potent antiproliferative effect against HepG2, MCF-7 and MDA-MB- 231 human cancer cells lines. Triterpenoids-enriched fraction (S9) prepared by Semi-preparative HPLC, and its predominant ingredient ursolic acid (UA) demonstrated remarkably antiproliferative activities for all the tested cancer cell lines. DNA flow cytometric analysis showed that S9 fraction and UA significantly induced G1 arrest in MDA-MB-231 cells in a dose-dependent manner. Western blotting analysis revealed that S9 fraction and UA significantly induced PCNA, CDK4, and Cyclin D1 downregulation in MDA-MB-231 cells, followed by p21Waf1/Cip1 up-regulation. Additionally, flow cytometer and DNA ladder assays indicated that S9 fraction and UA significantly induced MDA-MB-231 cells apoptosis. Mitochondrial death pathway was involved in this apoptosis as significantly induced caspase-9 and caspase-3 activation. These results suggested that triterpenoids-enriched fraction and UA exhibited antiproliferative activity through the cell cycle arrest and apoptosis induction, and was majorly responsible for the potent anticancer activity of Chinese hawthorn.

The acid- and alkali-soluble polysaccharides (DIPs I and II) were extracted from the fruiting body of Dictyophora indusiata in this work. DIP I comprised of Glc (glucose), Fru (fructose) and Man (mannose), whereas DIP II was of Glc and Fru. Glc was the dominant monosaccharide in both DIPs with relatively molar percentage of >60%, which constructed the backbone of polysaccharide chain. The analysis of the glycosidic linkages indicated that Glc occurred as Glc 1 → 6 in DIP II. The immunological assays showed that both DIPs I and II had a noticeable effect on the hemolysis antibody level in the tested dosage range. However, DIP I could improve the weight of thymus organ and phagocytosis of monocyte. DIP II could restore delayed-type hypersensitivity reaction to dinitrofluorobenzene (DNFB), improving the activity of natural killer cells and the proliferation of splenocytes at high dose.

In this work, quercetin, p -courmaric acid and their derivatives were chosen to evaluate the prooxidant activity in NADPH/peroxidase/H 2 O 2 and DNA cleavage systems. The balance between antioxidant and prooxidant effect was not apparent. The number of hydroxyl groups, hydrophilicity, steric hindrance, concentration and affinity to peroxidase were critical for the prooxidation behaviour of tested compounds. Ortho -methoxy substitution led to a decreased prooxidant activity for p -courmaric acid. The DNA cleavage activity was in a decreasing order, quercetin = rutin > p -courmaric acid > ferulic acid > quercetin 3-O-glucoside. By calculation of Δ E (LUMO−HOMO) and ΔHOF, the reactivity of forming phenoxyl radicals was quercetin > rutin > quercetin 3-O-glucoside, which was in agreement with their DNA cleavage activities. The prooxidant activity order of p -courmaric acid and ferulic acid was in contrast to their reactivities of forming phenoxyl radical. The log P difference should play a critical role in the prooxidation behaviour.

Longan (Dimocarpus longan Lour.) is a non-climacteric subtropical fruit which is widely accepted by consumers all over the world for its pleasant flavor and health benefits. In the present work, the effects of ultrasonic power (120–300 W), temperature (30–70 °C) and ethanol concentration (40–80%) on the yield of total phenolics and 1,1- diphenyl-2- picrylhydrazyl (DPPH) radical scavenging activity were investigated with artificial neural network, and they were proved to be interactional and significant on the dependent variables. The R 2 and MSE values of the models suggested good fitness and generalization of the artificial neural network. The results indicated a positive linear relationship between antioxidant activity and total phenolic content. Compared with conventional extraction, ultrasound-assisted extraction showed a higher yield of total phenolics and required a shorter extraction time. A stronger antioxidant activity of the ultrasonic extract was also found compared with conventional extraction.

Rabdosia serra has been used in traditional Chinese medicine for centuries. In order to illustrate the pharmaceutical activity of R. serra as hypoglycaemic and skin-whitening agents, rosmarinic acid (confirmed as the major compound in R. serra), methyl rosmarinate and pedalitin isolated from R. serra were evaluated for their inhibitory effects and mechanisms on tyrosinase and α-glucosidase. The inhibitory effects on both tyrosinase and α-glucosidase were in decreasing order, pedalitin>methyl rosmarinate>rosmarinic acid. The IC50 values for the tyrosinase and α-glucosidase activity inhibited by pedalitin were 0.28 and 0.29mM, respectively. Both rosmarinic acid and methyl rosmarinate were considered as noncompetitive inhibitors of tyrosinase, while pedalitin was suggested to be a mixed-type inhibitor of tyrosinase. In the assay of α-glucosidase inhibition, rosmarinic acid was found to be a competitive inhibitor, whereas both methyl rosmarinate and pedalitin were considered as mixed-type inhibitors.

Ultrasound-assisted extraction was employed to prepare polysaccharides from Isodon lophanthoides var. gerardianus (Bentham) H. Hara (Xihuangcao). Response surface methodology was used to optimize the ultrasound-assisted extraction parameters. Central-composite design was applied to estimate the effects of ultrasonic time, liquid/solid ratio and pH on the yield of the polysaccharides from I. lophanthoides var. gerardianus (Bentham) H. Hara (ILHP). A mathematical model with high fitness was obtained. Ultrasonic time, liquid/solid ratio and pH exhibited independent and interactive effects on ILHP yield. Gas chromatography analysis suggested that ILHP-3 comprised Rha, Man, Glc with relative molar percentages of 3.9%, 8.0% and 88.1%, respectively. The assay of glycosidic linkage showed that ILHP-3 was consisted of →2)-Man-(1→, →6)-Glc-(1→, →3)-Rha-(1→ with a molar proportion of 1.9:26.5:1. The average molecular weight of ILHP-3 was measured to be 247 kDa by high-performance gel permeation chromatography. Furthermore, a good antioxidant activity was observed for ILHP-3.

The leaf and stem of Rabdosia serra were extracted by different solvents in this work. The results indicated that 60% ethanol was the most suitable solvent for efficiently extracting antioxidants with strong free radical-scavenging capacity and ferrous ion chelating capacity. The butanol and 60% ethanol extracts of stem, methanol and 60% ethanol extracts of leaf were analysed by HPLC–PDA. A similar chemical composition was observed for these stem and leaf extracts. The major compound was obtained by column chromatography and identified by mass spectrometry and nuclear magnetic resonance spectroscopy, which was confirmed to be rosmarinic acid. The contents of rosmarinic acid were in a descending order: butanol extract of stem > 60% ethanol extract of leaf > 60% ethanol extract of stem > methanol extract of leaf.

It is evident from various epidemiological studies that consumption of fruits and vegetables is essential to maintain health and in the disease prevention. Present study was designed to examine phenolic contents and antioxidant properties of three varieties of Crataegus pinnatifida (Chinese hawthorn). Shanlihong variety exhibited elevated levels of total phenolics and flavonoid contents, including free and bond phenolics. Procyanidin B2 was most abundant phenolic compound in all samples, followed by epicatechin, chlorogenic acid, hyperoside, and isoquercitrin. The free ORAC values, and free hydro-PSC values were 398.3-555.8 μmol TE/g DW, and 299.1-370.9 μmol VCE/g DW, respectively. Moreover, the free cellular antioxidant activity (CAA) values were 678-1200 μmol of QE/100 g DW in the no PBS wash protocol, and 345.9-532.9 μmol of QE/100 g DW in the PBS wash protocol. C. pinnatifida fruit could be valuable to promote consumer health.

Litchi leaf is a good resource for phenolics, which are good candidates for medicines. In this work, three phenolics were isolated from litchi leaf by column chromatography. Their structures were identified by electrospray ionization–mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR) spectroscopy as secoisolariciresinol 9′-O-β- D- xyloside (1), 4,7,7′,8′,9,9′-hexahydroxy-3,3′-dimethoxy-8,4′-oxyneolignan (2), and cinnamtannin B1 (3). Cinnamtannin B1 showed better extra- and intracellular antioxidant activities than Compound 1 , Compound 2 . The intracellular antioxidant activity of cinnamtannin B1 was related to the upregulation of endogenous antioxidant enzyme activities (superoxide dismutase, catalase, and glutathione peroxidase), and inhibition of ROS generation. Furthermore, cinnamtannin B1 exhibited strong antiproliferative effects against HepG2 and Siha cell lines with no significant cytotoxicities. In the case of the HepG2 cell line, cell cycle arrest and apoptosis induction were the underlying anticancer mechanisms of cinnamtannin B1. The results indicated that cinnamtannin B1 was a potent cancer cell proliferation inhibitor and a good intracellular antioxidant.

Longan is a delicious subtropical fruit with great health-beneficial effects. It has been utilized for disease prevention and health care since ancient age. To explore the chemicals responsible for the health benefits, water-soluble polysaccharides were extracted from longan flesh in this work. A pure polysaccharide (LPS1) was obtained through column purification. Analysis by gas chromatography showed LPS1 was a homopolysaccharide of glucose with glycosidic linkage of →6)-d-Glc-(1→. Nuclear magnetic resonance (NMR) spectra indicated that the configuration of anomeric carbon in glucose residual was α-form. The polysaccharide structure was further confirmed to be (1→6)-α-d-glucan by chemcial shift of C6. The molecular weight of LPS1 was calculated to be 108 kDa, which had 661 glucose residuals. Anticancer assay showed that LPS1 had anticancer activity against the growth of HepG2 cells to a certain extent. However, it did not show any cytotoxicity against MCF-7 breast cancer cells.

Ultrasound-assisted extraction was employed to extract polysaccharides from longan seed (LSP), with aids of a Box-Behnken statistical design to investigate the effects of ultrasonic power, time and liquid/solid ratio on the extraction recovery of the LSP. The structural analysis indicated that arabinose, galactose, glucose and mannose were major components of LSP, with →6)-Gal-(→1, Glc-(→1 and →6)-Glc-(1→ glycosidic linkages. In an in vitro antioxidant activity of the 1,1-diphenyl-2-picryldydrazyl radical-scavenging assay, LSP exhibited a dose-dependent property within the concentration range tested.

The air-dried fruit hull of Phyllanthus emblica L. was extracted with 95% ethanol, and then the extract was partitioned by diethyl ether and ethyl acetate (EA). The EA fraction was then subjected to separation and purification using silica gel and Sephadex LH-20 column chromatography repeatedly to obtain five hydrolysable tannins. They were identified as mucic acid 1,4-lactone 3-o-gallate (C1), isocorilagin (C2), chebulanin (C3), chebulagic acid (C4) and isomallotusinin (C5) using mass spectrometry and nuclear magnetic resonance (NMR) spectrometry. Isomallotusinin and chebulanin were identified from emblica dried fruit hull for the first time, and isomallotusinin was the first time identified from Phyllanthus. Furthermore, the antioxidant abilities of these hydrolysable tannins were investigated using DPPH and ABTS+ radical scavenging systems. All hydrolysable tannins showed strong DPPH and ABTS+ radical scavenging activities. Isomallotusinin and chebulagic acid exhibited the highest antioxidant activity compared to other purified compounds tested.