Sugars, sugar alcohols, fruit acids, and ascorbic acid in wild Chinese sea buckthorn (Hippophaë rhamnoides ssp. sinensis) with special reference to influence of latitude and altitude

Wild berries of Hippophaë rhamnoides ssp. sinensis were collected from nine natural growth sites in China in three consecutive years in order to get an overall profile of the sugars, sugar alcohols, fruit acids, and ascorbic acid, and especially of the influence of the latitude and altitude of the growth place on these components. The contents of fructose, glucose, and l-quebrachitol in the berry juice varied in the ranges of 0.01-7.17, 0.05-7.85 and 0.21-1.09 g/100 mL, respectively, those of malic, quinic, and ascorbic acids were 1.55-8.84, 0.07-2.94, and 0.25-1.66 g/100 mL, respectively. The berries from Hebei and Inner Mongolia were characterized by high contents of sugars and l-quebrachitol and low contents of malic acid and ascorbic acid. In contrast, the berries from Sichuan and Qinghai contained lower contents of sugars and higher contents of malic acid and ascorbic acid than the berries from other growth areas. The berries from Sichuan differed considerably from others by the remarkably low contents of sugars and the exceptionally high contents of acids. The contents of fructose, glucose, and total sugar decreased as the altitude increased and as the latitude decreased (p < 0.05). In contrast, the contents of malic acid and ascorbic acid increased as the altitude increased and as the latitude decreased (p < 0.05). The contents of quinic acid and l-quebrachitol correlated strongly and positively with the latitude (p < 0.01).     

Phytosterol content of sea buckthorn (Hippophae rhamnoides L.) seed oil: Extraction and identification

Phytosterols in sea buckthorn (Hippophae rhamnoides L.) seed oil extracted by cold pressing, hexane, and supercritical carbon dioxide were identified by GC–MS and FID. Compounds identified were campesterol, clerosterol, lanosterol, sitosterol, β-amyrin, sitostanol, Δ⁵-avenasterol, Δ²⁴⁽²⁸⁾-stigmasta-en-ol, α-amyrin, Δ^5,24(25)-stigmastadienol, lupeol, gramisterol, Δ⁷-sitosterol, cycloartenol, cycloeucalenol, Δ⁷-avenasterol, 28-methylobtusifoliol, 24-methylenecycloartanol, erythrodiol, citrostadienol, uvaol, and oleanol aldehyde. Sitosterol and Δ⁵-avenasterol were, quantitatively, the most important phytosterols. Total sterols and most individual sterols differed significantly (P ? 0.05) among all three extraction methods with supercritical carbon dioxide extracting the highest total sterol levels (1640 mg/100 g oil) and cold pressed the lowest levels (879 mg/100 g oil).     

Antimicrobial, antioxidant and phytochemical investigations of sea buckthorn (Hippophaë rhamnoides L.) leaf, stem, root and seed

The antimicrobial and antioxidant activities of crude ethanolic extract from Hippophaë rhamnoides L. (Elaeagnaceae) leaf, stem, root and seed, and their respective fractions, obtained by liquid-liquid extraction (LLE) using hexane (HF), ethyl acetate (EAF) and water (WF), were investigated. The crude extract was obtained by Pressurised Liquid Extraction (PLE), using ethanol at 100 bar and 60 °C. Antimicrobial activity was tested against food-borne and clinical microorganisms. Antioxidant activity was measured using the DPPH-radical scavenging and the ferric reducing antioxidant power (FRAP) assays. The phytochemical contents were examined by colorimetric methods. The results showed that crude extracts were active against Gram − and + strains, and that seed and root extracts were better radical scavengers than leaf and stem extracts. For all organs, the two activities tested were found to be higher in WF. These activities were correlated with the presence of phenolic compounds in active fractions. High Performance Thin Layer Chromatography (HPTLC) fingerprints confirmed presence of phenolic compounds in active extracts and fractions.     

New flavonol glycosides from Barbeya oleoides Schweinfurth

Three new flavonol glycosides, 3′,5′ dimethoxymyricetin-4″-O-α-l-rhamnopyranosyl (1–4) β-d-glucopyranoside (1), 3′-methoxyquercetin-4″-O-α-l-rhamnopyranosyl (1–4) β-d-glucopyranoside (2) and 3′-methoxyqurecetin-6″-O-α-l-rhamnopyranosyl (1–6) β-d-glucopyranoside (3), have been isolated from the aerial part of Barbeya oleoides Schweinf., along with twelve known compounds, uvaol (4), ursolic acid (5), corosolic acid (6), arjunolic acid (7), β-sitosterol-3-O-β-d-glucoside (8), (+)–catechin (9), (-)-epicatechin (10), isorhamnetin-4′-O-glucoside (11), arjunglucoside I (12), d-(-)-bornesitol (13), gallocatechin (14) and epigallocatechin (15). Compounds 4–15 were isolated for the first time from Barbeyaceae. Structure elucidation of compounds 1–3 was based on MS and NMR data. The ethyl acetate extract of the stems as well as compounds 5, 6, 14 and 15 showed significant antimicrobial activity, while the ethanol extracts of leaves, stems and compounds 4, 7, 8, 13–15 have dose-dependent spasmolytic action.     

Preparation and antioxidant activity of enzymatic hydrolysates from purple sea urchin (Strongylocentrotus nudus) gonad

Purple sea urchin (Strongylocentrotus nudus) gonad was treated separately with neutral protease, papain, pepsin and trypsin. The resultant hydrolysates were fractionated using a series of ultrafiltration membranes (molecular weight cut-offs of 10, 5, 3 and 1 kDa). Five fractions were prepared from each hydrolysate and the corresponding molecular weight ranges were below 10 kDa, 5-10 kDa, 3-5 kDa, 1-3 kDa and below 1 kDa. The peptide fractions were evaluated for antioxidant activity by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and reducing power assay. Results indicated that all peptide fractions possessed DPPH radical scavenging capacity and reducing power in a dose-dependent manner. For all four hydrolysates, the below 1 kDa fractions exhibited the highest DPPH radical scavenging capacity. The below 1 kDa fractions prepared with neutral protease, papain and pepsin, and the 1-3 kDa fraction prepared with trypsin showed the highest reducing capacity among corresponding hydrolysates.     

Influence of origin,harvesting time and weather conditions on content of inositols and methylinositols in sea buckthorn (Hippophaë rhamnoides) berries

Inositols and methylinositols play an important role in human physiology. Inositols and methylinositols in berries of three subspecies of sea buckthorn (Hippophaë rhamnoides) were analysed using gas chromatography combined with a flame ionisation detector and mass spectrometry. The wild Chinese berries (H. rhamnoides ssp. sinensis) contained higher levels of l-quebrachitol (1l-2-O-methyl-chiro-inositol) and methyl-myo-inositol (average 615 and 58 mg/100 ml juice, respectively) than the Finnish (H. rhamnoides ssp. rhamnoides, 276 and 11 mg/100 ml juice, respectively) and the Russian (H. rhamnoides ssp. mongolica, 228 and 16 mg/100 ml juice, respectively) berries (P < 0.001). The content of myo-inositol was higher in the Chinese and the Russian berries than in the Finnish berries (26 and 20 mg/100 ml juice vs. 8 mg/100 ml juice, P < 0.001). In the Chinese berries, the contents of methyl-myo-inositol and l-quebrachitol increased, whereas that of myo-inositol decreased from late September to late November. The content of the l-quebrachitol in the Chinese berries correlated negatively with the air temperature and the number of frost-free days, suggesting a possible role of the compound in the cold resistance of sea buckthorn.     

Subcritical water extraction of antioxidant compounds from Seabuckthorn (Hippophae rhamnoides) leaves for the comparative evaluation of antioxidant activity

A novel environmentally friendly technique, subcritical water extraction (SWE) was employed for the extraction of antioxidant compounds from Seabuckthorn leaves (SBT). Antioxidant activity of the extracts was evaluated using commonly accepted chemical assays. Also, present study reports the cytoprotective and antioxidant properties of SBT against tertiary-butyl hydroperoxide (tert-BOOH) induced oxidative stress in murine macrophages (Raw 264.7). Exposure of cells to tert-BOOH resulted, increase in cytotoxicity, reactive oxygen species (ROS) production and decrease in mitochondrial membrane potential, which is responsible for fall in intracellular antioxidant levels. Pretreatment of cells with SBT extracts inhibited cytotoxicity, ROS production and maintained antioxidants levels similar to that of control cells.     

Three new flavanonol glycosides from leaves of Engelhardtia roxburghiana, and their anti-inflammation, antiproliferative and antioxidant properties

The ethyl acetate fraction of the leaves of Engelhardia roxburghiana Wall exhibited strong anti-inflammatory, anti-proliferative, and antioxidant activities. From this fraction, three new flavanonol glycosides: (2R, 3R)-3,5,7,4′-tetrahydroxyflavanonol-3-O-(3″-O-galloyl)-α-l-rhamnopyranoside (1), (2R, 3R)-3,5,7,3′,4′-pentahydroxyflavanonol-3-O-(3″-O-galloyl)-α-l-rhamnopyranoside (2), (2R, 3R)-3,5,7,3′,4′-pentahydroxyflavanonol-3-O-(3″-O- p-(E)-coumaroyl)-α-l-rhamnopyranoside (3), were isolated. The structures of these compounds were elucidated based on spectroscopic, and chemical analyses. The anti-inflammatory activities of 1-3 were examined as their inhibitory abilities on the expression of IL-1β, TNF-α, MCP-1, and COX-2 mRNA, in lipopolysaccharide-stimulated mouse J774A.1 macrophage cells. At the concentration of 50 μM, 2 and 3 significantly reduced the IL-1β expression, while 1 induced its expression contrarily. Meanwhile, 1 and 3 exhibited significant inhibition of TNF-α expression at the concentration of 10 μM, while 2 could achieve weak but significant inhibition at 50 μM. Furthermore, 1-3 did not suppress the mRNA expression of MCP-1 and COX-2. Compounds 1-3 showed significant anti-proliferative effect in Hep G2 cells. 3 showed the most potent anti-proliferative effect in HT-29 human colon cancer cells, while 1 and 2 had no inhibition. In addition, 1 and 2 exhibited antioxidant activities. The ORAC values of 1 and 2 were 12.8 and 17.0 mmol TE/g and the HOSC values of 1 and 2 were 14.4 and 16.0 mmol TE/g, respectively.     

Antioxidant activity of phenolic and phenylethanoid glycosides from Teucrium polium L

In the present study, the chemical composition and antioxidant activities of Teucrium polium L. (Lamiaceae) were assessed. Fractionation of methanol extract obtained from the aerial parts of T. polium yielded one new phenylethanoid glycoside, named poliumoside B, together with four known flavonoids, two iridoid glycosides and a known poliumoside. The structures of all of these compounds were elucidated on the basis of spectroscopic data from 1D and 2D NMR experiments and MS spectral analyses. The antioxidant activities of the crude extracts and of the isolated compounds were evaluated through tests such as DPPH radical-scavenging capability, reducing power, xanthine oxidase inhibitory effect and inhibition of linoleic acid peroxidation. The highest antioxidant activity was found in the n-butanol extract, which also contained active polyphenols, thus suggesting that this plant could be used as a source of natural molecules, to provide safe antioxidant additives and nutraceuticals. The structure–activity relationships of the isolated compounds are also discussed.     

Constituents of Sideritis syriaca. ssp. syriaca (Lamiaceae) and their antioxidant activity

The aerial parts of Sideritis syriaca ssp. syriaca (Lamiaceae) were extracted, after defatting, with diethyl ether, ethyl acetate and n-butanol. The antioxidant activities of the extracts were evaluated through in vitro model systems, such as 1,1-diphenyl-2-picryl hydrazyl (DPPH) and Co(II) EDTA-induced luminol chemiluminescence. In both model systems the ethyl acetate extract was the most effective. Phytochemical analysis of ethyl acetate extract showed the presence of two new isomeric compounds (1 and 1′), identified as 1-rhamnosyl, 1-coumaroyl, dihydrocaffeoyl, protocatechuic tetraester of quinic acid, as well as chlorogenic acid (2), apigenin 7-O-glucoside (3), apigenin (4), 4′-O-methylisoscutellarein 7-O-[6′′′-O-acetyl-β-D-allopyranosyl-(1 → 2)-β-d-glucopyranoside] (5), isoscutellarein 7-O-[6′′′-O-acetyl-β-D-allopyranosyl-(1 → 2)-β-d-glucopyranoside] (6), 4′-O-methylisoscutellarein 7-O[β-d-allopyranosyl-(1 → 2)-β-d-glucopyranoside] (7) and 4′-O-methylisoscutellarein 7-O-[β-d-allopyranosyl-(1 → 2)-6′′-O-acetyl-β-d-glucopyranoside] (8). The above compounds were identified by spectroscopic methods.     

Inhibition of lipid oxidation and dynamics of polyphenol content in mechanically deboned meat supplemented with sea buckthorn (Hippophae rhamnoides) berry residues

Mechanically deboned meat (MDM) contains about 10 times more polyunsaturated fatty acids (PUFAs) and also more hemoproteins than hand deboned meat (HDM) and is essentially more susceptible to both chemical and biochemical oxidation. The oxidation, leading to the formation of potentially mutagenic and carcinogenic derivatives of PUFAs, can be inhibited by berry extracts rich in antioxidant polyphenols. Using the 2-thiobarbituric acid reactive substances (TBARS) method, we have established that the ethanol slurry of the juice-free solid residue of sea buckthorn (Hippophae rhamnoides – SB) berries inhibits oxidation of unsaturated fatty acids, of both chicken and turkey MDM. The polyphenols, mainly flavonols, responsible for this inhibition, are comparatively stable during short-term cooking and 6-day storage of cooked SB-MDMs at +6 °C. About half of the polyphenols are lost, obviously oxidised, during the storage of the uncooked samples of turkey 2%SB-MDM at +6 °C. The loss of polyphenols is much smaller in the case of chicken MDM, which is characterised by an in situ lower content of fatty acids, including the polyunsaturated ones. The liquid chromatography–diode array detection–tandem mass spectrometry (LC–DAD–ESI-MS/MS) method was used for identification and ranking of the potent polyphenolic antioxidants in the berry residue.     

Antimicrobial and antioxidant properties of the essential oils and methanol extract from Mentha longifolia L. ssp. longifolia

This study was designed to evaluate antimicrobial and antioxidant activities of the essential oil and methanol extract from Mentha longifolia ssp. longifolia. The essential oil showed strong antimicrobial activity against all 30 microorganisms tested whereas the methanol extract almost remained inactive. In contrast, the extract showed much better activity than the essential oil in antioxidant activity assays employed, e.g. in the inhibition of free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene/linoleic acid systems. In the former, the extract was able to reduce the stable free radical DPPH with an IC₅₀ of 57.4 μg/ml while that of the oils was 10 700 μg/ml. When compared to BHT, a synthetic antioxidant, both showed weaker antioxidative potential. Similarly, in β-carotene/linoleic acid assay, these samples were not effectively able to inhibit the linoleic acid oxidation; exhibiting only 24% and 36% inhibitions at 2 mg/ml, respectively; both were far below than that of BHT. Total phenolic constituent of the extract was 4.5 g/100 g as gallic acid equivalent. GC–MS analysis of the oil resulted in the identification of 45 constituents, cis-piperitone epoxide, pulegone and piperitenone oxide being the main components.     

Variation of glucosinolates in 62 varieties of Chinese cabbage (Brassica rapa L. ssp. pekinensis) and their antioxidant activity

Glucosinolate (GSL) and antioxidant activity in 62 varieties of Chinese cabbage (Brassica rapa L. ssp. pekinensis) were determined by HPLC and DPPH, HRSA, and FRAP assays. Five aliphatic GSLs: progoitrin, sinigrin, glucoalyssin, gluconapin, and glucobrassicanapin; four indolyl GSLs: 4-hydroxyglucobrassicin, glucobrassicin, 4-methoxyglucobrassicin, and neoglucobrassicin; one aromatic GSL: gluconasturtiin were identified. Glucobrassicanapin and gluconapin documented the most abundant (average 4.52 and 3.72 μmol/g DW, respectively). The contents of total GSLs varied extensively among 62 varieties (range from 2.83 to 48.53 μmol/g DW). Comprehensive differences in total and individual GSL contents have also been observed among different varieties. Indolyl and aromatic GSL together accounted 26% of the total GSLs; but there are few differences among varieties. FC7 and FI17 could be good candidates for future breeding programs since they had a high quantity of glucobrassicin (2.10 and 1.66 μmol/g DW, respectively). Most of the Chinese cabbage varieties showed significant antioxidant activities when compare with positive control. However, three antioxidant assays were not significantly correlated with total GSLs. The presence of significant quantities of glucobrassicin in some varieties should be studied more extensively, since GSL is the precursor of indole-3-carbinol, a potent anticancer isothiocyanate.     

Novel acylflavones from Sideritis syriaca ssp. syriaca

In the framework of the detailed phytochemical analysis of the aerial parts of Sideritis syriaca, two novel acylflavones were isolated together with three acetylated flavone glycosides and acylated flavone glycosides. The novel acylflavones were identified as isoscutellarein 7-trans-p-coumarate and apigenin 7-,4′-bis(trans-p-coumarate). Their structures were elucidated by means of UV, 1D and 2D NMR, LC–DAD–MS and confirmed by HR-MS spectroscopy.     

Antiproliferative effects of sea buckthorn (Hippophae rhamnoides L.) extracts on human colon and liver cancer cell lines

Sea buckthorn berries contain many bioactive compounds that have anticancer properties. To investigate whether the antiproliferative effects could be associated with the presence of certain compounds, a sequential extraction was performed. The extraction started with heptane followed by ethyl acetate, ethanol, and water. A second protocol using ethanol:water (1:1) was also used. The contents of the extracts were determined and their effects on cell proliferation were investigated in both Caco-2 and Hep G2 cells. The ethyl acetate fraction was exclusively found to contain high levels of ursolic acid, together with low amounts of phenolics. The ethanol:water extracts contained high levels of phenolic compounds and proanthyocyanidin, but little ursolic acid. When the antiproliferative effects were examined, the strongest inhibitory effect was found in the ethyl acetate extract for the Caco-2 cells and in the ethanol:water extract for the Hep G2 cells. The antiproliferative effects were in both cases dose-dependent and were in the case of the ethyl acetate extract associated with an increase in apoptosis. The results obtained show that the choice of extraction solvent is of considerable importance and that ursolic acid might be more important than the polyphenols in inhibiting the cancer cell proliferation.     

Effects of drying method on the extraction yields and quality of oils from quebec sea buckthorn (Hippophaë rhamnoides L.) seeds and pulp

The effects of air-drying and freeze-drying on the extraction yields and quality of oils from Quebec sea buckthorn (cv. Indian-summer) seeds and pulp were studied. Oil extractions were carried out using hexane. Air-dried (ADS) and freeze-dried (FDS) seeds, gave a similar extraction yields (∼12% w/w), whereas those of air-dried (ADP) and freeze-dried (FDP) pulps were significantly different (35.9 ± 0.8 vs. 17.1 ± 0.6% w/w). Fatty acid analysis revealed that α-linolenic (37.2–39.6%), linoleic (32.4–34.2%) and oleic (13.1%) acids were the main fatty acids in seed oils, while pulp oils were rich in palmitoleic (39.9%), palmitic (35.4%) and linoleic (10.6%) acids. Lipid fractionation of crude oils, obtained by solid phase extraction (SPE), yielded mainly neutral lipids (93.9–95.8%). The peroxide values of seed and pulp oils were ca. 1.8 meq/kg and between 3.0 and 5.4 meq/kg, respectively. The melting behavior of seed and pulp oils showed multiple endothermic transitions, as observed normally in vegetable oils.     

Phytochemicals and antioxidant activity of different parts of bambangan (Mangifera pajang) and tarap (Artocarpus odoratissimus)

Mangifera pajang (family: Anacardiaceae; local name: bambangan) and Artocarpus odoratissimus (familiy: Moraceae; local name: tarap) are popular edible fruits in Sabah, Malaysia. The flesh, kernel and peel from M. pajang; seed and flesh from A. odoratissimus were analysed for total antioxidant activity, total polyphenol, total flavonoid and total anthocyanins contents. M. pajang kernel extract displayed the highest free radical scavenging and ferric reducing activities. Total phenolic content of the samples were in the range of 5.96–103.3 mg gallic acid equivalent/g. M. pajang kernel and M. pajang flesh contained the highest and lowest total flavonoid content with the values of 10.98 and 0.07 mg rutin equivalent/g, respectively. The antioxidant activities of extracts were significantly correlated with the total phenolic and flavonoid content (but not the anthocyanins content). The phytochemicals and antioxidant properties of M. pajang and A. odoratissimus, especially their by-products (kernel/seed), indicate that they may impart health benefits when consumed and should be regarded as a valuable source of antioxidant-rich nutraceuticals.     

The in vitro and in vivo antioxidant properties of seabuckthorn (Hippophae rhamnoides L.) seed oil

The antioxidant capacity of seabuckthorn (Hippophae rhamnoides L.) seed oil was investigated with a number of established in vitro assays and in an in vivo study of carbon tetrachloride (CCl₄)-induced oxidative stress in mice. The results showed that DPPH radical scavenging activity, ferrous ion chelating activity, reducing power and inhibition of lipid peroxidation activity all increased with increasing concentrations of seabuckthorn seed oil. Moreover, the EC₅₀ values of seabuckthorn seed oil from the hydrogen peroxide, superoxide radical, hydroxyl radical scavenging assays were 2.63, 2.16 and 0.77 mg/ml, respectively. In the in vivo study, seabuckthorn seed oil inhibited the toxicity of CCl₄, as seen from the significantly increased activities of the antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase. The GSH content in the liver was also increased, whereas hepatic malondialdehyde was reduced. Taken together, these results clearly indicate that seabuckthorn seed oil has significant potential as a natural antioxidant agent.