Sulfated Extract of Abelmoschus Esculentus: A Potential Cancer Chemo-preventive Agent.

BACKGROUND: Abelmoschus esculentus (AE) (okra), is an edible plant used in many food applications. OBJECTIVE: This study explored whether sulfated AE (SAE) has promising cancer chemopreventive activities that may recommend it as a functional food supplement instead of (or in addition to) AE for the population at risk of cancer and in the health food industry. METHODS: Cytochrome P450-1A (CYP1A) was estimated by fluorescence enzymatic reaction, using ß-naphthoflavone-treated cells (CYP1A inducer). Peroxyl and hydroxyl radical scavenging was assayed by oxygen radical absorbance capacity assay. Flow cytometry was used to analyze apoptosis/necrosis in MCF-7 cells, cell cycle phases in MCF-7 cells, and macrophage binding to fluorescein isothiocyanate-lipopolysaccharide (FITC-LPS). Nitric oxide was determined by Griess assay in LPS-stimulated macrophages, and cytotoxicity was determined by MTT assay. Diethylnitrosamine (DEN) was used to induce hepatic tumor initiation in rats. Placental glutathione-S-transferase (GSTP; an initiation marker) was stained in a fluorescence immunohistochemical analysis of liver sections, and histopathological changes were examined. RESULTS: SAE exhibited strong antitumor initiation and antitumor promotion activities. It suppressed CYP1A, scavenged peroxyl and hydroxyl radicals, induced macrophage proliferation, suppressed macrophage binding to FITC-LPS, inhibited nitric oxide generation, showed specific cytotoxicity to human breast MCF-7 adenocarcinoma cells, and disturbed the cell cycle phases (S and G2/M phases) in association with an increased percentage of apoptotic/necrotic MCF-7 cells. Over a short time period, DEN stimulated liver cancer initiation, but SAE treatment reduced the DEN-induced histopathological alterations and inhibited CYP1A and GSTP. CONCLUSION: SAE extract has the potential for use as an alternative to AE in health foods to provide cancer chemoprevention in populations at risk for cancer.

Unraveling the anti-biofilm potential of green algal sulfated polysaccharides against Salmonella enterica and Vibrio harveyi.

One of the main reasons for the bacterial resistance to antibiotics is caused by biofilm formation of microbial pathogens during bacterial infections. Salmonella enterica and Vibrio harveyi are known to form biofilms and represent a major health concern worldwide, causing human infections responsible for morbidity and mortality. The current study aims to investigate the effect of purified sulfated polysaccharides (SPs) from Chlamydomonas reinhardtii (Cr) on planktonic and biofilm growth of these bacteria. The effect of Cr-SPs on bacterial planktonic growth was assessed by using the agar well diffusion method, which showed clear zones ranging from 13 to 26 mm in diameter from 0.5 to 8 mg/mL of Cr-SPs against both the bacteria. Time-kill activity and reduction in clonogenic propagation further help to understand the anti-microbial potential of Cr-SPs. The minimum inhibitory concentration of Cr-SPs against S. enterica and V. harveyi was as low as 440 µg/mL and 490 µg/mL respectively. Cr-SPs inhibited bacterial cell attachment up to 34.65-100% at 0.5-8 mg/mL in S. enterica and V. harveyi respectively. Cr-SPs also showed 2-fold decrease in the cell surface hydrophobicity, indicating their potential to prevent bacterial adherence. Interestingly, Cr-SPs efficiently eradicated the preformed biofilms. Increased reduction in total extracellular polysaccharide (EPS) and extracellular DNA (eDNA) content in a dose-dependent manner demonstrates Cr-SPs ability to interact and destroy the bacterial EPS layer. SEM analysis showed that Cr-SPs effectively distorted preformed biofilms and also induced morphological changes. Furthermore, Cr-SPs also showed anti-quorum-sensing potential by reducing bacterial urease and protease activities. These results indicate the potential of Cr-SPs as an anti-biofilm agent and will help to develop them as alternative therapeutics against biofilm-forming bacterial infections. KEY POINTS: • Cr-SPs not only inhibited biofilm formation but also eradicated preformed biofilms. • Cr-SPs altered bacterial cell surface hydrophobicity preventing biofilm formation. • Cr-SPs efficiently degraded eDNA of the EPS layer disrupting mature biofilms. • Cr-SPs reduced activity of quorum-sensing-mediated enzymes like protease and urease.

Anti-melanogenic activity of salacinol by inhibition of tyrosinase oligosaccharide processing.

Hyperpigmentation that manifests through melasma and solar lentigo (age spots), although mostly harmless for health, bothers many people. Controlling the rate-limiting activity of tyrosinase is most effective for suppressing excessive melanin formation and accordingly recent research has focused on the maturation of tyrosinase. Salacia, a medicinal plant, has been used to treat diabetes in India and Sri Lanka. Salacia extract reportedly contains components that inhibit the activity of α-glucosidase. Salacinol, the active ingredient in Salacia extract, has unique thiosugar sulphonium sulphate inner salt structure. Here, we observed that the salacinol component of Salacia extract possesses anti-melanogenic activity in comparison to various existing whitening agents. Although the anti-melanogenic mechanism of salacinol is presumably medicated by inhibition of tyrosinase activity, which is often found in existing whitening agents, salacinol did not inhibit tyrosinase activity in vitro. Analysis of the intracellular state of tyrosinase showed a decrease in the mature tyrosinase form due to inhibition of N-linked oligosaccharide processing. Salacinol inhibited the processing glucosidase I/II, which are involved in the initial stage of N-linked glycosylation. Owing to high activity, low cytotoxicity and high hydrophilicity, salacinol is a promising candidate compound in whitening agents aimed for external application on skin.

Evaluating the antibacterial and antibiofilm potential of sulphated polysaccharides extracted from green algae Chlamydomonas reinhardtii.

AIM OF THE STUDY: In this study, antibacterial and antibiofilm potential of sulphated polysaccharides (SPs) extracted from Chlamydomonas reinhardtii (Cr) was evaluated against Neisseria mucosa, Escherichia coli, Streptococcus sp. and Bacillus subtilis. METHODS AND RESULTS: Antibacterial potential of Cr-SPs was evaluated by agar-cup diffusion, time-kill and colony-forming ability (CFU), minimum inhibitory and bactericidal concentration assays. Antibiofilm potential was evaluated by biofilm inhibition, eradication, extracellular-DNA, metabolic activity and microscopy assays. Cr-SPs at 0·5 mg ml-1 showed 34·52, 48·6, 66·1 and 55·6% reduced CFU in B. subtilis, Streptococcus, N. mucosa and E. coli respectively. Minimum inhibitory concentration of Cr-SPs was as low as 480 µg ml-1 for Streptococcus, N. mucosa and 420 µg ml-1 for B. subtilis and E. coli. At 1 mg ml-1 , Cr-SPs showed 50% biofilm inhibition, whereas 4-8 mg ml-1 showed 100% inhibition. Cr-SPs also effectively dissolved preformed biofilms. Dose-dependent reduction in extracellular DNA revealed that Cr-SPs interacts with the extra polymeric substance of the biofilm and destroys them. Light microscopy reconfirmed the above results. CONCLUSION: Cr-SPs not only inhibited biofilm formation but also effectively dissolved preformed-biofilms. SIGNIFICANCE AND IMPACT OF THE STUDY: The current study showed the promising potential of Cr-SPs as antibiofilm agents. Further validation will help in developing Cr-SPs as natural antibiotics against biofilm-causing bacteria.

Pollutant removal and bioelectricity generation from urban river sediment using a macrophyte cathode sediment microbial fuel cell (mSMFC).

Sediment microbial fuel cell (SMFC) efficacy depends highly on organic matter flux and dissolved oxygen (DO) at the anode and cathode, respectively. However, utilizing floating-macrophyte for elevated DO supply at the cathode has not been fully explored. Therefore, a novel floating-macrophyte implanted biocathode single-chamber SMFC (mSMFC) was developed for the simultaneous removal of pollutant and bioelectricity generation from polluted urban river sediment. With Lemna minor L. employed in mSMFC, high pollutant removal was feasible as opposed to the control bioreactor. Total COD, nitrate and sulfate removal reached 57%, 99%, and 99%, respectively. Maximum voltage output, power density, columbic efficiency, normalized energy recovery, and net energy production observed was 0.56 ±â€¯0.26 V, 86.06 mW m-3, 24.7%, 0.033 kWh m-3 and 0.020 kWh m-3, respectively. Alternatively, when floating-macrophyte (predominantly Pistia stratiotes) was employed in the catholyte, DO increased significantly to about 10 mg L-1 in the mSMFC. 16S rRNA gene sequencing revealed Euryarchaeota-(90.91%) and Proteobacteria-(59.68%) as the dominant phyla affiliated to archaea and bacteria, respectively. Pollutant removal mechanisms observed within the mSMFC included bioelectrochemical oxidation at the anode and reduction reaction and macrophyte hyperaccumulation at the cathode. The novel mSMFC system provided an effective approach for the removal of pollutant and bioelectricity generation.

Anti-Thrombin, Anti-Adhesive, Anti-Migratory, and Anti-Proliferative Activities of Sulfated Galactans from the Tropical Green Seaweed, Udotea flabellum.

In this study, sulfated polysaccharide-rich extracts were isolated from 22 tropical seaweeds (4 red, 11 brown, and 7 green) found in northeastern Brazil, and evaluated for the role of anticoagulant agents. Fifteen of the extracts showed anticoagulant activity, including all the extracts from green seaweeds. Udotea flabellum (a green seaweed) extract was the most potent, requiring an amount of only 3 µg to double the plasma coagulation time in the activated partial thromboplastin time test. A similar result was obtained with 1 µg of heparin. Two sulfated homogalactans with anticoagulant activity, F-I (130 kDa) and F-II (75 kDa), were isolated from this extract using several bio-guided purification steps. Their anticoagulant activity, as well as properties related to antitumor activity (anti-proliferative, anti-adhesive, and anti-migratory), were accessed. Their anticoagulant activities were close to that of heparin. We found that F-I and F-II (0.5⁻10 µg/mL) were not able to directly inhibit thrombin. In the presence of anti-thrombin, F-I (0.5 µg/mL) was more effective than heparin (0.5 µg/mL) in inhibiting thrombin, while F-II showed similar effects as heparin. F-I and F-II also inhibited B16-F10 (murine melanoma cells) adhesion, migration, and proliferation on a fibronectin-coated surface, but not on laminin- or collagen I-coated surfaces. Except for the antiproliferative activity, the other effects of F-I and F-II were eliminated upon their desulfation (~50%), indicating that the degree of sulfation is not as important for F-I and F-II anti-proliferative activity as the sulfation position. Taken together, the results provide strong evidence for the potential utility of sulfated galactans from U. flabellum, making these compounds an interesting option for future investigations that aim to design new anticoagulant/antitumor agents.

Salicin-7-sulfate: A new salicinoid from willow and implications for herbal medicine.

Willow (Salix sp.) is a historically well-known herbal medicine that provided the lead compound (salicin) for the discovery of aspirin, one of the most successful plant derived drugs in human medicine. During a metabolomics screen of 86 Salix species contained in the UK National Willow Collection, we have discovered, isolated and fully characterised a new natural salicinoid - salicin-7-sulfate. This molecule may have important human pharmacological actions that need to be considered in determining the efficacy and safety of willow herbal medicines.

Preparation of cationized starch from food industry waste biomass and its utilization in sulfate removal from aqueous solution.

In this work, untreated starch-rich potato peel waste was used as a starting material in preparation of cationized starch (CS)1 in water solution with 2-chloro-3-hydroxypropyltrimethylammonium chloride (CHPTAC) as the cationization reagent. The impact of various factors (activation time, temperature, reaction time, the amount of CHPTAC and NaOH) on the degree of substitution (DS) of CS was studied by using experimental design. The DS values were determined by 1H NMR. The highest DS (0.40) was obtained when the reaction time was 8h, temperature 30°C, the molar ratio of CHPTAC and NaOH to AGU 3 and 3.75, respectively. The prepared CS was successfully used to remove sulfate ions from an aqueous solution with ultrafiltration technique. Sulfate is a major pollutant of water bodies so development of efficient techniques for its removal is detrimental. The removal of sulfate in study was 74% at best.

Sulfated Galactans from Red Seaweed Gracilaria fisheri Target EGFR and Inhibit Cholangiocarcinoma Cell Proliferation.

Cholangiocarcinoma (CCA) is increasing in incidence worldwide and is resistant to chemotherapeutic agents, making treatment of CCA a major challenge. Previous studies reported that natural sulfated polysaccharides (SPs) disrupted growth factor receptor activation in cancer cells. The present study, therefore, aimed at investigating the antiproliferation effect of sulfated galactans (SG) isolated from the red seaweed Gracilaria fisheri (G. fisheri) on CCA cell lines. Direct binding activity of SG to CCA cells, epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) were determined. The effect of SG on proliferation of CCA cells was investigated. Cell cycle analyses and expression of signaling molecules associated with proliferation were also determined. The results demonstrated that SG bound directly to EGFR. SG inhibited proliferation of various CCA cell lines by inhibiting EGFR and extracellular signal-regulated kinases (ERK) phosphorylation, and inhibited EGF-induced increased cell proliferation. Cell cycle analyses showed that SG induced cell cycle arrest at the G0/G1 phase, down-regulated cell cycle genes and proteins (cyclin-D, cyclin-E, cdk-4, cdk-2), and up-regulated the tumor suppressor protein P53 and the cyclin-dependent kinase inhibitor P21. Taken together, these data demonstrate that SG from G. fisheri inhibited proliferation of CCA cells, and its mechanism of inhibition is mediated, to some extent, by inhibitory effects on EGFR activation and EGFR/ERK signaling pathway. SG presents a potential EGFR targeted molecule, which may be further clinically developed in a combination therapy for CCA treatment.

Greenhouse wastewater treatment by baffled subsurface-flow constructed wetlands supplemented with flower straws as carbon source in different modes.

Four laboratory-scale baffled subsurface-flow constructed wetlands (BSCWs) were established for the treatment of greenhouse wastewater containing high levels of nitrate and sulfate in the present study. Each BSCW microcosm involved a treatment zone and another post-treatment zone with a surface area ratio of 2:1. Evenly mixed straws of carnation and rose (w/w: 1/1), two common ornamental flowers, were supplemented as an organic carbon source into the treatment zone through a hydrolysis zone (CW 1), decentralized vertically installed perforated pipes (CW 2), and centralized pipes (CW 3 in the figures), except the blank system. Removals and transformations of nitrogen and sulfate as well as carbon release in the BSCWs were investigated and comparatively assessed. Results showed that the supplements of flower straws could greatly enhance both the nitrate and sulfate removals, and good performance was achieved during the beginning operation period of 30 days, followed by decline due to insufficient organic carbon supply. Nitrate removal efficiency was significantly higher and more stable compared to sulfate. The highest removal rates of nitrate and sulfate were achieved in the CW 3, with a mean value of 4.33 g NO3--N·m-2 d-1 and 2.74 g SO42--S·m-2 d-1, respectively, although the differences among the experimental microcosms were not statistically significant. However, almost the same TN removal rate (3.40-3.47 g N·m-2 d-1) was obtained due to the productions of NO2--N and NH4+-N and leaching of organic N from the straws. High contents of organic carbon and colored substance were leached from the straws during the initial 10 days, but dropped rapidly to low levels, and could hardly determined after 30 days operation. The post-treatment zone could further eliminate various contaminants, but the capability was limited. Inorganic carbon (IC) concentration was detected to be a highly good indicator for the estimation of nitrate and sulfate removal efficiencies of the BSCWs, particularly for nitrate.

Antifungal Long-Chain Alkenyl Sulphates Isolated from Culture Broths of the Fungus Chaetopsina sp.

During a high-throughput screening program focused on the discovery and characterization of new antifungal compounds, a total of 8320 extracts from Fundacion MEDINA's collection were screened against a panel of 6 fungal parasitic strains, namely Candida glabrata, Candida krusei, Candida parapsilosis, Candida tropicalis, Candida albicans, and Aspergillus fumigatus. A total of 127 extracts displayed antifungal properties and, after LC/MS dereplication, 10 were selected for further fractionation. Bioassay-guided fractionation from a 1-L fermentation of one of these extracts, belonging to the fungus Chaetopsina sp., led to the isolation of linoleyl sulphate (1), linolenyl sulphate (2), and oleyl sulphate (3) as the compounds responsible for the antifungal activity. These molecules were previously described as synthetic products with the ability to produce the allosteric inhibition of soybean lipoxygenase and human lipoxygenase.

Structure analysis of a heteropolysaccharide from Taraxacum mongolicum Hand.-Mazz. and anticomplementary activity of its sulfated derivatives.

A homogenous water-soluble polysaccharide, DPSW-A, with a deduced chemical structure was extracted from the herb Taraxacum mongolicum Hand.-Mazz. Moreover, 80.813-kDa DPSW-A is composed of three types of monosaccharide, namely rhamnose, arabinose, and galactose, at a molar ratio of 1.0:10.7:11.9. The main chain of DPSW-A contains Terminal-Galp, 1,3-Galp, 1,6-Galp, 1,3,6-Galp, and 1,2,4-Rhap; the branched chain contains Terminal-Araf, 1,5-Araf, and 1,3,5-Araf. The sulfated derivatives prepared from DPSW-A showed inhibitory effects on complement activation through the classical pathway (CH50: Sul-DPSW-A, 3.94±0.43µg/mL; heparin, 104.40±3.82µg/mL) and alternative pathway (AP50: Sul-DPSW-A, 42.76±0.46µg/mL; heparin, 43.42±0.22µg/mL). Mechanism studies indicated that Sul-DPSW-A inhibited complement activation by blocking C1q, C1r, C1s, and C9, but not C2, C3, C4, and C5. In addition, Sul-DPSW-A displayed limited anticoagulant effects. These results suggest that Sul-DPSW-A prepared from DPSW-A is valuable for treating diseases caused by excessive complement system activation.

Hydrophobic substituents increase the potency of salacinol, a potent α-glucosidase inhibitor from Ayurvedic traditional medicine 'Salacia'.

Using an in silico method, seven analogs bearing hydrophobic substituents (8a: Me, 8b: Et, 8c: n-Pent, 8d: n-Hept, 8e: n-Tridec, 8f: isoBu and 8g: neoPent) at the 3'-O-position in salacinol (1), a highly potent natural α-glucosidase inhibitor from Ayurvedic traditional medicine 'Salacia', were designed and synthesized. In order to verify the computational SAR assessments, their α-glucosidase inhibitory activities were evaluated in vitro. All analogs (8a-8g) exhibited an equal or considerably higher level of inhibitory activity against rat small intestinal α-glucosidases compared with the original sulfonate (1), and were as potent as or higher in potency than the clinically used anti-diabetics, voglibose, acarbose or miglitol. Their activities against human maltase exhibited good relationships to the results obtained with enzymes of rat origin. Among the designed compounds, the one with a 3'-O-neopentyl moiety (8g) was most potent, with an approximately ten fold increase in activity against human maltase compared to 1.

Salt Effect on the Antioxidant Activity of Red Microalgal Sulfated Polysaccharides in Soy-Bean Formula.

Sulfated polysaccharides produced by microalgae, which are known to exhibit various biological activities, may potentially serve as natural antioxidant sources. To date, only a few studies have examined the antioxidant bioactivity of red microalgal polysaccharides. In this research, the effect of different salts on the antioxidant activities of two red microalgal sulfated polysaccharides derived from Porphyridium sp. and Porphyridium aerugineum were studied in a soy bean-based infant milk formula. Salt composition and concentration were both shown to affect the polysaccharides' antioxidant activity. It can be postulated that the salt ions intefer with the polysaccharide chains' interactions and alter their structure, leading to a new three-dimensional structure that better exposes antiooxidant sites in comparison to the polysaccharide without salt supplement. Among the cations that were studied, Ca(2+) had the strongest enhancement effect on antioxidant activities of both polysaccharides. Understanding the effect of salts on polysaccharides' stucture, in addition to furthering knowledge on polysaccharide bioactivities, may also shed light on the position of the antioxidant active sites.

Evaluation of Salacia species as anti-diabetic natural resources based on quantitative analysis of eight sulphonium constituents: a new class of α-glucosidase inhibitors.

INTRODUCTION: Stems and roots of Salacia genus plants have been used in Ayurveda as a specific remedy for early stage diabetes. Previous investigations identified four sulphonium sulphates, that is, salacinol (1), kotalanol (3), ponkoranol (5) and salaprinol (7), as the compounds responsible for the anti-diabetic activity. Their desulphonates (2, 4, 6 and 8) were also isolated as active constituents. Two separate quantitative analytical protocols, that is, for 1 and 3 and for 2 and 4, have been developed recently. OBJECTIVE: To: validate the two analytical protocols with respect to all eight sulphoniums; evaluate the quality of a variety of Salacia samples collected in different geographical regions, that is, Thailand, Sri Lanka and India; and determine their distribution in each part of the plant, that is, stems/roots, leaves and fruits. METHODS: Analyses of four sulphonium sulphates in 32 Salacia extracts were carried out on an Asahipak NH2P-50 column, and those of the corresponding desulphonates were conducted on an Inertsil ODS-3 column. RESULTS: Neokotalanol (4) was the major constituent in Salacia samples from Thailand, whereas 1 was the primary constituent in extracts of the stems/roots of plants from Sri Lanka and India. These sulphoniums were only present in trace amounts in leaves and fruits of the plants. CONCLUSION: Two analytical protocols were successfully applied to analyse 32 Salacia samples, and revealed that sulphoniums (1-8) had characteristic distributions due to the plant part and/or due to geographical region.

Structure of a homofructosan from Saussurea costus and anti-complementary activity of its sulfated derivatives.

A homogeneous water-soluble polysaccharide APS-W1, (2→1)-ß-d-fructofuranosan, with an average molecular weight of 3.9kDa, was isolated and characterized from the roots of Saussurea costus. Five sulfated derivatives of APS-W1 with different degrees of sulfation were prepared and they showed strong inhibitory effect on the complement activation through the classical pathway (CP50: 2.2-18.9µg/mL; 8.3µg/mL for heparin) and alternative pathway (AP50: 11.4-115.8µg/mL; 89.2µg/mL for heparin). Mechanism studies by using complement-depleted sera indicated that sulfated derivatives with different positions of sulfation targeted to different complement proteins. Meanwhile the sulfated derivatives have limited anticoagulant effect based on re-calcification time and thrombin time. These results suggested that the sulfated derivatives prepared from APS-W1 could be promising potential complement inhibitors for the treatment of diseases caused by an over-activated complement system.

A soil infiltration system incorporated with sulfur-utilizing autotrophic denitrification (SISSAD) for domestic wastewater treatment.

To enhance the denitrification performance of soil infiltration, a soil infiltration system incorporated with sulfur-utilizing autotrophic denitrification (SISSAD) for domestic wastewater treatment was developed, and the SISSAD performance was evaluated using synthetic domestic wastewater in this study. The aerobic respiration and nitrification were mainly taken place in the upper aerobic stage (AES), removed 88.44% COD and 89.99% NH4(+)-N. Moreover, autotrophic denitrification occurred in the bottom anaerobic stage (ANS), using the CO2 produced from AES as inorganic carbon source. Results demonstrated that the SISSAD showed a remarkable performance on COD removal efficiency of 95.09%, 84.86% for NO3(-)-N, 95.25% for NH4(+)-N and 93.15% for TP. This research revealed the developed system exhibits a promising application prospect for domestic wastewater in the future.

Sulfated galactans isolated from the red seaweed Gracilaria fisheri target the envelope proteins of white spot syndrome virus and protect against viral infection in shrimp haemocytes.

The present study was aimed at evaluating an underlying mechanism of the antiviral activity of the sulfated galactans (SG) isolated from the red seaweed Gracilaria fisheri against white spot syndrome virus (WSSV) infection in haemocytes of the black tiger shrimp Penaeus monodon. Primary culture of haemocytes from Penaeus monodon was performed and inoculated with WSSV, after which the cytopathic effect (CPE), cell viability and viral load were determined. Haemocytes treated with WSSV-SG pre-mix showed decreased CPE, viral load and cell mortality from the viral infection. Solid-phase virus-binding assays revealed that SG bound to WSSV in a dose-related manner. Far Western blotting analysis indicated that SG bound to VP 26 and VP 28 proteins of WSSV. In contrast to the native SG, desulfated SG did not reduce CPE and cell mortality, and showed low binding activity with WSSV. The current study suggests that SG from Gracilaria fisheri elicits its anti-WSSV activity by binding to viral proteins that are important for the process of viral attachment to the host cells. It is anticipated that the sulfate groups of SG are important for viral binding.

Depletion of high-abundance flavonoids by metal complexation and identification of low-abundance flavonoids in Scutellaria baicalensis Georgi.

The complexation of metal cations and flavonoids with 5-hydroxyl or ortho-hydroxyl groups was successfully used for high-abundance flavone depletion from a botanical extract in this study. Due to their structural differences, five of the most highly abundant constituents, baicalin, wogonoside, baicalein, wogonin and oroxylin A, were successfully depleted from the ethanol extract of Radix Scutellariae. The depletion rates were approximately 99%, 85%, 99%, 70% and 76%, respectively. The recoveries of low-abundance constituents were very strong (approximately 70-100%). The efficiency of the low-abundance compounds' identification by high performance liquid chromatography electrospray tandem mass spectrometry (HPLC ESI MS/MS) was remarkable after the high-abundance constituents were removed. The number of compounds identified from the HPLC MS/MS data was 250% greater than the number of compounds identified in the untreated total extract. One hundred seventeen flavonoids were identified in the ethanol extract of Radix Scutellariae using this method, which was much greater than the number identified in previous studies without high-abundance constituent depletion. Among them, 13 sulphated flavonoids were identified. These low-abundance sulphated flavonoids can barely be detected in untreated total extracts. To the best of our knowledge, this is the first reported evidence that sulphated flavonoids have been identified from Radix Scutellariae. This method will facilitate the removal of high-abundance flavonoids and the identification of low-abundance compounds in botanical extracts.

Removal of dissolved organic carbon and nitrogen during simulated soil aquifer treatment.

Soil aquifer treatment was simulated in 1 m laboratory soil columns containing silica sand under saturated and unsaturated soil conditions to examine the effect of travel length through the unsaturated zone on the removal of wastewater organic matter, the effect of soil type on dissolved organic carbon removal and also the type of microorganisms involved in the removal process. Dissolved organic carbon removal and nitrification did enhance when the wastewater travelled a longer length through the unsaturated zone. A similar consortium of microorganisms was found to exist in both saturated and unsaturated columns. Microbial concentrations however were lowest in the soil column containing silt and clay in addition to silica sand. The presence of silt and clay was detrimental to DOC removal efficiency under saturated soil conditions due to their negative effect on the hydraulic performance of the soil column and microbial growth.