Black Sesame Pigment: DPPH Assay-Guided Purification, Antioxidant/Antinitrosating Properties, and Identification of a Degradative Structural Marker

An improved purifn. procedure leading to black sesame (Sesamum Indicum L.) pigment was developed involving fat removal by treatment of ground black sesame seeds with dichloromethane followed by an optimized hydrolytic protocol with 6 M HCl, at 100 °C, overnight. The black pigment thus obtained displayed good antioxidant efficiency by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical assay (82% redn. at 0.5 mg/mL), good ferric ion-reducing capacity (61 ??M Trolox equiv. concn. at 0.5 mg/mL), and potent antinitrosating properties (74% inhibition of 2,3-diaminonaphthalene (DAN) nitrosation at gastric pH at 2.5 mg/mL). A synthetic pigment obtained by oxidative polymn. of coniferyl alc. (polyconiferyl alc., PCA), the putative biosynthetic precursor to the sesame pigment, was characterized as a ref. std. FT IR spectra of the purified sesame pigment and PCA supported the structural similarity. HPLC anal. of degrdn. products by alk. hydrogen peroxide of purified black sesame pigment showed the formation of vanillic acid (VA) as the main isolable fragment. Similar yields of VA were obtained by degrdn. of PCA. A pos. correlation between VA yields and DPPH activity was detd. in samples of different purities. It is suggested that VA is a structural marker of black sesame pigment, confirming the biosynthetic origin from coniferyl alc. and pointing to the o-methoxyphenol motif as the key factor accounting for the potent antioxidant properties of the pigment

Black Sesame Pigment: DPPH Assay-Guided Purification, Antioxidant/Antinitrosating Properties, and Identification of a Degradative Structural Marker

An improved purifn. procedure leading to black sesame (Sesamum Indicum L.) pigment was developed involving fat removal by treatment of ground black sesame seeds with dichloromethane followed by an optimized hydrolytic protocol with 6 M HCl, at 100 \ub0C, overnight. The black pigment thus obtained displayed good antioxidant efficiency by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical assay (82% redn. at 0.5 mg/mL), good ferric ion-reducing capacity (61 ??M Trolox equiv. concn. at 0.5 mg/mL), and potent antinitrosating properties (74% inhibition of 2,3-diaminonaphthalene (DAN) nitrosation at gastric pH at 2.5 mg/mL). A synthetic pigment obtained by oxidative polymn. of coniferyl alc. (polyconiferyl alc., PCA), the putative biosynthetic precursor to the sesame pigment, was characterized as a ref. std. FT IR spectra of the purified sesame pigment and PCA supported the structural similarity. HPLC anal. of degrdn. products by alk. hydrogen peroxide of purified black sesame pigment showed the formation of vanillic acid (VA) as the main isolable fragment. Similar yields of VA were obtained by degrdn. of PCA. A pos. correlation between VA yields and DPPH activity was detd. in samples of different purities. It is suggested that VA is a structural marker of black sesame pigment, confirming the biosynthetic origin from coniferyl alc. and pointing to the o-methoxyphenol motif as the key factor accounting for the potent antioxidant properties of the pigment

Epilutein for Early-Stage Age-Related Macular Degeneration: A Randomized and Prospective Study

Purpose: The hypothesis that oral supplementation of the epilutein/lutein combination could augment the macular pigment optical density (MPOD) in patients with age-related macular degeneration (AMD) was tested. Methods: In a prospective randomized interventional study, 40 consecutive patients with early-stage AMD were recruited. After a 2-week run-in period, patients were randomly treated with a daily oral administration of 8 mg epilutein and 2 mg lutein (group 1) or 10 mg lutein (group 2) for 2 months. At baseline (BL) and 1-month (M1) and 2-month visits (M2), all patients underwent a complete ophthalmological examination, including measurement of MPOD in a 7° area (Visucam 200; Carl Zeiss Meditec, Milan, Italy). Xanthophylls were quantified in plasma, as well as the HDL, non-HDL, and erythrocyte fractions at each study visit. Results: Twenty-one patients (mean age 69.4 ± 6.7 years, 35 eyes) were included in group 1. Mean MPOD was 0.203 ± 0.02 optical density units (ODU) at BL, and increased to 0.214 ± 0.04 ODU at M1 (p = 0.008) and 0.206 ± 0.03 ODU at M2 (p = 0.04). Sixteen patients (mean age 72.0 ± 6.3 years, 29 eyes) were included in group 2. Mean MPOD was 0.215 ± 0.03 at BL, which reduced to 0.202 ± 0.03 ODU at M1 (p = 0.003) and 0.207 ± 0.02 ODU at M2 (p < 0.001). A rise in the systemic level of total xanthophylls was observed at M1 for both groups. At M2, total xanthophylls were significantly increased only in group 1 and decreased in group 2. Conclusion: In patients with early-stage AMD, the administration of lutein in combination with epilutein was associated with an increased MPOD compared to the administration of lutein alon

Superior heavy metal binding, antioxidant amd chemopreventive action of black sesame pigment after simulated gastrointestinal digestion: toward the development of a food supplement

E-mail: [email protected] We recently developed an improved purification procedure to obtain black sesame pigment (BSP), involving fat removal followed by an optimized hydrolytic protocol. BSP thus obtained displayed good antioxidant efficiency in several chemical assays.1,2 In order to assess the potential of BSP as food supplement, we have now explored the structural transformations of this pigment in model systems of stomach and gut digestion. The release of low molecular weight compounds from BSP was evaluated by a simulated digestion procedure involving an initial treatment with pepsin at pH 1.7 followed by treatment with a mixture of porcine bile salts and pancreatin at pH 7.5. HPLC analysis indicated that BSP is transformed under the slight alkaline pH conditions mimicking the intestinal environment and favoring swelling of the pigment and hydrolytic reactions. All of the low molecular weight components released have a potential to pass into the serum as evidenced by a serum availability model. The most abundant of these components was identified as vanillic acid. Both the insoluble pigment fraction (fraction A) and the low molecular weight components (fraction B) exhibited efficient antioxidant properties in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical assay. Both fractions proved to be non-toxic and exhibited marked protective effects against reactive oxygen species (ROS) generation and cell damage evaluated as lactate dehydrogenase (LDH) leakage (Fig. 1) induced by 400 M tert-butylhydroperoxide (t-BOOH) in human hepatocarcinoma HepG2 cell line. In other experiments the chelating properties of the digested pigment were evaluated toward heavy metals such as lead, mercury and cadmium, which occur in food (e.g. 0.05 g/g, 0.09 g/g and 0.035 g/g, respectively in fish and shellfish)3 and are highly toxic due to their non-biodegradable nature and prolonged biological half-life. At a metal concentration in the range 1.5-3 g/g with a pigment dose of 0.05 mg/mL a removal higher than 80% was obtained with lead and mercury, but less than 40% in the case of cadmium (Fig.2). The metal binding properties together with the chemopreventive activity open new perspectives toward the use of BSP as a food supplement for the prevention of neurodegenerative and oxidative stress based diseases. 1. Eidenberger, T. PCT Int. Appl. WO 2010012751, 2010 2. Panzella, L.; Eidenberger, T.; Napolitano, A.; d’Ischia, M. J. Agric. Food Chem. 2012, 60,8895-8901. 3. Llobet, J. M.; Falcoä, G.; Casas, C.; Teixidoä, A.; Domingo, J. L. J. Agric. Food Chem. 2003, 51, 838-842

Semantics in Content-based Multimedia Retrieval

This contribution investigates the content-based feature extraction methods used in visual information retrieval, focusing on concepts that are employed for the semantic representation of media content. The background part describes the building blocks of feature extraction functions. Since numerous methods have been proposed we concentrate on the metaconcepts. The building blocks lead to a discussion of starting points for semantic enrichment of low-level features. The second part reviews features from the perspective of data quality. A case study on content-based MPEG-7 features illustrates the relativity of terms like “low-level, ” “highlevel” and “semantics”. For example, often more semantics mean just more redundancy. The final part sketches the application of features in retrieval scenarios. The results of a case study suggest that – from the retrieval perspective, too – “semantic enrichment of low-level features ” is a partially questionable concept. The performance of classification-based retrieval, it seems, does hardly depend on the context of features.