jose trigos - Academia.edu (original) (raw)

Papers by jose trigos

Research paper thumbnail of Letter to the Editor: Retinal and retinol are potential regulators of gene expression in the keratinocyte cell line HaCaT: Letter to the Editor

Research paper thumbnail of Characterization of the Volatile Pattern and Antioxidant Capacity of Essential Oils from Different Species of the Genus Ocimum

Journal of Agricultural and Food Chemistry, Jun 1, 2006

The antioxidant capacity of essential oils obtained by steam hydrodistillation from five species ... more The antioxidant capacity of essential oils obtained by steam hydrodistillation from five species of the genus Ocimum, namely Ocimum basilicum var. purpurascens, Ocimum basilicum, Ocimum gratissimum, Ocimum micranthum, and Ocimum tenuiflorum (syn. O. sanctum), were evaluated using a high-performance liquid chromatography-based hypoxanthine/xanthine oxidase and the DPPH assays. The yield of oils from the leaves of the five species was variable with the greater amount obtained from Ocimum gratissimum (3.5%) and the least from Ocimum basilicum var. purpurascens (0.5%). In the hypoxanthine/xanthine oxidase assay, strong antioxidant capacity was evident in all the oils but the greater was shown by that obtained from Ocimum tenuiflorum (syn. O. sanctum) (IC50 = 0.46 microL/mL) compared to Ocimum basilicum var. purpurascens (IC50 = 1.84 microL/mL). Antioxidant capacity was positively correlated (r = 0.92, p < 0.05) with a high proportion of compounds possessing a phenolic ring such as eugenol, while a strong negative correlation (r = -0.77, p > 0.1) with other major volatiles was observed. These correlations were confirmed to a large extent in the DPPH assay. The results of a 24 h experiment with Ocimum tenuiflorum (syn. O. sanctum) shows that the antioxidant capacity factor (amount of essential oil obtained x free radical scavenging capacity; mg x %/100) reaches a threshold between 10 and 12.00 h, corresponding to maximum sunlight intensity in Brasil and furthermore exhibits a clear diurnal variation. The data generated with Ocimum species indicates that essential oils obtained from various herbs and spices may have an important role to play in cancer chemoprevention, functional foods, and in the preservation of pharmacologic products.

Research paper thumbnail of Olive-oil consumption and health: the possible role of antioxidants.(Brief Article)

Alternative Medicine Review, Jun 1, 2002

Research paper thumbnail of CIB White Paper on IDDS Integrated Design & Delivery Solutions

School of Civil Engineering Built Environment Institute For Future Environments Science Engineering Faculty, 2009

Research paper thumbnail of Does position of the patient adversely affect successful intubation whilst wearing CBRN-PPE?

Resuscitation, Sep 1, 2010

Research paper thumbnail of Challenges for Integrated Design and Delivery Solutions

Architectural Engineering and Design Management, 2010

Research paper thumbnail of Identification of lignans as major components in the phenolic fraction of olive oil

Clinical chemistry, 2000

Because olive oil is an important component of the Mediterranean diet, it is necessary to establi... more Because olive oil is an important component of the Mediterranean diet, it is necessary to establish unequivocal identification of the major potential antioxidant phenolic compounds it contains. The major phenolic antioxidants in extra virgin olive oil were isolated and purified. Structural analysis was conducted using several spectroscopic techniques, including mass spectrometry and nuclear magnetic resonance (NMR). In particular, detailed (1)H and (13)C NMR data are presented, and several assignment errors in the literature are corrected. The data show for the first time that the lignans (+)-1-acetoxypinoresinol and (+)-pinoresinol are major components of the phenolic fraction of olive oils. These lignans, which are potent antioxidants, are absent in seed oils and virtually absent in refined virgin oils but are present at concentrations of up to 100 mg/kg (mean +/- SE, 41.53+/-3.93 mg/kg; range, 0.65-99.97 mg/kg) in extra virgin oils. As with the simple phenols and secoiridoids, th...

Research paper thumbnail of Estimation of the effects of angioplasty on coronary stenosis using quantitative video angiography

Catheterization and cardiovascular diagnosis, 1985

In this study, we compared stenosis severity by quantitative coronary angiography from video and ... more In this study, we compared stenosis severity by quantitative coronary angiography from video and cine images with visual estimation in 14 patients who underwent PTCA. Both cine and video analysis demonstrated a change from 65.2 +/- 2.5 to 36.5 +/- 3.1% diameter stenosis following PTCA, whereas visual estimation (average of three observers) showed improvement from 89.9 +/- 1.7 to 36.0 +/- 3.2%. Percent area stenosis from quantitative angiography showed improvement from 87.9 +/- 1.8 to 56.4 +/- 5.8. These data indicate that visual assessment overestimated percent diameter of severe lesions. To determine if video analysis could provide rapid quantitative assessment of PTCA results, we compared percent diameter and percent area stenosis by video with cine (diameter: correlation coefficient, 0.82; slope, 0.79; area: correlation coefficient, 0.86; slope, 0.83). These results indicate that video-based measurements are not different from cine-derived measurements. Quantitative coronary angi...

Research paper thumbnail of (2R∗,3S∗,4S∗,2″R∗,3″S∗)-Guibourtinidol-(4α→8)-catechin, a biflavanoid procyanidin of the proguibourtinidin group from Senna macranthera: its relative stereochemistry and conformation

Tetrahedron: Asymmetry, 2015

ABSTRACT Comprehensive NMR data for the previously presumed structure of the procyanidin (2R∗,3S∗... more ABSTRACT Comprehensive NMR data for the previously presumed structure of the procyanidin (2R∗,3S∗,4S∗,2″R∗,3″S∗)-guibourtinidol-(4α→8)-catechin, isolated in this case from the roots of the medicinal plant Senna macranthera, is reported. Earlier reports provided a basic plausible structure based on mass spectrometry data but lacked confirmation by NMR. Therefore the 3D structure of the compound in terms of its full relative configuration and conformational preference in CD3OD solution was established by molecular modeling using DFT in conjunction with both chemical shift, δH and δC, and NOE contact, ηH,H, NMR data.

Research paper thumbnail of Does position of the patient adversely affect successful intubation whilst wearing CBRN-PPE?

Research paper thumbnail of Plasma 25-hydroxyvitamin D3, folate and vitamin B12 biomarkers among international colorectal cancer patients: a pilot study

Journal of Nutritional Science, 2013

Vitamin D and folate are associated with decreased colorectal cancer risk and their association w... more Vitamin D and folate are associated with decreased colorectal cancer risk and their association with colorectal cancer prognosis is under investigation. We assessed the levels of plasma 25-hydroxyvitamin D3 (25(OH)D3), folate and vitamin B12 in an international pilot study in order to determine variability of these biomarkers based on geographical location. Plasma 25(OH)D3, folate and vitamin B12 concentrations were measured in 149 invasive, newly diagnosed colorectal cancer cases from Heidelberg (Germany), Seattle (WA, USA), and Tampa (FL, USA) and in ninety-one age- and sex-matched controls. Their associations with potential predictors were assessed using multivariate linear regression analyses. Plasma 25(OH)D3, folate and vitamin B12 concentrations differed by location. Other predictors were season for 25(OH)D3 and tumour stage (vitamin B12). Season-corrected average 25(OH)D3 concentrations were higher in Heidelberg (31·7 ng/ml; range 11·0–83·0 ng/ml) than in Seattle (23·3 ng/ml;...

Research paper thumbnail of Impact of chemical, biological, radiation, and nuclear personal protective equipment on the performance of low- and high-dexterity airway and vascular access skills

Resuscitation, 2010

Impact of chemical, biological, radiation, and nuclear personal protective equipment on the perfo... more Impact of chemical, biological, radiation, and nuclear personal protective equipment on the performance of low-and highdexterity airway and vascular access skills Sir,

Research paper thumbnail of Polyphenolic compounds in the fruits of Egyptian medicinal plants (Terminalia bellerica, Terminalia chebula and Terminalia horrida): Characterization, quantitation and determination of antioxidant capacities

Research paper thumbnail of A new dietary model to study colorectal carcinogenesis: Experimental design, food preparation, and experimental findings

Nutrition and Cancer, 1996

Experimental dietary studies of human colorectal carcinogenesis are usually based on the AIN-76A ... more Experimental dietary studies of human colorectal carcinogenesis are usually based on the AIN-76A diet, which is dissimilar to human food in source, preparation, and content. The aims of this study were to examine the feasibility of preparing and feeding rats the diet of a specific human population at risk for colorectal neoplasia and to determine whether changes in the colonic morphology and metabolic contents would differ from those resulting from a standard rat diet. The mean daily food intake composition of a previously evaluated adenoma patient case-control study was used for the "human adenoma" (HA) experimental diet. Foods were prepared as for usual human consumption and processed by dehydration to the physical characteristics of an animal diet. Sixty-four female Sprague-Dawley rats were randomized and fed ad libitum the HA or the AIN-76A diet. Every eight weeks, eight rats from each group were sacrificed, and the colons and contents were examined. Analysis of the prepared food showed no significant deleterious changes; food intake and weight gain were similar in both groups. Compared with the controls, the colonic contents of rats fed the HA diet contained significantly less calcium, concentrations of neutral sterols, total lipids, and cholic and deoxycholic acids were increased, and there were no colonic histological changes other than significant epithelial hyperproliferation. This initial study demonstrated that the HA diet can be successfully processed for feeding to experimental animals and is acceptable and adequate for growth but induces significant metabolic and hyperproliferative changes in the rat colon. This dietary model may be useful for studies of human food, narrowing the gap between animal experimentation and human nutritional research.

Research paper thumbnail of Progressive genome-wide introgression in agricultural Campylobacter coli

Research paper thumbnail of Olive-oil consumption and health: the possible role of antioxidants

The Lancet Oncology, 2000

In the Mediterranean basin, olive oil, along with fruits, vegetables, and fish, is an important c... more In the Mediterranean basin, olive oil, along with fruits, vegetables, and fish, is an important constituent of the diet, and is considered a major factor in preserving a healthy and relatively disease-free population. Epidemiological data show that the Mediterranean diet has significant protective effects against cancer and coronary heart disease. We present evidence that it is the unique profile of the phenolic fraction, along with high intakes of squalene and the monounsaturated fatty acid, oleic acid, which confer its health-promoting properties. The major phenolic compounds identified and quantified in olive oil belong to three different classes: simple phenols (hydroxytyrosol, tyrosol); secoiridoids (oleuropein, the aglycone of ligstroside, and their respective decarboxylated dialdehyde derivatives); and the lignans [(+)-1-acetoxypinoresinol and pinoresinol]. All three classes have potent antioxidant properties. High consumption of extra-virgin olive oils, which are particularly rich in these phenolic antioxidants (as well as squalene and oleic acid), should afford considerable protection against cancer (colon, breast, skin), coronary heart disease, and ageing by inhibiting oxidative stress.

Research paper thumbnail of Characterization and Quantitation of Polyphenolic Compounds in Bark, Kernel, Leaves, and Peel of Mango ( Mangifera indica L.)

Journal of Agricultural and Food Chemistry, 2008

Research paper thumbnail of Characterization of the Volatile Pattern and Antioxidant Capacity of Essential Oils from Different Species of the Genus Ocimum

Journal of Agricultural and Food Chemistry, 2006

The antioxidant capacity of essential oils obtained by steam hydrodistillation from five species ... more The antioxidant capacity of essential oils obtained by steam hydrodistillation from five species of the genus Ocimum, namely Ocimum basilicum var. purpurascens, Ocimum basilicum, Ocimum gratissimum, Ocimum micranthum, and Ocimum tenuiflorum (syn. O. sanctum), were evaluated using a high-performance liquid chromatography-based hypoxanthine/xanthine oxidase and the DPPH assays. The yield of oils from the leaves of the five species was variable with the greater amount obtained from Ocimum gratissimum (3.5%) and the least from Ocimum basilicum var. purpurascens (0.5%). In the hypoxanthine/xanthine oxidase assay, strong antioxidant capacity was evident in all the oils but the greater was shown by that obtained from Ocimum tenuiflorum (syn. O. sanctum) (IC50 = 0.46 microL/mL) compared to Ocimum basilicum var. purpurascens (IC50 = 1.84 microL/mL). Antioxidant capacity was positively correlated (r = 0.92, p < 0.05) with a high proportion of compounds possessing a phenolic ring such as eugenol, while a strong negative correlation (r = -0.77, p > 0.1) with other major volatiles was observed. These correlations were confirmed to a large extent in the DPPH assay. The results of a 24 h experiment with Ocimum tenuiflorum (syn. O. sanctum) shows that the antioxidant capacity factor (amount of essential oil obtained x free radical scavenging capacity; mg x %/100) reaches a threshold between 10 and 12.00 h, corresponding to maximum sunlight intensity in Brasil and furthermore exhibits a clear diurnal variation. The data generated with Ocimum species indicates that essential oils obtained from various herbs and spices may have an important role to play in cancer chemoprevention, functional foods, and in the preservation of pharmacologic products.

Research paper thumbnail of Isolation, structure elucidation and antioxidant potential of the major phenolic and flavonoid compounds in brined olive drupes

Food and Chemical Toxicology, 2003

Research paper thumbnail of Characterization of a rare triterpenoid and minor phenolic compounds in the root bark of Anisophyllea dichostyla R. Br

Food and Chemical Toxicology, 2009

Anisophyllea dichostyla R. Br. (Anisophylleaceae), is a small shrub which grows widely in regions... more Anisophyllea dichostyla R. Br. (Anisophylleaceae), is a small shrub which grows widely in regions of the Democratic Republic of Congo (DRC) where its root barks are used in folk medicine for the treatment of many debilitating diseases. In a previous work [Khallouki, F., Haubner, R., Hull, W.E., Erben, G., Spiegelhalder, B., Bartsch, H., Owen, R.W., 2007. Isolation, purification and identification of ellagic acid derivatives, catechins and procyanidins from the root barks of Anisophyllea dichostyla R. Br. Food and Chemical Toxicology 45, 472-485] on this species, an appreciable number (16) of phenolic antioxidants (3.32 g/kg) such as ellagitannins (27%) and polyhydroxyflavan-3-ols (catechins and procyanidins; 73%) were isolated and identified. Two fractions, as well as containing minor phenolic compounds also showed evidence of a secondary plant substance similar to a triterpenoid. Following purification of the triterpenoid by semi-preparative HPLC, and recrystallization, the structure was elucidated as bryonolic acid as evinced by comprehensive spectroscopic analyses including (1)H and (13)C NMR, DEPT, COSY, ROESY, HMQC, HMBC, HPLC-ESI-MS and GC-MS experiments. Bryonolic acid, which is extremely rare in nature, is therefore reported in the family Anisophylleaceae for the first time. Furthermore, the following minor phenolic compounds namely tyrosol, 2-(3-methoxy, 4-hydroxyphenyl)-ethanol, vanillin, syringaldehyde, vanillic acid, syringic acid, gallic acid and ferulic acid were also identified by GC-MS in this species for the first time.

Research paper thumbnail of Letter to the Editor: Retinal and retinol are potential regulators of gene expression in the keratinocyte cell line HaCaT: Letter to the Editor

Research paper thumbnail of Characterization of the Volatile Pattern and Antioxidant Capacity of Essential Oils from Different Species of the Genus Ocimum

Journal of Agricultural and Food Chemistry, Jun 1, 2006

The antioxidant capacity of essential oils obtained by steam hydrodistillation from five species ... more The antioxidant capacity of essential oils obtained by steam hydrodistillation from five species of the genus Ocimum, namely Ocimum basilicum var. purpurascens, Ocimum basilicum, Ocimum gratissimum, Ocimum micranthum, and Ocimum tenuiflorum (syn. O. sanctum), were evaluated using a high-performance liquid chromatography-based hypoxanthine/xanthine oxidase and the DPPH assays. The yield of oils from the leaves of the five species was variable with the greater amount obtained from Ocimum gratissimum (3.5%) and the least from Ocimum basilicum var. purpurascens (0.5%). In the hypoxanthine/xanthine oxidase assay, strong antioxidant capacity was evident in all the oils but the greater was shown by that obtained from Ocimum tenuiflorum (syn. O. sanctum) (IC50 = 0.46 microL/mL) compared to Ocimum basilicum var. purpurascens (IC50 = 1.84 microL/mL). Antioxidant capacity was positively correlated (r = 0.92, p < 0.05) with a high proportion of compounds possessing a phenolic ring such as eugenol, while a strong negative correlation (r = -0.77, p > 0.1) with other major volatiles was observed. These correlations were confirmed to a large extent in the DPPH assay. The results of a 24 h experiment with Ocimum tenuiflorum (syn. O. sanctum) shows that the antioxidant capacity factor (amount of essential oil obtained x free radical scavenging capacity; mg x %/100) reaches a threshold between 10 and 12.00 h, corresponding to maximum sunlight intensity in Brasil and furthermore exhibits a clear diurnal variation. The data generated with Ocimum species indicates that essential oils obtained from various herbs and spices may have an important role to play in cancer chemoprevention, functional foods, and in the preservation of pharmacologic products.

Research paper thumbnail of Olive-oil consumption and health: the possible role of antioxidants.(Brief Article)

Alternative Medicine Review, Jun 1, 2002

Research paper thumbnail of CIB White Paper on IDDS Integrated Design & Delivery Solutions

School of Civil Engineering Built Environment Institute For Future Environments Science Engineering Faculty, 2009

Research paper thumbnail of Does position of the patient adversely affect successful intubation whilst wearing CBRN-PPE?

Resuscitation, Sep 1, 2010

Research paper thumbnail of Challenges for Integrated Design and Delivery Solutions

Architectural Engineering and Design Management, 2010

Research paper thumbnail of Identification of lignans as major components in the phenolic fraction of olive oil

Clinical chemistry, 2000

Because olive oil is an important component of the Mediterranean diet, it is necessary to establi... more Because olive oil is an important component of the Mediterranean diet, it is necessary to establish unequivocal identification of the major potential antioxidant phenolic compounds it contains. The major phenolic antioxidants in extra virgin olive oil were isolated and purified. Structural analysis was conducted using several spectroscopic techniques, including mass spectrometry and nuclear magnetic resonance (NMR). In particular, detailed (1)H and (13)C NMR data are presented, and several assignment errors in the literature are corrected. The data show for the first time that the lignans (+)-1-acetoxypinoresinol and (+)-pinoresinol are major components of the phenolic fraction of olive oils. These lignans, which are potent antioxidants, are absent in seed oils and virtually absent in refined virgin oils but are present at concentrations of up to 100 mg/kg (mean +/- SE, 41.53+/-3.93 mg/kg; range, 0.65-99.97 mg/kg) in extra virgin oils. As with the simple phenols and secoiridoids, th...

Research paper thumbnail of Estimation of the effects of angioplasty on coronary stenosis using quantitative video angiography

Catheterization and cardiovascular diagnosis, 1985

In this study, we compared stenosis severity by quantitative coronary angiography from video and ... more In this study, we compared stenosis severity by quantitative coronary angiography from video and cine images with visual estimation in 14 patients who underwent PTCA. Both cine and video analysis demonstrated a change from 65.2 +/- 2.5 to 36.5 +/- 3.1% diameter stenosis following PTCA, whereas visual estimation (average of three observers) showed improvement from 89.9 +/- 1.7 to 36.0 +/- 3.2%. Percent area stenosis from quantitative angiography showed improvement from 87.9 +/- 1.8 to 56.4 +/- 5.8. These data indicate that visual assessment overestimated percent diameter of severe lesions. To determine if video analysis could provide rapid quantitative assessment of PTCA results, we compared percent diameter and percent area stenosis by video with cine (diameter: correlation coefficient, 0.82; slope, 0.79; area: correlation coefficient, 0.86; slope, 0.83). These results indicate that video-based measurements are not different from cine-derived measurements. Quantitative coronary angi...

Research paper thumbnail of (2R∗,3S∗,4S∗,2″R∗,3″S∗)-Guibourtinidol-(4α→8)-catechin, a biflavanoid procyanidin of the proguibourtinidin group from Senna macranthera: its relative stereochemistry and conformation

Tetrahedron: Asymmetry, 2015

ABSTRACT Comprehensive NMR data for the previously presumed structure of the procyanidin (2R∗,3S∗... more ABSTRACT Comprehensive NMR data for the previously presumed structure of the procyanidin (2R∗,3S∗,4S∗,2″R∗,3″S∗)-guibourtinidol-(4α→8)-catechin, isolated in this case from the roots of the medicinal plant Senna macranthera, is reported. Earlier reports provided a basic plausible structure based on mass spectrometry data but lacked confirmation by NMR. Therefore the 3D structure of the compound in terms of its full relative configuration and conformational preference in CD3OD solution was established by molecular modeling using DFT in conjunction with both chemical shift, δH and δC, and NOE contact, ηH,H, NMR data.

Research paper thumbnail of Does position of the patient adversely affect successful intubation whilst wearing CBRN-PPE?

Research paper thumbnail of Plasma 25-hydroxyvitamin D3, folate and vitamin B12 biomarkers among international colorectal cancer patients: a pilot study

Journal of Nutritional Science, 2013

Vitamin D and folate are associated with decreased colorectal cancer risk and their association w... more Vitamin D and folate are associated with decreased colorectal cancer risk and their association with colorectal cancer prognosis is under investigation. We assessed the levels of plasma 25-hydroxyvitamin D3 (25(OH)D3), folate and vitamin B12 in an international pilot study in order to determine variability of these biomarkers based on geographical location. Plasma 25(OH)D3, folate and vitamin B12 concentrations were measured in 149 invasive, newly diagnosed colorectal cancer cases from Heidelberg (Germany), Seattle (WA, USA), and Tampa (FL, USA) and in ninety-one age- and sex-matched controls. Their associations with potential predictors were assessed using multivariate linear regression analyses. Plasma 25(OH)D3, folate and vitamin B12 concentrations differed by location. Other predictors were season for 25(OH)D3 and tumour stage (vitamin B12). Season-corrected average 25(OH)D3 concentrations were higher in Heidelberg (31·7 ng/ml; range 11·0–83·0 ng/ml) than in Seattle (23·3 ng/ml;...

Research paper thumbnail of Impact of chemical, biological, radiation, and nuclear personal protective equipment on the performance of low- and high-dexterity airway and vascular access skills

Resuscitation, 2010

Impact of chemical, biological, radiation, and nuclear personal protective equipment on the perfo... more Impact of chemical, biological, radiation, and nuclear personal protective equipment on the performance of low-and highdexterity airway and vascular access skills Sir,

Research paper thumbnail of Polyphenolic compounds in the fruits of Egyptian medicinal plants (Terminalia bellerica, Terminalia chebula and Terminalia horrida): Characterization, quantitation and determination of antioxidant capacities

Research paper thumbnail of A new dietary model to study colorectal carcinogenesis: Experimental design, food preparation, and experimental findings

Nutrition and Cancer, 1996

Experimental dietary studies of human colorectal carcinogenesis are usually based on the AIN-76A ... more Experimental dietary studies of human colorectal carcinogenesis are usually based on the AIN-76A diet, which is dissimilar to human food in source, preparation, and content. The aims of this study were to examine the feasibility of preparing and feeding rats the diet of a specific human population at risk for colorectal neoplasia and to determine whether changes in the colonic morphology and metabolic contents would differ from those resulting from a standard rat diet. The mean daily food intake composition of a previously evaluated adenoma patient case-control study was used for the "human adenoma" (HA) experimental diet. Foods were prepared as for usual human consumption and processed by dehydration to the physical characteristics of an animal diet. Sixty-four female Sprague-Dawley rats were randomized and fed ad libitum the HA or the AIN-76A diet. Every eight weeks, eight rats from each group were sacrificed, and the colons and contents were examined. Analysis of the prepared food showed no significant deleterious changes; food intake and weight gain were similar in both groups. Compared with the controls, the colonic contents of rats fed the HA diet contained significantly less calcium, concentrations of neutral sterols, total lipids, and cholic and deoxycholic acids were increased, and there were no colonic histological changes other than significant epithelial hyperproliferation. This initial study demonstrated that the HA diet can be successfully processed for feeding to experimental animals and is acceptable and adequate for growth but induces significant metabolic and hyperproliferative changes in the rat colon. This dietary model may be useful for studies of human food, narrowing the gap between animal experimentation and human nutritional research.

Research paper thumbnail of Progressive genome-wide introgression in agricultural Campylobacter coli

Research paper thumbnail of Olive-oil consumption and health: the possible role of antioxidants

The Lancet Oncology, 2000

In the Mediterranean basin, olive oil, along with fruits, vegetables, and fish, is an important c... more In the Mediterranean basin, olive oil, along with fruits, vegetables, and fish, is an important constituent of the diet, and is considered a major factor in preserving a healthy and relatively disease-free population. Epidemiological data show that the Mediterranean diet has significant protective effects against cancer and coronary heart disease. We present evidence that it is the unique profile of the phenolic fraction, along with high intakes of squalene and the monounsaturated fatty acid, oleic acid, which confer its health-promoting properties. The major phenolic compounds identified and quantified in olive oil belong to three different classes: simple phenols (hydroxytyrosol, tyrosol); secoiridoids (oleuropein, the aglycone of ligstroside, and their respective decarboxylated dialdehyde derivatives); and the lignans [(+)-1-acetoxypinoresinol and pinoresinol]. All three classes have potent antioxidant properties. High consumption of extra-virgin olive oils, which are particularly rich in these phenolic antioxidants (as well as squalene and oleic acid), should afford considerable protection against cancer (colon, breast, skin), coronary heart disease, and ageing by inhibiting oxidative stress.

Research paper thumbnail of Characterization and Quantitation of Polyphenolic Compounds in Bark, Kernel, Leaves, and Peel of Mango ( Mangifera indica L.)

Journal of Agricultural and Food Chemistry, 2008

Research paper thumbnail of Characterization of the Volatile Pattern and Antioxidant Capacity of Essential Oils from Different Species of the Genus Ocimum

Journal of Agricultural and Food Chemistry, 2006

The antioxidant capacity of essential oils obtained by steam hydrodistillation from five species ... more The antioxidant capacity of essential oils obtained by steam hydrodistillation from five species of the genus Ocimum, namely Ocimum basilicum var. purpurascens, Ocimum basilicum, Ocimum gratissimum, Ocimum micranthum, and Ocimum tenuiflorum (syn. O. sanctum), were evaluated using a high-performance liquid chromatography-based hypoxanthine/xanthine oxidase and the DPPH assays. The yield of oils from the leaves of the five species was variable with the greater amount obtained from Ocimum gratissimum (3.5%) and the least from Ocimum basilicum var. purpurascens (0.5%). In the hypoxanthine/xanthine oxidase assay, strong antioxidant capacity was evident in all the oils but the greater was shown by that obtained from Ocimum tenuiflorum (syn. O. sanctum) (IC50 = 0.46 microL/mL) compared to Ocimum basilicum var. purpurascens (IC50 = 1.84 microL/mL). Antioxidant capacity was positively correlated (r = 0.92, p < 0.05) with a high proportion of compounds possessing a phenolic ring such as eugenol, while a strong negative correlation (r = -0.77, p > 0.1) with other major volatiles was observed. These correlations were confirmed to a large extent in the DPPH assay. The results of a 24 h experiment with Ocimum tenuiflorum (syn. O. sanctum) shows that the antioxidant capacity factor (amount of essential oil obtained x free radical scavenging capacity; mg x %/100) reaches a threshold between 10 and 12.00 h, corresponding to maximum sunlight intensity in Brasil and furthermore exhibits a clear diurnal variation. The data generated with Ocimum species indicates that essential oils obtained from various herbs and spices may have an important role to play in cancer chemoprevention, functional foods, and in the preservation of pharmacologic products.

Research paper thumbnail of Isolation, structure elucidation and antioxidant potential of the major phenolic and flavonoid compounds in brined olive drupes

Food and Chemical Toxicology, 2003

Research paper thumbnail of Characterization of a rare triterpenoid and minor phenolic compounds in the root bark of Anisophyllea dichostyla R. Br

Food and Chemical Toxicology, 2009

Anisophyllea dichostyla R. Br. (Anisophylleaceae), is a small shrub which grows widely in regions... more Anisophyllea dichostyla R. Br. (Anisophylleaceae), is a small shrub which grows widely in regions of the Democratic Republic of Congo (DRC) where its root barks are used in folk medicine for the treatment of many debilitating diseases. In a previous work [Khallouki, F., Haubner, R., Hull, W.E., Erben, G., Spiegelhalder, B., Bartsch, H., Owen, R.W., 2007. Isolation, purification and identification of ellagic acid derivatives, catechins and procyanidins from the root barks of Anisophyllea dichostyla R. Br. Food and Chemical Toxicology 45, 472-485] on this species, an appreciable number (16) of phenolic antioxidants (3.32 g/kg) such as ellagitannins (27%) and polyhydroxyflavan-3-ols (catechins and procyanidins; 73%) were isolated and identified. Two fractions, as well as containing minor phenolic compounds also showed evidence of a secondary plant substance similar to a triterpenoid. Following purification of the triterpenoid by semi-preparative HPLC, and recrystallization, the structure was elucidated as bryonolic acid as evinced by comprehensive spectroscopic analyses including (1)H and (13)C NMR, DEPT, COSY, ROESY, HMQC, HMBC, HPLC-ESI-MS and GC-MS experiments. Bryonolic acid, which is extremely rare in nature, is therefore reported in the family Anisophylleaceae for the first time. Furthermore, the following minor phenolic compounds namely tyrosol, 2-(3-methoxy, 4-hydroxyphenyl)-ethanol, vanillin, syringaldehyde, vanillic acid, syringic acid, gallic acid and ferulic acid were also identified by GC-MS in this species for the first time.