Identification of Compounds in Coleus forskohlii Extract Involved in the Induction of Hepatic CYP and Fatty Liver in Mice.

Coleus forskohlii extract (CFE), a popular weight-loss herbal product, induces hepatic cytochrome P450 (CYP) and fatty liver in mice; however, its main bioactive ingredient, forskolin, does not show such effects. To ensure the safety of CFE as a dietary supplement, identification of the compounds implicated in the induction of hepatic CYP and fatty liver is required. In this study, we separated a crude CFE extract into 5 fractions (Fr.) by column chromatography and administered the fractions to mice for one week to assess their ability to induce CYP and fatty liver. CYP induction was detected for all fractions, indicating that many compounds may be involved in CYP induction, while fatty liver was only detected for Fr. 2. Further isolation and purification of Fr. 2 by column chromatography identified 14-deoxycoleon U as a major compound and crocetin dialdehyde as a pigment compound. An in vivo mouse study revealed that crocetin dialdehyde had no effect on the liver and, as 14-deoxycoleon U was the major compound in Fr. 2, it is likely that the active compound inducing fatty liver in CFE is 14-deoxycoleon U. These findings will facilitate the preparation of standardized safe CFE ingredients for dietary supplements.

Biotransformation of (+)-isofraxinellone by Aspergillus niger and insect antifeedant activity.

The biotransformation of (+)-isofraxinellone (1) by Aspergillus niger was investigated. Compound 1 was transformed to only one new compound 2. The structure of 2 was identified as (-)-(4S)-4-hydroxyisofraxinellone which was regio- and stereo-selective hydroxylated at the C-4 position by IR, EI-MS 1D and 2D NMR. Absolute configuration of hydroxyl group at the C-4 position was detected by modified Mosher's method. Antifeedant activity of compounds 1 and 2 against larvae of Spodoptera litura was assayed. These compounds showed potent antifeedant activity and ED50 (50% of effective dose) values were 3.91 and 4.43 µg/cm2, respectively.

Antimutagenic activity of flavonoids from Sozuku.

Pinocembrin (1) and cardamonin (2) from Sozuku showed a suppressive effect on umu gene expression of SOS response in Salmonella typhimurium TA1535/pSK1002 against the mutagen furylfuramide. Compounds 1 and 2 suppressed 52% and 36% of SOS-inducing activity at a concentration of 0.20 µmol/mL. The ID50 value of 1 was 0.18 µmol/mL. These compounds showed the suppression of 2-amino-3,4-dimethylimidazo-[4,5-f]quinolone (MeIQ) and UV irradiation-induced SOS response. Pinostrobin (3) and 5,7-dimethoxyflavanone (4), methyl ethers of 1, showed similar activity to 1 against MeIQ-induced SOS response, but that of furylfuramide and UV irradiation were decreased. On the other hand, compounds 1-4 did not show the suppression of activated MeIQ-induced SOS response. Furthermore, compounds 1-4 showed potent antimutagenic activity against MeIQ mutagenesis in Ames test using the S. typhimurium TA100 and TA98 strains.

Inhibition of ß-Secretase Activity by Monoterpenes, Sesquiterpenes, and C13 Norisoprenoids.

Inhibition of ß-secretase (BACE1) is currently regarded as the leading treatment strategy for Alzheimer's disease. In the present study, we aimed to screen the in vitro inhibitory activity of 80 types of aroma compounds (monoterpenes, sesquiterpenes, and C13 norisoprenoids), including plant-based types, at a 200-µM concentration against a recombinant human BACE1. The results showed that the most potent inhibitor of BACE1 was geranyl acetone followed by (+)-camphor, (-)-fenchone, (+)-fenchone, and (-)-camphor with the half-maximal inhibitory concentration (IC50) values of 51.9 ± 3.9, 95.9 ± 11.0, 106.3 ± 14.9, 117.0 ± 18.6, and 134.1 ± 16.4 µM, respectively. Furthermore, the mechanism of inhibition of BACE1 by geranyl acetone was analyzed using Dixon kinetics plus Cornish-Bowden plots, which revealed mixed-type mode. Therefore aroma compounds may be used as potential lead molecules for designing anti-BACE1 agents.

In Vitro Regio- and Stereoselective Oxidation of ß-Ionone by Human Liver Microsomes.

The metabolism of the norisoprenoid ß-ionone was investigated in vitro using human liver microsomes and 11 different recombinant cytochrome P450 enzymes expressed in Trichoplusia ni cells. ß-Ionone was found to be oxidized via 4S-hydroxylation by CYP2B6 in human liver microsomes. CYP1A2 also regioselectively catalyzed the hydroxylation of ß-ionone to yield 4-hydroxylation; this conversion was not stereoselective. Further kinetic analysis revealed that CYP2B6 exhibited the highest activity for ß-ionone 4-hydroxylation. Kinetic analysis showed that Km and Vmax for oxidation of ß-ionone by CYP1A2 and CYP2B6 was 107.9 ± 36.0 µM and 3200.3 ± 323.0 nmol/min/nmol P450 and 5.6 ± 1.2 µM and 572.8 ± 29.8 nmol/min/nmol P450, respectively. The reaction rates observed using human liver microsomes and recombinant CYP2B6 were very high compared with those of other CYP2B6 substrates reported thus far. These results suggest that ß-ionone, a norisoprenoid present in nature, is one of the effective substrates for CYP2B enzymes in human liver microsomes. To the best of our knowledge, this is the first time that 4-hydroxy ß-ionone has been described as a human metabolite of ß-ionone.

Sexual Differences in Chemical Composition and Aroma-active Compounds of Essential Oil from Flower Buds of Eurya japonica.

This study was conducted to determine the composition of essential oil from buds of male and female Eurya japonica flowers and to determine the aroma-active compounds of this plant by gas chromatography-mass spectrometry (GC-MS), sensory evaluation, and odor activity values (OAV). The oils contained eighty-five compounds. We identified for the first time forty-four compounds in E. japonica. Through sensory evaluation, nineteen aroma-active compounds were identified by gas chromatography-olfactometry (GC-O). Because the chemical composition can affect the interaction between plants and herbivorous insects, our results suggest that essential oils from male and female flower buds of E. japonica differently affect herbivores. Sexual differences in essential oils deserve further investigations in this plant-insect system.

Chemical composition, aroma evaluation, and inhibitory activity towards acetylcholinesterase of essential oils from Gynura bicolor DC.

The compositions of the essential oils obtained from leaves and stems of Gynura bicolor DC. were analyzed by GC-MS. One hundred eight components of these oils were identified. (E)-ß-caryophyllene (31.42 %), α-pinene (17.11 %), and bicyclogermacrene (8.09 %) were found to be the main components of the leaf oil, while α-pinene (61.42 %), ß-pinene (14.39 %), and myrcene (5.10 %) were the major constituents of the stem oil. We found 73 previously unidentified components in these oils from G. bicolor. The oils were also subjected to odor evaluation. Eleven and 12 aroma-active compounds were detected in the leaf and stem oils, respectively. The abilities of these oils to inhibit acetylcholinesterase (AChE) activity were determined. The sesquiterpenoids in the oils were found to inhibit AChE activity more strongly than the monoterpenoids in the oils did. It was suggested that the three main components in each essential oil act synergistically against AChE activity. These results show that the essential oils obtained from G. bicolor are a good dietary source of AChE activity inhibition.

Chemical Composition and Aroma Evaluation of Essential Oils from Skunk Cabbage (Symplocarpus foetidus).

Two sample preparation methods, namely hydrodistillation (HD) and solvent-assisted flavor evaporation (SAFE), have been used to investigate the essential oils of the aerial parts (leaves and stems) of Symplocarpus foetidus, a plant with a characteristic odor, by gas chromatography mass spectrometry (GC-MS). Characteristic aroma-active compounds in the oils were detected by GC-Olfactometry (GC-O) and aroma extract dilution analysis (AEDA). From the HD method, the main compounds in the oil were found to be p-vinyl-guaiacol (15.5%), 2-pentyl-furan (13.4%), and (Z)-ligustilide (9.5%). From the SAFE method, the main compounds were 2-butoxy-ethanol (49.6%), ethyl-pentanoate (4.5%), and mesitylene (4.0%). In HD oil, the most intense aroma-active compounds were 2-pentyl-furan (flavor dilution factor (FD) = 32, odor activity value (OAV) = 57), p-vinyl-guaiacol (FD = 16, OAV = 41), and dimethyl disulfide (FD = 16, OAV = 41). In SAFE oil, the main aroma-active compounds were 2-butoxy ethanol (FD = 32, OAV = 16), and 2-methoxy thiazole (FD = 32, OAV = 25).

Evaluation of the Key Odorants in Volatile Oils from Tubers of Apios americana Medikus.

This study was investigated the chemical composition of volatile oils and aroma evaluation from the tubers of Apios americana Medikus. Theses volatile oils were obtained by the hydrodistillation (HD) and the solvent-assisted flavor evaporation (SAFE) methods. These oils were analyzed by Gas chromatography (GC), GC-mass spectrometry (GC-MS), GC-olfactometry (GC-O), aroma extract dilution analysis (AEDA) and odor activity values (OAV) for the first time. The major compounds in the HD oil were palmitic acid (36.5%), linoleic acid (10.5%) and nonadecanol (5.7%). Meanwhile, in the SAFE oil, the major compounds were 4-hydroxy-4-methyl-2-pentanone (34.2%), hexanal (11.0%) and hexanol (7.9%). Through aroma evaluation, 20 (HD) and 14 (SAFE) aroma-active compounds were identified by GC-O. As a result, the most intense aroma-active compounds in both extraction methods were 1-octen-3-ol and hexanal, both of which showed high odor activity values (OAV).

Identification of Aroma-active Compounds in Essential Oil from Uncaria Hook by Gas Chromatography- Mass Spectrometry and Gas Chromatography-Olfactometry.

The chemical composition of essential oil extracted from Uncaria Hook ("Chotoko" in Japanese), the branch with curved hook of the herbal medicine Uncaria rhynchophylla has been investigated by GC and GC-MS analyses. Eighty-four compounds, representing 90.8% of the total content was identified in oil obtained from Uncaria Hook. The main components i were (E)-cinnamaldehyde (13.4%), α-copaene (8.0%), methyl eugenol (6.8%), δ-cadinene (5.3%), and curcumene (3.6%). The important key aroma-active compounds in the oil were detected by gas chromatography-olfactometry (GC-O) and aroma extract dilution analysis (AEDA), using the flavor dilution (FD) factor to express the odor potency of each compounds. Furthermore, the odor activity value (OAV) has been used as a measure of the relative contribution of each compound to the aroma of the Uncaria Hook oil. The GC-O and AEDA results showed that α-copaene (FD = 4, OAV = 4376), (E)-linalool oxide (FD = 64, OAV = 9.1), and methyl eugenol (FD = 64, OAV = 29) contributed to the woody and spicy odor of Uncaria Hook oil, whereas furfural (FD = 8, OAV = 4808) contributed to its sweet odor. These results warrant further investigations of the application of essential oil from Uncaria Hook in the phytochemical and medicinal fields.

Characteristic Chemical Components and Aroma-active Compounds of the Essential Oils from Ranunculus nipponicus var. submersus Used in Japanese Traditional Food.

Ranunculus nipponicus var. submersus is an aquatic macrophyte; it is known as a wild edible plant in Japan for a long time. In this study, the essential oils from the fresh and dried aerial parts of R. nipponicus var. submersus were extracted by hydrodistillation and analyzed by gas chromatography (GC) and GC-mass spectrometry (GC-MS). Moreover, important aroma-active compounds were also detected in the oil using GC-olfactometry (GC-O) and aroma extract dilution analysis (AEDA). Thus, 98 compounds (accounting for 93.86%) of the oil were identified. The major compounds in fresh plant oil were phytol (41.94%), heptadecane (5.92%), and geranyl propionate (5.76%), while those of. Dried plant oil were ß-ionone (23.54%), 2-hexenal (8.75%), and dihydrobovolide (4.81%). The fresh and dried oils had the green-floral and citrus-floral odor, respectively. The GC-O and AEDA results show that phenylacetaldehyde (green, floral odor, FD-factor = 8) and ß-ionone (violet-floral odor, FD-factor = 8) were the most characteristic odor compounds of the fresh oils. ß-Cyclocitral (citrus odor, FD-factor = 64) and ß-ionone (violet-floral odor, FD-factor = 64) were the most characteristic odor compounds of the dried oil. These compounds are thought to contribute to the flavor of R. nipponicus var. submersus.

Isolation and biological activity of a novel cadinane-type sesquiterpenoid from the essential oil of Alangium salviifolium.

The components of the essential oil from the roots of Alangium salviifolium were analyzed by capillary gas chromatography-mass spectrometry (GC-MS). Ninety compounds, representing 74.5% of the total oil, were identified; the main components of the oil were epi-α-cadinol, followed by trans-2-hydroxycalamenene, cadalene, and cadina-4,10(15)-dien-3-one. A further unknown component comprised 5.5% of the oil. Therefore, the essential oil was purified by flash column chromatography to isolate this component. Its structure was established using extensive spectroscopic data analyses, including NMR, HR-EI-MS, and IR. The results showed that this isolated compound was (-)-7, 8-dihydroxycalamenal, which is a novel cadinane-type sesquiterpenoid. This compound was tested for its antioxidant activity and inhibition of tyrosinase, and showed particularly strong inhibition effects.

Aroma evaluation of setonojigiku (Chrysanthemum japonense var. debile) by hydrodistillation and solvent-assisted flavour evaporation.

INTRODUCTION: The Chrysanthemum genus consisting of about 200 species is mainly distributed over the Northern Hemisphere. Despite the pleasant odour of C. japonense var. debile (setonojigiku), no detailed analysis of the aroma-active compounds has been reported using sensory evaluation. OBJECTIVES: Using a hydrodistillation (HD) and a solvent-assisted flavour evaporation (SAFE) method to obtain the volatile oil from the leaf parts. METHODS: To clarify odorants contributing to the characteristic aroma-active compounds, the aroma-extract dilution analysis (AEDA) method was performed through gas chromatography olfactometry (GC/O) analysis. In addition, the odour activity value (OAV) was calculated in order to determine the relative contribution of each compound to the aroma-active compounds. RESULTS: A total of 42 components by HD oil were identified by GC-MS, whereas 34 components were identified in SAFE oil. Thirteen compounds were identified by GC/O analysis in HD and SAFE oils respectively. CONCLUSION: Each extraction method has its own advantages and disadvantages, and they are generally complementary to each other. On the basis of AEDA, OAV and sensory evaluations, [2.2.1] bicyclic monoterpenes (borneol, bornyl acetate and camphor) and ß-caryophyllene are considered to be the main aroma-active compounds of both extraction methods.

Characterization of volatile components and odor-active compounds in the oil of edible mushroom Boletopsis leucomelas.

The volatile oil from Boletopsis leucomelas (Pers.) Fayod was extracted by hydrodistillation with diethylether, and the volatile components of the oil were analyzed by gas chromatography-mass spectrometry. The oil contained 86 components, representing 87.5% of the total oil. The main components of the oil were linoleic acid (15.0%), phenylacetaldehyde (11.2%), and palmitic acid (9.4%). Furthermore, sulfur-containing compounds including 3-thiophenecarboxaldehyde, 2-acetylthiazole, S-methyl methanethiosulfonate, and benzothiazole were detected using gas chromatography-pulsed flame photometric detection. The odor components were evaluated by the odor activity value, and aroma extract dilution analysis was performed through gas chromatography-olfactometry analysis. The oil had a mushroom-like, fatty, and burnt odor. The main components contributing to the mushroom-like and fatty odor were hexanal, nonanal, 1-octen-3-ol, and (2E)-nonenal, while the burnt odor was due to furfuryl alcohol, benzaldehyde, 5-methyl furfural, 2,3,5-trimethylpyrazine, 2-acethylthiazole, and indole.

Chemical composition and aroma evaluation of essential oils from Evolvulus alsinoides L.

The aim of this study was to investigate the chemical composition and the odor-active compounds of the essential oils from Evolvulus alsinoides, which is a well-known edible and medicinal plant. The volatile compounds in the oils were identified by hydrodistillation (HD) and solvent-assisted flavor evaporation (SAFE) in combination with GC, GC/MS, GC/O (=olfactometry), aroma extract dilution analysis (AEDA), and relative flavor activities (RFA values). The most abundant compound in the HD oil was cis-α-necrodol (12.62%), an irregular monoterpene with a cyclopentane skeleton, which is very unusual in the plant kingdom. In the SAFE oil, the main components included 2-butoxyethanol (9.01%), benzyl alcohol (8.01%), and γ-butyrolactone (7.37%). Through sensory analysis, 21 aroma-active compounds were identified by GC/O. The most intense aroma-active compounds in the HD oil were hexan-1-ol and γ-nonalactone, both of which showed high RFA values. α-Methyl-γ-butyrolactone and dimethyl sulfone contributed more strongly to the aroma of the SAFE oil. These results imply that the essential oils of E. alsinoides deserve further investigation in the food industry.

Volatile composition and sensory properties of Indian herbal medicine-Pavonia odorata-used in Ayurveda.

The chemical composition of volatile oil obtained from aerial parts of Pavonia odorata were investigated using gas chromatography-mass spectrometry (GC-MS). Its aroma-active compounds were identified using gas chromatography-olfactometry (GC-O) and aroma extraction dilution analysis (AEDA). In order to determine the relative contribution of each compound to the aroma of P. odorata, relative flavour activity (RFA) was calculated. The hydrodistillation of P. odorata afforded yellowish oil and the yield was 0.009% (w/w) with a spicy, sweet, and green odour. Eighty-five compounds were identified in the oil by GC-MS; the major constituents of the volatile oil were ageratochromene (11.95%), palmitic acid (9.95%), hexahydrofarnesyl acetone (5.96%), ß-eudesmol (4.53%) and ß-caryophyllene oxide (3.08%). The most characteristic aroma compounds in the volatile oil were identified for ß-caryophyllene oxide (FD-factor = 128, spicy), (E)-pinocarveol (FD-factor = 64, sweet), 3-butylpyridine (FD-factor = 64, spicy), and 2-nonanone (FD-factor = 32, green) by GC-MS, GC-O and AEDA. It seems that these compounds are responsible for the spicy, sweet and green odour of the aerial parts of P. odorata. The antioxidant activity of the volatile oil was also investigated by the oxygen radical absorbance capacity (ORAC) assay using fluorescein (FL) as the fluorescent probe. The ORAC value of the oil was 594.2 ± 25.9 µM TE/g. The results indicated that the volatile oil from the aerial parts of P. odorata could be considered as a natural antioxidant effect agent.

Characterization of aroma-active compounds in dry flower of Malva sylvestris L. by GC-MS-O analysis and OAV calculations.

In this study, the aroma-active compounds in the dried flower of Malva sylvestris L. were extracted by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS), and gas chromatography-olfactometry (GC-O) and aroma extraction dilution analysis (AEDA). A light yellow oil with a sweet odor was obtained with a percentage yield of 0.039% (w/w), and 143 volatile compounds (89.86%) were identified by GC-MS. The main compounds were hexadecanoic acid (10.1%), pentacosane (4.8%) and 6,10,14-trimethyl-2-pentadecanone (4.1%). The essential oil consisted mainly of hydrocarbons (25.40%) followed by, alcohols (18.78%), acids (16.66%), ethers (5.01%) ketones (7.28%), esters(12.43%), aldehydes (2.30%) and others (2.00%). Of these compounds, 20 were determined by GC-O and AEDA, to be odor-active (FD (flavor dilution) factor ≥ 1). ß-Damascenone (FD = 9, sweet), phenylacetaldehyde (FD = 8, floral, honey-like) and (E)-ß-ocimene (FD = 8, spicy) were the most intense aroma-active compounds in M. sylvestris. In order to determine the relative contribution of each of the compounds to the aroma of M. sylvestris, odor activity values (OAVs) were used. ß-Damascenone had the highest odor activity values (OAV) (50,700), followed by (E)-ß-ionone (15,444) and decanal (3,510). In particular, ß-damascenone had a high FD factors, and therefore, this compound was considered to be the main aroma-active components of the essential oil. On the basis of AEDA, OAVs, and sensory evaluation results, ß-damascenone is estimated to be the main aroma-active compound of the essential oil.

Comparison of volatile compounds with characteristic odor in flowers and leaves of nojigiku (Chrysanthemum japonense).

The aim of the present study was to investigate the essential oils isolated from flower and leaf in order to get insight into similarities and differences as to their aroma-active composition. The essential oil obtained from the two parts were analyzed by gas chromatography-mass spectrometry and gas chromatography olfactometry (GC-O). Flower and leaf oils, 38 and 36 constituents, representing 96.4 and 91.0% of the total oil composition, respectively, were identified. The main compounds in flower oil were camphor (47.64%), bornyl acetate (11.87%), and nojigiku alcohol (6.29%), whereas those in leaf oil were camphor (39.14%), nojigiku alcohol (10.76%) and γ-muurolene (7.02%). 13 Aroma-active compounds were identified by GC-O analysis in flower oil and 12 in leaf oil. The main aroma-active compounds in flower oil were camphor (camphor, FD (flavor dilution) = 7, OAV (odor active value) = 136913), bornyl acetate (camphor, FD = 6, OAV = 113711), and ß-caryophyllene (spicy, FD = 5, OAV = 116480). In leaf oil, the main aroma-active compounds were camphor (camphor, FD = 7, OAV = 106784), nojigiku alcohol (camphor, FD = 5, OAV = not determined), and ß-caryophyllene (spicy, FD = 6, OAV = 526267).

Characteristic odor components of essential oil from Scutellaria laeteviolacea.

The essential oils from aerial parts of Scutellaria laeteviolacea was analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The characteristic odor components were also detected in the oil using gas chromatography-olfactometry (GC-O) analysis and aroma extraction dilution analysis (AEDA). As a result, 100 components (accounting for 99.11 %) of S. laeteviolacea, were identified. The major components of S. laeteviolacea oil were found to be 1-octen-3-ol (27.72 %), germacrene D (21.67 %),and ß-caryophyllene (9.18 %). The GC-O and AEDA results showed that 1-octen-3-ol, germacrene D, germacrene B, and ß-caryophyllene were the most characteristic odor components of the oil. These compounds are thought to contribute to the unique flavor of this plant.

Aroma evaluation of gamazumi (Viburnum dilatatum) by aroma extract dilution analysis and odour activity value.

INTRODUCTION: Viburnum dilatatum (gamazumi) is widely distributed in Japan and China. Recently, juice from V. dilatatum fruits has been manufactured in Japan. Concerning the aroma of V. dilatatum, phenethyl alcohol, 3Z-hexenol and l-linalool have been identified in the essential oil from the flowers of V. dilatatum, however, there are no detailed reports on the aroma of V. dilatatum elucidated using sensory evaluation. OBJECTIVE: To clarify odourants contributing to the characteristic aroma, the aroma extract dilution analysis (AEDA) method was performed through gas chromatography olfactometry (GC-O) analysis. METHODOLOGY: The aroma-active compounds were identified by GC-O and AEDA, and in order to determine the relative contribution of each compound to the aroma of V. dilatatum, odour activity value (OAV) has been used. RESULTS: The hydrodistillation of the leaf and branch of V. dilatatum afforded pale yellowish oils, with yields of 0.008 and 0.015% (w/w). The main components of the leaf oil were 3Z-hexenal (12.7%) and linalool (10.8%). In branch oil, palmitic acid (18.3%) and linoleic acid (8.2%) were identified. With regard to aroma components, 24 and 14 compounds were identified in the leaf and branch oils respectively, by GC-O analysis. CONCLUSION: On the basis of AEDA, OAVs and sensory evaluations, nonanal is estimated as the main aroma compound of leaf and branch oil, as the other aroma compounds, C6 compounds and 2-pentyl furan make green odour; linalool, eugenol and ß-ionone play important role in the sweet odour of leaf oil. In branch oil, cis-furanlinalool oxide and eugenol make sweet odour, and ß-eudesmol contributes to woody odour.