1'-Acetoxychavicol acetate, a potent transient receptor potential ankyrin 1 agonist derived from Thai ginger, prevents visceral fat accumulation in mice fed with a high-fat and high-sucrose diet.

1'-Acetoxychavicol acetate (ACA) is found in Thai ginger (Alpinia galanga) and is a powerful agonist of transient receptor potential ankyrin 1 (TRPA1). In a diet-induced obesity mouse model, ACA reduced fat deposition. Sympathetic nerve activation was also indicated in the ACA-fed group. This study is expected to promote the utilization of food containing TRPA1 agonists to treat obesity.

Volatile compounds of black cumin (Nigella sativa L.) seeds cultivated in Bangladesh and India.

The compositional analysis of volatile compounds of Nigella sativa L. seeds obtained from India and Bangladesh was carried out in this study. Apart from the proportion of volatile compounds, the chemical composition of seeds from both sources were similar. The major volatile compounds in Bangladesh seeds were p-cymene (36.35%), thymoquinone (29.77%), α-thujene (12.40%), carvacrol (2.85%), ß-pinene (2.41%), limonene (1.64%), methyl linoleate (1.33%) and sabinene (1.18%), contribution of these is 87.93% of the total volatile oil. On the other hand, the major volatile compounds in Indian seeds were p-cymene (41.80%), α-thujene (13.93%), thymoquinone (10.27%), methyl linoleate (4.02%), carvacrol (3.65%), ß-pinene (2.96%), d-limonene (2.11%), 4,5-epoxy-1-isopropyl-4- methyl-1-cyclohexene (1.80%), sabinene (1.50%) and 4-terpineol (1.22%); contribution of these were 83.24% of the total volatile oil. In both seeds, p-cymene, thymoquinone, and α-thujene were the major components. Importantly, N. sativa seeds of Bangladesh contained almost 3-fold thymoquinone compared to Indian seeds. In conclusion, the seeds from Bangladesh contain a higher amount of terpene ketones (29.86%) represented by thymoquinone in comparison to Indian seeds (10.61%); on the other hand, Indian seeds contained a higher amount of terpene hydrocarbons (63.18%) mainly p-cymene, compared to Bangladesh seeds (54.53%). This is the first study to report detailed compositional analysis and comparison of Nigella sativa L. seeds from Bangladesh and India.

Compositional changes of the floral scent volatile emissions from Asian skunk cabbage (Symplocarpus renifolius, Araceae) over flowering sex phases.

INTRODUCTION: Flowering of the Asian skunk cabbage (Symplocarpus renifolius, Araceae) shows a sequential expression of female, bisexual and male sex phases. The protogynous thermogenic inflorescence has unpleasant odours, but the contributing chemical composition is poorly understood. OBJECTIVE: To determine the volatile composition of odour emissions from each S. renifolius flowering phase. METHODOLOGY: The dynamic headspace method was used to collect floral volatiles from six intact S. renifolius inflorescences in their natural habitat. Collected volatiles from the three flowering phases were analysed using gas chromatography-mass spectrometry/olfactometry (GC-MS/O). RESULTS: Female-phase inflorescences were characterised by an earthy-rotten-minty odour, while male-phase inflorescences typically exhibited a rotten-oily odour. Approximately 160 compounds were detected in volatiles from the three phases. Common to all phases were 3-methylbutyl 3-methylbutanoate, 1,8-cineole, dimethyl disulphide and sabinene, together accounting for 52 to 54% of total volatiles. GC-MS/O revealed that at least 28 volatiles including eight S-containing compounds contributed to the unpleasant odour of S. renifolius. Among them, dimethyl disulphide (onion-like), methional (potato-like), and the tentatively identified methyl dithioformate (garlic-like) were intense odour-active compounds in each floral phase. Additionally, 2-isopropyl-3-methoxypyrazine (IPMP) was a major contributor to the earthy odour that was characteristic of the female phase. CONCLUSIONS: No marked changes were observed in floral volatile compositions over the three flowering phases of S. renifolius. Instead, flower phase-dependent proportional changes of minor components (e.g. IPMP and 2,3-butanedione) altered the odour characteristics between the female and male phases.

Identification of Odor-Active Compounds Released from a Damaged Plant of the Asian Skunk Cabbage Symplocarpus renifolius.

Symplocarpus renifolius (Asian skunk cabbage) is a perennial herb of the Araceae family. As its common name implies, this plant produces a strong garliclike irritant odor with a rotten note when the plant parts are crushed. To elucidate the odor characteristics, the volatile compounds released from crushed plant parts (rhizome, petioles, and leaf blades) of S. renifolius were identified by a dynamic headspace method. Fifteen sulfur compounds were identified as odor-active compounds by gas chromatography-mass spectrometry-olfactometry (GC-MS-O). The sulfur compounds may be responsible for the strong odor emitted by crushed skunk cabbage. Many of the compounds lack a carbon-carbon bond, and all of the carbon atoms are connected to sulfur. This is regarded as the characteristic structure of the sulfur compounds released from the damaged plant parts of the skunk cabbage. Nine of the sulfur compounds were detected in all three of the plant parts analyzed in this study: hydrogen sulfide, methanethiol, 1-hexanethiol, methyl dithioformate, 2,4-dithiapentane, dimethyl trisulfide, methional, 2,3,5-trithiahexane, and tris(methylthio)methane. Methyl dithioformate and methylthiomethyl dithioformate were identified for the first time as natural products.

Galangal pungent component, 1'-acetoxychavicol acetate, activates TRPA1.

We investigated the activation of transient receptor potential cation channel (TRP) subfamily V, member 1 (TRPV1) and TRP subfamily A, member 1 (TRPA1) by 1'-acetoxychavicol acetate (ACA), the main pungent component in galangal. ACA did not activate TRPV1-expressing human embryonic kidney (HEK) cells, but strongly activated TRPA1-expressing HEK cells. ACA was more potent than allyl isothiocyanate, the typical TRPA1 agonist.

Aroma characteristics of cocoa tea (Camellia ptilophylla Chang).

Three types of Cocoa tea, green, oolong, and black, were prepared from fresh young leaves of Camellia ptilophylla. Their aroma characteristics were compared by a sensory evaluation with corresponding traditional tea samples made from C. sinensis. The aroma profile of Cocoa green tea was quite different from that of traditional green tea, but fermented Cocoa oolong tea and black tea showed aroma profiles similar to those of traditional oolong tea and black tea. Cocoa green tea contained vanillin as the most abundant aroma constituent. Almost the same aroma compounds of jasmine lactone, indole and monoterpene alcohols, which are known as important aroma constituents in commercial oolong tea and black tea, were identified as the main aroma compounds in the fermented Cocoa tea types. The composition of these aroma compounds well explained the aroma profile of each Cocoa tea. The monoterpene alcohols seemed to be released during fermented tea manufacture, because seventeen glycosides consisting of the aglycons of terpene alcohols were identified in Cocoa tea leaves, and hydrolytic activity of crude enzymes in the p-nitrophenol glycoside substrate was also detected.

Aroma character impact compounds in Kinokuni mandarin orange (Citrus kinokuni) compared with Satsuma mandarin orange (Citrus unshiu).

The odor-active volatiles of Kinokuni mandarin (Citrus kinokuni Hort. ex Tanaka), an original mandarin orange in Japan, were characterized by a combination of instrumental and sensory analyses and compared with those of Satsuma mandarin (Citrus unshiu Marcovitch). An aroma extract dilution analysis (AEDA) of the polar fractions of Kinokuni and Satsuma mandarin peel oils identified five odorants in common as the most odor-active volatiles: (Z)-hex-3-enal, decanal, linalool, yuzuol, and (2E)-trans-4,5-epoxydec-2-enal. In addition, seven odorants were identified solely in Kinokuni mandarin as significant contributors: octanal, dodecanal, (2E,4E)-deca-2,4-dienal, geraniol, yuzunone, (2E,7Z)-trans-4,5-epoxydeca-2,7-dienal, and thymol. The odor-active volatiles in both the non-polar components of the peel oil and an extract of the juice prepared from Kinokuni mandarin were also identified. The (S)-isomer of linalool in Kinokuni mandarin peel oil was dominant in the enantiomeric distribution (92%), whereas the (R)-isomer was dominant in Satsuma mandarin peel oil (90%).

Influence of the isolation procedure on coriander leaf volatiles with some correlation to the enzymatic activity.

Coriander leaves (Coriandrum sativum L.) have become popular worldwide because of their pleasant and delicate aroma. By a hot water extraction method, in which coriander leaves were cut before suspending in boiling water for 2 min, the contents of the main volatile compounds such as alkanals and 2-alkenals from C10 to C14 decreased, while the levels of corresponding alcohols increased in comparison to those obtained by solvent extraction. To investigate the reasons for this variation, an enzyme activity was assayed. By using aliphatic aldehyde as a substrate and NADPH as a coenzyme, strong activity of an aliphatic aldehyde reductase was found for the first time in this herb in the relatively wide pH range of 5.0-9.0, with the maximum activity at pH 8.5. Additionally, the aliphatic aldehyde dehydrogenase, responsible for acid formation, was also found to have a relatively weak activity compared to that of reductase.

Aliphatic aldehyde reductase activity related to the formation of volatile alcohols in Vietnamese coriander leaves.

Vietnamese coriander (Persicaria odorata Lour.) belongs to a group known as cilantro mimics with the 'cilantro' flavor, in which C10 and C12 aldehydes and alcohols have been found as the potent odor compounds. Their composition isolated by different extraction methods varied. The enzyme activity was assayed, and the reductase acting on some aliphatic aldehydes with NADH/NADPH as a coenzyme was found in a crude enzymatic system of fresh leaves. The maximum activity was observed at pH 8.0 in Na-phosphate and at pH 8.5 to 9.0 in a glycine-NaOH buffer, using heptanal as a substrate. The activated reductase that caused the alcohol generation to increase after a time was inhibited by p-hydroxymercuribenzoate. Our results, which are the first to be reported on Vietnamese coriander leaves, reveal the presence of aliphatic aldehyde dehydrogenase, which is responsible for acid formation, and elucidate the strong activity of the aliphatic aldehyde reductase.

Quantification and odor contribution of 2-furanmethanethiol in different types of fermented soybean paste miso.

2-Furanmethanethiol, a compound contained in many kinds of food, was identified for the first time in five types of miso fermented soybean paste (red salty rice miso, thin-colored salty rice miso, weak salty rice miso, barley miso, and soy miso) by specific extraction of volatile thiols using p-hydroxymercuribenzoate. In the triangle test with red salty rice miso, which included a higher concentration of 2-furanmethanethiol, and thin-colored salty rice miso, which included a lower concentration of 2-furanmethanethiol, it was shown that the aroma of thin-colored salty rice miso was similar to that of red salty rice miso by adding 2-furanmethanethiol into thin-colored salty rice miso. In addition, a quantitative descriptive analysis (QDA) clearly shows that 2-furanmethanethiol contributed to the intensity of three odor qualities "thick, complex", "sweet", and "pleasant aroma like coffee beans" in six odor qualities and was a very important component of miso aroma.

Mioganal, a novel pungent principle in myoga (Zingiber mioga Roscoe) and a quantitative evaluation of its pungency.

We isolated a novel pungent principle from the flower buds of myoga. Based on an interpretation of the HR-MS, EI-MS, IR, UV, and NMR data, this compound was (8betaH)-14,17-cyclolabda-12,14(17)-diene-15,16-dial (mioganal, 1). We determined the threshold value of mioganal to be 5.6x10(-5) g/ml, which is about eight times greater than that of 8beta(17)-epoxy-12(E)labdene-15,16-dial (miogadial), the main pungent principle in the flower buds of myoga. In addition, we examined the content of mioganal in different parts of different varieties. Mioganal is mainly distributed in the leaves of both natsumyoga and akimyoga varieties at 1.60 mg/100 g fresh weight on average, its amount being three times higher than that in the flower buds.

6-Shogaol and 6-gingerol, the pungent of ginger, inhibit TNF-alpha mediated downregulation of adiponectin expression via different mechanisms in 3T3-L1 adipocytes.

In this study, we demonstrated that the two ginger-derived components have a potent and unique pharmacological function in 3T3-L1 adipocytes via different mechanisms. Both pretreatment of 6-shogaol (6S) and 6-gingerol (6G) significantly inhibited the tumor necrosis factor-alpha (TNF-alpha) mediated downregulation of the adiponectin expression in 3T3-L1 adipocytes. Our study demonstrate that (1) 6S functions as a PPARgamma agonist with its inhibitory mechanism due to the PPARgamma transactivation, and (2) 6G is not a PPARgamma agonist, but it is an effective inhibitor of TNF-alpha induced c-Jun-NH(2)-terminal kinase signaling activation and thus, its inhibitory mechanism is due to this inhibitory effect.

Flavor enhancement of chicken broth from boiled celery constituents.

The flavor-enhancing effects of the volatile constituents in celery were investigated. The test samples were prepared by adding celery fractions to chicken broth at a concentration that distinct odors of them were not detected, and the samples were sensorially evaluated for the perceived intensities of 8 terms such as "thick," "impactful," "mild," "lasting," "satisfied," "complex," "refined," and "clarified," which are considered to be the elements of the complex flavor and for 3 terms such as "sweet," "salty," and "umami" taste. A comparison of effects between the volatile and nonvolatile fractions of celery revealed that the volatile compounds in celery enhanced the complex flavor of chicken broth more than the nonvolatile compounds. Among the characteristic odorants of celery, three phthalides, namely, sedanenolide, 3- n-butylphthalide, and sedanolide, were shown to contribute to the complex flavor of chicken broth, and sedanenolide was most effective. The three phthalides enhanced perceived intensities of "umami" and "sweet" despite their no taste properties in addition to the complex flavor.

Effects of the amino-carbonyl reaction of ribose and glycine on the formation of the 2(or 5)-ethyl-5(or 2)-methyl-4-hydroxy-3(2H)-furanone aroma component specific to miso by halo-tolerant yeast.

The formation of HEMF[2(or 5)-ethyl-5(or 2)-methyl-4-hydroxy-3(2H)-furanone], the aroma component specific to miso and soy sauce, was promoted by cultivating the halo-tolerant yeast, Zygosaccharomyces rouxii, in a medium including the amino-carbonyl reaction products based on ribose and glycine. The glucose concentration in the medium influenced the HEMF formation by Z. rouxii.

The formation mechanism by yeast of 4-hydroxy-2(or 5)-ethyl-5(or 2)-methyl-3(2H)-furanone in Miso.

The mechanism of the formation of 4-hydroxy-2(or 5)-ethyl-5-(or 2)-methyl-3(2H)-furanone (HEMF) with yeast under caltivation in a medium containing amino-carbonyl reactants of ribose and glycine was investigated using stable isotopes of the corresponding compounds. It was confirmed that the skeleton of the five-membered ring and the methyl group of the side chain of HEMF was formed from ribose, and that the ethyl group was derived from the glucose metabolite by yeast. The formation of HEMF was confirmed when acetaldehyde as the glucose metabolite and a cell-free extract from yeast were added to the medium containing amino-carbonyl reactants. These results suggest that the role of yeast in HEMF formation is not only to provide the glucose metabolite, but also in combining the amino-carbonyl reactants with the glucose metabolite.

A nonpungent component of steamed ginger--[10]-shogaol--increases adrenaline secretion via the activation of TRPV1.

We investigated the components of ginger that are involved in increasing body temperature. Gingerols ([6,8,10]-gingerols) and shogaols ([6,8,10]-shogaols) having different alkyl carbon chain lengths were targeted. All the gingerols and shogaols increased intracellular calcium concentration in rat transient receptor potential vanilloid subtype 1 (TRPV1)-expressing HEK293 cells via TRPV1. In this regard, the shogaols were more potent than the gingerols. Aversive responses were induced by [6]-, [10]-gingerol, and [6]-shogaol (5 mmol/l) in rats when these compounds were applied to the eye; however, no response was observed in response to [10]-shogaol (5 and 10 mmol/l). [10]-Shogaol induced nociceptive responses via TRPV1 in rats following its subcutaneous injection into the hindpaw; the pungent compound capsaicin (CAP) and [6]-shogaol were observed to have similar effects. Moreover, adrenal catecholamine secretion, which influences energy consumption, was promoted in rats in response to [6]- and [10]-gingerols and [6]- and [10]-shogaols (1.6 micromol/kg, i.v.). [10]-Shogaol-induced adrenaline secretion was inhibited by administration of capsazepine, a TRPV1 antagonist. In conclusion, gingerols and shogaols activated TRPV1 and increased adrenaline secretion. Interestingly, [10]-shogaol is the only nonpungent compound among the gingerols and shogaols, suggesting its usefulness as a functional ingredient in food.

Potent odorants characterize the aroma quality of leaves and stalks in raw and boiled celery.

The raw and boiled odors of celery leaves and stalks were investigated. Among 12 compounds identified as potent odorants, 3-n-butylphthalide 1, sedanenolide 2, and trans- and cis-sedanolides 3, 4 were assessed to be most contributive to the overall odor of celery. These three phthalides, (3E,5Z)-1,3,5-undecatriene, myrcene, and (E)-2-nonenal were common to both raw and boiled materials. Two compounds, ((Z)-3-hexenal and (Z)-3-hexenol), were dominant in raw materials and four compounds, (2-methylbutanoic acid, sotolon, beta-damascenone, and beta-ionone), were dominant in boiled materials. Sensory evaluations were performed on natural celery odor and a series of reconstructed model aromas by assigning each intensity ratings for a set of seven odor qualities which aptly describe the odors of raw and boiled celery. According to the evaluation results, six common components contributed to the moderate odor of raw celery, two components dominant in raw materials enhanced the raw celery character, and four components dominant in boiled materials reduced the raw celery character and enhanced the boiled celery character. It was clarified that boiling-induced changes in celery odor were not affected by the amounts of phthalides, but by thermally generated compounds such as sotolon, beta-damascenone, and beta-ionone, which reduce the "green spicy" note.

Pungent qualities of sanshool-related compounds evaluated by a sensory test and activation of rat TRPV1.

The detection threshold and taste characteristics of sanshools were examined by sensory evaluation, after isolating four sanshools (alpha-, beta-, gamma-, and delta-), and two hydroxy sanshools (alpha- and beta-) from the pericarp of Japanese pepper. The Scoville unit (SU) values of the four sanshools were in the range of 80,000-110,000, while those of hydroxy sanshools were 3-5 fold lower than corresponding sanshools. The pungent qualities of each sanshool were different. Burning and tingling were predominantly perceived and lasted for the longest time with alpha-sanshool. Burning and fresh for gamma-sanshool, and tingling and numbing for hydroxy alpha-sanshool were perceived. Tests on the activation of rat TRPV1 were also performed. All of them were weak agonists. Among them, gamma-sanshool was the most potent agonist, although its EC50 value of 5.3 microM was 230 fold higher than that of capsaicin. These results indicate that it would be difficult to explain the pungent quality of each sanshool simply in terms of TRPV1 activation.

Quantitative analysis of sanshool compounds in Japanese pepper (Xanthoxylum piperitum DC.) and their pungent characteristics.

The distributions of each sanshool in the Japanese pepper plant grown in various regions and the change in composition of sanshools during maturation of the fruit were investigated. The degree of pungency, defined as the amount of a sanshool/the threshold value, was calculated, and the pungent qualities of the products were evaluated and compared. The degree of pungency and amount of a sanshool showed a positive correlation. In young leaves and flowers, the degree of pungency was less than that in the fruits, the main compound being alpha-sanshool, while the two hydroxy sanshools were detected only in trace amounts. The main compound in fruits was hydroxy alpha-sanshool, whose threshold value was higher than that of alpha-sanshool. It is concluded that the pungency of Japanese pepper should be evaluated not only by the threshold values, but also by the pungent qualities, the composition of sanshools, and the usage of each product of Japanese pepper.

Sedative effects of the jasmine tea odor and (R)-(-)-linalool, one of its major odor components, on autonomic nerve activity and mood states.

We investigated the effects of the odor of jasmine tea on autonomic nerve activity and mood states in a total of 24 healthy volunteers. We used the odor of jasmine tea at the lowest concentration that could be detected by each subject but that did not elicit any psychological effects. R-R intervals and the POMS test were measured before and after inhalation of the odors for 5 min. Both jasmine tea and lavender odors at perceived similar intensity caused significant decreases in heart rate and significant increases in spectral integrated values at high-frequency component in comparison with the control (P < 0.05). In the POMS tests, these odors produced calm and vigorous mood states. We also examined the effects of (R)-(-)-linalool, one of its major odor components, at the same concentration as in the tea, and (S)-(+)-linalool. Only (R)-(-)-linalool elicited a significant decrease in heart rate (P < 0.05) and an increase in high-frequency component in comparison with the controls, and produced calm and vigorous mood states. Thus, the low intensity of jasmine tea odor has sedative effects on both autonomic nerve activity and mood states, and (R)-(-)-linalool, one of its components, can mimic these effects.