Analysis of Volatile Compounds from Different Parts of Houttuynia cordata Thunb.

Houttuynia cordata Thunb. is a medicinal and edible plant that has been commonly used in traditional Chinese medicine since ancient times. This study used headspace solid-phase microextraction (HS-SPME) and direct injection, combined with gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS), to identify the volatile compounds in H. cordata. Extraction from different parts of the plant using different extraction techniques for the identification of volatile compounds were determined. A total of 93 volatile components were analyzed in the leaves, stems, rhizomes, and whole plant samples of H. cordata. The leaves contained more (Z)-3-hexenal, ß-myrcene, (Z)-ß-ocimene, and (4E,6E)-allo-ocimene; the stems contained more geranyl acetate and nerolidol; and rhizomes contained more α-pinene, ß-pinene, limonene, 2-undecanone, and decanoyl acetaldehyde. Among them, the essential oil extracted by HS-SPME could produce more monoterpenes, while direct injection could obtain higher contents of aliphatic ketones, terpene esters, sesquiterpenes, and was more conducive to the extraction of 2-undecanone and decanoyl acetaldehyde.

Effects of Different Extraction Methods on Vanilla Aroma.

To establish the analytic conditions for examining the aroma quality of vanilla pods, we compared different extraction methods and identified a suitable option. We utilized headspace solid-phase microextraction (HS-SPME), steam distillation (SD), simultaneous steam distillation (SDE) and alcoholic extraction combined with gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) to identify volatile components of vanilla pods. A total of 84 volatile compounds were identified in this experiment, of which SDE could identify the most volatile compounds, with a total of 51 species, followed by HS-SPME, with a total of 28 species. Ten volatile compounds were identified by extraction with a minimum of 35% alcohol. HS-SPME extraction provided the highest total aroma peak areas, and the peak areas of aldehydes, furans, alcohols, monoterpenes and phenols compounds were several times higher than those of the other extraction methods. The results showed that the two technologies, SDE and HS-SPME, could be used together to facilitate analysis of vanilla pod aroma.

Headspace Solid-Phase Microextraction Analysis of Volatile Components in Peanut Oil.

Peanut oil is favored by consumers due to its rich nutritional value and unique flavor. This study used headspace solid-phase microextraction (HS-SPME) combined with gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) to examine the differences in the peanut oil aroma on the basis of variety, roasting temperatures, and pressing components. The results revealed that the optimal conditions for extracting peanut oil were achieved through the use of 50/30 µm DVB/CAR/PDMS fibers at 60 °C for 50 min. The primary compounds present in peanut oil were pyrazines. When peanuts were roasted, the temperature raised from 120 °C to 140 °C and the content of aldehydes in peanut oil increased; however, the content of aldehydes in No. 9 oil at 160 °C decreased. The components of peanut shell oil varied depending on the peanut variety. The most marked difference was observed in terms of the main compound at the two roasting temperatures. This compound was a pyrazine, and the content increased with the roasting temperature in hekei oils. When the roasting temperature was lower, No. 9 oil contained more fatty acid oxidation products such as hexanal, heptanal, and nonanal. When the roasting temperature increased, No. 9 oil contained more furfural and 5-methylfurfural. Heren oil was easier to oxidize and produced nonanal that possessed a fatty aroma.

Sesamol Inhibited Melanogenesis by Regulating Melanin-Related Signal Transduction in B16F10 Cells.

Melanin is synthesized through a series of interactions catalyzed by melanogenic enzymes such as tyrosinase, dopachrome tautomerase (tyrosinase-related protein-2; TRP-2), and tyrosinase-related protein-1 (TRP-1). Tyrosinase plays a key role in catalysing the initial and limiting steps of melanogenesis. The melanin that results from melanogenesis has the protective effect of absorbing ultraviolet radiation. However, overproduction of melanin, in addition to altering the appearance of skin, may lead to skin disorders such as melasma, solar lentigo, and postinflammatory hyperpigmentation. Previous studies have revealed that sesamol is a strong antioxidant and a free radical scavenger. In this study, we investigated the effects of sesamol on the regulation of melanogenesis and related mechanisms in B16F10 cells. The results indicated that sesamol inhibited tyrosinase activity and melanogenesis induced by α-melanocyte-stimulating hormone (α-MSH) in B16F10 melanoma cells. Sesamol decreased the protein level of melanocortin 1 receptor (MC1R), microphthalmia-associated transcription factor (MITF), tyrosinase, and TRP-1 by downregulating cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathways that had been activated by α-MSH. Sesamol increased glycogen synthase kinase 3 beta (GSK3ß), protein kinase B (AKT), and extracellular signal-related kinase (ERK) phosphorylation, thus inhibiting the transcription of MITF. Sesamol also inhibited melanin synthesis and tyrosinase expression by modulating ERK, phosphoinositide 3-kinase (PI3K)/AKT, p38, and c-Jun amino-terminal kinase (JNK) signalling pathways. These results indicate that sesamol acted as a potent depigmenting agent.

N-(4-methoxyphenyl) caffeamide-induced melanogenesis inhibition mechanisms.

BACKGROUND: The derivative of caffeamide exhibits antioxidant and antityrosinase activity. The activity and mechanism of N-(4-methoxyphenyl) caffeamide (K36E) on melanogenesis was investigated. METHODS: B16F0 cells were treated with various concentrations of K36E; the melanin contents and related signal transduction were studied. Western blotting assay was applied to determine the protein expression, and spectrophotometry was performed to identify the tyrosinase activity and melanin content. RESULTS: Our results indicated that K36E reduced α-melanocyte-stimulating hormone (α-MSH)-induced melanin content and tyrosinase activity in B16F0 cells. In addition, K36E inhibited the expression of phospho-cyclic adenosine monophosphate (cAMP)-response element-binding protein, microphthalmia-associated transcription factor (MITF), tyrosinase, and tyrosinase-related protein-1 (TRP-1). K36E activated the phosphorylation of protein kinase B (AKT) and glycogen synthase kinase 3 beta (GSK3ß), leading to the inhibition of MITF transcription activity. K36E attenuated α-MSH induced cAMP pathways, contributing to hypopigmentation. CONCLUSIONS: K36E regulated melanin synthesis through reducing the expression of downstream proteins including p-CREB, p-AKT, p-GSK3ß, tyrosinase, and TRP-1, and activated the transcription factor, MITF. K36E may have the potential to be developed as a skin whitening agent.

Headspace solid-phase microextraction analysis of volatile components in Phalaenopsis Nobby's Pacific Sunset.

Phalaenopsis is the most important economic crop in the Orchidaceae family. There are currently numerous beautiful and colorful Phalaenopsis flowers, but only a few species of Phalaenopsis have an aroma. This study reports the analysis volatile components present in P. Nobby's Pacific Sunset by solid-phase microextraction (SPME) coupled with gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS). The results show that the optimal extraction conditions were obtained by using a DVB/CAR/PDMS fiber. A total of 31 compounds were identified, with the major compounds being geraniol, linalool and α-farnesene. P. Nobby's Pacific Sunset had the highest odor concentration from 09:00 to 13:00 on the eighth day of storage. It was also found that in P. Nobby's Pacific Sunset orchids the dorsal sepals and petals had the highest odor concentrations, whereas the column had the lowest.

Tyrosol and its analogues inhibit alpha-melanocyte-stimulating hormone induced melanogenesis.

Melanin is responsible for skin color and plays a major role in defending against harmful external factors such as ultraviolet (UV) irradiation. Tyrosinase is responsible for the critical steps of melanogenesis, including the rate-limiting step of tyrosine hydroxylation. The mechanisms of action of skin hypopigmenting agents are thought to be based on the ability of a given agent to inhibit the activity of tyrosinase and, hence, down regulate melanin synthesis. Tyrosol and its glycoside, salidroside, are active components of Rhodiola rosea, and in our preliminary study we found that Rhodiola rosea extract inhibited melanogenesis. In this study, we examined the effects of tyrosol and its analogues on melanin synthesis. We found that treatment of B16F0 cells to tyrosol (1), 4-hydroxyphenylacetic acid (5), 3-hydroxyphenylacetic acid (6), 2-hydroxyphenylacetic acid (7), or salidroside (11) resulted in a reduction in melanin content and inhibition of tyrosinase activity as well as its expression. Tyrosol (1), 4-hydroxyphenylacetic acid (5) and 2-hydroxyphenylacetic acid (7) suppressed MC1R expression. Tyrosol (1), 4-hydroxyphenylacetic acid (5), 3-hydroxyphenylacetic acid (6), and 2-hydroxyphenylacetic acid (7) inhibited α-MSH induced TRP-1 expression, but salidroside (11) did not. All the compounds did not affect MITF and TRP-2 expression. Furthermore, we found that the cell viability of tyrosol (1), 4-hydroxyphenylacetic acid (5), 3-hydroxyphenylacetic acid (6), and 2-hydroxyphenylacetic acid (7) at concentrations below 4 mM and salidroside (11) at concentrations below 0.5 mM were higher than 90%. The compounds exhibited metal-coordinating interactions with copper ion in molecular docking with tyrosinase. Our results suggest that tyrosol, 4-hydroxyphenylacetic acid, 3-hydroxyphenylacetic acid, 2-hydroxyphenylacetic acid, and salidroside are potential hypopigmenting agents.

Discussion on the Differences in Aroma Components in Different Fragrant Rice Varieties during Storage.

Rice (Oryza sativa L.) is an important food crop in Taiwan, among which fragrant rice is highly regarded for its special aroma when cooked. During the storage of fragrant rice, the aroma components will change, which will affect the aroma quality of fragrant rice. Therefore, headspace solid-phase microextraction (HS-SPME) was used in this study, combined with gas chromatography and gas chromatography-mass spectrometry, to analyze the difference in the aroma components of Taikeng No. 4 (TK4), Tainung No. 71 (TN71), Kaohsiung No. 147 (KH147), and Taichung No. 194 (TC194) fragrant rice. A total of 28 aroma components were identified in the four varieties of fragrant rice, and the main components were all Nonanal. Among them, TK4 contains a very high content of hydrocarbons, including Tridecane and Dodecane; TN71, KH147, and TC194 contain mainly aldehydes such as Nonanal and Hexanal. During different storage times, the contents of alcohols, monoterpenes, aromatic aldehydes, and furans increased with storage time, while the content of aliphatic aldehydes decreased with storage time. After storage, the fragrant rice samples showed a tendency for the total volatile component content to decrease, with the most pronounced reduction observed in Nonanal content.

Analysis of Volatile Constituents in Platostoma palustre (Blume) Using Headspace Solid-Phase Microextraction and Simultaneous Distillation-Extraction.

Hsian-tsao (Platostoma palustre Blume) is a traditional Taiwanese food. It is admired by many consumers, especially in summer, because of its aroma and taste. This study reports the analysis of the volatile components present in eight varieties of Hsian-tsao using headspace solid-phase microextraction (HS-SPME) and simultaneous distillation-extraction (SDE) coupled with gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS). HS-SPME is a non-heating method, and the results show relatively true values of the samples during flavor isolation. However, it is a kind of headspace analysis that has the disadvantage of a lower detection ability to relatively higher molecular weight compounds; also, the data are not quantitative, but instead are used for comparison. The SDE method uses distillation 2 h for flavor isolation; therefore, it quantitatively identifies more volatile compounds in the samples while the samples withstand heating. Both methods were used in this study to investigate information about the samples. The results showed that Nongshi No. 1 had the highest total quantity of volatile components using HS-SPME, whereas SDE indicated that Taoyuan Mesona 1301 (TYM1301) had the highest volatile concentration. Using the two extraction methods, 120 volatile components were identified. Fifty-six volatile components were identified using HS-SPME, and the main volatile compounds were α-pinene, ß-pinene, and limonene. A total of 108 volatile components were identified using SDE, and the main volatile compounds were α-bisabolol, ß-caryophyllene, and caryophyllene oxide. Compared with SDE, HS-SPME sampling extracted a significantly higher amount of monoterpenes and had a poorer detection of less volatile compounds, such as sesquiterpenes, terpene alcohols, and terpene oxide.

Sesamol Inhibited Ultraviolet Radiation-Induced Hyperpigmentation and Damage in C57BL/6 Mouse Skin.

Melanin is synthesized through a series of oxidative reactions initiated with tyrosine and catalyzed by melanogenesis-related proteins such as tyrosinase, tyrosinase-related protein-1 (TRP-1), dopachrome tautomerase (TRP-2), and microphthalmia-associated transcription factor (MITF). Our previous study demonstrated that sesamol inhibited melanin synthesis through the inhibition of the melanocortin 1 receptor (MC1R)/MITF/tyrosinase pathway in B16F10 cells. In this study, sesamol was applied to C57BL/6 mouse skin to understand its activity with respect to skin pigmentation. The results indicated that ultraviolet (UV) B-induced hyperpigmentation in the C57BL/6 mouse skin was significantly reduced by topical application of sesamol for 4 weeks. Sesamol reduced the melanin index and melanin content of the skin. In addition, sesamol elevated the brightness (L* value) of the skin. Sesamol also reduced UVB-induced hyperplasia of epidermis and collagen degradation in dermis. In immunohistochemical staining, topical application of sesamol reduced UVB-induced tyrosinase, TRP-1, TRP-2, and MITF expression in the epidermis of the skin. These results demonstrated that sesamol is a potent depigmenting agent in the animal model.

Rhodiola plants: Chemistry and biological activity.

Rhodiola is a genus of medicinal plants that originated in Asia and Europe and are used traditionally as adaptogens, antidepressants, and anti-inflammatory remedies. Rhodiola plants are rich in polyphenols, and salidroside and tyrosol are the primary bioactive marker compounds in the standardized extracts of Rhodiola rosea. This review article summarizes the bioactivities, including adaptogenic, antifatigue, antidepressant, antioxidant, anti-inflammatory, antinoception, and anticancer activities, and the modulation of immune function of Rhodiola plants and its two constituents, as well as their potential to prevent cardiovascular, neuronal, liver, and skin disorders.

Volatile compounds from roots, stems and leaves of Angelica acutiloba growing in Taiwan.

The present study analyzed and compared the volatile compounds in fresh Angelica acutiloba roots, stems and leaves both qualitatively and quantitatively. The volatile compounds were isolated by either steam distillation (SD) or headspace-solid phase microextraction (HS-SPME). A total of 61 compounds were identified using gas chromatography/mass spectrometry (GC/MS). All 61 compounds were verified by SD, with 3n-butyl phthalide, gamma-terpinene, p-cymene and cis-beta-ocimene as the main compounds. Thirty-three compounds were verified by HS-SPME, with gamma-terpinene and p-cymene as the main compounds. The leaf samples contained the highest essential oil content. Compared with SD, HS-SPME sampling resulted in relatively higher amounts of highly volatile monoterpenes and lower amounts of less volatile compounds such as 3n-butyl phthalide. These findings demonstrate that A. acutiloba roots, stems and leaves have high 3n-butyl phthalide contents; thus, all parts of A. acutiloba may be used for further application and development.