Sugunya Wongpornchai

A SNP in GmBADH2 gene associates with fragrance in vegetable soybean variety ''Kaori'' and SNAP marker development for the fragrance

Fragrance in soybean is due to the presence of 2-acetyl-1-pyrroline (2AP). BADH2 gene coding for betaine aldehyde dehydrogenase has been identified as the candidate gene responsible for fragrance in rice (Oryza sativa L.). In this study, using the RIL population derived from fragrant soybean cultivar “Kaori” and non-fragrant soybean cultivar “Chiang Mai 60” (CM60), STS markers designed from BADH2 homolog were found associating with 2AP production. Genetic mapping demonstrated that QTL position of fragrance and 2AP production coincides with the position of GmBADH2 (Glycine max betaine aldehyde dehydrogenase 2). Sequence comparison of GmBADH2 between Kaori and non-fragrant soybeans revealed non-synonymous single-nucleotide polymorphism (SNP) in exon 10. Nucleotide substitution of G to A in the exon results in an amino acid change of glycine (GGC; G) to aspartic acid (GAC; D) in Kaori. The amino acid substitution changes the conserved EGCRLGPIVS motif of GmBADH2, which is essential for functional activity of GmBADH2 protein, to EGCRLDPIVS motif, suggesting that the SNP in GmBADH2 is responsible for the fragrance in Kaori. Five single nucleotide-amplified polymorphism (SNAP) markers which are PCR-based allele specific SNP markers were developed for fragrance based on the SNP in GmBADH2. Two markers specific to A allele produced a band in only Kaori, while three markers specific to G alleles produced a band in only CM60. The simple PCR-based allele specific SNAP markers developed in the present study are useful in marker-assisted breeding of fragrant soybean.

Highly Volatile Constituents of Vetiveria zizanioides Roots Grown under Different Cultivation Conditions

Roots of Vetiveria zizanioides Nash (Mae Hae; Thai ecotype) planted in three different cultivation systems (normal soil, normal soil with added microbes and semi- hydroponically) were extracted using a simultaneous steam distillation and solvent extraction (SDE) apparatus. Yields of the essential oils obtained were 0.27, 0.18 and 0.06%, respectively. The separation profiles obtained by comprehensive two-dimensional gas chromatography (GCxGC) and solid phase microextraction (SPME)-GCxGC analyses of the crude essential oils showed a total of 156 and 48 well-resolved components, respectively. The highly volatile fractions isolated from the three essential oils by SPME were subjected to analysis by GC-MS and 42 compounds were identified in total. Volatile component profiles of the oils obtained by normal soil and semi-hydroponic cultivation were similar, whereas a quantitative difference was noted in some major volatiles when the cultivation system containing microbes was utilized.

Enhanced sensitivity and selectivity in the detection of polycyclic aromatic hydrocarbons using sequential simplex optimization, the addition of an organic modifier and wavelength programming

Optimized separation of a mixture of 16 priority pollutant polycyclic aromatic hydrocarbons (PAHs) by high performance liquid chromatography (HPLC) using the sequential simplex optimization method was accomplished by varying the starting and ending compositions of acetonitrile and water, linear gradient time, mobile phase flow rate, column temperature and holding time of the final mobile phase composition. Focusing on the two sets of difficult-to-separate pairs (acenaphthene-fluorene and benzo[g,h,i]perylene-indeno[1,2,3-c,d]pyrene), analysis time was reduced by about ten percent through the use of an organic modifier (isopropanol or methanol), under both optimum and near-optimum conditions, while maintaining good separation of the remaining PAHs. High sensitivity for all of the 16 PAHs was achieved by wavelength programming during elution using five wavelengths (224, 235, 254 270 and 296 nm), depending upon the molar absorptivities of the individual compounds. Detection limits (DLs) ranging from 0.002 (benzo[a]pyrene) to 0.140 mug ml(-1) (acenaphthene) were achieved for this set of 16 standard compounds.

Comprehensive Two-Dimensional Gas Chromatography-Mass Spectrometry Analysis of Volatile Constituents in Thai Vetiver Root Oils Obtained by Using Different Extraction Methods

INTRODUCTION Vetiver root oil is known as one of the finest fixatives used in perfumery. This highly complex oil contains more than 200 components, which are mainly sesquiterpene hydrocarbons and their oxygenated derivatives. Since conventional GC-MS has limitation in terms of separation efficiency, the comprehensive two-dimensional GC-MS (GC x GC-MS) was proposed in this study as an alternative technique for the analysis of vetiver oil constituents. OBJECTIVE To evaluate efficiency of the hyphenated GC x GC-MS technique in terms of separation power and sensitivity prior to identification and quantitation of the volatile constituents in a variety of vetiver root oil samples. METHODOLOGY. Dried roots of Vetiveria zizanioides were subjected to extraction using various conditions of four different methods; simultaneous steam distillation, supercritical fluid, microwave-assisted, and Soxhlet extraction. Volatile components in all vetiver root oil samples were separated and identified by GC-MS and GC x GC-MS. The relative contents of volatile constituents in each vetiver oil sample were calculated using the peak volume normalization method. RESULTS Different techniques of extraction had diverse effects on yield, physical and chemical properties of the vetiver root oils obtained. Overall, 64 volatile constituents were identified by GC-MS. Among the 245 well-resolved individual components obtained by GC x GC-MS, the additional identification of 43 more volatiles was achieved. CONCLUSION In comparison with GC-MS, GC x GC-MS showed greater ability to differentiate the quality of essential oils obtained from diverse extraction conditions in terms of their volatile compositions and contents.

Investigation of plant hormone level changes in shoot tips of longan (Dimocarpus longan Lour.) treated with potassium chlorate by liquid chromatography–electrospray ionization mass spectrometry

The endogenous levels of indole-3-acetic acid (IAA), gibberellins (GAs), abscisic acid (ABA) and cytokinins (CKs) and their changes were investigated in shoot tips of ten longan (Dimocarpus longan Lour.) trees for off-season flowering until 60 days after potassium chlorate treatment in comparison with those of ten control (untreated) longan trees. These analytes were extracted and interfering matrices removed with a single mixed-mode solid phase extraction under optimum conditions. The recoveries at three levels of concentration were in the range of 72-112%. The endogenous plant hormones were separated and quantified by liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS). Detection limits based on the signal-to-noise ratio ranged from 10 ng mL(-1) for gibberellin A4 (GA4) to 200 ng mL(-1) for IAA. Within the first week after potassium chlorate treatment, dry weight (DW) amounts in the treated longan shoot tips of four gibberellins, namely: gibberellin A1(GA1), gibberellic acid (GA3), gibberellin A19 (GA19) and gibberellin A20 (GA20), were found to increase to approximately 25, 50, 20 and 60 ng g(-1) respectively, all of which were significantly higher than those of the controls. In contrast, gibberellin A8 (GA8) obtained from the treated longan was found to decrease to approximately 20 ng g(-1)DW while that of the control increased to around 80 ng g(-1)DW. Certain CKs which play a role in leaf bud induction, particularly isopentenyl adenine (iP), isopentenyl adenosine (iPR) and dihydrozeatin riboside (DHZR), were found to be present in amounts of approximately 20, 50 and 60 ng g(-1)DW in the shoot tips of the control longan. The analytical results obtained from the two-month off-season longan flowering period indicate that high GA1, GA3, GA19 and GA20 levels in the longan shoot tips contribute to flower bud induction while high levels of CKs, IAA and ABA in the control longan contribute more to the vegetative development.

Decrease in rice aroma after application of growth regulators

Aromatic rices (Oryza sativa L.) compared to the leading varieties are low-yielding, susceptible to lodging and prone to attack by a number of insect pests and diseases. Under these conditions, various agricultural chemicals such as fertilizers, pesticides and growth regulators have been used for their cultivation. Few investigations, however, have examined the influence of these chemicals on rice aroma and flavor. In this study, changes in rice aroma after treatment with gibberellic acid, paclobutrazol, 3-indole acetic acid, and a regulator mixture consisting of paclobutrazol, proline and zinc chloride were for the first time examined using two aromatic rice cultivars. Applications were carried out after 25% of panicles had emerged. We studied 12 odor-active compounds, extracted and identified using static headspace coupled with gas chromatography. At the concentrations tested, all treatments with growth regulators resulted in reduced aroma content that affected overall flavor. In a smelling evaluation, control samples were significantly higher in intensity than treated samples. The difference between the aromas of control and treated samples was largely related to 2-acetyl-1-pyrroline, the major rice aroma compound, and lipid oxidation volatiles. For instance, in the cultivar Guixiangzhan grown during the late season, gibberellic acid treatment decreased the content of 2-acetyl-1-pyrroline by 19%, 3-indole acetic acid by 9%, paclobutrazol by 22%, and the regulator mixture by 21% compared with the control. Similar trends were observed in the Peizaruanxiang cultivar, with decreases ranging from 10 to 24%. Our findings demonstrate that treatments with growth regulators inhibited the metabolic processes associated with the formation of volatile compounds.

Odor and Flavor Volatiles of Different Types of Tea

The fingerprints and individual volatile flavor components of teas grown in different areas of the world are discussed, along with classical to modern analytical methods applied to teas. The structures of most volatiles were investigated by gas chromatography-mass spectrometry. The odor and flavor volatiles of various teas are controlled by specific combinations of key chemical components. These volatiles are terpenes, together with their derivatives, and other organic compounds. The terpenoids and their derivatives found in teas impart sweet and floral aromas, while other odors of teas are from non-terpenoids and products of the lipid degradation which occurs during manufacturing. The variation of quality and volatile flavor components in teas is also due to different environmental and ecological conditions, along with tea-processing methods.

Composition of essential oils from the rhizomes of three Alpinia species grown in Thailand

The genus Alpinia is an herbaceous plant belonging to the family Zingiberaceae and comprising more than 230 species. It has medicinal properties especially useful in conditions such as flatulence, dyspepsia, vomiting, and stomach sickness [1, 2]. Products of Alpinia rhizome have also been used as biological agents, for example, antibacterial [3], antifungal [4], anticlastogenic [5], antimutagenic [6], and as antioxidant agents [7]. The essential oil of Alpinia is useful in the treatment of respiratory illnesses and has been used as a flavoring agent for beverages in some European countries. Chemical studies of some main species of Alpinia have been widely reported [8–12], while a few studies have been conducted on the chemical compositions of some less common species [13–14]. In this study, the composition of essential oil obtained from rhizome of the rare A. malaccensis, which grows wild in areas of Northern Thailand, was investigated in comparison with those of the common species, A. galanga and A. officinarum, which are cultivated extensively. The essential oils extracted by SDE from rhizome parts of A. galanga, A. officinarum, and A. malaccensis appeared as pale yellow viscous liquids with percentage yields of 0.5, 0.1, and 0.2 (w/w), respectively. GC×GC profiles of rhizome oils from common species, A. galanga and A. officinarum, were almost the same, while those for a wild Alpnia, A. malaccensis, were different. The volatile constituents in the monoterpene region of all essential oil profiles are similar, thus are the characteristic of Alpinia rhizome oil. The overall GC×GC profile of volatile constituents of A. galanga oil was similar to that obtained from oil of A. officinarum, which revealed the similar genotype of both plants. These profiles of the common Alpinia were rather different from that of A. malaccensis. GC-MS analysis of the three Alpinia essential oils confirmed the regions of monoterpenes and sesquiterpenes as well as their derivatives. Overall, 71 volatile components were identified among the three Alpinia essential oils. The structural assignments of these volatiles, their relative percentages, and retention indices are summarized in Table 1. Individually, A. galanga essential oil yielded 60 identified components. The dominant components were 1,8-cineole (21.6%), chavicol (17.7%), and α-bisabolene (15.6%). Fifty-three components were identified in the essential oil of A. officinarum; the major component was α-bisabolene (10.6%) followed by α-trans-bergamotene (7.9%), and β-sesquiphellandrene (6.9%). Forty-one constituents were investigated in A. malaccensis, with 1,8-cineole (11.9%) as the major component followed by linalool (9%), and fenchyl acetate (8.6%). According to the GC×GC profiles, at least 122, 117, and 145 volatile components were detected in A. galanga, A. officinarum, and A. malaccensis essential oils, of which the extents of the identified components were 49, 45, and 28%, respectively. Comparison of the oil compositions of these Alpinia species by GC-MS showed that the high proportion of oxygenated monoterpenes was typical both in the A. galanga oil (72%) and A. malaccensis oil (45%), whereas sesquiterpene hydrocarbons dominated in A. officinarum essential oil (47%). Although most of the identified components were similar in all the essential oils, the quantity of some of these components in each essential oil was significantly different.

Adaptogenic-active components from Kaempferia parviflora rhizomes

Kaempferia parviflora rhizome extracts obtained by maceration with hexane, chloroform, methanol, and ethanol were screened for their adaptogenic activities using swimming tests of mice. The effective adaptogenic extract dose was 500mg/kg of body weight and was given orally once a day. Crude hexane extract showed significantly shorter mouse immobilisation time than those of the other and control extracts. This crude hexane extract was separated into three fractions by column chromatography. Among these fractions, the fraction rich in terpenoids possessed the highest adaptogenic activity and was comparable to that of the crude ginseng root powder used as a reference control. Therefore, terpenes contained in this fraction could be attributed to the decrease in exhaustion during the swimming of mice. There was no effect on body weight, heart, liver, kidneys, and adrenal glands of the mice. Chemical characterisation of this adaptogenic-active fraction by NMR and GC-MS showed germacene D, β-elemene, α-copaene, and E-caryophyllene as major constituents. Accordingly, these terpenes are considered the adaptogenic agents of K. parviflora rhizomes.