Contribution of dimethyl sulfide to the aroma of Syrah and Grenache Noir wines and estimation of its potential in grapes of these varieties

The contribution of dimethyl sulfide (DMS) to the aroma of Syrah and Grenache Noir wines from the Rhone Valley of France was investigated by sensory analysis, and its levels in these wines were measured. The potential DMS in the corresponding grapes and wines, susceptible to release during wine aging, was evaluated. Free DMS and potential DMS assessed by a heat-alkaline treatment were measured in grape juices and wines by SPME-GC-MS using methods previously reported and slightly modified. A relationship between potential DMS from grapes and the total DMS levels in wine was demonstrated. Furthermore, a linear regression between the ratio of free DMS levels to these total DMS levels in wine and time of storage was found. Free and potential DMS levels in grapes and wines depended on grape variety, vintage, and vine location. DMS imparted a noticeable and complex contribution to the aroma of the wines investigated, depending on the mode of sensory perception used, either before or after glass swirling. It significantly enhanced the fruity notes of the wines, and additional truffle and black olive notes.     

Oxygen Consumption and Development of Volatile Sulfur Compounds during Bottle Aging of Two Shiraz Wines. Influence of Pre- and Postbottling Controlled Oxygen Exposure

The evolution of different volatile sulfur compounds (VSCs) during bottle maturation of two Shiraz wines submitted to controlled oxygen exposure prior to bottling (through micro-oxygenation, MOX) and postbottling (through the closure) was investigated. H(2)S, methyl mercaptan (MeSH), and dimethyl sulfide (DMS) were found to increase during aging. Lower postbottling oxygen exposure, as obtained by different degrees of oxygen ingress through the closure, resulted in increased H(2)S and methyl mercaptan. In one wine MOX increased the concentration of H(2)S and methyl mercaptan during maturation. Dimethyl disulfide and DMS were not affected by any form of oxygen exposure. Overall, postbottling oxygen had a stronger influence than MOX on the evolution of VSCs. Data suggest that dimethyl disulfide was not a precursor to methyl mercaptan during bottle maturation. For the two wines studied, a consumption of oxygen of 5 mg/L over 12 months was the most effective oxygen exposure regimen to decrease accumulation of MeSH and H(2)S during bottle aging.     

Dimethyl sulphoxide (DMSO) and dimethyl sulphide (DMS) as inhibitors of methane oxidation in forest soil

Dimethyl sulphoxide (DMSO) at 14 mM inhibits CH₄ oxidation in forest soil, but the inhibition mechanism is unknown. When soil slurries are incubated in gas tight flasks, there is a lag of about 45 h before DMSO inhibits CH₄ oxidation. We tried to determine if some metabolic compound derived from DMSO, as a result of microbial activity, is responsible for the inhibition. Dimethyl sulphide (DMS) accumulated in the sealed flasks up to 5-83 μl l⁻¹ in the headspace during a 2-week period. DMS at 1 μl l⁻¹ in the headspace (0.64 μM in soil-water slurry) had a negligible effect on CH₄ oxidation but 50 μl l⁻¹ DMS (32 μM) inhibited CH₄ oxidation completely. However, the inhibition by DMSO was already evident after 45 h, when DMS concentrations were generally non-inhibiting (0.1-0.7 μl l⁻¹). DMSO was also shown to inhibit CH₄ oxidation when the DMS produced was continuously removed. Results suggest that the production of DMS from DMSO makes a minor contribution to the inhibition of CH₄ oxidation by DMSO with incubation times relevant in CH₄ oxidation studies.     

Improved folate extraction and tracing deconjugation efficiency by dual label isotope dilution assays in foods

A dual label stable isotope dilution assay was developed to trace the deconjugation efficiency of polyglutamic folate vitamers converted to their monoglutamic analogues. For this purpose, [(13)C(5)]-pteroylheptaglutamate was synthesized and added during extraction of foods as a tracer isotopologue along with [(2)H(4)]-5-methyltetrahydrofolate, [(2)H(4)]-5-formyltetrahydrofolate, [(2)H(4)]-tetrahydrofolate, [(2)H(4)]-10-formylfolate, and [(2)H(4)]-folic acid. The [(2)H(4)]-labeled folates were used as internal standards for the monoglutamates. Deconjugation converted the addition tracer [(13)C(5)]-pteroylheptaglutamate to the detection tracer [(13)C(5)]-folic acid, which was quantified along with unlabeled folic acid using [(2)H(4)]-folic acid as the internal standard. LC-MS/MS enabled the unequivocal differentiation of the three isotopologues. This tracing was used to optimize deconjugation efficiency, which was achieved by using 4-morpholineethanesulfonic acid buffer for extraction at pH 5.0 . The optimized assay revealed limits of detection for the folate vitamers ranging between 2.0 and 5.6 pmol per assay (equivalent to 2.2-6.6 μg/100 g dry mass), recoveries ranging between 98 and 105% and relative standard deviations in inter-assay precision ranging between 2 and 6%. The assay was applied to quantitate folates in spinach, beans, cheeses, bread, wheat germs, and yeast .     

Quantitative analysis, occurrence, and stability of (E)-1-(2,3,6-Trimethylphenyl)buta-1,3-diene in wine

A stable isotope dilution assay has been developed for quantification of (E)-1-(2,3,6-trimethylphenyl)buta-1,3-diene (4) in wine using a [(2)H(6)]-analogue. Using this method, 4 was found in 96 out of 97 white wines, but in none of 12 red wines analyzed. 4 was found to be most prevalent in Semillon wines, followed by Chardonnay, with Riesling showing the least amount of 4 among these three varieties. 4, like 1,1,6-trimethyldihydronaphthalene (TDN, 3), appears to be formed during the aging process. 4 was found to be unstable in model wine, and in both white and red wine, with the order of stability being model > white > red. In a PVPP-stripped red wine, the rate of degradation of 4 was substantially lessened, with the final concentrations very close to those observed in model wine. When treated with either grape or wine tannin extracts in model wine, the concentration of 4 was found to decrease to levels very close to those observed with an untreated red wine. When white wine was heated at 45 degrees C, 4 was formed, indicating the presence of precursor forms. The amounts formed were much higher than those found in a commercial white wine. 4 was also observed in red wine heated to 45 degrees C, but the concentration produced was much less than that with white wine.     

Quantitative determination of sulfur-containing wine odorants at sub parts per billion levels. 2. Development and application of a stable isotope dilution assay

[(2)H(10)]-4-Mercapto-4-methylpentan-2-one (d(10)-1), [(2)H(2)]-3-mercaptohexan-1-ol (d(2)-2), and [(2)H(5)]-3-mercaptohex-1-yl acetate (d(5)-3), deuterated analogues of impact odorants of wines, were used to determine quantitatively the natural compounds in white wines (Muscadet, Sauvignon, and Bacchus) with a stable isotope dilution assay using gas chromatography coupled either with ion trap tandem mass spectrometry (GC-ITMS-MS) or with atomic emission detection monitored on sulfur-selective acquisition (GC-AED). The thiol compounds were recovered from wines by liquid-liquid extraction, then purified from the wine extracts by covalent chromatography, and analyzed. The quantitative determination of 4-mercapto-4-methylpentan-2-one 1 in the wines that were analyzed was performed better with GC-AED than with GC-ITMS-MS under the conditions that were used. However, the detection limit of the method was higher than the odor threshold of 4-mercapto-4-methylpentan-2-one 1 in wine (5 vs 0.8 ng/L). The levels of this compound in the Sauvignon and Bacchus wines were much higher than its odor threshold, but it was not detectable in the Muscadet wines. On the contrary, GC-ITMS-MS was much more sensitive than GC-AED for detection of 3-mercaptohexan-1-ol 2 and 3-mercaptohex-1-yl acetate 3, and the detection limits were much lower than their odor thresholds in wine. The former compound was detected in all of the Muscadet wines that were analyzed at levels always higher than its odor detection threshold, while the latter occurred at levels higher than its odor threshold in only one Muscadet wine.     

Model aging and oxidation effects on varietal, fermentative, and sulfur compounds in a dry botrytized red wine

From harvest until wine arrives to the consumer, oxygen plays a crucial role in the definition of the final aroma. In the present research, the effect of the model oxidative aging on a dry red Botrytis wine, such as Italian Amarone, was considered. Amarone wine was submitted to model oxidative aging and then analyzed with two different approaches (SPE-GC-MS and HS-SPME/GC-MS). The same sampling plan was adopted to study the model aging of the same Amarone wine in anaerobic conditions. The HS-SPME/GC-MS method was applied to investigate for the first time the effect of the oxidative aging on a vast number of fermentative sulfur compounds. This research highlighted peculiar evolutions for several volatile compounds. In particular, benzaldehyde showed a sensitive increment during the oxidative aging, with a rate much higher than that reported for non-Botrytis red wines. On the other hand, several sulfides (dimethyl sulfide, 3-(methylthio)-1-propanol, etc.) disappeared after just 15 days of oxidative aging. A wine oxidation marker such as 3-(methylthio)-propanal was not found in any of the oxidized wines; conversely methionol-S-oxide was tentatively identified. This evidence has not been mentioned in the literature. A possible involvement of grape withering process and Botrytis in these mechanisms was supposed: a dry red wine, produced from the same but without any grape withering process and Botrytis infection (e.g., Bardolino wine), was submitted to oxidative aging and analysis. This red wine showed an evolution similar to those reported in the literature for dry red wines but significantly different from the Amarone wine.     

An experimental study of two potential methylation agents of mercury in the atmosphere: CH3I and DMS

Experimental results from a study of the gas and aqueous phase reactions of elemental mercury (Hg⁰) with methyl iodide (CH₃I) and dimethyl sulfide (DMS) are presented. In aqueous phase experiments with CH₃I we found no observable increase in methyl mercury (MeHg). A small formation of MeHg, however, was observed in some (but not all) gas phase experiments in sunlight. A loss of Hg⁰ and a simultaneous formation of oxidized mercury (Hg(II)) was also observed in these experiments. No reaction, neither methylation or oxidation, was found between Hg⁰ and DMS under any conditions investigated. These experiments suggest that a simple homogeneous gas or aqueous phase methylation of Hg⁰ by DMS or CH₃I in the atmosphere cannot account for the significant levels of MeHg observed in precipitation.     

The effects of sample preparation and gas chromatograph injection techniques on the accuracy of measuring guaiacol, 4-methylguaiacol and other volatile oak compounds in oak extracts by stable isotope dilution analyses

The deuterium-labeled standards [(2)H(3)]-guaiacol and [(2)H(3)]-4-methylguaiacol were synthesized and utilized in a method employing gas chromatography-mass spectrometry to determine the concentration of guaiacol and 4-methylguaiacol in wine or extracts of oak shavings. The method was combined with previously published methods for 4-ethylphenol, 4-ethylguaiacol, cis- and trans-oak lactone and vanillin, so that all these compounds could be quantified in a single analysis. The method can employ either liquid-liquid extraction or headspace solid-phase microextraction (SPME) and is rapid, robust, precise, and accurate. Under certain conditions, there was artifactual generation, to varying degrees, of guaiacol, 4-methylguaiacol, cis-oak lactone, and vanillin during the analysis of oak extracts, especially when diethyl ether extraction and injector block temperatures at or above 225 degrees C were employed. The most substantial effects were observed for guaiacol, in which results could be exaggerated by over 10 times. These artifacts could be avoided by using headspace SPME or by preparing liquid-liquid extracts with pentane or pentane/diethyl ether (2:1) injected at 200 degrees C providing spot checks using headspace SPME were performed. Data obtained for previously published quantitative determination of guaiacol in oak extracts should be reexamined carefully, with special attention paid to their respective methods of sample preparation and analysis.     

Study of the formation mechanisms of some volatile compounds during the aging of sweet fortified wines.

Sweet fortified wines, traditionally aged under strong oxidation conditions, have a characteristic aroma. An experimental laboratory study investigated the aging of red and white sweet fortified wines under various conditions. The formation of various molecules, previously identified as characteristic of the aroma of this type of wine, was monitored by analysis. The development of these compounds during accelerated aging was affected by oxidation and the color of the wine. Among the molecules studied, sotolon [3-hydroxy-4, 5-dimethyl-2(5H)-furanone] was one of the few molecules present in concentrations above the perception threshold, in both red and white wines. Buildup was strongly affected by the presence of oxygen in white wine subjected to accelerated aging. (Ethoxymethyl)furfural, formed from 5-(hydroxymethyl)furfural, and furfural, derived from sugars, are also involved in the aroma of sweet fortified white wines aged in oxygen-free conditions. The substances most characteristic of accelerated aging of sweet fortified red wines were 5-(hydroxymethyl)furfural, acetylformoin, and hydroxymaltol, the formation of which is affected by oxidation, and dihydromaltol, formed in the absence of oxidation.     

Quantitation of the intense aroma compound 3-mercapto-2-methylpentan-1-ol in raw and processed onions (Allium cepa) of different origins and in other Allium varieties using a stable isotope dilution assay

A stable isotope dilution assay was developed for the quantitation of the potent onion odorant 3-mercapto-2-methylpentan-1-ol (1) using mass chromatography and synthesized [(2)H(2)]-3-mercapto-2-methylpentan-1-ol as the internal standard. Application of the newly developed method on onions from different origins revealed amounts between 8 and 32 microg/kg in raw onions, whereas 34-246 microg was found in sliced, stored (50 min), and then cooked onions. In extracts prepared by simultaneous steam distillation-extraction the highest concentrations of 1 were formed, amounting to >1200 microg/kg. The much higher content of 3-mercapto-2-methylpentan-1-ol in cooked onions suggested its formation from specific, yet unkown, precursors enzymatically formed during cutting of raw onions. 1 was for the first time identified and also quantified in other Allium species such as chives, scallions, and leek, whereas surprisingly garlic and bear's garlic did not contain the aroma compound.     

Radioprotective-antimutagenic effects of rosemary phenolics against chromosomal damage induced in human lymphocytes by gamma-rays

The radioprotective effects of carnosic acid (CA), carnosol (COL), and rosmarinic acid (RO) against chromosomal damage induced by gamma-rays, compared with those of L-ascorbic acid (AA) and the S-containing compound dimethyl sulfoxide (DMSO), were determined by use of the micronucleus test for antimutagenic activity, evaluating the reduction in the frequency of micronuclei (MN) in cytokinesis-blocked cells of human lymphocytes before and after gamma-ray irradiation. With treatment before gamma-irradiation, the most effective compounds were, in order, CA > RO > or = COL > AA > DMSO. The radioprotective effects (antimutagenic) with treatment after gamma-irradiation were lower, and the most effective compounds were CA and COL. RO and AA presented small radioprotective activity, and the sulfur-containing compound DMSO lacked gamma-ray radioprotection capacity. Therefore, CA and COL are the only compounds that showed a significant antimutagenic activity both before and after gamma-irradiation treatments. These results are closely related to those reported by other authors on the antioxidant activity of the same compounds, and the degree of effectiveness depends on their structure. Furthermore, the results for treatments before and after gamma-ray irradiation suggest the existence of different radioprotective mechanisms in each case.     

"Untypical aging off-flavor" in wine: synthesis of potential degradation compounds of indole-3-acetic acid and kynurenine and their evaluation as precursors of 2-aminoacetophenone

Kynurenine (1) and indole-3-acetic acid (2) are considered as potential precursors of 2-aminoacetophenone (3), which is regarded to be the aroma impact compound causing an "untypical aging off-flavor" (UTA) in Vitis vinifera wines. The mechanism of the formation of 3 was studied using model fermentation and model sulfuration media spiked with 1 or 2 as potential precursors. Possible degradation products such as kynurenamine (4) and kynurenic acid (5), or skatole (6), 2-oxoskatole (7), 2-formamidoacetophenone (8), 2-oxindole-3-acetic acid (9), and 3-(2-formylaminophenyl)-3-oxopropionic acid (10) were evaluated by HPLC-UV of the fermentation and sulfuration media and comparison with synthesized 7, 8, 9, and 10. The synthesis of the possible precursor 4-(2-aminophenyl)-2,4-dioxobutanoic acid (11), a proposed metabolite of 1 failed because a spontaneous cyclization yields 5 and N-oxo-kynurenic acid (12), but not 11. It could be shown that the formation of 3 is triggered by an oxidative degradation of 2 after sulfuration with potassium bisulfite via the intermediates 10 and 8. However, no formation of 3 occurred during sulfuration of a model wine spiked with 1 or during fermentation of a model must spiked with 1 or 2.     

Influence of some technological parameters on the formation of dimethyl sulfide, 2-mercaptoethanol,methionol, and dimethyl sulfone in port wines

Volatile sulfur compounds of 15 young port wines and 12 old port wines were determined. As there is a great difference in the pool of sulfur compounds between the two groups of wines, an experimental protocol was performed to determine which technological parameter (dissolved O(2), free SO(2) levels, pH, and time/temperature) was related with the formation/consumption of these compounds. Four sulfur compounds were selected for this purpose: dimethyl sulfide, 2-mercaptoethanol, dimethyl sulfone, and methionol. The synergistic effects of increasing temperature and O(2) at lower pH had the largest impact. Dimethyl sulfide was formed during the experimental period in the presence of O(2). Dimethyl sulfone had the same behavior. Methionol decreased significantly in the presence of O(2), but no methional was formed. 2-Mercaptoethanol, considered to be an important "off-flavor" in dry wines, also decreased during the experimental period (54 days) in the presence of O(2), and the respective disulfide was formed. These results corroborate the fact that old port wine (barrel aged) never develops "off-flavors" associated with the presence of methionol (cauliflower), 2-mercaptoethanol (rubber/burnt), or methional (cooked potato). In fact, temperature and oxygen are the major factors in the consumption of these molecules. However, some notes of "quince" and "metallic" can appear during port wine aging, and these can be associated with the presence of dimethyl sulfide.     

Hydrolysis and transformation of grape glycosidically bound volatile compounds during fermentation with three Saccharomyces yeast strains

The ability of three Saccharomyces wine yeasts (S. cerevisiae AWRI 838, S. cerevisiae AWRI 1537, and S. bayanus AWRI 1375) to liberate volatile compounds from sugar-bound aroma precursors was investigated using synthetic and grape glycosides under different experimental conditions. In model systems involving the incubation of yeast cells with either synthetic or grape-derived glycosides under conditions more favorable for glycosidase activities and less favorable for acid-catalyzed hydrolysis (pH 5.0 and 30 degrees C), all yeast strains studied proved to be capable of hydrolyzing glycosides, with S. bayanus AWRI 1375 displaying greater hydrolytic activity than S. cerevisiae AWRI 838 and AWRI 1537. During the fermentation of a chemically defined grape juice-like medium containing glycosidic precursors extracted from Vitis vinifera cv. White Frontignac (synonym Muscat à Petit Grains Blanc), all yeasts promoted a significant hydrolysis of different precursors, which varied according to the chemical structures of both the sugar and the aglycon moieties, as determined by GC-MS analysis of trifluoroacetylated derivatives. Hydrolysis of the White Frontignac derived glycosidic precursors during fermentation resulted in the release of monoterepene alcohols, terpene oxides, terpene diols, and 3-oxo-alpha-ionol, demonstrating the significant potential of these yeast strains to contribute to wine varietal volatile composition during alcoholic fermentation.     

Antioxidant properties of trans-epsilon-viniferin as compared to stilbene derivatives in aqueous and nonaqueous media

trans-Epsilon-viniferin, the dimer of resveratrol, extracted from Vitis vinifera, has been evaluated for its antioxidant capacity. Its properties have been compared to those of resveratrol and synthetic stilbenic derivatives (4-hydroxystilbene, 4,4'-dihydroxystilbene, 3,5-dihydroxystilbene, and trimethylresveratrol), in regard to their liposolubility using two media with different polarity. The bleaching of beta-carotene by lipoperoxyl (LOO.) radicals in an oil/water (O/W) emulsion and the scavenging of superoxide anions (O(-)(2) in dimethyl sulfoxide (DMSO) using 5,5-dimethyl-1-pyrroline-N-oxide as a spin trap were followed using UV-visible and electron paramagnetic resonance, respectively. Epsilon-viniferin exhibits the best antioxidant capacity in the DMSO/O(-)(2) polar system (IC(50) = 0.14 mM) while 4,4'-dihydroxystilbene presents the highest antioxidant capacity in the O/W/LOO. system (inhibition of beta-carotene bleaching, 82%). Partition coefficients and kinetics of partition between 1-octanol and water were measured to discuss the antioxidant efficiency of the compounds in relation with their chemical structure.     

Reversible and covalent binding of 5-(hydroxymethyl)-2-furaldehyde (HMF) with lysine and selected amino acids

The chemical reactivity of 5-(hydroxymethyl)-2-furaldehyde (HMF) with lysine, glycine, and proline was studied using isotope labeling technique. To confirm the formation of HMF adducts in glucose amino acid model systems, a useful strategy was developed in which products simultaneously possessing six glucose (HMF moiety) and any number of amino acid carbon atoms in addition to nitrogen were targeted using specifically labeled precursors such as [(15)N(α)]lysine·2HCl, [(15)N(ε)]lysine·2HCl, [U-(13)C(6)]lysine·2HCl, [(13)C(6)]lysine·2HCl, and [U-(13)C(6)]glucose in the case of lysine model system. In addition, model systems containing HMF and amino acids were also studied to confirm specific adduct formation. Complete labeling studies along with structural analysis using appropriate synthetic precursors such as HMF Schiff base adducts of piperidine and glycine have indicated that HMF generated in the glucose/amino acid model systems initially forms a Schiff base adduct that can undergo decarboxylation through an oxazolidin-5-one intermediate and form two isomeric decarboxylated Schiff bases. Unlike the Schiff bases resulting from primary amines or amino acids such as glycine or lysine, those resulting from secondary amino acids such as proline or secondary amines such as piperidine can further undergo vinylogous Amadori rearrangement, forming N-substituted 5-(aminomethyl)furan-2-carbaldehyde derivatives.     

Influence of temperature, modified atmosphere packaging, and heat treatment on aroma compounds in broccoli

The aroma compounds in broccoli stored in different modified atmospheres were studied. The packaging materials used were oriented polypropylene (OPP), poly(vinyl chloride) (PVC), and low-density polyethylene (LDPE) containing an ethylene-absorbing sachet. All samples were stored for either 1 week at a constant temperature of 10 degrees C or for 3 days at 4 degrees C, followed by 4 days at 10 degrees C. The atmospheres that developed inside the packaging materials differed significantly. The broccoli samples were analyzed raw and after cooking, with regard to volatile compounds, using gas-phase (headspace) extraction followed by gas chromatography-mass spectrometry (GC-MS) and GC-olfactometry. Dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), hexanal, 3-cis-hexen-1-ol, nonanal, ethanol, and a group of thiocyanates were selected for a detailed study because these compounds cause off-odor and can be used as indicators of stress. Significant differences were found in the aroma profiles of the broccoli samples relative to the packaging materials used for storage. Storage in OPP (14% O(2), 10.5% CO(2)) resulted in most of the off-odors, while storage in LDPE (6% O(2), 7% CO(2)) and PVC (17.9% O(2), 4% CO(2)) was found to maintain the concentration of DMS, DMDS, and DMTS during storage. Heat treatment of the broccoli increased the content of aroma compounds as well as the number of compounds containing sulfur.     

Formation of methanethiol and dimethyl disulfide in crushed tissues of broccoli florets and their inhibition by freeze-thawing

The formation of methanethiol and dimethyl disulfide in crushed, homogenized, and frozen-thawed tissues of broccoli florets was investigated. These volatile sulfur compounds were produced in crushed florets, but their formation was inhibited in frozen-thawed tissues. Only dimethyl disulfide was formed in homogenized tissues. High pH treatment triggered the release of dimethyl disulfide in frozen-thawed tissues and also enhanced the action of cysteine sulfoxide lyase in all disrupted tissues. Methyl methanethiosulfinate and methyl methanethiosulfonate were not detected in crushed florets; thus, the favored mechanism for the formation of methanethiol and dimethyl disulfide is the chemical disproportionation of methanesulfenic acid. In contrast, the formation of dimethyl disulfide in frozen-thawed and homogenized tissues occurs from the chemical disproportionation of methyl methanethiosulfinate that was detected in these tissues. The inhibition of dimethyl disulfide production during freeze-thawing must be caused by a sudden drop in the pH of the tissue, adherence of dimethyl disulfide on the tissue surfaces, and weakening of the cysteine sulfoxide lyase activity under acidic conditions.     

Heteronuclear single-quantum coherence nuclear magnetic resonance (HSQC NMR) characterization of acetylated fir (Abies sachallnensis MAST) wood regenerated from ionic liquid

An ionic liquid, 1-butyl-3-methylimidazolium chloride ([Bmim]Cl), was used to dissolve Japanese fir (Abies sachallnensis MAST) wood. Milled woods prepared by planetary ball-milling for 8 h dissolved completely in [Bmim]Cl at 100 °C in 2 h. The dissolved woods were then subjected to in situ acetylation, and the fully acetylated woods were regenerated from [Bmim]Cl. (1)H-(13)C correlation heteronuclear single-quantum coherence (HSQC) nuclear magnetic resonance (NMR) experiments were successfully conducted with the acetylated woods in dimethyl sulfoxide (DMSO)-d(6). The acetylated lignin and polysaccharide signals dispersed reasonably well on the 2D spectra. Characterization of the NMR signals for the whole cell-wall components, including lignin, cellulose, and hemicelluloses, was achieved by comparison with isolated lignin and commercial cellulose and hemicelluloses (arabinoxylan, galactomannan, and glucomannan). The procedure used here is applicable for the characterization of cell-wall components in various plant biomasses.