Acid Degradation Products Research Articles

Behavior of Eucalyptus Kraft Pulp Extractives Components across ECF Bleaching and Their Impact on Brightness Reversion

This study investigated the chemical composition of the dichloromethane and acetone extracts of eucalypt pulp across D(EP)DP and AZDP bleaching sequences by gas chromatography-mass spectrometry (GC-MS). The bleaching stages led to the partial removal and to several oxidative transformations of fatty acids and sterols, the main lipophilic extractives found in the unbleached pulp. The pulp samples were bleached to 90–91% ISO by D(EP)DP and AZDP sequences and their brightness stability and chemical characteristics determined. The effect of aging on brightness was investigated. The AZDP bleaching sequence resulted in pulps of higher brightness stability. Furoic structures representing the main acid degradation products of HexA are suggested as the actual intermediates that cause yellowing by forming colored compounds. The AZDP process removed larger amounts of HexA across bleaching.

Antioxidant Action of Glutathione and the Ascorbic Acid/Glutathione Pair in a Model White Wine

Glutathione was assessed individually, and in combination with ascorbic acid, for its ability to act as an antioxidant with respect to color development in an oxidizing model white wine system. Glutathione was utilized at concentrations normally found in wine (30 mg/L), as well as at concentrations 20-fold higher (860 mg/L), the latter to afford ascorbic acid (500 mg/L) to glutathione ratios of 1:1. The model wine systems were stored at 45 °C without sulfur dioxide and at saturated oxygen levels, thereby in conditions highly conducive to oxidation. Under these conditions the results demonstrated the higher concentration of glutathione could initially provide protection against oxidative coloration, but eventually induced color formation. In the period during which glutathione offered a protective effect, the production of xanthylium cation pigment precursors and o-quinone-derived phenolic compounds was limited. When glutathione induced coloration, polymeric pigments were formed, but these were different from those found in model wine solutions without glutathione. In the presence of ascorbic acid, high concentrations of glutathione were able to delay the decay in ascorbic acid and inhibit the reaction of ascorbic acid degradation products with the wine flavanol compound (+)-catechin. However, on depletion, the glutathione again induced the production of a range of different polymeric pigments. These results highlight new mechanisms through which glutathione can offer both protection and spoilage during the oxidative coloration of a model wine.

Stability-indicating HPTLC method for analysis of torsemide in pharmaceutical preparations

Summary A simple, precise, and accurate stability-indicating high-performance thinlayer chromatographic method for analysis of torsemide in the presence of its degradation products has been established and validated. Optimum separation among torsemide and its degradation products was achieved by use of silica gel 60F254 as stationary phase with ethyl acetate-acetonitrile-water 6.5:3.0:0.5 (v/v) as mobile phase. Densitometric quantification was performed at 297 nm. The retention factors, RF, were 0.59 ± 0.02 for the parent drug, 0.74 ± 0.02 for the degradation product from oxidation, and 0.78 ± 0.02 and 0.96 ± 0.02 for two products of acid degradation. The method was found to be linear in the range 200–800 ng per band both by area and height. The results from analysis of commercial formulations were found to be 98.49 ± 0.32 and 101.75 ± 1.54%. The method was validated for precision, accuracy, specificity, robustness, and ruggedness.

Degradation of tannic acid by cold-adapted Klebsiella sp NACASA1 and phytotoxicity assessment of tannic acid and its degradation products

The focus of the present study is to know the potential of bacterial isolate for tannic acid degradation at low temperature. Also, we tried to evaluate the suitability of phytotoxicity testing protocol for the determination of tannic acid toxicity. Screening for tannic acid degrading bacterial strains was carried out by using microbial isolation techniques. The 16S rDNA amplicon of the isolate was used to identify the isolate. The effect of different concentrations of tannic acid and its degradation products on germination of Vigna unguiculata was evaluated. The study was carried out to determine total sugar and starch content of the used seeds and even to check the presence of α-amylase activity during seed germination. The isolated bacterium was identified as Klebsiella sp NACASA1 and it showed degradation of tannic acid in 40 (±0.85***) h at 15°C and pH7.0. A gradual decrease in root/shoot length was observed with increasing concentration of tannic acid. There was 95.11 (±0.24**)% inhibition in α-amylase activity at 20,000ppm tannic acid, as compared to control. No such effects were observed on germination, root-shoot length, and α-amylase activity with tannic acid degradation products. The results obtained confirmed that tannic acid may act as a toxic agent in plant cells. The simple biodegradation process presented in this study was found to be effective in reducing toxicity of tannic acid. Also, it reveals the potential of soil bacterium to degrade tannic acid at low temperature.

Effects of Food on a Gastrically Degraded Drug: Azithromycin Fast-Dissolving Gelatin Capsules and HPMC Capsules

Commercial azithromycin gelatin capsules (Zithromax®) are known to be bioequivalent to commercial azithromycin tablets (Zithromax®) when dosed in the fasted state. These capsules exhibit a reduced bioavailability when dosed in the fed state, while tablets do not. This gelatin capsule negative food effect was previously proposed to be due to slow and/or delayed capsule disintegration in the fed stomach, resulting in extended exposure of the drug to gastric acid, leading to degradation to des-cladinose-azithromycin (DCA). Azithromycin gelatin capsules were formulated with "superdisintegrants" to provide fast-dissolving capsules, and HPMC capsule shells were substituted for gelatin capsule shells, in an effort to eliminate the food effect. Healthy volunteers were dosed with these dosage forms under fasted and fed conditions; pharmacokinetics were evaluated. DCA pharmacokinetics were also evaluated for the HPMC capsule subjects. In vitro disintegration of azithromycin HPMC capsules in media containing food was evaluated and compared with commercial tablets and commercial gelatin capsules. When the two fast-dissolving capsule formulations were dosed to fed subjects, the azithromycin AUC was 38.9% and 52.1% lower than after fasted-state dosing. When HPMC capsules were dosed to fed subjects, the azithromycin AUC was 65.5% lower than after fasted-state dosing. For HPMC capsules, the absolute fasting-state to fed-state decrease in azithromycin AUC (on a molar basis) was similar to the increase in DCA AUC. In vitro capsule disintegration studies revealed extended disintegration times for commercial azithromycin gelatin capsules and HPMC capsules in media containing the liquid foods milk and Ensure®. Interaction of azithromycin gelatin and HPMC capsules with food results in slowed disintegration in vitro and decreased bioavailability in vivo. Concurrent measurement of serum azithromycin and the acid-degradation product DCA demonstrates that the loss of azithromycin bioavailability in the fed state is largely (and probably entirely) due to gastric degradation to DCA. Capsules can provide a useful and elegant dosage form for almost all drugs, but may result in a negative food effect for drugs as acid-labile as azithromycin.

Pyroglutamic acid development during grape must cooking

A study of the pyroglutamic acid development during must cooking as glutamine and glutamic acid degradation product was carried out. Pyroglutamic acid was detected in two white musts (Trebbiano toscano and Spergola) and in a red one (Lambrusco) previously cooked by means of a laboratory-scale equipment emulating the real process. Results showed that pyroglutamic acid sharply increased and glutamine quickly disappeared during the first stages of the cooking process, while glutamic acid was almost linearly reduced throughout all the process. A study carried out by heating the model solutions of the single amino acids showed that both of them underwent degradation following the same trend observed in the musts.

Use of Green Rooibos (Aspalathus linearis) Extract and Water-Soluble Nanomicelles of Green Rooibos Extract Encapsulated with Ascorbic Acid for Enhanced Aspalathin Content in Ready-to-Drink Iced Teas

Heat-induced changes in aspalathin, iso-orientin, and orientin content of ready-to-drink (RTD) green rooibos iced tea formulations were investigated. An organic-solvent-based aspalathin-enriched extract prepared from green rooibos was used "as-is" or encapsulated with ascorbic acid in a water-soluble nanomicelle-based carrier system. The common iced tea ingredients, ascorbic acid, and/or citric acid were added to the iced tea containing green rooibos extract. Only citric acid was added to the iced tea containing the nanomicelles. Heat treatments consisted of pasteurization (93 °C/5 min and 93 °C/30 min), normal-temperature sterilization (NTS; 121 °C/15 min), and high-temperature sterilization (HTS; 135 °C/4 min). Pasteurization had little or no effect on the flavonoid content. NTS and HTS induced significant losses in the flavonoids. The addition of citric and ascorbic acids improved the stability of the flavonoids, but encapsulation of green rooibos extract with ascorbic acid in nanomicelles did not offer additional stability. The only benefit of using the water-soluble nanomicelles was the improved clarity of the RTD product. Iso-orientin and orientin contents were substantially less affected than aspalathin by the heat treatments, partially because of conversion of aspalathin to these flavones, which countered losses. 5-Hydroxymethylfurfural (HMF), a known dehydration product of hexoses under mild acidic conditions and also a degradation product of ascorbic acid, was observed in formulations containing citric and/or ascorbic acids.

Simultaneous Screening of Herbicide Degradation Byproducts in Water Treatment Plants Using High Performance Liquid Chromatography−Tandem Mass Spectrometry

Currently, herbicides are widely used in various combinations at many stages of cultivation and during postharvest storage. There are increasing concerns about the public health impact of herbicide degradation byproducts that may be present in water bodies used either as drinking water or for recreational purposes. This work investigated the sulfonic acid and oxanilic acid degradation products of metolachlor, alachlor, acetochlor, and propachlor in a variety of water bodies. The objective was to develop a fast, accurate, and easy method for quantitative analysis of herbicide degradation products using liquid chromatography with tandem mass spectrometry without solid phase extraction, but performing levels of detection lower than those obtained in previous studies with solid phase extraction. This research also screened 68 water samples, both untreated source water and treated water, from 34 water treatment plants in Missouri. Finally, it examined seasonal trends in levels of those degradation products by collecting and testing samples monthly. This highly sensitive method can analyze these degradation products to low ng/L levels. The method limit of quantification ranges from 0.04 to 0.05 ppb for each analyte; and quantitative analyses show a precision with RSDs of around 0.6% to 3% in treated water and 2% to 19% in untreated source water. Concentrations of alachlor ESA, acetochlor OA, metolachlor OA, and metolachlor ESA were detected from the Missouri River and the Mississippi River water bodies in summer time. Occurrences of these compounds in treated water samples are all lower than those in the untreated source water samples.

Acid and base degraded products of ketorolac

The stability of ketorolac tromethamine was investigated in acid (0.5 M HCl) and alkaline conditions (0.5 M NaOH), using the same procedure reported by Devarajan et al. [2]. The acid and base degradation products were identified by liquid chromatography–mass spectrometry (LC–MS).

Stripping voltammetric methods for determination of the antiparasitic drug nitazoxanide in bulk form, pharmaceutical formulation and human serum

Cyclic voltammograms of nitazoxanide recorded at the hanging mercury drop electrode in the Britton-Robinson universal buffer of pH values 2 to 11 containing 20% (v/v) ethanol exhibited a single 4-electron irreversible cathodic peak corresponding to the reduction of its NO2 group to the hydroxylamine stage. Nitazoxanide was found to adsorb onto surface of the mercury electrode in a monolayer surface coverage of 3.16×10-10 mol cm-2 in which each adsorbed molecule occupies an area of 0.525 nm². Based on its adsorption behavior onto the mercury electrode surface, validated linear sweep (LS), differential pulse (DP) and square wave (SW) adsorptive cathodic stripping voltammetric methods were described for determination of bulk nitazoxanide. Limits of detection of 1.5×10-10, 2.4×10-10 and 3.0×10-11 mol L-1 and limits of quantification of 5.0×10-10, 8.0×10-10 and 1.0×10-10 mol L-1 nitazoxanide in the bulk form were achieved by means of the described LS, DP and SW adsorptive cathodic stripping voltammetric methods, respectively. The described methods were successfully applied for determination of nitazoxanide in its pharmaceutical formulation (Cryptonaz powder) and in spiked human serum without the necessity for sample pretreatment, time consuming extraction steps or formation of colored chromogens prior to the analysis. Besides, nitazoxanide was successfully determined without interference from its acid or base-induced degradation products indicating the stability-indicating power of the described voltammetric methods.

Optimisation of extracellular tannase production from Paecilomyces variotii

The tannase production by Paecilomyces variotii was confirmed by high performance thin layer chromatography (HPTLC), and substrate specificity of the tannase was determined by zymogram analysis in sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS–PAGE). A clear band of activity observed after electrophoresis of culture filtrate in non-denaturing gels indicated the production of extracellular tannase by P. varoitii. HPTLC analysis revealed that gallic acid was the enzymatic degradation product of tannic acid during the fermentation process. The optimum condition for tannase production was at 72 h of incubation in shaking condition and addition of 1.5% tannic acid, 1% glucose and 0.2% sodium nitrate at temperature of 35°C and pH of 5–7. The production of extracellular tannase from Paecilomyces variotii was investigated under optimized conditions in solid-state fermentation (SSF), submerged fermentation (SmF) and liquid surface fermentation (LSF) processes. The maximum extracellular tannase production was obtained within 60 h of incubation under SSF followed by SmF and LSF.

PARTICULAR FEATURES OF HOP-DERIVED COMPOUNDS AND BEER QUALITY

Beer quality can be defined in many ways. Combining consumer liking data and trained panel sensory descriptive data, this presentation will present a case study whereby the importance of hops on beer quality is demonstrated. Hop-related descriptive attributes such as grapefruit and piney aromas as well as bitterness intensity were positively correlated with consumer liking. Furthermore, DMS and sulfide aroma were significantly, inversely correlated with liking. Having demonstrated the importance of hops on consumer liking, and in turn on beer quality, this presentation turns to where and how hops influence beer flavor quality with an emphasis on bitterness. Naturally, the amount and timing of hops additions during brewing and fermenting influence the intensities of the aromatic and taste contributors from hops which in turn controls the trueness-to-type and the balance/complexity aspects of beer quality. Iso-alpha-acid concentration and, to a lesser degree, analogous types are responsible for the bitterness intensity in beer. Beyond intensity, the nature of the bitterness (for example, fine and fleeting versus coarse and lingering) may also significantly impact beer quality. This is apparent when comparing iso-alpha-acids with rho-iso-alpha-acids or tetrahydroiso-alpha-acids, and may also be important when comparing these compounds against alpha and beta acid degradation products. In addition to alpha-acid-derived bitterness, hop polyphenols contribute their own bitterness, albeit at much lower intensities, plus they contribute to the physical and flavor stability/instability of beer.

Toxigenic effects of diatoms on grazers, phytoplankton and other microbes: a review

Traditionally, diatoms have been regarded as providing the bulk of the food that sustains the marine food chain and important fisheries. However, this view was challenged almost two decades ago on the basis of laboratory and field studies showing that when copepods, the principal predators of diatoms, feed on certain diatom diets, they produce abnormal eggs that either fail to develop to hatching or hatch into malformed (i.e. teratogenic) nauplii that die soon afterwards. Over the years, many explanations have been advanced to explain the causes for reproductive failure in copepods and other marine and freshwater invertebrates including diatom toxicity, or nutritional deficiency and poor assimilation of essential compounds in the animal gut. Here we review the literature concerning the first possibility, that diatoms produce cytotoxic compounds responsible for growth inhibition and teratogenic activity, potentially sabotaging future generations of grazers by inducing poor recruitment. The cytotoxic compounds responsible for these effects are short chain polyunsaturated aldehydes (PUAs) and other oxygenated fatty acid degradation products such as hydroxides, oxo-acids, and epoxyalcohols (collectively termed oxylipins) that are cleaved from fatty acid precursors by enzymes activated within seconds after crushing of cells. Such toxins are suggested to have multiple simultaneous functions in that they not only deter herbivore feeding but some also act as allelopathic agents against other phytoplankton cells, thereby affecting the growth of competitors, and also signalling population-level cell death and termination of blooms, with possible consequences for food web structure and community composition. Some oxylipins also play a role in driving marine bacterial community diversity, with neutral, positive or negative interactions depending on the species, thereby shaping the structure of bacterial communities during diatom blooms. Several reviews have already been published on diatom-grazer interactions so this paper does not attempt to provide a comprehensive overview, but rather to consider some of the more recent findings in this field. We also consider the role of diatom oxylipins in mediating physiological and ecological processes in the plankton and the multiple simultaneous functions of these secondary metabolites.

Nitrogen recycling and nutritional provisioning byBlattabacterium, the cockroach endosymbiont

Nitrogen acquisition and assimilation is a primary concern of insects feeding on diets largely composed of plant material. Reclaiming nitrogen from waste products provides a rich reserve for this limited resource, provided that recycling mechanisms are in place. Cockroaches, unlike most terrestrial insects, excrete waste nitrogen within their fat bodies as uric acids, postulated to be a supplement when dietary nitrogen is limited. The fat bodies of most cockroaches are inhabited by Blattabacterium, which are vertically transmitted, Gram-negative bacteria that have been hypothesized to participate in uric acid degradation, nitrogen assimilation, and nutrient provisioning. We have sequenced completely the Blattabacterium genome from Periplaneta americana. Genomic analysis confirms that Blattabacterium is a member of the Flavobacteriales (Bacteroidetes), with its closest known relative being the endosymbiont Sulcia muelleri, which is found in many sap-feeding insects. Metabolic reconstruction indicates that it lacks recognizable uricolytic enzymes, but it can recycle nitrogen from urea and ammonia, which are uric acid degradation products, into glutamate, using urease and glutamate dehydrogenase. Subsequently, Blattabacterium can produce all of the essential amino acids, various vitamins, and other required compounds from a limited palette of metabolic substrates. The ancient association with Blattabacterium has allowed cockroaches to subsist successfully on nitrogen-poor diets and to exploit nitrogenous wastes, capabilities that are critical to the ecological range and global distribution of cockroach species.

Stability-Indicating Micellar Liquid Chromatographic Method for the Determination of Clopidogrel. Application to Tablets and Content Uniformity Testing

A simple, stability-indicating, reversed-phase micellar liquid chromatographic method was developed for the analysis of the antiplatelet drug clopidogrel. Clopidogrel was determined in presence of its carboxylic acid degradation product, namely; SR26334. The analysis was carried out using a 150 mm × 4.6 mm i.d., 5 µm particle size Nucleodur MN-C18 column. The Mobile phase used was a solution containing 0.15 M sodium dodecyl sulphate and 10% n-propanol and 0.3% triethylamine in 0.02 M phosphoric acid at pH = 3.0 pumped at a flow rate of 1 mL/min with UV-detection at 235 nm. The method showed good linearity in the range of 1-20 µg/mL with limit of detection (S/N = 3) 0.06 µg/mL (1.86 × 10−7 M). The suggested method was successfully applied for the analysis of clopidogrel in bulk and in commercial tablets with average recoveries of 99.67% ± 0.94%, and 100.27 ± 0.89%, respectively. The results were favorably compared to those obtained by a reference method. The proposed method was successfully applied to the content uniformity testing of tablets. The proposed method was also applied for the determination of clopidogrel in the presence of its co-administered drug, acetyl salicylic acid, with application to synthetic mixtures and prepared tablets.

Chromatographic Application on Calixarene Bonded Stationary Phases: A Stability Indicating Method for Simultaneous Determination of Paracetamol, Caffeine and Acetylsalicylic Acid in Excedrin Tablets

A simple, rapid and accurate, routine-LC method is described for simultaneous determination of paracetamol, caffeine and acetylsalicylic acid in a tablet formulation. This study represents a new application for the calixarene stationary phases. The chromatographic separation of the three pharmaceuticals was achieved on a Caltrex BIIE column (250 × 4 mm, 5 μm) using a binary mobile phase of 14% ACN and 86% 50 mM NaH2PO4 pH 3.0 at 1 mL min−1 flow rate. Detection was at 214 nm. Separation was achieved in less than 15 min. The method was validated for system efficiency, linearity, accuracy, precision, limit of detection and quantification, specificity, stability and robustness. The limits of detection were 4.88, 9.77 and 78.13 ng per 10 μL of their injected volumes, respectively. The recovery values of this method were between 94.63 and 101.85 and the reproducibility was within 3.88. The method could also be used for separation and determination of salicylic acid which is considered the most important degradation product of acetylsalicylic acid.

Formation of Pigment Precursor (+)-1′′-Methylene-6′′-hydroxy-2H-furan-5′′-one-catechin Isomers from (+)-Catechin and a Degradation Product of Ascorbic Acid in a Model Wine System

The present study investigates the contribution of ascorbic acid to the formation of pigment precursors in model white wine systems containing (+)-catechin as the oxidizable phenolic substrate. The two main colorless products in these systems were structurally characterized as isomers of (+)-catechin substituted at either C6 or C8 on the A ring with a furan-type unit, namely, (+)-1''-methylene-6''-hydroxy-2H-furan-5''-one-6-catechin and (+)-1''-methylene-6''-hydroxy-2H-furan-5''-one-8-catechin. A known degradation product of ascorbic acid, L-xylosone, was separately prepared and, when reacted with (+)-catechin, generated the same (+)-furanone-catechin isomers as in model white wine systems. Incubation of these isomers in wine-like conditions yielded yellow xanthylium cation pigments. This study has shown that undesirable spoilage reactions (yellow coloration) can occur from a breakdown product of ascorbic acid-L-xylosone.

Oxidizability of unsaturated fatty acids and of a non-phenolic lignin structure in the manganese peroxidase-dependent lipid peroxidation system

Unsaturated fatty acids have been proposed to mediate the oxidation of recalcitrant, non-phenolic lignin structures by fungal manganese peroxidases (MnP), but their precise role remains unknown. We investigated the oxidizability of three fatty acids with varying degrees of polyunsaturation (linoleic, linolenic, and arachidonic acids) by measuring conjugated dienes formation when lipid peroxidation was initiated either by MnP in the presence of Mn(II) or by chelated Mn(III). An inverse relationship between the degree of fatty acid unsaturation and the rate of peroxidation was found in both cases, but we also noted some differences between the two types of reaction. With MnP/Mn(II), the reaction developed slowly and resulted in sustained lipid peroxidation as determined by the formation of late-stage fatty acid degradation products. By contrast, the reaction with chelated Mn(III) was very rapid and did not result in the formation of these late-stage products, which suggests that this system failed to propagate the sustained radical chain reaction that is characteristic of complete lipid peroxidation. All three polyunsaturated fatty acids supported the co-oxidation of a non-phenolic lignin model compound by MnP, again showing an inverse relationship between the degree of unsaturation and reactivity, but chelated Mn(III) by itself supported only very low levels of fatty acid-mediated lignin model oxidation. These parallels in fatty acid reactivity are consistent with a reaction scheme in which Mn(III) acts as the proximal oxidant that initiates lipid peroxidation by MnP, thus generating fatty acid-derived radicals which in turn oxidize lignin structures. However, the results also suggest that the initial peroxyl radicals formed may not be the ligninolytic oxidants in this system. Instead, other radical oxidants produced during late-stage reactions of lipid peroxidation may be required.

Stability-indicating methods for the determination of sertaconazole nitrate by micelle-enhanced spectrofluorimetry and TLC-densitometry

Two sensitive and selective stability-indicating methods were developed for the determination of sertaconazole nitrate (Ser-NO3), in the presence of its acid, alkaline and oxidative degradation products. The first method was based on measuring the fluorescence intensity of the drug at λex/λem = 231 nm/312 nm. The influence of micelle medium on the fluorescence emission was studied. The nonionic surfactant of Triton® X-100 showedstrong sensitizing effect for the fluorescence. The fluorescence intensity plot was linear over concentrations 0.5–5 μg mL-1 with mean percentage recoveries 100.59 ± 1.49 %. The second method was based on TLC separation of the drug from its degradation products followed by densitometric measurement of the intact drug spot at 302 nm. The developing system used for separation was chloroform-acetone-33 % ammonia (14:2:0.1 v/v/v). The linear range was 1–8 μg/spot with mean percentage recoveries 100.07 ± 1.97 %. The methods were validated according to ICH guidelines. Statistical analysis of the results revealed high accuracy and good precision. The suggested procedures could be used for the determination of sertaconazole nitrate in drug substance and drug products as well as in presence of its degradation products.

Role of Roasting Conditions in the Profile of Volatile Flavor Chemicals Formed from Coffee Beans

The volatile chemicals in dichloromethane extracts from green coffee beans, roasted at 230 degrees C for 12 min (light), at 240 degrees C for 14 min (medium), at 250 degrees C for 17 min (city), or at 250 degrees C for 21 min (French), were analyzed by gas chromatography and gas chromatography-mass spectrometry. Among the 52 volatile compounds identified, the major compounds were 5-hydroxymethylfurfural, furfuryl alcohol, and 6-methyl-3,5-dihydroxy-4H-pyran-4-one in light-roasted beans; furfuryl alcohol, 5-hydroxymethylfurfural, and gamma-butyrolactone in medium-roasted beans; furfuryl alcohol, gamma-butyrolactone, and 2-acetylpyrrole in city-raosted beans; and gamma-butyrolactone, furfuryl alcohol, and catechol in French-roasted beans. Furfural derivatives and furanones were yielded in relatively high concentrations under mild roasting conditions and then reduced at higher roasting intensities. More pyridines and pyrroles were formed by high roasting intensities than by mild roasting intensities. Chlorogenic acid degradation products, phenols, and a lactone were produced more by high roasting intensities than by low roasting intensities. The results of the present study suggest that controlling the roasting conditions according to the formation of particular chemicals can prepare a roasted coffee with preferable flavor.