• Food Science and Biotechnology
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• v.14 no.2
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• pp.297-300
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• 2005

Effects of allyl sulfides on kinetic behavior of cytochrome P450 1 (CYP1)-catalyzed ethoxyresorufin O-deethylase (EROD) activity were studied using microsomes from benzo[a]pyrene-treated human hepatoma cells. Apparent $K_m$ and $V_{max}$ values were calculated as $2.8\;{\mu}M$ and $3.0\;{\mu}mol$ resorufin/min/mg protein based on Lineweaver-Burk plot of microsomal EROD activity, respectively. Diallyl disulfide (DADS) and diallyl trisulfide (DATS) affected $K_m$ and $V_{max}$ values of EROD activity and acted as mixed-type inhibitors for CYP1 isozymes. Apparent Ki values of DADS and DATS were calculated as 1.07 and 0.88 mM, respectively, by re-plotting slopes of Lineweaver-Burk plot and inhibitor concentrations.

• Journal of Photoscience
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• v.10 no.1
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• pp.1-7
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• 2003

The results of recent work on the dye-sensitized photooxygenation of sulfides is discussed. In the case of dialkyl sulfides, the weakly bonded adduct initially formed with singlet oxygen (the persulfoxide) decays unproductively unless protonation by an acid (an alcohol or a carboxylic acid) facilitates its conversion to the sulfoxide. The effect is proportional to the strength of the acid (eg., less than 0.1 % chloroacetic acid in benzene is sufficient for maximal efficiency) and corresponds to general acid catalysis, suggesting that protonation of the persulfoxide occurs. On the other hand, with sulfides possessing an activated hydrogen in ${\alpha}$ position (eg., benzyl and allyl sulfides), hydrogen transfer becomes an efficient process in aprotic media and yields a S-hydroperoxysulfoniumm ylide, possibly arising from a conformation of the persulfoxide that is different from the one protonated in the presence of acids. Calculations on some substituted sulfides support this hypothesis. This process, which leads to C-S bond fragmentation with formation of an aldehyde, may be viewed as a general method for the preparation of aryl and heteroaryl aldehydes. In this effort, mechanistic studies offered new hints on the structure of the intermediate persulfoxide.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.1
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• pp.16-23
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• 1998

Effect of Fermentation temperature on the changes of chemical components in Kakudgi during fermentation was investigated by measuring free sugar, organic acid and volatile compounds up to 57 days at several temperatures. The mannitol was increased in palatable period in contrast with those of other free sugars. The higher the initial fermentation temperature was and the longer the initial fermentation time at 2$0^{\circ}C$ was, the faster the second increasing period was and the less the initial contents was. Lactic acid was increased 6~31 times from a little amount at the initial period. The higher the initial fermentation temperature was and the more the increasing content was. But malic acid which was abundant(55.1% of total nonvolatile organic acid) in the initial fermentation period was remarkably decreased in the palatable period. The change of the sulfides among the volatile compounds was remarkable. Methyl allyl sulfide which was a little in the initial fermentation period was remarkably increased in the final fermentation period, and the correlation coefficients between the content of methyl allyl sulfide and aroma in sensory evaluation were high. It could be suggested that the fermentation temperature should be set to 4$^{\circ}C$ after fermentating at 2$0^{\circ}C$ for 36 hours in the view point of keeping the Kakdugi taste and quality well because of high content of free sugar and nonvolatile organic acids.

• Journal of Food Hygiene and Safety
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• v.21 no.3
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• pp.145-152
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• 2006

Efforts have been made to explore the possibility of using garlic as an antimicrobial therapeutic agent since garlic extract and its individual sulfur compounds show antimicrobial activities against all kinds of microorganisms including bacteria, molds, yeasts and protozoa. Staphylococcus aureus has been the most studied bacteria along with many other Gram positive and negative pathogenic bacteria, including species of the genera Clostridium, Mycobacterium, Escherichia, Klebsiella, Bacillus, Salmonella and Shigella. Candida albicans has been the most studied among the eukaryotic microorganisms. A pathogenic protozoa, Giardia intestinalis, was also tested. All the microorganisms tested was inhibited by garlic extract or its sulfur components. Garlic has been known to be growth inhibitory only when fresh garlic is crushed, since allicin-generating reaction is enzyme-catalyzed. Allicin is known to be growth inhibitory through a non-specific reaction with sulfhydryl groups of enzyme proteins that are crucial to the metabolism of microorganisms. Another plausible hypothesis is that allicin inhibits specific enzymes in certain biological processes, e.g. acetyl CoA synthetase in fatty acid synthesis in microorganisms. Allicin transforms into other compounds like ajoene and various sulfides which are also inhibitory to microorganisms, but not as potent as their mother compound. It is reported recently that garlic heated at cooking temperatures is growth inhibitory especially against yeasts, and that the growth inhibitory compound is allyl alcohol thermally generated from alliin in garlic.

• Journal of the Korean Society of Food Culture
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• v.25 no.3
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• pp.324-333
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• 2010

Off-flavor in foods and in raw materials is quite concerning, as it could signify deeper-rooted problems. Methods of reduction of "off-flavors" in traditional food such as Cheonggukjan and Kimchi, and in raw materials of soybean paste were studied by means of a literature review. It was found that the major components of "off-flavor" were due to butyric acid, valeric acid, alkylpyrazines, ammonia, and sulfides for Cheonggukjang, and for Kimchi were sulfur containing components such as methyl allylsulfide, dimethyl disulfide, diallyl disulfide, methyl allyl trisulfide, methyl 2-propenyldisulfide, dipropenyldisulfide. There is a demand for a scientific and systematic approach in overcoming the "off-flavor" problem. Nutritional aspects and safety should be considered. Several methods have been attempted, such as masking, binding, improving cooking process, inhibiting rancidity, and controlling the growth of micro-organism. Methods of masking were the most frequently ones used for the reduction of "off-flavor", and in some cases, othertechniques were additionally applied. The masking method would be useful in the reduction of "off-flavor" in traditional Korean foods, i.e. Cheonggukjang, Kimchi, as well as in new product development.

• Natural Product Sciences
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• v.11 no.2
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• pp.67-74
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• 2005

The ethanolic extracts of the leaves and bulbs of Allium victorialis var. platyphyllum (Liliaceae) collected from Daegwallyoung (D) and Ullung Island (U) in Korea were obtained using three different extracting methods. The first extracts, DL-1 DB-1, UL-1 and UB-1, were obtained from leaves (L) and bulbs (B) dried at $90^{\circ}C$, respectively, and the second extracts, DL-2, DB-2, UL-2 and UB-2, were obtained by extracting the leaves and bulbs of fresh plant parts. The third extracts DL-3, DB-3, UL-3 and UB-3 were obtained by incubating leaves and bulbs at $36^{\circ}C$. The six extracts obtained from A. victorialis var. platyphyllum at Daegwanllyoung (cultivated site) were orally administered to examine for a possible antihepatotoxic effect in $CCl_4-induced$ rats. DL-1 exhibited the most pronounced effect. The extracts inhibited serum ALT, AST, SDH, ${\gamma}-GT$, ALP and LDH activities elevated by $CCl_4$ injection and attenuated decreased glutathione S-transferase, glutatione reductase and ${\gamma}-glutamylcysteine$ synthetase activities and a decreased hepatic glutathione. However, the extracts obtained from Ullung Is. (native site) were less active than the extracts from Daegwallyoung, suggesting that A. victorialis var. platyphyllum from the cultivated site is more useful for functional food than of native site. These results also suggest that the antihepatotoxic effect is due to a higher content of hepatic glutathione. Gas chromatography of the twelve extracts showed significantly different sulfides, disulfides or trisulfides contents belonging to volatile sulfur substances (VSS). Nine components were identified on the basis of their mass spectra, namely, dimethyl disulfide, dimethyl trisulfide, diallyl disulfide, dipropyl disulfide, allyl methyl sulfide, allyl methyl trisulfide, 2-vinyl-4H-1,3-dithiin, 3,4-dihydro-3-vinyl-1,2-dithiin, and allithiamine. Extract DL-1 had the highest VSS content. Dried plant materials contained larger amounts of the VSSs than other extracts, and the leaves contained larger amount than the bulbs. These results suggest that heat treatment increases the antiheaptotoxic ability of A. victorialis var. platyphyllum by increasing the proportion of VSSs.

• Toxicological Research
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• v.13 no.4
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• pp.339-347
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• 1997

Disulfiram (DSF) and diethyldithiocarbamate (DDC), a reduced form of DSF, protect the liver against toxicant-induced injury through inhibition of cytochrome P450 2E1. The effect of DSF and DDC on the levels of major hepatic microsomal epoxide hydrolase (mEH) and glutathione S-transferase (GST) expression was comparatively studied, given the view that these enzymes are involved in terminal detoxification events for high energy intermediates of xenobiotics. Treatment of rats with a single dose of DSF (20-200 mg/kg, po) resulted in 2- to 15-fold increases in the mEH mRNA level at 24 hr with the ED$_{50}$ value being noted as 60 mg/kg. The mEH mRNA level was elevated ~15-fold at 24 hr after treatment at the dose of 100 mg/kg, whereas the hepatic mRNA level was rather decreased from the maximum at the dose of 200 mg/kg, indicating that DSF might cause cytotoxicity at the dose. In contrast to the effect of DSF, DDC only minimally elevated the mEH mRNA level at the doses employed. DSF moderately increased the major GST mRNA levels in the liver as a function of dose, resulting in rGSTA2, rGSTA3/5 or rGSTM1 mRNA levels being elevated 3- to 4-fold at 24 hr post-treatment, whereas the rGSTM2 mRNA level was not altered. DDC, however, failed to stimulate the mRNA levels for major GST subunits, indicating that the reduced form of DSF was ineffective in stimulating the GST the expression. The effect of other organosulfides including aldrithiol, 2, 2'-dithiobis(benzothiazole) (DTB), tetramethylthiouram disulfide (TMTD) and allyl disulfide (ADS) on the hepatic mEH and GST mRNA expression was assessed in rats in order to further confirm the increase in the gene expression by other disulfides. Treatment of rats with aldrithiol (100 mg/kg, po) resulted in a 16-fold increase in the mEH mRNA level at 24 hr post-treatment. DTB, TMTD and ADS also caused 5-, 9- and 12-fold increases in the rnRNA level, respectively, as compared to control. Thus, all of the disulfides examined were active in stimulating the mEH gene in the liver. The organosulfides significantly increased the rGSTA2, rGSTA3, rGSTA5 and rGSTM1 mRNA levels at 24 hr after administration. In particular, aldrithiol was very efficient in stimulating the rGSTA and rGSTM genes among the disulfides examined. These results provide evidence that DSF and other sulfides effectively stimulate the mEH and major GST gene expression at early times in the liver and that DDC, a reduced form of DSF, was ineffective in stimulating the expression of the genes, supporting the conclusion that reduced form(s) of organosulfur compound(s) might be less effective in inducing the mEH and GST genes through the antioxidant responsive element(s).

• Applied Biological Chemistry
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• v.44 no.1
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• pp.12-19
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• 2001

The major volatiles from Allium species were found to be sulfide compounds and the ratio of sulfide to volatiles was 66.1% in garlic, 66.1% in scallion, 62.3% in green onion, 39.2% in onion, and 4.2% in chive. Trace of cyclooctasulfur was found to be present among the volatiles. The most oviposition of 17.2% occurred at diallyl sulfide and the least of 0.8% at acetylthiophene whereas the most oviposition of 43.3% occurred at ethyl alcohol if concentration was 100%. Among the organic solvents used for dilution, ethyl alcohol received the highest 52.5% of oviposition and ether the lowest of 5.9%. Furfuryl mercaptan which is also one of the volatiles, received 46.9% of oviposition. For oviposition site, D. antiqua preferred sulfides at near 1%, ethyl alcohol at high, and other volatiles at various concentrations. At 100% concentration, most volatiles except dimethyl disulfide and ethyl alcohol received less oviposition than the control which was watered sand with no volatiles added.