• Food Science and Biotechnology
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• 제17권5호
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• pp.1032-1037
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• 2008

Lowly volatile heterocyclic sulfur compounds generated in autoclaved garlic extract were isolated and identified, and their antimicrobial activity was determined. Two kinds of unusual volatile sulfur compounds were separated from heated garlic by preparative recycling high performance liquid chromatography (HPLC), and identified by gas chromatography (GC)-mass spectrometry (MS) and $^1H$-nuclear magnetic resonance (NMR). They had heterocyclic structures with 4 to 5 sulfur atoms in the molecules. 4-Methyl-1,2,3-trithiolane (MTTT) is highly volatile and was not able to be concentrated, and was identified by GCMS only. MTTT and 6-methyl-1,2,3,4,5-pentathiepane (MPTP) are lowly volatile and were obtained in pure states to be positively identified for the first time. All 3 heterocyclic sulfur compounds began to appear by the time when the early-formed diallyl sulfides started to disappear. The minimum inhibitory concentration range of MTTT and MPTP was determined to be between 1 and 6 ppm against all yeasts tested. MTTT and MPTP were lowly volatile and sparingly soluble in water.

• Tribology and Lubricants
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• 제16권5호
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• pp.332-340
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• 2000

The reduction of sulfur content in the diesel fuel has caused the poor lubricity of diesel fuel in the distributor type injection pumps of diesel engines that use the diesel for lubrication of their moving parts. To investigate the reason for poor lubricity of low sulfur diesel fuels, the wear scar diameters by HFRR (High Frequency Reciprocating Rig) were measured on the diesel fuels from Korean markets and the results were compared with their physical and chemical properties. Also, the lubricity change and the improvement effects on lubricity additives for the ultra low sulfur diesel fuel, were made experimentally, that will be regulated to a maximum of 0.005 wt% from about 2005 were evaluated. As a result, a good correlation was found between the wear scar diameter and the polyaromatic compound which includes heterocyclic compound in the diesel fuel. It was also found that the content of polyaromatic compound including heterocyclic compound was affected by the amount of desulfurization treatment fraction. And the lubricity additives with ester base were more effective than that with acid base on the ultra low sulfur diesel fuel. Therefore, it is suggested that the factors affecting the lubricity stated above should be taken into account to improve the lubricity property of the diesel fuel in the refining process.

• Food Science and Biotechnology
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• 제18권3호
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• pp.771-775
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• 2009

Antimicrobial activity of garlic (pH 6.0) heated at $120^{\circ}C$ reached its maximum at 45 min of heating and maintained the level for the rest of heating time (300 min) when tested against Candida utilis ATCC42416. The principal antimicrobial compound was allyl alcohol (AA), a highly volatile compound without sulfur in its molecule. The concentration of AA in heated garlic gradually increased to over 2,000 ppm for the first 90 min and stayed at the level without appreciable changes in spite of further heating. Other antimicrobial compounds secondary to AA were lowly volatile sulfur compounds including diallyl polysulfides (diallyl trisulfide, diallyl tetrasulfide, and diallyl pentasulfide) and heterocyclic sulfur compounds (4-methyl-1,2,3-trithiolane, 5-methyl-1,2,3,4-tetrathiane, and 6-methyl-1,2,3,4,5-pentathiepane). When the pH of the garlic extract was lowered before heating, considerably more secondary antimicrobial sulfur compounds were formed and the antimicrobial activity was stronger than the pH unadjusted garlic. Lowly volatile sulfur compounds contributed a significant part of antimicrobial activity of heated garlic only during the early period (45-120 min) of heating regardless of pH treatment.

• Bulletin of the Korean Chemical Society
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• 제18권5호
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• pp.484-488
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• 1997

The angular and planar heterocyclic compounds containing nitrogen, sulfur and oxygen were synthesized by reaction of 6,7-dichloro-5,8-quinoxalinedione with aromatic and aliphatic dinucleophiles. Nucleophilic reactivity was somewhat different between 2,3-dichloro-1,4-naphthoquinone and 6,7-dichloro-5,8-quinolinedione with dinucleophiles. The distribution of electron in heterocycle appeared to contribute to this difference. The intercalation comple of planar heterocyclic compound between GC/GC base pairs showed the optimum intercalation but the intercalation of angular heterocyclic compound was not good. Thus, the planar compound was expected to have antitumor activity.

• 한국식품영양과학회지
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• 제30권6호
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• pp.1033-1037
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• 2001

마늘의 이용성 증진에 관한 기초자료와 제품의 품질 향상에 기여하고자 마늘 oleoresin 제조과정 중의 휘발성 향기성분의 변화를 알기 위해 휘발성 향기성분을 4가지 용매로 추출하여 농축한 후, 가스크로마토그래피와 질량 분석 검출기 (mass selective detector)를 이용하여 polar(Supelcowax-$10^{TM}$)와 nonpolar capillary column(HP-5)에서 각각 분리, 동정하였다. 용매에 따른 oreoresin 추출을 보면 methanol을 사용하여 추출한 경우가 가장 peak area가 높았고 그외 acetone, methy acetate, hexane을 사용한 경우는 비슷하였다 Polar capillary column에서 총 41종이 분류되었고, pyran 및 그 유도체 물질 13종, 황화합물이 11여종, furan 및 그 유도체들이 6종, alcohol류 2종 분류되었고 그밖에도 2종의 heterocyclic compound가 각각 확인되었다. Nonpolar capillary column에서는 32종의 향기성분이 동정되었고, pyran및 그 유도체물질이 11종, 황화합물 11여 종, acid류 5종, pyran 및 그 유도체들이 3종 그밖에 eugenol 등이 나타났다. Nonpolar 보다 polar에서 휘발성성분의 다량 검출되었으며, 대부분의 휘발성 향기성분이 극성이 강한 methanol에서 잘 추출되었지만 마늘의 주요휘발성 성분인 황화합물 즉, 3,3'-thiobis 1-propene, methyl 2-propenyl disulfide, dimethyl trisulfide, di-2-propenyl -trisulfide, 2-thiophenecarboxylic acid는 비극성용매인 methyl acetate와 hexane에서 잘 추출되었다.

• Food Science and Biotechnology
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• 제18권1호
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• pp.66-72
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• 2009

An aqueous ribose-cysteine model system (initial pH 5.6) was conventionally heated to the same browning at varying temperatures ($120-180^{\circ}C$), supercritical carbon dioxide (SC-$CO_2$, 20 MPa) was also applied on the same matrices for same periods at each temperature and about 20% reduction of the absorbance at 420 nm was observed as compared with sole thermal treatment. The headspace volatiles from Maillard reaction mixtures were analyzed by solid-phase microextraction (SPME) in combination with gas chromatography and mass spectrometry (GC-MS), and predominated with sulfur containing compounds, such as thienothiophenes, polysulfur alicyclics, thiols, and disulfides. Reaction temperature exhibited complex effects on volatiles formation and those effects became further complicated by the SC-$CO_2$ treatment. The formation of noncarbonyl polysulfur heterocyclic compounds and thienothiophenes was generally favored at high temperatures. Most volatiles were inhibited in SC-$CO_2$ as compared with thermal treatment alone, however, the well-known meaty aromatic compounds, such as thiols and disulfides, were obviously enhanced.

• 문화기술의 융합
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• 제9권4호
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• pp.503-508
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• 2023

트립탄 유도체는 급성 편두통을 치료하는 물질로 크로마토그래피, 전기화학, 분광학 및 모세관 전기영동학 등의 분석법과 관련된 연구가 많이 진행되었다. 최근 분석화학자들의 약물 분석과 생물학적 중요성에 대한 근본적인 문제 해결에 더욱 관심이 깊어지고 있다. 따라서 본 연구에서는 트립탄 유도체의 분자단위 수준의 구조적 특성을 알아보기 위하여 HyperChem8.0의 반경험적 PM3 방법을 이용하여 수마트립탄, 리자트립탄, 나라트립탄 그리고 엘레트립탄의 전체에너지, 밴드갭, 정전포텐셜, 전하량을 계산하여 각 유도체의 분자 구조적 변화에 따른 화학적 특성을 조사하였다. 본 연구의 결과 수마트립탄, 나라트립탄 그리고 엘레트립탄의 경우 황 원자에 결합된 산소와 질소 원자를 중심으로 화학작용이 진행될 것으로 예상된다. 또한, 황원자가 없는 리자트립탄의 경우는 5원헤테로 고리화합물의 17, 19번 질소에서 화학작용이 진행될 것으로 나타났다.