Analysis and Comparison of Cerebroside Components from Soybean Fermented Foods

Cerebroside fatty acids, sugars and long-chain sphingoid bases in raw soybean and soybean fermented foods (chongkukjang and deunjang) were analyzed using gas chromatography-mass spectrometry (GC-MS) and high-pH anion exchange chromatography with pulsed amerometric detection (HPAEC-PAD). Fatty acids of acid-hydrolyzed cerebrosides were derivatized to O-TMS methylester and analysed. The major fatty acids in raw soybean and chongkukjang cerebrosides were identified as 2-hydroxyhexadecanoic acid (16 : 0h), 2-hydroxydocosanoic acid (22 : 0h) and 2-hydroxytetracosanoic acid (24 : 0h). In the case of deunjang cerebroside, 24 : 0h (40.9%) and 22 : 0h (23.4%) were major fatty acids, but 16 : 0h, 23 : 0h, 25 : 0h and 26 : 0h were also detected. Long-chain sphingoid bases of acid-hydrolyzed cerebrosides from raw soybean, chongkukjang and deunjang consisted primarily of 4-tracts, 8-tracts-sphingadienine (dihydroxy base, d18 : 2$\Delta$$^{4trans, 8trans}$) and sis-tracts isomers of 4-hydroxy-sphingenine (trihydroxy base, tl8:1$\Delta$$^{4trans or cis}$) with much less amounts of phytosphingosine (tl8: 0) and isomers of sphingenine (d18 : 1). Although deunjang is a soybean food fermented by fungi and microorganisms for a long period, 2-hydroxyoctadec-3-enoic acid (18 : 1h) and branched 9-methyl-4,8-sphingadienine known as compositional cerebroside fatty acids in Aspergillus species were not detected. Mass spectrum for sugar derivatives in cerebrosides of soybean foods including raw soybean and fermented soybean showed that C-1 of glucose moiety was linked to ceramide backbone as like a monoglucosylceramide.

대두발효식품 Cerebroside의 구성성분 분석 및 비교

대두 및 대두발효식품인 청국장과 된장의 cerebroside 구성성분인 지방산, 당 및 장쇄 sphingoid base들을 GC-MS로 분석하였다. Cerebroside 산-가수분해물의 지방산들을 O-TMS methylester 유도체로 만들어 분석하였으며 대두 및 청국장의 경우 2-hydroxyhexadecanoic acid(16 : 0h)가 각각 52.2% 및 62.0%로 가장 많았고 2-hydroxydocosanoic acid(22 : 0h) 및 2-hydroxytetracosanoic acid(24 : 0h)도 15.0~17.6%이었다. 그러나 된장의 경우 16 : 0h는 10.2%로 많은 감소를 보인 반면 24 : 0h는 40.9%, 22 : 0h는 23.4% 었으며 23 : 0h, 25 : 0h 및 26 : 0h도 대두 및 청국장에 비하여 많았다. Cerebroside 산-가수분해물의 장쇄 sphingoid base들은 N-acetyl-O-TMS 유도체로 분석하였으며 대두 및 청국장에서 4- trans, 8-trans-sphingadienine (d18 : 2 $\Delta$$^{4trans, 8trans}$) 는 59.9% 및 44.5%이었으며 4-hydroxy-8-trans, cis-sphingening (t18 : 1$\Delta$$^{8trans or cis}$)는 20.9% 및 35.9% 이었고 된장 cerebroside 역시 dl8 : 2$\Delta$$^{4trans, 8trans}$가 가장 많았다. 그러나 phytosphingosine(t18 : 0) 및 sphingosine 이 성질체(d18 : 1)들은 거의 보이지 않았다. 또한 된장의 경우 오랜 기간 미생물들에 의하여 발효되었지만 Aspergillus 속들의 cerebroside가 가지는 것으로 알려진 2-hydroxyoxtadec-3-enoic acid(18 : 1h) 및 9-methyl-4,8-sphingadienine 등은 발견되지 않았다. 대두, 청국장 및 된장 cerebroside의 당유도체 mass spectrum 분석 결과 99%이상이 glucose 1번 탄소가 ceramide backbone에 결합된 monoglucocerebroside 인 것으로 나타났다.