CAJ | 학술논문

运用基质辅助激光解析电离_飞行时间串联质谱( MALDI_TOF/TOF MS)和电喷雾_四级杆_飞行时间质谱(ESI_Q_TOF MS)快速确证环脂肽达托霉素的结构。首先,ESI检测达托霉素相对分子量为1619.7107,与理论值偏差0.0007。选择其双电荷峰m/z 809.848作为母离子进行ESI串联质谱(MS/MS)测定,成功匹配了达托霉素环外氨基酸序列 C9 H19 CO_Trp_Asn_Asp。其次,优化 LiOH 裂解达托霉素的实验条件,以 MALDI_TOF/TOF MS监测开环效果,获得95%以上的开环样本后,分别运用MALDI和ESI进行MS/MS测定,达托霉素开环产物的b+和y+全部被匹配,达托霉素全部氨基酸序列得到确证。最后,对开环产物的ESI_MS/MS条件进一步优化,获得了丰富的低端碎片离子,解析了脂肪酸链结构,并绘制了脂肪酸链的裂解图。本方法快速、简便、准确,是确证环脂肽类化合物结构的可靠方法。
운용기질보조격광해석전리_비행시간천련질보( MALDI_TOF/TOF MS)화전분무_사급간_비행시간질보(ESI_Q_TOF MS)쾌속학증배지태체탁매소적결구。수선,ESI검측체탁매소상대분자량위1619.7107,여이론치편차0.0007。선택기쌍전하봉m/z 809.848작위모리자진행ESI천련질보(MS/MS)측정,성공필배료체탁매소배외안기산서렬 C9 H19 CO_Trp_Asn_Asp。기차,우화 LiOH 렬해체탁매소적실험조건,이 MALDI_TOF/TOF MS감측개배효과,획득95%이상적개배양본후,분별운용MALDI화ESI진행MS/MS측정,체탁매소개배산물적b+화y+전부피필배,체탁매소전부안기산서렬득도학증。최후,대개배산물적ESI_MS/MS조건진일보우화,획득료봉부적저단쇄편리자,해석료지방산련결구,병회제료지방산련적렬해도。본방법쾌속、간편、준학,시학증배지태류화합물결구적가고방법。
Matrix_assisted laser desorption ionization_time of flight tandem mass spectrometry ( MALDI_TOF/TOF MS) and electrospray ionization_quadrupole_time of flight mass spectrometry ( ESI_Q_TOF MS) were used to confirm the structure of cyclic lipopeptide daptomycin fastly. First, the relative molecular weight 1916. 7107 of daptomycin was measured by ESI with error 0. 0007. The sample’s doubly charged peak m/z 809. 848 was selected as precursor ion for ESI_MS/MS analysis, and the exocyclic amino acid sequence C9 H19 CO_Trp_Asn_Asp was successfully matched. Second, the experimental conditions of cleaving daptomycin by lithium hydroxide ( LiOH) were optimized and the ring_opened process was monitored by MALDI_TOF/TOF MS. After obtaining ring_opened product with purity of above 95%, the MS/MS measurements by MALDI and ESI were carried out. The b+and y+of ring_opened product were completely matched, which confirmed the amino acid sequence of daptomycin. Finally, ESI_MS/MS conditions of ring_opened product were further optimized to obtain more low mass fragment ions for analyzing the structure of fatty acid chain and the cleavage pattern of fat chain in mass spectrometry was proposed. The method was fast, convenient, accurate and reliable for identifying cyclic lipopeptide compounds.