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Natural Product Research: Formerly Natural Product Letters Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/gnpl20
Identification and quantitative analysis of polyphenolic compounds from the indigo plant (Polygonum tinctorium Lour) a
a
a
Hideto Kimura , Tomoe Ishihara , Mahoko Michida , Satoshi a
b
Ogawa , Takashi Akihiro & Kazushige Yokota
cd
a
Department of Research and Development, Kotobuki Seika Co. Ltd., 2028 Hatagasaki, Yonago, Tottori 683-0845, Japan b
Department of Biological Science, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsucho, Matsue, Shimane 690-8504, Japan c
Department of Life Science and Biotechnology, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu-cho, Matsue, Shimane 690-8504, Japan d
The United Graduate School of Agricultural Sciences, Tottori University, 4-101 Koyama-Minami, Tottori-Shi, Tottori 680-8553, Japan Published online: 17 Jan 2014.
To cite this article: Hideto Kimura, Tomoe Ishihara, Mahoko Michida, Satoshi Ogawa, Takashi Akihiro & Kazushige Yokota (2014) Identification and quantitative analysis of polyphenolic compounds from the indigo plant (Polygonum tinctorium Lour), Natural Product Research: Formerly Natural Product Letters, 28:7, 492-495, DOI: 10.1080/14786419.2013.871719 To link to this article: http://dx.doi.org/10.1080/14786419.2013.871719
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content
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This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/termsand-conditions
Natural Product Research, 2014 Vol. 28, No. 7, 492–495, http://dx.doi.org/10.1080/14786419.2013.871719
SHORT COMMUNICATION Identification and quantitative analysis of polyphenolic compounds from the indigo plant (Polygonum tinctorium Lour) Hideto Kimuraa, Tomoe Ishiharaa, Mahoko Michidaa, Satoshi Ogawaa, Takashi Akihirob and Kazushige Yokotac,d*
Downloaded by [Umeå University Library] at 12:50 22 April 2014
a
Department of Research and Development, Kotobuki Seika Co. Ltd., 2028 Hatagasaki, Yonago, Tottori 683-0845, Japan; bDepartment of Biological Science, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu-cho, Matsue, Shimane 690-8504, Japan; cDepartment of Life Science and Biotechnology, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu-cho, Matsue, Shimane 690-8504, Japan; dThe United Graduate School of Agricultural Sciences, Tottori University, 4-101 Koyama-Minami, Tottori-Shi, Tottori 680-8553, Japan (Received 27 August 2013; final version received 1 December 2013) The indigo plant (Polygonum tinctorium Lour) has been used traditionally as a medicinal plant with a variety of biological effects. Of these, polyphenolic ingredients are postulated to contribute to these activities. However, the identification and quantification of polyphenolic compounds in indigo plants have not been conducted comprehensively until now. This study was undertaken to identify the related ingredients by combined instrumental analyses using ultra-performance liquid chromatography electrosprayionisation mass spectrometry and gas chromatography-mass spectrometry after the extracts of plant tissues were fractionated by absorption column chromatography. These analyses allowed the identification of kaempferol, quercetin-3-O-glucuronide, quercetin, kaempferol-3-O-glucopyranoside, caffeic acid, chlorogenic acid and tentative 3,5,40 trihydroxy-6,7-methylenedioxyflavone. Furthermore, predominant polyphenolic compounds were quantified by reverse-phase high-performance liquid chromatography and capillary gas chromatography, revealing the higher proportions of kaempferol, quercetin-3O-glucuronide and quercetin among them. The results indicate that the indigo plant is a promising source for flavonoids and the related compounds with beneficial medicinal effects. Keywords: indigo plant; Polygonum tinctorium Lour; polyphenol; flavonoid; kaempferol; quercetin-3-O-glucuronide
1. Introduction Indigo plant (Polygonum tinctorium Lour) is an annual herb, a species of the buckwheat family that was found originally in Southeast Asia. Its leaves were an important source of the colour indigo blue in East Asia inherited from ancient times. In addition, indigo plant has been utilised as a medicinal plant with a variety of biological activities, such as detoxifying, antipyretic, antiinflammatory, anti-cancer, anti-allergy and anti-bacterial effects (Hashimoto et al. 1999; KoyaMiyata et al. 2001; Iwaki & Kurimoto 2002). Moreover, the indigo plant is known to contain several types of antioxidant polyphenolic compounds, such as gallic acid, caffeic acid and kaempferol (Hashimoto et al. 1999; Kimoto et al. 1999; Iwaki & Kurimoto 2002; Micallef et al. 2002). However, no quantitative analysis has been done extensively regarding those polyphenolic ingredients until now. Moreover, previous studies have mostly reported the
*Corresponding author. Email: [email protected] q 2014 Taylor & Francis
Natural Product Research
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Downloaded by [Umeå University Library] at 12:50 22 April 2014
analysis of polyphenolic compounds after extraction of them with ethyl acetate (Koya-Miyata et al. 2001; Iwaki & Kurimoto 2002; Micallef et al. 2002), which is considered to be insufficient for extracting more polar phenolic components. Hence, this study was undertaken to identify and quantify antioxidant ingredients in leaves and stems of indigo plant after the extraction of total polyphenols with methanol. For the identification of individual compounds, we carried out instrumental analyses of the isolated polyphenols by means of ultra-performance liquid chromatography-electrospray-ionisation mass spectrometry (UPLC-ESI/MS) and gas chromatography-mass spectrometry (GC-MS). As well, the predominant polyphenolic ingredients were quantified by a combination of high-performance liquid chromatography (HPLC) and capillary GC. Based on the results, we discuss the usefulness of polyphenolic components in indigo plant. 2. Results and discussion 2.1. Identification of polyphenolic compounds by UPLC-ESI/MS and GC-MS The extracts of total polyphenolic compounds with methanol were then fractionated by column chromatography on Diaion HP-20 into two fractions of the stepwise elution with 50% methanol and 100% methanol. The resulting individual fractions were subjected to the analysis by UPLCESI/MS using reverse-phase C18 column in the negative-ion mode. The analysis enabled us to identify three peaks of 1– 3 in the fraction of 50% methanol and four peaks of 4– 7 in the fraction of 100% methanol (Figures S1 and S2). The retention time and MS data of the identified peaks are shown in Table 1. Based on the data, the peaks of 1 and 2 were identified as chlorogenic acid and caffeic acid, respectively. The analytical data of peak 3 led us to confirm quercetin-3-Oglucuronide by the comparison with the standard compound (Figure S3). The peak 4 in the 100% methanol fraction was considered as kaempferol-3-Oglucopyranoside because of the data on the molecular ion and the fragment ion of the aglycon moiety corresponding to [M-glucose]2. A previous study has reported the identification of kaempferol-3-O-b-D -glucopyranoside in indigo plant (Iwaki & Kurimoto 2002). The peak 5 was found to co-elute with authentic quercetin at 6.0 min, but overlapped an unidentified compound. Therefore, the 100% methanol fraction was furthermore subjected to trimethylsilyl (TMS) derivatisation and subsequent analysis by GC-MS (Figure S4). The resulting analysis enabled us to separate clearly the mixture to give a single GC peak corresponding to quercetin. The MS data of this GC confirmed the peak as quercetin. The peak 6 detected by UPLC-ESI/MS was Table 1. UPLC-ESI/MS analysis of the fractions of 50% methanol and 100% methanol separated by column chromatography on Diaion HP-20. Fraction 50% methanol
100% methanol
Retention time (min)
Polyphenolic compound
2.3
Chlorogenic acid (1)
2.7
Caffeic acid (2)
4.8
Quercetin-3-O-glucuronide (3)
4.5
Kaempferol-3-O-glucopyranoside (4)
6.0 7.0 9.1
Quercetin (5) Kaempferol (6) 3,5,40 -Trihydroxy-6,7methylenedioxyflavone (tentative) (7)
m/z 353.1 [M-H]2, 179.0 [M-quinic acid]2 179.3 [M-H]2, 135.0 [M-CHCOOH]2 477.1 [M-H]2, 301.0 [M-glucuronic acid]2 447.1 [M-H]2, 285.0 [M-glucose]2 301.0 [M-H]2 285.0 [M-H]2 313.0 [M-H]2
Downloaded by [Umeå University Library] at 12:50 22 April 2014
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H. Kimura et al.
Figure 1. Quantification of polyphenolic ingredients. The contents of individual polyphenolic constituents were quantified by reverse-phase HPLC and capillary GC. The values are represented as the amount of individual polyphenolic compounds (mg/fresh weight). Data represent the mean ^ SEM of triplicate experiments.
identified as kaempferol. Moreover, the presence of kaempferol was also revealed by the GCMS analysis. The UPLC-ESI/MS analysis made us to assume that the peak 7 is 3,5,40 -trihydroxy6,7-methylenedioxyflavone as described earlier (Iwaki & Kurimoto 2002). 2.2. Quantification of polyphenolic ingredients by reverse-phase HPLC and GC The amount of each compound in indigo plant was quantified by reverse-phase HPLC using the C18 column while monitoring the eluents at the absorbance of 320 nm. According to this procedure, we were able to determine the levels of cholorogenic acid, caffeic acid, quercetin-3-O-glucuronide and kaempferol by generating the straight regression line between peak areas and injected amounts using the respective authentic compound (Table S1). For the quantification of quercetin and kaempferol, GC analysis was also carried out after the preparation of the TMS derivatives of them from the fraction of 100% methanol. The determination gave satisfactory straight regression lines between their peak areas and the injected amounts (Table S2). The quantification of individual ingredients revealed higher contents of them in the order of kaempferol, quercetin-3-O-glucuronide, quercetin, chlorogenic acid and caffeic acid (Figure 1). Thus, flavonoids and the derivatives were found to be abundant polyphenolic ingredients in indigo plant. Recent studies have suggested that kaempferol is a useful biofactor that exerts multiple effects, such as anti-cancer, antioxidant, anti-inflammatory, anti-bacterial and anti-osteoporosis activities (Calderon-Montan˜o et al. 2011). As well, quercetin-3-O-glucuronide has been shown to exhibit anti-inflammatory and anti-virus effects (Fan et al. 2011). Our study here showed that kaempferol was the most abundant polyphenolic ingredient and followed by higher content of quercetin-3-O-glucuronide among the analytes. Taken together, these results indicate that indigo plant is a promising source of these polyphenolic compounds for beneficial effects. 3. Conclusion We have successfully conducted the identification and quantitation of several species of polyphenolic compounds from indigo plant using the combined instrumental analyses with chromatography and mass spectrometry. The quantification of individual ingredients identified in the ground tissues from indigo plant revealed higher contents of them in the order of
Natural Product Research
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kaempferol, quercetin-3-O-glucuronide, quercetin, chlorogenic acid and caffeic acid. These findings indicate that the indigo plant is a useful source for flavonoids and the derivatives which serve as medicinal factors. Supplementary material Experimental details relating to this article are available online, alongside Tables S1 and S2 and Figures S1 –S4.
Downloaded by [Umeå University Library] at 12:50 22 April 2014
References Calderon-Montan˜o JM, Burgos-Moron E, Perez-Guerrero C, Lopez-Lazaro M. 2011. A review on the dietary flavonoid kaempferol. Mini-Rev Med Chem. 11:298– 344. Fan D, Zhou X, Zhao C, Chen H, Zhao Y, Gong X. 2011. Anti-inflammatory, antiviral and quantitative study of quercetin-3-O-D -glucuronide in Polygonum perfoliatum L. Fitoterapia. 82:805–810. Hashimoto T, Aga H, Chaen H, Fukuda S, Kurimoto M. 1999. Isolation and identification of anti-helicobacter pyrori compounds from Polygonum tinctorium Lour. Nat Med. 53:27–31. Iwaki K, Kurimoto M. 2002. Cancer preventive effects of the indigo plant Polygonum tinctorium. Recent Res Develop Cancer. 4:429– 437. Kimoto T, Koya S, Hino K, Yamamoto Y, Aga H, Hashimoto T, Masaki N, Hanaya T, Micallef MJ, Iwaki K, et al. 1999. Protection by indigo plant (Polygonum tinctorium Lour.) against renal oxidative damage in mice treated with ferric nitrilotriacetate. Nat Med. 53:291–296. Koya-Miyata S, Kimoto T, Micallef MJ, Hino K, Taniguchi M, Ushio S, Iwaki K, Ikeda M, Kurimoto M. 2001. Prevention of azoxymethane-induced intestinal tumors by a crude ethyl acetate-extract and tryptanthrin extracted from Polygonum tinctorium Lour. Anticancer Res. 21:3295–3300. Micallef MJ, Iwaki K, Ishihara T, Ushio S, Aga M, Kunikata T, Koya-Miyata S, Kimoto T, Ikeda M, Hino K, Kurimoto M. 2002. The natural plant product tryptanthrin ameliorates dextran sodium sulfate-induced colitis in mice. Int Immunopharmacol. 2:565–578.
Natural Product Research: Formerly Natural Product Letters Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/gnpl20
Identification and quantitative analysis of polyphenolic compounds from the indigo plant (Polygonum tinctorium Lour) a
a
a
Hideto Kimura , Tomoe Ishihara , Mahoko Michida , Satoshi a
b
Ogawa , Takashi Akihiro & Kazushige Yokota
cd
a
Department of Research and Development, Kotobuki Seika Co. Ltd., 2028 Hatagasaki, Yonago, Tottori 683-0845, Japan b
Department of Biological Science, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsucho, Matsue, Shimane 690-8504, Japan c
Department of Life Science and Biotechnology, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu-cho, Matsue, Shimane 690-8504, Japan d
The United Graduate School of Agricultural Sciences, Tottori University, 4-101 Koyama-Minami, Tottori-Shi, Tottori 680-8553, Japan Published online: 17 Jan 2014.
To cite this article: Hideto Kimura, Tomoe Ishihara, Mahoko Michida, Satoshi Ogawa, Takashi Akihiro & Kazushige Yokota (2014) Identification and quantitative analysis of polyphenolic compounds from the indigo plant (Polygonum tinctorium Lour), Natural Product Research: Formerly Natural Product Letters, 28:7, 492-495, DOI: 10.1080/14786419.2013.871719 To link to this article: http://dx.doi.org/10.1080/14786419.2013.871719
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content
should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content.
Downloaded by [Umeå University Library] at 12:50 22 April 2014
This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/termsand-conditions
Natural Product Research, 2014 Vol. 28, No. 7, 492–495, http://dx.doi.org/10.1080/14786419.2013.871719
SHORT COMMUNICATION Identification and quantitative analysis of polyphenolic compounds from the indigo plant (Polygonum tinctorium Lour) Hideto Kimuraa, Tomoe Ishiharaa, Mahoko Michidaa, Satoshi Ogawaa, Takashi Akihirob and Kazushige Yokotac,d*
Downloaded by [Umeå University Library] at 12:50 22 April 2014
a
Department of Research and Development, Kotobuki Seika Co. Ltd., 2028 Hatagasaki, Yonago, Tottori 683-0845, Japan; bDepartment of Biological Science, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu-cho, Matsue, Shimane 690-8504, Japan; cDepartment of Life Science and Biotechnology, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu-cho, Matsue, Shimane 690-8504, Japan; dThe United Graduate School of Agricultural Sciences, Tottori University, 4-101 Koyama-Minami, Tottori-Shi, Tottori 680-8553, Japan (Received 27 August 2013; final version received 1 December 2013) The indigo plant (Polygonum tinctorium Lour) has been used traditionally as a medicinal plant with a variety of biological effects. Of these, polyphenolic ingredients are postulated to contribute to these activities. However, the identification and quantification of polyphenolic compounds in indigo plants have not been conducted comprehensively until now. This study was undertaken to identify the related ingredients by combined instrumental analyses using ultra-performance liquid chromatography electrosprayionisation mass spectrometry and gas chromatography-mass spectrometry after the extracts of plant tissues were fractionated by absorption column chromatography. These analyses allowed the identification of kaempferol, quercetin-3-O-glucuronide, quercetin, kaempferol-3-O-glucopyranoside, caffeic acid, chlorogenic acid and tentative 3,5,40 trihydroxy-6,7-methylenedioxyflavone. Furthermore, predominant polyphenolic compounds were quantified by reverse-phase high-performance liquid chromatography and capillary gas chromatography, revealing the higher proportions of kaempferol, quercetin-3O-glucuronide and quercetin among them. The results indicate that the indigo plant is a promising source for flavonoids and the related compounds with beneficial medicinal effects. Keywords: indigo plant; Polygonum tinctorium Lour; polyphenol; flavonoid; kaempferol; quercetin-3-O-glucuronide
1. Introduction Indigo plant (Polygonum tinctorium Lour) is an annual herb, a species of the buckwheat family that was found originally in Southeast Asia. Its leaves were an important source of the colour indigo blue in East Asia inherited from ancient times. In addition, indigo plant has been utilised as a medicinal plant with a variety of biological activities, such as detoxifying, antipyretic, antiinflammatory, anti-cancer, anti-allergy and anti-bacterial effects (Hashimoto et al. 1999; KoyaMiyata et al. 2001; Iwaki & Kurimoto 2002). Moreover, the indigo plant is known to contain several types of antioxidant polyphenolic compounds, such as gallic acid, caffeic acid and kaempferol (Hashimoto et al. 1999; Kimoto et al. 1999; Iwaki & Kurimoto 2002; Micallef et al. 2002). However, no quantitative analysis has been done extensively regarding those polyphenolic ingredients until now. Moreover, previous studies have mostly reported the
*Corresponding author. Email: [email protected] q 2014 Taylor & Francis
Natural Product Research
493
Downloaded by [Umeå University Library] at 12:50 22 April 2014
analysis of polyphenolic compounds after extraction of them with ethyl acetate (Koya-Miyata et al. 2001; Iwaki & Kurimoto 2002; Micallef et al. 2002), which is considered to be insufficient for extracting more polar phenolic components. Hence, this study was undertaken to identify and quantify antioxidant ingredients in leaves and stems of indigo plant after the extraction of total polyphenols with methanol. For the identification of individual compounds, we carried out instrumental analyses of the isolated polyphenols by means of ultra-performance liquid chromatography-electrospray-ionisation mass spectrometry (UPLC-ESI/MS) and gas chromatography-mass spectrometry (GC-MS). As well, the predominant polyphenolic ingredients were quantified by a combination of high-performance liquid chromatography (HPLC) and capillary GC. Based on the results, we discuss the usefulness of polyphenolic components in indigo plant. 2. Results and discussion 2.1. Identification of polyphenolic compounds by UPLC-ESI/MS and GC-MS The extracts of total polyphenolic compounds with methanol were then fractionated by column chromatography on Diaion HP-20 into two fractions of the stepwise elution with 50% methanol and 100% methanol. The resulting individual fractions were subjected to the analysis by UPLCESI/MS using reverse-phase C18 column in the negative-ion mode. The analysis enabled us to identify three peaks of 1– 3 in the fraction of 50% methanol and four peaks of 4– 7 in the fraction of 100% methanol (Figures S1 and S2). The retention time and MS data of the identified peaks are shown in Table 1. Based on the data, the peaks of 1 and 2 were identified as chlorogenic acid and caffeic acid, respectively. The analytical data of peak 3 led us to confirm quercetin-3-Oglucuronide by the comparison with the standard compound (Figure S3). The peak 4 in the 100% methanol fraction was considered as kaempferol-3-Oglucopyranoside because of the data on the molecular ion and the fragment ion of the aglycon moiety corresponding to [M-glucose]2. A previous study has reported the identification of kaempferol-3-O-b-D -glucopyranoside in indigo plant (Iwaki & Kurimoto 2002). The peak 5 was found to co-elute with authentic quercetin at 6.0 min, but overlapped an unidentified compound. Therefore, the 100% methanol fraction was furthermore subjected to trimethylsilyl (TMS) derivatisation and subsequent analysis by GC-MS (Figure S4). The resulting analysis enabled us to separate clearly the mixture to give a single GC peak corresponding to quercetin. The MS data of this GC confirmed the peak as quercetin. The peak 6 detected by UPLC-ESI/MS was Table 1. UPLC-ESI/MS analysis of the fractions of 50% methanol and 100% methanol separated by column chromatography on Diaion HP-20. Fraction 50% methanol
100% methanol
Retention time (min)
Polyphenolic compound
2.3
Chlorogenic acid (1)
2.7
Caffeic acid (2)
4.8
Quercetin-3-O-glucuronide (3)
4.5
Kaempferol-3-O-glucopyranoside (4)
6.0 7.0 9.1
Quercetin (5) Kaempferol (6) 3,5,40 -Trihydroxy-6,7methylenedioxyflavone (tentative) (7)
m/z 353.1 [M-H]2, 179.0 [M-quinic acid]2 179.3 [M-H]2, 135.0 [M-CHCOOH]2 477.1 [M-H]2, 301.0 [M-glucuronic acid]2 447.1 [M-H]2, 285.0 [M-glucose]2 301.0 [M-H]2 285.0 [M-H]2 313.0 [M-H]2
Downloaded by [Umeå University Library] at 12:50 22 April 2014
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H. Kimura et al.
Figure 1. Quantification of polyphenolic ingredients. The contents of individual polyphenolic constituents were quantified by reverse-phase HPLC and capillary GC. The values are represented as the amount of individual polyphenolic compounds (mg/fresh weight). Data represent the mean ^ SEM of triplicate experiments.
identified as kaempferol. Moreover, the presence of kaempferol was also revealed by the GCMS analysis. The UPLC-ESI/MS analysis made us to assume that the peak 7 is 3,5,40 -trihydroxy6,7-methylenedioxyflavone as described earlier (Iwaki & Kurimoto 2002). 2.2. Quantification of polyphenolic ingredients by reverse-phase HPLC and GC The amount of each compound in indigo plant was quantified by reverse-phase HPLC using the C18 column while monitoring the eluents at the absorbance of 320 nm. According to this procedure, we were able to determine the levels of cholorogenic acid, caffeic acid, quercetin-3-O-glucuronide and kaempferol by generating the straight regression line between peak areas and injected amounts using the respective authentic compound (Table S1). For the quantification of quercetin and kaempferol, GC analysis was also carried out after the preparation of the TMS derivatives of them from the fraction of 100% methanol. The determination gave satisfactory straight regression lines between their peak areas and the injected amounts (Table S2). The quantification of individual ingredients revealed higher contents of them in the order of kaempferol, quercetin-3-O-glucuronide, quercetin, chlorogenic acid and caffeic acid (Figure 1). Thus, flavonoids and the derivatives were found to be abundant polyphenolic ingredients in indigo plant. Recent studies have suggested that kaempferol is a useful biofactor that exerts multiple effects, such as anti-cancer, antioxidant, anti-inflammatory, anti-bacterial and anti-osteoporosis activities (Calderon-Montan˜o et al. 2011). As well, quercetin-3-O-glucuronide has been shown to exhibit anti-inflammatory and anti-virus effects (Fan et al. 2011). Our study here showed that kaempferol was the most abundant polyphenolic ingredient and followed by higher content of quercetin-3-O-glucuronide among the analytes. Taken together, these results indicate that indigo plant is a promising source of these polyphenolic compounds for beneficial effects. 3. Conclusion We have successfully conducted the identification and quantitation of several species of polyphenolic compounds from indigo plant using the combined instrumental analyses with chromatography and mass spectrometry. The quantification of individual ingredients identified in the ground tissues from indigo plant revealed higher contents of them in the order of
Natural Product Research
495
kaempferol, quercetin-3-O-glucuronide, quercetin, chlorogenic acid and caffeic acid. These findings indicate that the indigo plant is a useful source for flavonoids and the derivatives which serve as medicinal factors. Supplementary material Experimental details relating to this article are available online, alongside Tables S1 and S2 and Figures S1 –S4.
Downloaded by [Umeå University Library] at 12:50 22 April 2014
References Calderon-Montan˜o JM, Burgos-Moron E, Perez-Guerrero C, Lopez-Lazaro M. 2011. A review on the dietary flavonoid kaempferol. Mini-Rev Med Chem. 11:298– 344. Fan D, Zhou X, Zhao C, Chen H, Zhao Y, Gong X. 2011. Anti-inflammatory, antiviral and quantitative study of quercetin-3-O-D -glucuronide in Polygonum perfoliatum L. Fitoterapia. 82:805–810. Hashimoto T, Aga H, Chaen H, Fukuda S, Kurimoto M. 1999. Isolation and identification of anti-helicobacter pyrori compounds from Polygonum tinctorium Lour. Nat Med. 53:27–31. Iwaki K, Kurimoto M. 2002. Cancer preventive effects of the indigo plant Polygonum tinctorium. Recent Res Develop Cancer. 4:429– 437. Kimoto T, Koya S, Hino K, Yamamoto Y, Aga H, Hashimoto T, Masaki N, Hanaya T, Micallef MJ, Iwaki K, et al. 1999. Protection by indigo plant (Polygonum tinctorium Lour.) against renal oxidative damage in mice treated with ferric nitrilotriacetate. Nat Med. 53:291–296. Koya-Miyata S, Kimoto T, Micallef MJ, Hino K, Taniguchi M, Ushio S, Iwaki K, Ikeda M, Kurimoto M. 2001. Prevention of azoxymethane-induced intestinal tumors by a crude ethyl acetate-extract and tryptanthrin extracted from Polygonum tinctorium Lour. Anticancer Res. 21:3295–3300. Micallef MJ, Iwaki K, Ishihara T, Ushio S, Aga M, Kunikata T, Koya-Miyata S, Kimoto T, Ikeda M, Hino K, Kurimoto M. 2002. The natural plant product tryptanthrin ameliorates dextran sodium sulfate-induced colitis in mice. Int Immunopharmacol. 2:565–578.
