Preparation and Characterization of Quercetin-Loaded Solid Dispersion by Solvent Evaporation and Freeze-Drying Method

Park, Sang Hyun,Song, Im-Sook,Choi, Min-Koo Korean Society for Mass Spectrometry 2016 Mass spectrometry letters Vol.2 No.2

We prepared solid dispersion formulations of quercetin to enhance its solubility and dissolution rate. Various quercetin-loaded solid dispersion were tested with quercetin, poloxamer 407, and carrier such as hydroxypropyl methyl cellulose (HPMC), polyethylene glycol 8000 (PEG 8000), and polyvinylpyrrolidone K40 (PVP K40) using solvent evaporation and freeze drying methods in terms of both the aqueous solubility and the dissolution rates of quercetin. The solubility of quercetin as its solid dispersion formulations was markedly improved compared with that of quercetin powder. Especially, highest solubility of quercetin was observed when HPMC was used as a carrier. The cumulative dissolution of quercetin within 360 min from solid dispersion composed of quercetin, poloxamer 407, and HPMC was 8.8-fold higher than the dissolution of pure quercetin. The results of powder X-ray diffraction (XRD) and scanning electron microscope (SEM) indicated that quercetin transformed from a crystalline to an amorphous form through the solid dispersion formulation process. These results suggest that the solid dispersion formulation of quercetin with poloxamer 407 and HPMC could be a promising option for enhancing the solubility and dissolution rate of quercetin.

Quercetin의 급여가 육계 다리육의 산화 안정성에 미치는 영향

장애라(Aera Jang),박정은(Jung-Eun Park),김상호(Sang-Ho Kim),채현석(Hyun-Seok Chae),함준상(Jun-Sang Ham),오미화(Mi-Hwa Oh),김현욱(Hyoun-Wook Kim),설국환(Kuk-Hwan Seol),조수현(Soo-Hyun Cho),김동훈(Dong-Hun Kim) 韓國家禽學會 2010 韓國家禽學會誌 Vol.37 No.4

본 연구는 quercetin의 급여가 닭고기 다리육의 지방산패 억제 효과에 미치는 영향을 구명하고자 실시하였다. 1일령 Ross 320마리 육계 병아리를 8처리군으로 나누어 대조군(T1), 항생제 처리군(T2), 비타민 E 20 ppm 처리군(T3), 비타민 E 200 ppm 처리군(T4), quercetin 20 ppm(T5), quercetin 200 ppm(T6), methoxylated quercetin 20ppm(T7), methoxylated quercetin 200 ppm(T8) 처리구로 나누어 35일간 급여하였다. 급여 후 36일째 도계하여 다리육만 분리하였고, 0, 3, 7일 냉장 저장 기간 동안의 단백질 변패도(VBN), 지방산패도(TBARS), 지방산 조성 변화, 미생물학적 특성을 조사하였다. 저장 3일에는 대조군보다 항생제처리군(T2), 비타민 E처리군(T3, T4)와 quercetin 20 ppm 처리군(T5)에서 유의적인 감소를 나타내어 quercetin 20 ppm의 높은 단백질 산패 억제 효과를 보였다(P<0.05). 도계 직후 다리살의 지방산패도는 대조군보다 비타민 E 200 IU 급여한 T4에서 가장 낮은 값을 나타내었으며, 이 값은 항생제 처리구인 T2, quercetin 200 ppm 첨가구인 T5와 유의적인 차이를 나타내지 않아, 비타민 E 200 IU와 유사한 항산화력을 나타냄을 보여주었다(p<0.05). 그러나 저장 7일에 quercetin 20 ppm 처리군(T5)과 200 ppm 처리군(T6)은 항생제 처리군보다도 낮은 총 균수를 나타내어 높은 항균력을 나타내었다(P<0.05). 대장균군은 도계 직후부터 냉장 저장 7일까지 quercetin 처리에 의한 유의적인 감소 효과는 없었다. This study was carried out to determine the effect of dietary supplementation of quercetin and methoxylated quercetin extracted from onions on oxidation of chicken thigh during cold storage. For 35 days, 1-day-old 320 broiler chicks (Ross) were divided into 8 groups and supplemented the diet; basal diet only (T1), T1 with antibiotics (T2), vitamin E 20 IU (T3), vitamin E 200 IU (T4), quercetin 20 ppm (T5), quercetin 200 ppm (T6), methoxylated quercetin 20 ppm (T7), methoxylated quercetin 200 ppm (T8). After slaughtering the broilers, thigh meats were collected and analyzed the oxidation stability during storage at 4℃ for 7 days. Volatile basic nitrogen (VBN) was ranged from 10.98~15.37 mg% until day 3 and quercetin 20 ppm (T5) significantly reduced (p<0.05) the VBN value of thigh as much as antibiotics treatment group (T2). The supplementation of quercetin at a 200 ppm level significantly reduced 2-thiobarbituric acid reactive substances value when compared with the control. Supplementation of 20 ppm quercetin also affected fatty acid composition of chicken thigh and resulted in increase of C18:1w9 and decrease of C18:2w6 on day 3. In microbes of chicken thigh during storage, supplementation of 20 ppm quercetin significantly reduced total microbes compare to control on day 7 (p<0.05). There was no effect on the number of coliforms in thigh with quercetin diet. From these results, the dietary supplementation of 20 ppm of quercetin may have effects on enhancing oxidation stability.

HepG2 cell에서 quercetin의 HO-1 발현을 통한 mitochondria의 생합성 유도 효과에 관한 연구

강재구,장상철,이기승,김진희,정명수,Kang, Jaekoo,Jang, Sang Chul,Lee, Ki Seung,Kim, Jin Hee,Chong, Myong Soo 대한한의정보학회 2015 大韓韓醫情報學會誌 Vol.21 No.1

Flavonoids show diverse bioactivities, such as anti-oxidant, anti-cancer, anti-allergic, anti-inflammatory, and anti-viral. Quercetin is one of the flavonoids present in a wide range of plants, especially onions and consumed all over the world. Recently, it is known that quercetin induces mitochondrial biogenesis in vivo and in vitro. However, detail mechanism of these actions remains unknown. We investigated quercetin's effects on mitochondrial biogenesis in HepG2 cells, and determined the mechanisms involved. We found that quercetin treatment induced the expression of mitochondrial biogenesis activators, $PGC-1{\alpha}$, NRF-1, TFAM, and mitochondrial proteins, cytochorome c and complex IV (COXIV). Moreover, amount of mitochondrial DNA was also increased by quercetin. Quercetin has been known to induce heme oxygenase (HO)-1 in several types of cells. Here, we found quercetin induces HO-1, and inhibition of HO-1 or CO, which is product of HO-1, decreased quercetin-induced mitochondrial biogenesis such as induction of $PGC-1{\alpha}$, NRF-1, TFAM, cytochorome c, COXIV, and mitochondrial DNA. These findings imply that quercetin can increase mitochondrial biogenesis via HO-1/CO system. High glucose results in dysfunction of mitochondria biogenesis. In the present study, 25 mM glucose decreased mitochondrial biogenesis and this damage was restored by quercetin. Conversely, inhibition of HO-1 or CO inhibited quercetin-induced mitochondrial biogenesis rescue. These results suggest that quercetin enhances mitochondrial biogenesis via HO-1/CO system and hence, can rescue mitochondria from damage by high glucose.

고지방 식이로 유도된 비만쥐에서 Quercetin의 지방조직 염증개선 효과

김추숙,유리나 대한비만학회 2014 The Korean journal of obesity Vol.23 No.3

Background: Obesity-induced adipose inflammation contributes to the development of metabolic disorders such as insulin resistance and type 2 diabetes. In this study, we investigated whether quercetin, a naturally occurring phytochemical, can attenuate adipose tissue inflammation in obese mice. Methods: Male C57BL/6 mice were randomly assigned into either control (RD, N=6), high fat diet (HFD, N=6), or HFD supplemented with 0.05% quercetin (HFD+Que, N=6) groups and treated with their respective diets for 9 weeks. The inflammatory cytokine proteins were measured by ELISA, and macrophage populations were determined by immunohistochemistry. The inflammatory receptors and downstream signaling molecules were measured by qPCR and western blot, respectively. Results: We show here that in an HFD-fed mice model, quercetin supplementation reduced adipose tissue weight without affecting HFD-induced body weight gain. Quercetin supplementation reduced expression of inflammatory cytokines (TNF-α, MCP-1, MIP-1α) and macrophage accumulation (F4/80) in adipose tissue of an HFD-fed mice. Quercetin also suppressed the expression of inflammatory receptors (CCR2, TLR4, TNFRSF9) and the activation of downstream inflammatory signaling molecules (JNK, NF-κB) in adipose tissue. Conclusion: These findings indicate that quercetin can reduce adipose inflammatory responses in mice exposed to HFD by inhibiting inflammatory cytokines production, inflammatory receptor expression and their signaling pathway. Quercetin may be useful for preventing HFD-induced adipose tissue inflammation. 배경: 비만으로 유도되는 염증은 지방조직으로 대식세포의 침윤과다양한 염증성 사이토카인의 생성을 수반하며, 인슐린 저항성, 제2형당뇨, 비알콜성 지방간, 심혈관계 질환 등 비만성 대사질환의 발생에 중요한 역할을 한다. 식품에 널리 존재하는 플라보놀 유도체인 quercetin은항염증, 항산화 효과를 가진다고 알려져 있으나, 비만성 지방조직 염증조절 작용에 대해서는 아직 확인되어 있지 않다. 따라서, 본연구에서는 식이 quercetin 투여가 고지방식이로 유도된 지방조직 염증반응에 미치는 영향을 조사하였다. 방법: 8주령의 수컷 C57BL/6 마우스는 정상식이군(RD), 고지방식이대조군(HFD), 0.05% 식이 quercetin 투여군(HFD+Que)으로 나누어 9주간 각 실험식이를 제공한 후, 지방조직을 채취하여 실험에 사용하였다. 대식세포의 축적 정도는 면역학적 염색으로 분석하였고, 염증성 사이토카인의 단백질 수준은 ELISA를 통해 측정하였다. 그리고, 염증수용체 발현과 세포 내 염증신호경로는 각각 qPCR과 westernblot을 통해 측정하였다. 결과: 고지방식이 모델에서 식이 quercetin 투여가 체중 증가량에는차이가 없었으나 지방조직 중량의 증가를 억제하였다. 지방조직에서의 염증성 사이토카인 발현(TNF-α, MCP-1, MIP-1α)과 대식세포의축적(F4/80)은 고지방식이 대조군에 비해 식이 quercetin 투여군에서유의적으로 감소하였다. 또한, 염증수용체의 발현(CCR2, TLR4, TNFRSF9)과 세포 내 염증신호경로 활성화(JNK, NF-κB) 정도는 고지방식이 대조군에 비해 식이 quercetin 투여군에서 억제되었다. 결론: 이러한 결과들은 식이 quercetin이 염증성 사이토카인 발현, 대식세포 침윤, 염증수용체 및 염증신호전달 경로를 저해함으로써 지방조직 염증반응을 예방할 수 있음을 시사한다. 따라서, quercetin은 고지방 식이로 유도된 지방조직 염증을 제어하는 데 유용할 것으로 사료된다.

Differential Effects of Quercetin and Quercetin Glycosides on Human α7 Nicotinic Acetylcholine Receptor-Mediated Ion Currents

Lee, Byung-Hwan,Choi, Sun-Hye,Kim, Hyeon-Joong,Jung, Seok-Won,Hwang, Sung-Hee,Pyo, Mi-Kyung,Rhim, Hyewhon,Kim, Hyoung-Chun,Kim, Ho-Kyoung,Lee, Sang-Mok,Nah, Seung-Yeol The Korean Society of Applied Pharmacology 2016 Biomolecules & Therapeutics(구 응용약물학회지) Vol.24 No.4

Quercetin is a flavonoid usually found in fruits and vegetables. Aside from its antioxidative effects, quercetin, like other flavonoids, has a various neuropharmacological actions. Quercetin-3-O-rhamnoside (Rham1), quercetin-3-O-rutinoside (Rutin), and quercetin-3-(2(G)-rhamnosylrutinoside (Rham2) are mono-, di-, and tri-glycosylated forms of quercetin, respectively. In a previous study, we showed that quercetin can enhance ${\alpha}7$ nicotinic acetylcholine receptor (${\alpha}7$ nAChR)-mediated ion currents. However, the role of the carbohydrates attached to quercetin in the regulation of ${\alpha}7$ nAChR channel activity has not been determined. In the present study, we investigated the effects of quercetin glycosides on the acetylcholine induced peak inward current ($I_{ACh}$) in Xenopus oocytes expressing the ${\alpha}7$ nAChR. $I_{ACh}$ was measured with a two-electrode voltage clamp technique. In oocytes injected with ${\alpha}7$ nAChR copy RNA, quercetin enhanced $I_{ACh}$, whereas quercetin glycosides inhibited $I_{ACh}$. Quercetin glycosides mediated an inhibition of $I_{ACh}$, which increased when they were pre-applied and the inhibitory effects were concentration dependent. The order of $I_{ACh}$ inhibition by quercetin glycosides was Rutin${\geq}$Rham1>Rham2. Quercetin glycosides-mediated $I_{ACh}$ enhancement was not affected by ACh concentration and appeared voltage-independent. Furthermore, quercetin-mediated $I_{ACh}$ inhibition can be attenuated when quercetin is co-applied with Rham1 and Rutin, indicating that quercetin glycosides could interfere with quercetin-mediated ${\alpha}7$ nAChR regulation and that the number of carbohydrates in the quercetin glycoside plays a key role in the interruption of quercetin action. These results show that quercetin and quercetin glycosides regulate the ${\alpha}7$ nAChR in a differential manner.

용매 추출과 병용 추출법을 이용한 양파 과육으로부터 quercetin 관련물질의 추출

진은영,박영서,장재권,정명수,박훈,심건섭,최영진 한국산업식품공학회 2009 산업 식품공학 Vol.13 No.2

양파 과육부에 함유되어 있는 유용 성분인 quercetin과 그 배당체를 다양한 착즙 및 추출방법에 따른 수율을 측정, 분석하였으며 그 결과를 요약하면 다음과 같다. 양파과육의 quercetin과 배당체의 최적 추출 조건으로는 50oC에서 60% methanol를 용매로 사용했을 때 15분의 추출시간인 것으로 나왔으며 용매와 시료의 비율이 0.8 mL/g일 때 추출 수율이 가장 좋았다. 초음파를 60분 동안 처리 시 대조군에 비하여 2.06배의 추출 증가 효과를 볼 수 있었으며 microwave는 60초 조사 시에 최대의 추출 증가 효과를 나타내어 microwave를 처리하지 않은 시료와 비교하여 quercetin과 배당체가 2.14배 많이 추출되었다. 효소 처리 시 cellulase 용액과 시료의 비율이 0.5 mL/g일 때 quercetin과 배당체의 수율이 가장 높았으며 1.65 배 더 많이 추출되었고 viscozyme과 시료의 비율이 0.5 mL/g일 때 quercetin과 배당체의 수율이 가장 높았으며 추출증가율은 2.29 배인 것으로 나왔다. 가장 많은 quercetin과 배당체의 추출 수율을 보인 방법은 viscozyme과 시료의 비율이 0.5 mL/g일 때의 0.070±0.002 mg/g인 것으로 나타났다. Quercetin is one of the main flavonoids from onion. To use quercetin as a functional component for onion food products, the effects of various extraction assisting methods such as juicing methods, microwave, ultrasound and enzyme treatments on the yield of quercetin and its glucosides were investigated. For conventional solvent extraction, the highest yield of quercetin and its glycosides was achieved with 0.8 mL/g of 60% methanol at 50oC for 15 min. The juicing methods using mixer and screw showed no influence on the yield. Microwave and ultrasound treatments showed 2.14 times and 2.06 times more quercetin yields than non-treated extraction, respectively. For cellulase and viscozyme treatments, the highest yields of quercetin were achieved with 0.5 mL/g of 1% enzyme-0.1M sodium acetate (pH 5.2) buffer solution. Cellulase and viscozyme treatment improved quercetin yield 1.65 times and 2.29 times more than non-treated one, respectively.

3T3-L1 지방전구세포에서 Quercetin이 Matrix Metalloproteinases 억제에 의한 지방세포 분화에 미치는 영향

송승민(Seung Min Song),정수민(Soo Min Jung),최수진(Su Jin Choi),김우경(Woo Kyoung Kim) 한국식품영양과학회 2022 한국식품영양과학회지 Vol.51 No.4

본 연구는 3T3-L1 지방전구세포에서 quercetin이 MMPs를 억제하여 지방세포의 분화와 지방축적, 신혈관생성을 억제한다는 기전을 규명하는 것을 목적으로 수행되었다. 3T3-L1 지방전구세포에 PMA를 처리하면 MMP-2와 MMP-9의 mRNA 발현과 활성이 유의적으로 증가하였으며, PMA와 함께 quercetin을 처리하면 quercetin의 처리농도가 증가함에 따라 MMP-2와 MMP-9의 mRNA 발현과 활성이 유의적으로 감소하였다. 그리고 PMA를 처리하면 3T3-L1 세포에서 세포 내 지방축적과 GPDH 활성, 지방세포분화와 관련된 전사인자인 C/EBPβ, C/EBPα, PPARγ 및 FABP4의 mRNA 발현이 유의적으로 증가하였으며, PMA와 quercetin을 함께 처리하면 세포 내 지방축적과 GPDH 활성, 지방세포분화와 관련된 전사인자들의 mRNA 발현이 quercetin의 처리농도가 증가함에 따라 유의적으로 감소하였다. 또한 3T3-L1 지방전구세포에 PMA를 처리하면 혈관내피세포 성장인자인 VEGF-A와 그 수용체인 VEGFR-2의 mRNA 발현이 유의적으로 증가하였으며, PMA와 함께 quercetin을 처리하면 quercetin의 처리농도가 증가함에 따라 VEGF-A와 그 수용체인 VEGFR-2의 mRNA 발현이 감소하였다. 그러므로 본 실험 조건에서 quercetin은 MMPs를 억제해 지방세포의 분화와 지방축적, 신혈관생성을 저해한다는 작용기전을 확인하였다. The purpose of this study was to investigate the inhibitory effects of quercetin on differentiation and angiogenesis via matrix metalloproteinases (MMPs) in 3T3-L1 preadipocytes. The adipocytes were treated with quercetin (0, 5, 10, and 20 μM) for 24 h and the activation of the MMPs was induced by phorbol 12-myristate 13-acetate (PMA) (100 ng/mL) (PMA+) for 2 h. The mRNA expression and activity of MMP-2 and MMP-9 were measured using a real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay kit, respectively. Oil-Red-O (ORO) staining and glycerol-3-phosphate dehydrogenase (GPDH) activity were measured. Also, the mRNA expressions of CCAAT/enhancer-binding protein (C/EBP) β, C/EBPα, peroxisome proliferator-activated receptor (PPAR) γ, fatty acid-binding protein (FABP) 4, vascular endothelial growth factor (VEGF)-A, and vascular endothelial growth factor receptor (VEGFR)-2 were measured using a real-time PCR. The mRNA expression and activity of MMP-2 and MMP-9 were significantly increased in the quercetin 0 μM (PMA+) group compared to the quercetin 0 μM (PMA−) group, and they were significantly decreased by quercetin treatment (P<0.05). ORO staining and GPDH activity were significantly increased in the quercetin 0 μM (PMA+) group compared to the quercetin 0 μM (PMA−) group, and they were significantly decreased by quercetin treatment (P<0.05). The mRNA expressions of C/EBPβ, C/EBPα, PPARγ, FABP4, VEGF-A, and VEGFR-2 were significantly increased in the quercetin 0 μM (PMA+) group compared to the quercetin 0 μM (PMA−) group, and they were significantly decreased by the quercetin treatment (P<0.05). In conclusion, quercetin can inhibit differentiation and angiogenesis in 3T3-L1 preadipocytes through the suppression of MMPs.

Effects of Quercetin on the Bioavailability of Doxorubicin in Rats: Role of CYP3A4 and P-gp Inhibition by Quercetin

Choi, Jun-Shik,Piao, Yong-Ji,Kang, Keon-Wook 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.4

Quercetin, a flavonoid, is an inhibitor of P-glycoprotein-mediated efflux transport, and its oxidative metabolism is catalyzed by CYP enzymes. Thus, it is expected that the pharmacokinetics of both intravenous and oral doxorubicin can be changed by quercetin. The purpose of this study was to investigate the effect of oral quercetin on the bioavailability and pharmacokinetics of orally and intravenously administered doxorubicin in rats. The effects of quercetin on the P-glycoprotein (P-gp) and CYP3A4 activities were also evaluated. Quercetin inhibited CYP3A4 enzyme activity in a concentration-dependent manner with a 50% inhibition concentration ($IC_{50}$) of $1.97{\mu}M$. In addition, quercetin significantly enhanced the intracellular accumulation of rhodamine-123 in MCF-7/ADR cells overexpressing P-gp. The pharmacokinetic parameters of doxorubicin were determined in rats after oral (50 mg/kg) or intravenous (10 mg/kg) administration of doxorubicin to rats in the presence and absence of quercetin (0.6, 3 or 15 mg/kg). Compared to control, quercetin significantly (p < 0.05 for 0.6 mg/kg, p < 0.01 for 3 and 15 mg/kg) increased the area under the plasma concentration-time curve ($AUC_{0-{\infty}}$, 31.2-136.0% greater) of oral doxorubicin. Quercetin also significantly increased the peak plasma concentration ($C_{max}$) of doxorubicin, while there was no significant change in $T_{max}$ and $T_{1/2}$ of doxorubicin. Consequently, the absolute bioavailability of doxorubicin was increased by quercetin compared to control, and the relative bioavailability of oral doxorubicin was increased by 1.32 to 2.36 fold. In contrast, the pharmacokinetics of intravenous doxorubicin were not affected by quercetin. These results suggest that the quercetin-induced increase in bioavailability of oral doxorubicin can be attributed to enhanced doxorubicin absorption in the gastrointestinal tract via quercetin-induced inhibition of P-gp and reduced first-pass metabolism of doxorubicin due to quercetin-induced inhibition of CYP3A in the small intestine and/or in the liver rather than reduced renal and/or hepatic elimination of doxorubicin. Therefore, it appears that the development of oral doxorubicin preparations is possible, which will be more convenient than the intravenous dosage forms. Therefore, concurrent use of quercetin provides a therapeutic benefit - it increases the bioavailability of doxorubicin administered orally.

Differential Effects of Quercetin and Quercetin Glycosides on Human α7 Nicotinic Acetylcholine Receptor-Mediated Ion Currents

이병환,최선혜,김현중,정석원,황성희,표미경,임혜원,김형춘,김호경,이상목,나승열 한국응용약물학회 2016 Biomolecules & Therapeutics(구 응용약물학회지) Vol.24 No.4

Quercetin is a flavonoid usually found in fruits and vegetables. Aside from its antioxidative effects, quercetin, like other flavonoids, has a various neuropharmacological actions. Quercetin-3-O-rhamnoside (Rham1), quercetin-3-O-rutinoside (Rutin), and quercetin- 3-(2(G)-rhamnosylrutinoside (Rham2) are mono-, di-, and tri-glycosylated forms of quercetin, respectively. In a previous study, we showed that quercetin can enhance α7 nicotinic acetylcholine receptor (α7 nAChR)-mediated ion currents. However, the role of the carbohydrates attached to quercetin in the regulation of α7 nAChR channel activity has not been determined. In the present study, we investigated the effects of quercetin glycosides on the acetylcholine induced peak inward current (IACh) in Xenopus oocytes expressing the α7 nAChR. IACh was measured with a two-electrode voltage clamp technique. In oocytes injected with α7 nAChR copy RNA, quercetin enhanced IACh, whereas quercetin glycosides inhibited IACh. Quercetin glycosides mediated an inhibition of IACh, which increased when they were pre-applied and the inhibitory effects were concentration dependent. The order of IACh inhibition by quercetin glycosides was Rutin≥Rham1>Rham2. Quercetin glycosides-mediated IACh enhancement was not affected by ACh concentration and appeared voltage-independent. Furthermore, quercetin-mediated IACh inhibition can be attenuated when quercetin is co-applied with Rham1 and Rutin, indicating that quercetin glycosides could interfere with quercetin-mediated α7 nAChR regulation and that the number of carbohydrates in the quercetin glycoside plays a key role in the interruption of quercetin action. These results show that quercetin and quercetin glycosides regulate the α7 nAChR in a differential manner.

Characterization of quercetin and its glycoside derivatives in Malus germplasm

Lei Zhang,Qipeng Xu,Yaohua You,Weifeng Chen,Zhengcao Xiao,Pengmin Li,Fengwang Ma 한국원예학회 2018 Horticulture, Environment, and Biotechnology Vol.59 No.6

Quercetin and its glycoside derivatives were identifi ed and quantifi ed using high-performance liquid chromatograph (HPLC)and liquid chromatograph/mass spectrometer/mass spectrometer (LC/MS/MS) in the leaves, flowers, and fruits of 22 Malusgenotypes. In all genotypes, small amounts of quercetin aglycone were present, with water-soluble glycoside forms were themost abundant in diff erent Malus plant tissues, including quercetin-3-galactoside, quercetin-3-rutinoside, quercetin-3-glucoside,quercetin-3-xyloside, quercetin-3-arabinoside, and quercetin-3-rhamnoside. Among these six quercetin glycosides,quercetin-3-galactoside was the common form in Malus plants, except in the leaves and flowers of M. ceracifolia and M. magdeburgensis , and in the fruits of M. micromalus ‘Haihong Fruit’, where there was a higher concentration of quercetin-3-glucoside. Among the diff erent tissues tested, leaves contained the highest concentration of quercetin and its glycosides,while fruits contained the lowest concentrations of these compounds. Among the genotypes we analyzed, no specifi c genotypeconsistently contained the highest concentration of quercetin and its glycoside derivatives. M. domestica ‘Honeycrisp’had the highest total compound concentration (approximately 1600 mg kg −1 ), whereas M. hupehensis contained the lowestin its fruits. In contrast, the concentration of total quercetin and its glycosides was more than 5000 mg kg −1 in the leaves ofeight genotypes and greater than 2500 mg kg −1 in the flowers of seven species. In general, the concentration of quercetinand its glycoside derivatives depended on the species and tissue type. These results may provide useful information for theevaluation and selection of edible Malus fruits and the materials for quercetin glycoside extraction.