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Recent Trends in the Application of Chromatographic Techniques in the Analysis of Luteolin and Its Derivatives

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Recent Trends in the Application of Chromatographic Techniques in the Analysis of Luteolin and Its Derivatives biomolecules Review Recent Trends in the Application of Chromatographic Techniques in the Analysis of Luteolin and Its Derivatives Aleksandra Maria Juszczak 1 , Marijana Zovko-Konˇci´c 2 and Michał Tomczyk 1,* 1 Department of Pharmacognosy, Faculty of Pharmacy, Medical University of Białystok, ul. Mickiewicza 2a, 15-230 Białystok, Poland; [email protected] 2 Department of Pharmacognosy, University of Zagreb, Faculty of Pharmacy and Biochemistry, A. Kovaˇci´ca1, 10000 Zagreb, Croatia; [email protected] * Correspondence: [email protected]; Tel.: +48-85-748-5694 Received: 1 October 2019; Accepted: 8 November 2019; Published: 12 November 2019 Abstract: Luteolin is a flavonoid often found in various medicinal plants that exhibits multiple biological effects such as antioxidant, anti-inflammatory and immunomodulatory activity. Commercially available medicinal plants and their preparations containing luteolin are often used in the treatment of hypertension, inflammatory diseases, and even cancer. However, to establish the quality of such preparations, appropriate analytical methods should be used. Therefore, the present paper provides the first comprehensive review of the current analytical methods that were developed and validated for the quantitative determination of luteolin and its C- and O-derivatives including orientin, isoorientin, luteolin 7-O-glucoside and others. It provides a systematic overview of chromatographic analytical techniques including thin layer chromatography (TLC), high performance thin layer chromatography (HPTLC), liquid chromatography (LC), high performance liquid chromatography (HPLC), gas chromatography (GC) and counter-current chromatography (CCC), as well as the conditions used in the determination of luteolin and its derivatives in plant material. Keywords: luteolin; hyphenated techniques; chromatography 1. Introduction Luteolin (Figure1) is a yellow dye commonly found in fresh plants. It is a flavonoid of the flavone type that is distributed widely throughout the plant kingdom. Similar to other derivatives of 2-phenylbenzo-γ-pyrone, its basic skeleton has a characteristic C6-C3-C6 system, containing two benzene rings and a bridge with a C2-C3 double carbon bond and an attached oxygen atom [1–4]. Structure-activity studies have demonstrated that the pharmacological effects of luteolin and other flavonoids are strongly related to the presence of hydroxyl groups at the C5, C7, C3’ and C4’ carbons as well as to the presence of the double bond in the C2-C3 position [3,5]. The presence of the -OH group at position C3’ distinguishes luteolin from apigenin, and the lack of this group at the C3 carbon is an element that places luteolin in the flavone group [6]. Biomolecules 2019, 9, 731; doi:10.3390/biom9110731 www.mdpi.com/journal/biomolecules Biomolecules 2019, 9, 731 2 of 38 Biomolecules 2019, 9, 731 2 of 38 OH OH HO O OH O Figure 1. Chemical structure of luteolin. LuteolinOrientin, an exhibits 8-C-glucoside multiple derivative biological of eluteolin,ffects such displays as antioxidant, an array of health-related anti-inflammatory biological and immunomodulatoryproperties, such activity.as antioxidant, Plants rich anti-ageing, in luteolin are oftenantiviral, used inantibacterial, traditional medicine anti-inflammatory, for treatment ofvasodilatation, various diseases cardioprotective, such as hypertension, radiation inflammatory protective, disorders,neuroprotective, and even antidepressant-like, cancer [7]. anti- adipogenesis,Because luteolin and antinociceptive bears four hydroxyl effects. groups It may (at thebe C5,found C7, C3’in different and C4’ positions), medicinal many plants derivatives such as ofOcimum luteolin sanctum can be created.(holy basil), Various Phyllostachys types of functional nigra (bamboo groups leaves), and/or sugarPassiflora molecules sp. (passion can be attachedflower), toLinum those usitatissimum positions, creating (flax), aEuterpe huge number oleracea of (Acai different palm) but and structurally many others similar [10]. molecules. Another The luteolin most commonderivative, are isoorientin methyl derivatives, (luteolin-6- asC well-glucoside) as C- and acts -O -glycosidesas an antioxidant, [8,9]. photoprotective [11], skin lighteningOrientin, [12], an hepatoprotective 8-C-glucoside derivative [13] and anti-inflammatory of luteolin, displays agent an array[14]. O of-glucosides health-related of luteolin biological also properties,display biological such as activities. antioxidant, For anti-ageing, example, luteolin antiviral, 7- antibacterial,O-glucoside anti-inflammatory,alleviates skin lesions vasodilatation, in murine cardioprotective,models of atopic radiation dermatitis protective, [15] and neuroprotective, protects cells antidepressant-like, against apoptosis anti-adipogenesis, induced by andhypoxia/reoxygenation antinociceptive eff [16].ects. It may be found in different medicinal plants such as Ocimum sanctumAn increasing(holy basil), numberPhyllostachys of herbal nigra preparations(bamboo on leaves), the marketPassiflora containsp. luteolin (passion and flower),its derivatives,Linum usitatissimumeither as single-ingredient(flax), Euterpe oleraceaproducts(Acai or in palm) mixtur andes manywith othersother phytochemi [10]. Anothercals, luteolin e.g., in derivative, form of isoorientinmedicinal plants (luteolin-6- extracts.C-glucoside) To establish acts the as quality an antioxidant, of such products, photoprotective it is important [11], skin to use lightening appropriate [12], hepatoprotectiveanalytical methods. [13] andHowever, anti-inflammatory there is a agentlack of [14 quality]. O-glucosides reviews of of luteolin the available also display methods biological for activities.quantification For of example, luteolin luteolinderivatives, 7-O -glucosideand the info alleviatesrmation on skin their lesions comparison in murine is lacking. models Therefore, of atopic dermatitisthe aim of [this15] andarticle protects is to systematize cells against knowledge apoptosis inducedand information by hypoxia in /thereoxygenation field of chromatographic [16]. analyticalAn increasing techniques number used for of herbalquantification preparations of luteolin on the and market its derivatives. contain luteolin The presented and its derivatives, review is eitherthe first as description single-ingredient of this products type and or provides in mixtures a systematic with other phytochemicals,overview of chromatographic e.g., in form of analytical medicinal plantstechniques extracts. including To establish thin the layer quality chromatogr of such products,aphy it(TLC), is important high toperformance use appropriate thin analytical layer methods.chromatography However, (HPTLC), there isliquid a lack chromatography of quality reviews (LC), of high the availableperformanc methodse liquid for chromatography quantification of(HPLC), luteolin gas derivatives, chromatography and the (GC) information and counter- on theircurrent comparison chromatography is lacking. (CCC), Therefore, as well the aimas the of thisconditions article used is to systematizeto assess luteolin knowledge and its andderivatives. information in the field of chromatographic analytical techniques used for quantification of luteolin and its derivatives. The presented review is the first description2. Chromatographic of this type Techniques and provides for athe systematic Analysis overview of Luteolin of chromatographic Derivatives analytical techniques including thin layer chromatography (TLC), high performance thin layer chromatography (HPTLC), Chromatography occupies a leading position among other instrumental methods in the analysis liquid chromatography (LC), high performance liquid chromatography (HPLC), gas chromatography of chemical compounds. As a physicochemical method of separation and analysis of mixtures of (GC) and counter-current chromatography (CCC), as well as the conditions used to assess luteolin and chemical compounds, it allows detection and identification as well as quantitative determination of its derivatives. the test substance with high accuracy. The coupling of chromatography with other methods of 2.analysis Chromatographic contributes to Techniques a more accurate for the detection Analysis and of Luteolin expansion Derivatives of analytical capabilities, especially for complex mixtures of organic compounds [2,17,18]. Chromatography occupies a leading position among other instrumental methods in the analysis Chromatographic techniques are based on the interaction of the mixture components with the of chemical compounds. As a physicochemical method of separation and analysis of mixtures of mobile and stationary phases of the chromatographic system. This results in the division of the chemical compounds, it allows detection and identification as well as quantitative determination of the mixture components between the two phases. In addition, the interaction of the mobile and stationary test substance with high accuracy. The coupling of chromatography with other methods of analysis phases is also important in the separation process [17,18]. According to the aggregation state of the contributes to a more accurate detection and expansion of analytical capabilities, especially for complex mobile phase, chromatographic techniques are divided into gas, liquid and supercritical mixtures of organic compounds [2,17,18]. chromatography. Another criterion for classification of chromatographic techniques is the type of stationary phase. If the stationary phase is a liquid, the chromatography technique
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