One of the tasks of pharmaceutical science is to find new sources of effective drugs. Such sources include plants such as Angelica archangelica L. and Angelica sylvestris L., which have been used for many years to treat various diseases in folk medicine. Because the chemical composition of these plants is poorly understood, the aim of our study was to investigate the amino acid composition of the leaves of A. archangelica L. and A. sylvestris L. The amino acids of the leaves of the study species of the genus Angelica L. were determined by the HPLC method. Eighteen free and nineteen bound amino acids were identified in the leaves of A. archangelica L. The A. sylvestris L. leaves contained nineteen free and the same amount of bound amino acids. High concentrations of free and bound amino acids such as L-glutamic acid and L-aspartic acid predominate in A. archangelica L. and A. sylvestris L. This allowed these amino acids to be considered distinguishing markers of the study plants. Character metabolic processes in which these amino acids take part may be associated with the medicinal properties of these plants pursuant to their use in medicine and, therefore, may contribute to the insight of their therapeutic properties.

Angelica archangelica L., Angelica sylvestris L., leaves, amino acids, HPLC

One of the tasks of pharmaceutical science, at the present stage of development, is to find new sources of effective drugs (Feshchenko et al. 2021a). This is possible due to the expansion of the range of medicinal plants through the full use of own resources of wild raw materials. When creating new herbal remedies, scientists pay special attention to plants that have long been used in folk medicine (Budniak et al. 2021a, b, e; Marchyshyn et al. 2021c; Vasenda et al. 2021). The advantage of herbal medicine is the availability and relative cheapness compared to synthetic drugs. Herbal medicines show a wide range of pharmacological properties, which are realized through different groups of biologically active substances (Darzuli et al. 2021; Slobodianiuk et al. 2021d). Herbal medicines are low-toxic, can be used for a long time, have fewer side effects on the human body, and are well combined with synthetic drugs (Stoiko and Kurylo 2018; Darzuli et al. 2019; Budniak et al. 2020; Huzio et al. 2020; Budniak and Vasenda 2021). Plants of the genus Angelica L. are promising in this regard.

Angelica L. is among the largest genus of the Apiaceae family. It has approximately 110 species of biennial and perennial herbs (Daşkın and Kaynak 2012; Liao et al. 2020). More than 50 of these species are used in traditional medicine in many countries (Lobiuc et al. 2012; Ağalar et al. 2020). Angelica species are found on all continents of the Northern Hemisphere, reaching as far north as Iceland, Lapland, Greenland, and East Asia host the highest number of species (Liao et al. 2012; Pimenov 2017; Wang et al. 2017).

For many centuries, species of this genus namely A. archangelica, A. sylvestris, A. californica, A. atropupurea, A. dahurica, A. keiskei, A. lucida, A. tomentosa, A. venenosa, A. tenuissima, A. kingie have been used as an expectorant, diuretic, anti-inflammatory, and diaphoretic, and means for flu, chronic bronch, pleurisy, colds, fever, typhoid, coughs, hepatitis, indigestion, colic, headaches, rheumatism, arthritis, bacterial and fungal infections (Sarker and Nahar 2004). These properties are the result of the availability of many groups of biologically active compounds. Among them are coumarins, sesquiterpenes, flavonoids, polysaccharides, acetylenic compounds, and chalcones (Skakun and Stepanova 1988; Sarker and Nahar 2004; Wang et al. 2012; Wang et al. 2017; Shawky and Abou El Kheir 2018; Xie et al. 2018; Karakaya et al. 2020; Alkan Türkuçar et al. 2021).

A. archangelica and A. sylvestris are the most common species in Ukraine. They grow on wetlands and waterfronts (Ağalar et al. 2020). A. archangelica has a wide range of biological activities namely anti-inflammatory, antispasmodic, diuretic, antimutagenic, diaphoretic, sedative, cytotoxic, and anxiolytic properties, increases bile secretion, secretion of gastric and pancreatic juice, enhances intestinal motor function, inhibits fermentation (Salikhova and Poroshenko 1995; Pathak et al. 2010). The root is used for bronchitis, gastric ulcers, anorexia, chronic fatigue, migraine, and obstetric complaints (Bhat et al. 2011; Maurya et al. 2017). Yeh et al. established that A. archangelica is a cytoprotective agent effective against chronic hepatotoxicity, which hence indirectly protects the liver from oxidative stress (Yeh et al. 2003). Khayyal et al. found that extract of A. archangelica has anti-ulcerogenic activity associated with an increase in prostaglandin E2 release, a reduced acid output, a decrease in leukotrienes, and increased mucin secretion (Khayyal et al. 2001). Sigurdsson et al. revealed that the antiproliferative activity of a tincture is from fruits of this plant. It is results presence of A. archangelica two furanocoumarins, such as xanthotoxin (8-methoxypsoralen) and imperatorin (8-isopentenyloxypsoralen) (Sigurdsson et al. 2004; Sigurdsson and Gudbjarnason 2007; Wszelaki et al. 2011). Also, antitumor activity in vivo and antiproliferative activity in vitro of extract of Angelica archangelica leaves were found by researchers (Sigurdsson et al. 2005). The essential oil obtained from A. archangelica roots has good antimicrobial activity against Enterococcus faecalis, Peptostreptococcus anaerobius, Clostridium perfringen, Clostridium difficile, Eubacterium limosum, and Candida albicans. The main proportion of oil consists of monoterpene (up to 88%). α-pinene (21.3%), δ-3-carene (16.5%), limonene (16.4%), and α-phellandrene (8.7%) are its major compounds (Chalchat and Garry 1997; Doneanu and Anitescu 1998; Nivinskiene et al. 2003; Fraternale et al. 2014; Simonović et al. 2014). Also, A. archangelica contains the following biologically active substances: bittering agents, flavonoids, tanning agents, resins, silica, carbohydrates, terpenes, and organic acids (Wahlin and Blixt 1994).

A. archangelica is a plant that is part of the European Pharmacopoeia, the Ukrainian Pharmacopoeia, the British Herbal Pharmacopoeia, the Complete German Commission E, the British Pharmacopoeia, and many other pharmacopeias.

A. sylvestris, also known as “European wild angelica”, “wild angelica and is analogous to A. archangelica in terms of their common characteristics. As a result of ethnobotanical research, the use was established A. sylvestris disorders of digestive, respiratory, and nervous systems, fever, infection and influenza, in cases of indigestion, as an analgesic, anticarcinogenic, antipyretic remedy (Özek et al. 2008; Vogl et al. 2013). A. sylvestris contain simple coumarins and furanocoumarins, such as umbelliprenin, aviprin, imperatorin, bisabolangelone, bergapten, xanthotoxol, isoimperatorin, byakangelicin, 5-β-cyclolavandulyloxy-psoralen, 1’-O-β-D-glucopyranosyl-(2S,3R)-3-hydroxymarmesin, 4-[(2,4,4-trimethyl-1-cyclohexen-1-yl)methoxy]-7H-furo[3,2-g][1]-benzopyran-7-one, etc (Muckensturm et al. 1981; Carbonnier and Molho 1982; Lemmich et al. 1983; Murphy et al. 2004). Sitosterol, campesterol, a-saccharostenon, stigmasterol, ergosta-5,24-dien3a-ol, cholesterol, stigmast-7-en-3-ol were defined in the plant (Krzaczek and Nowak 2000). Ağalar et al. determined that the main compounds of essential oil of A. sylvestris were α-pinen (42.0%) and β-phellandrene (25.5%) in the flower; 10-epi-γ-eudesmol (5.4%), elemol (5.4%), spathulenol (4.8%) in the root; spathulenol (12.4%), germacrene D (10.6%), α-humulene (7.6%) in the leaves; α -pinen (23.2%) and β-phellandrene (9.1%) in the fruit (Ağalar et al. 2020).

Previous studies revealed various groups of biologically active substances in A. archangelica and A. sylvestris, but amino acids were not studied. Based on the literature data and analysis of the chemical composition of biologically active substances of A. archangelica and A. sylvestris, it is important to study the amino acids composition of these plants.

The amino acids profiles of A. archangelica leaves and A. sylvestris leaves were determined using HPLC method (Figs 1–4, Table 3).

The HPLC method identified eighteen free amino acids in the leaves of A. archangelica. Among them, eight amino acids are essential namely L-threonine, L-valine, L-methionine, L-isoleucine, L-leucine, L-phenylalanine, L-histidine, and L-lysine. Two acids, such as L-arginine and L-tyrosine are semi-essential amino acids. The other eight amino acids are nonessential amino acids.

Figure 1. 

HPLC chromatogram of free amino acids of Angelica archangelica L. leaves.

Free glutamic acid was present in the leaves of A. archangelica in the greatest amount, its content was 130.9 mg/100g. This acid takes part in a significant amount of metabolic reactions and affects metabolic processes in the brain. Glutamic acid is a source of glucose and holds its normal blood level (Okasha et al. 2019). It maintains acid-base homeostasis in blood and tissues (Lyisikov 2012). This acid is a precursor in the synthesis of ornithine and proline and contributes to the temporary neutralization of ammonia with the formation of non-toxic glutamine (Pharmaceutical encyclopedia 2016). Glutamic acid is used as a conjugate because it improves the efficiency of anticancer agent and reduces its toxicity in relation to normal cells. The synthetic amides acid show activity with relation to Ehrlich ascites carcinoma (Dutta et al. 2013). The content of other amino acids was lower.

Figure 2. 

HPLC chromatogram of amino acids after hydrolysis of Angelica archangelica L. leaves.

Nineteen bound amino acids were identified in the leaves of A. archangelica. Eight amino acids are essential, eight – nonessential, and three acids namely L-arginine, L-cysteine, and L-tyrosine are semi-essential amino acids. Among the bound amino acids, L-glutamic and L-aspartic acids were present in the leaves of A. archangelica in the greatest amount, their content was 1471.3 mg/100g, 1298.5 mg/100 g, respectively. Aspartic acid is a major component of antibodies, immunoglobulins, and the immune system as a whole. With this acid, carbohydrates are transformed into energy which helps the body to reduce ammonia levels after exercise. It has hepatoprotective properties and is involved in reamination reactions, and synthesis of methionine, threonine, and lysine (Sirovaya et al. 2014). Also, a significant content of L-alanine (849.1 mg/100 g), Glycine (830.1 mg/100 g), L-serine (779.2 mg/100 g), L-leucine (766.9 mg/100 g), L-arginine (735.2 mg/100 g), L-proline (667.2 mg/100 g), L-threonine (660.8 mg/100 g) bound amino acids was found. L-alanine contributes as an intermediary between protein catabolism and carbohydrates synthesis. Alanine plays a central role in the metabolism of muscle protein and is the main criterion in nitrogen metabolism. With help of this acid, muscles use the energy produced by other amino acids. It is used as a component in infusion solutions, a food additive, and a precursor for pharmaceutical and chemical products (VKM 2017; Hatazawa et al. 2018; Tomé 2018). Glycine is the nonessential amino acid, which is a substrate for the synthesis of several biologically important compounds and biomolecules. It participates in detoxification reactions, in the synthesis of tripeptide glutathione, and of proteins. Glycine has a wide spectrum of immunomodulatory, anti-inflammatory, and cytoprotective properties. To exert its effects, this acid binds to various receptors (Pérez-Torres et al. 2017). L-serine plays a major role in neurological development, cellular proliferation, brain development, and function (Koning et al. 2003). It has different functions and roles from primary protein structure to cell signaling. Deficits in this acid may have profound health effects from embryo to geriatrics. Dietary supplementation with serine is considered a probable therapy for progressive neurodegenerative diseases namely Alzheimer’s diseases and myotrophic lateral sclerosis (Metcalf et al. 2018). L-leucine promotes to energy metabolism renderenergy for protein synthesis, inhibiting protein degradation (Duan et al. 2016). It plays an exceptional signaling role in adipose tissue and skeletal muscle (Li et al. 2011; Carpentier 2020), mammary epithelial cells (Lei et al. 2012), placental cells, and as well as other cell views (Kim et al. 2007; Li et al. 2007; Kim et al. 2011). L-arginine is a semi-essential amino acid, which constitutes 5–7% of the total amino acids in people with normal nutrition. This amino acid is used by all cells and by the body for protein synthesis, tissue repairing, and immune cell function. It is also converted to citrulline and act as a vasodilator (Pahlavani et al. 2014). Because of arginine’s NO-stimulating effects, it can be utilized for congestive heart failure, preeclampsia, hypertension, angina pectoris, coronary heart disease, and erectile dysfunction (Appleton 2002). L-proline is an exceptional amino acid for maintaining cell structure and function (Hu et al. 2008; Kaul et al. 2008). They constitute one-third of amino acids in the collagen proteins which appertain about 30% of body proteins (Wu et al. 2011). It is the main component of collagen and promotes the healing of wounds, burns, ulcers, and good joint function. Proline contributes to buffering cellular redox potential under stress conditions, stabilizing sub-cellular structures, and scavenging free radicals (Serraj and Sinclair 2002; Hayat et al. 2012; Slobodianiuk et al. 2021b). L-threonine has been broadly used in food and pharmaceutical manufacturing. It protects the liver by preventing the accumulation of fat in the cells and has the ability to remove toxins (Dong et al. 2012; Liu et al. 2015; Wang et al. 2019). L‑cystine and L-cysteine were found only bound.

Figure 3. 

HPLC chromatogram of free amino acids of Angelica sylvestris L. leaves.

The leaves of A. sylvestris L. contained nineteen free amino acids and as many bound amino acids. L-glutamine, L-asparagine, and L-proline dominate among free amino acids in the studied plant these content was 547.8 mg/100 g, 377.6 mg/100 g, and 148.1 mg/100 g, respectively. Asparagine supports the normal functioning of the nervous system and liver, able to bind ammonia in tissues. Also, this acid prevents both excessive excitation and excessive inhibition, participates in metabolic processes and stimulates immunity (Sirovaya et al. 2014). Glutamine is responsible for the state of the immune system and is the main source of energy for the kidneys and intestines (Fedosov 2017). Among bound amino acids, L-glutamic and L-aspartic acids were present in the leaves of A. sylvestris in the greatest amount, which was 1155.6 mg/100 g, and 861.0 mg/100 g, respectively. L‑cystine was found only bound.

Figure 4. 

HPLC chromatogram of amino acids after hydrolysis of Angelica sylvestris L. leaves.

By HPLC method in the leaves of A. archangelica L. and A. sylvestris L. were identified amino acids and determined their quantitative content. As a result of this research there was found in study species a significant amount of free and bound amino acids. High concentrations of free and bound amino acids such as L-glutamic acid and L-aspartic acid predominate in A. archangelica L. and A. sylvestris L. This allowed these amino acids to be considered distinguishing markers of the study plants. Character metabolic processes in which these amino acids take part may be associated with the medicinal properties of these plants pursuant to their use in medicine and, therefore, may contribute to the insight of their therapeutic properties.