Yulian Voynikov

Medical University of Sofia · Faculty of Pharmacy

Sideritis scardica Griseb, also known as “mountain tea” and “Olympus tea” (Lamiaceae family) is an endemic plant from the mountainous regions of the Balkan Peninsula. In this study, we focused on an in-depth phytochemical analysis of S. scardica infusion using ultra-high-performance liquid chromatography hyphenated with high-resolution mass spectro...

Echinops ritro L. is a perennial herbaceous plant in the tribe Cardueae, Asteraceae family, widely distributed, up to 1000 m a.s.l. In the present study, the enzyme inhibitory and anti-proliferative activity of E. ritro leaves and flowering heads extracts were assayed. Quantitative determination of 22 analytes, including eleven acylquinic and one h...

Purslane ( Portulaca oleracea L., Portulacaceae) is a widespread edible plant with significant ethnobotanical and ethnopharmacological importance. The plant is characteristic for the presence of a class of indoline amide glucoside alkaloids, called cyclo-dopa amides, or oleraceins. Additionally, a new, structurally similar to oleraceins, class of i...

Alzheimer’s disease (AD) is considered a complex neurodegenerative condition which warrants the development of multitargeted drugs to tackle the key pathogenetic mechanisms of the disease. In this study, two novel series of melatonin- and donepezil-based hybrid molecules with hydrazone (3a–r) or sulfonyl hydrazone (5a–l) fragments were designed, sy...

Cicerbita alpina (L.) Wallr. is a perennial herbaceous plant in the tribe Cichorieae (Lactuceae), Asteraceae family, distributed in the mountainous regions in Europe. In this study, we focused on the metabolite profiling and the bioactivity of C. alpina leaves and flowering heads methanol-aqueous extracts. The antioxidant activity of extracts, as w...

Herein, a chemophenetic significance, based on the phenolic metabolite profiling of three Senecio (S. hercynicus, S. ovatus, and S. rupestris) and two Jacobaea species (J. pancicii and J. maritima), coupled to morphometric data, is presented. A set of twelve morphometric characters were recorded from each plant species and used as predictor variabl...

Herein, a chemophenetic significance, based on phenolic metabolite profiling of three Senecio (S. hercynicus, S. ovatus and S. rupestris) and two Jacobaea species (J. pancicii and J. maritima) coupled to morphometric data, is presented. A set of twelve morphometric characters were recorded from each plant species and used as predictor variables in...

Asteraceae species Tanacetum balsamita L. (costmary) is renowned for its traditional usage as an aromatic, carminative and tonic plant. This work aimed at in-depth study of the phytochemical and in vitro biological profilings of methanol–aqueous extracts from the costmary leaves, flower heads and roots. An UHPLC-HRMS analysis revealed more than 100...

In-depth characterization of specialized metabolites in the endemic Gypsophila perfoliata L. "tekirae" (G. tekirae Stef.) by liquid chromatography-quadrupol-Orbitrap mass spectrometry allowed dereplication/annotation of 22 flavonoids including 11 2 ′′-O-pentosyl/deoxyhexosyl/hexosyl-C-hexosyl-flavones in the aerial parts and 23 gypsogenin-and quill...

The widespread genus Cirsium Mill. (Asteraceae) is renowned in traditional medicine. In the present study, an innovative biochemometric-assisted metabolite profiling of the flower heads, aerial parts and roots of Cirsium appendiculatum Griseb. (Balkan thistle) in relation to their antioxidant and enzyme inhibitory potential was developed. The workf...

Oleraceins are a class of indoline amide glycosides found in Portulaca oleracea L. (Portulacaceae), or purslane. These compounds are characterized by 5,6-dihydroxyindoline-2-carboxylic acid N-acylated with cinnamic acid derivatives, and many are glucosylated. Herein, hydromethanolic extracts of the aerial parts of purslane were subjected to UHPLC-O...

Oleraceins are a class of indoline amide glycosides found in Portulaca oleracea L. (Portulacaceae), or purslane. These compounds are characterized with 5,6-dihydroxyin-doline-2-carboxylic acid N-acylated with cinnamic acid derivatives, and many are gluco-sylated. Herein, hydromethanolic extracts of the aerial parts of purslane were subjected to UHP...

Diclofenac is one of the most prescribed non-steroidal anti-inflammatory drugs (NSAIDs) for acute and chronic inflammatory conditions. Taking into consideration the extensive use of diclofenac, the crucial role of inflammation in tumorigenesis and data on the effects of NSAIDs on cancer cell lines, we investigated the cytotoxic potential of diclofe...

Despite the early access procedures for marketing authorization (MA) valid throughout the European Union still in the most of the Member states patient access to innovative medicines depends on cost-effectiveness, budget impact assessment and negotiations for price discount with the public payers. Retrospective analysis on the availability and time...

The aim of the study was to provide an in-depth characterization of the methanol-aqueous extract from the aerial parts of Gypsophila glomerata Pall. Ex Adams (Caryophyllaceae) (EGG) and to assess its protective potential on carbon tetrachloride (CCl 4 )-induced liver and kidney damage in male Wistar rats. Twenty-two flavonoid C- , O - and C,O --gly...

Herein, we present the synthesis and in-vitro anti-inflammatory, antioxidant, and anti-arthritic activities of new ibuprofen derivatives. All structures were confirmed by spectral analysis (1 H NMR, 13 C NMR, UV, IR and HRMS). The lipophilicity was established using reversed-phase thin layer chromatography and in silico calculations. The anti-infla...

Senecio hercynicus Herborg. (Asteraceae) is a perennial plant containing pyrrolizidine alkaloids and sesquiterpene lactones due to which it has analgesic, hypoglycaemic and insecticidal properties. Herein, a phytochemical profile of S. hercynicus together with an assessment of the antioxidant and enzyme inhibitory potential, is presented. The herba...

Asteraceae species Tanacetum macrophyllum (Walds. & Kit.) Sch.Bip. (Tm) and Telekia speciosa (Schreb.) Baumg. (Ts) are renowned for their ethnomedicinal use. This work aims to provide an in-depth characterization of the methanol-aqueous extracts from the flower heads, aerial parts and roots of the species. Annotation and dereplication of 113 second...

Geigeria alata Benth. & Hook.f. ex Oliv. & Hiern (Asteraceae) is used in Sudanese folk medicine for treatment of diabetes. The study aimed to estimate the acute oral toxicity of trans-3,5-dicaffeoylquinic acid (3,5-diCQA) from G. alata roots and to assess its antihypeglycemic, antioxidant and antihypertensive effects on chemically-induced diabetic...

Background: The 1,8-Naphthalimides constitute an important class of biologically active, DNAbinding compounds. There are no available data on the synthesis of 1,8-naphthalimide derivatives with nonprotein amino acids and their biological activity. The aim of this paper was to determine the synthesis, structural characterization and cytotoxic activ...

Portulaca oleracea L. (purslane) is a well-known edible and ethno-medicinal plant and it has been called "vegetable for long life" in the Chinese herbal medicine. The plant is recognized for the high content of polyphenols, including flavonoids and phenolic acids. In this study, hydromethanolic purslane extracts from Bulgarian and Greek locations w...

The compound in the title was prepared by reaction between tryptamine and ibuprofen using N,N′-dicyclohexylcarbodiimide as a “dehydrating” reagent. The structure of the newly synthesized compound was determined by nuclear magnetic resonance (NMR) (1H-NMR and 13C-NMR), UV, IR, and mass spectral data.

Cancer pain treatment is a big challenge for healthcare providers and patients as well. The wide range of non-steroidal anti-inflammatory drugs (NSAIDs) used as painkillers in cancer patients, requires in-depth characterization of their effect on the disease process. The effects of NSAIDs have been widely studied over the last decades as preventive...

Glucuronide Oleanane-type Triterpenoid Carboxylic Acid 3, 28-Bidesmosides (GOTCAB) saponins are bioactive natural compounds spread in Caryophyllidae. The high complexity of GOTCAB occurring as closely related isobaric and positional isomers is a challenge in their separation and identification. A new liquid chromatography - high resolution Orbitrap...

Methanol-aqueous extracts from the aerial parts of Gypsophila glomerata (GGE), G. trichotoma (GTE) and G. perfoliata (GPE) were investigated for antioxidant potential using different in vitro models, as well as for phenolic and flavonoid contents. The possible anti-cholinesterase, anti-tyrosinase, anti-amylase and anti-glucosidase activities were a...

Alzheimer’s disease (AD) is the most widespread neurodegenerative disorder which can be induced by scopolamine, but the underlying molecular mechanism is poorly understood. Recently, differential scanning calorimetry (DSC) has been used to study healthy and scopolamine-treated mice. A well-expressed exothermic transition minimum in the range of 35...

Solanum schimperianum Hochst. (syn. Solanum carense Dunal) is a tropical plant distributed in Sudan and Southern region of Saudi Arabia. The roots extract has been reported to possess antioxidant and antimicrobial potential. A solid-phase extraction (SPE) method followed by a liquid chromatography – mass spectrometry (LC-MS) in negative and positiv...

Glucuronide oleanane-type triterpenoid carboxylic acid 3,28-bidesmosides (GOTCAB) saponins are the major constituents of Gypsophila roots (Caryo-phyllaceae). In the present study, we aimed at investigating the sulphated GOTCAB in Bulgarian species: Gypsophila trichotoma and G. glomerata, using ultra high-performance liquid chromatography (UHPLC) co...

Series of aroyl hydrazones of 2H-chromene and coumarin carbaldehydes were synthesized and evaluated for their anticonvulsant activity and neurotoxicity. Further docking study on gamma-aminobutyric acid receptor was performed to elucidate their mechanisms of action. The highest protection was demonstrated by 2-furyl substituted 2H-chromene 8b in the...

Plants belonging to the Solanaceae family are generally used in Sudanese traditional medicine for the treatment of different ailments. This study aimed at the evaluation of in vitro antibacterial, antiproliferative and antioxidant activities of methanolic leaf extracts and steroidal glycoalkaloids fractions (SGAFs) of Solanum incanum L., S. schimpe...

A new convenient method for preparation of 2-aroyl-[1]benzopyrano[4,3-c]pyrazol-4(1H)-one derivatives 5b-g and coumarin containing hydrazide-hydrazone analogues 4a-e was presented. The antimycobacterial activity against reference strain Mycobacterium tuberculosis H37Rv and cytotoxicity against the human embryonic kidney cell line HEK-293 were teste...

Glucuronide oleanane-type triterpenoid carboxylic acid 3,28-bidesmosides (GOTCAB) saponins are the major constituents of Gypsophila roots (Caryophyllaceae). In the present study, we aimed at investigating the sulphated GOTCAB in Bulgarian species: Gypsophila trichotoma and G. glomerata, using ultra high-performance liquid chromatography (UHPLC) cou...

Objectives: The purpose of this study was to reveal different subgroups of patients with at least moderate risk of developing diabetes in the next 10 years, based on clustering of cardiovascular risk factors. Methods: We performed a one-center cross-sectional study of adult patients (n = 109, median age 45 years) with Findrisc score of above 11 out...

The presentation illustrates the isolation and identification of a new hydroxycinnamic acid amide (HCAA), as well as the tentative LC-HRMS identification of 16 known HCAAs from hydromethanolic extract of the roots of Solanum schimperianum Hochst.

Two coumarin based hydrazide/hydrazones were synthesized and their antineoplastic potential was investigated against two cell lines deriving from Chronic Lymphocytic Leukemia (CLL). Their cytotoxic effects were evaluated by MTT-dye reduction assay. The novel compounds showed strong cytotoxicity with notable IC50 values that were several times lower...

A newly discovered Nε-feruloyl lysine (1) together with 16 known hydroxycinnamic acid amides (HCAAs) were identified in the roots of Sudanese plant Solanum schimperianum Hochst (syn. Solanum carense Dunal, Solanaceae). The structure of 1 was established on the basis of 1D (¹H, ¹³C NMR) and 2D (¹H-¹H COSY, ¹H-¹³C HSQC) NMR analysis, together with UV...

Several 2H-chromene and coumarin based hydrazones were synthesized and evaluated for their anticonvulsant activity and neurotoxicity. The structures of the newly synthesized compounds were confirmed by 1H and 13C NMR, FTIR and HRMS (ESI) spectroscopy. The initial anticonvulsant screening was performed using the maximal electroshock induced seizure...

Vitamin D is a secosteroid produced in the skin from 7-dehydrocholesterol under the influence of ultraviolet irradiation. Vitamin D is also found in certain foods and is used to supplement dairy products. Both the natural form (vitamin D3, cholecalciferol) and the plant-derived form (vitamin D2, ergocalciferol) are present in the diet. These forms...

The theophylline-7-acetic acid (7-TAA) scaffold is a promising novel lead compound for antimycobacterial activity. Here, we derive a model for anti-TB activity prediction based on 14 7-TAA derivatives with amino acid moieties and their methyl esters. The model is applied to a combinatorial library, consisting of 40 amino acid and methyl ester deriv...

This study presents the LC-HRAM (Liquid Chromatography High-Resolution Accurate Mass) analysis of antioxidants as well as the total phenolic and flavonoid content of stem bark and root of Solanum carense (syn. Solanum schimperianum).

Para-aminosalicylic acid (INN aminosalicylic acid; PAS) is a bacteriostatic chemotherapeutic agent used in the therapy of all forms of tuberculosis, both pulmonary and extrapulmonary, caused by sensitive strains of the mycobacteria resistant to other antituberculotics or if the patient is intolerant towards other drugs. Since its clinical introduct...

Acetamides of theophylline-7-acetic acid (7-TAA) with amino acids were synthesized via a cost effective method directly from theophylline. The synthetic protocols involve: first the synthesis of N-chloroacetyl amino acid methyl ester, and second, its consequent interaction with deprotonated theophylline to give the corresponding acetamide. The desc...

The study evaluates the antimycobacterial activity of newly synthesized theophylline-7-acetic acid amides with different amino acids against Mycobacterium tuberculosis H37Rv, in vitro.

Theophylline-7-acetic acid (7-TAA) derivatives with several amino acids were screened for antiproliferative effects on acute (HL-60) and chronic (K-562) myeloid leukemia cells as well as on non-malignant cells derived from embryonic human kidney (HEK 293T). The anti-proliferative effects (IC 50) were revealed at relatively high concentrations, betw...

A series of amides were synthesized by condensation of theophylline-7-acetic acid and eight commercially available amino acid methyl ester hydrochlorides. Consecutive hydrolysis of six of the amido-esters resulted in the formation of corresponding amido-acids. The newly synthesized compounds were evaluated for their in vitro activity against Mycoba...

Pyrazinamide is an important antimycobacterial drug used in the contemporary short-course therapy of tuberculosis. Pyrazinamide is similar to isoniazid in its narrow spectrum of clinically-relevant antibacterial activity, which essentially includes only M. tuberculosis. The drug is bactericidal to slowly metabolizing organisms located within the ac...

A simple and efficient condensation of theophylline-7-acetic acid with aminoacid methyl ester is reported. The coupling reaction was carried out undermild conditions, utilizing the water soluble 1‑ethyl‑3‑(3‑dimethylaminopropyl)carbodiimide (EDCI) with hydroxybenzotriazole (HOBT) in dichloromethane(CH2Cl2). The method offered high yield, and easy h...

Part I of this review provided the pharmaceutical and non-clinical profile of metamizole, a non-narcotic analgesic with excellent analgesic and antipyretic effects. Metamizole is banned drug in many countries (United States, Japan, Australia, part of the European Union and nearly 30 other countries) for more than 40 years, where it is completely un...

Metamizole, a nonnarcotic analgesic, has been used to treat pain and fever for almost 90 years in some countries, while in others it is completely unknown or forgotten. It was synthesized by the German company Hoechst AG in 1920, and its mass production started in 1922. Metamizole remained freely available worldwide until the 1970s, when it was fou...

The present study is a review of known methods and strategies for synthesis of amides with emphasis on glutamic acid (GA) amides. Amides can be prepared by activation of the corresponding carboxylic acids to acyl halides (chlorides and fluorides), acyl azides, anhydrides or esters using various coupling reagents like carbodiimides (DCC, EDC, DIC, e...

A simple and rapid method of excised root cultures from six Gypsophila species was performed allowing continuous growth without phytohormones. Established on MH3 medium from solid-grown seedlings these roots were subcultured for 1 year on a solid medium before being transferred in a liquid medium to obtain substantial biomass for saponin content an...

The study describes the establishment and propagation, as well as saponin elucidation of in vitro root cultures of Gypsophila glomerata.