Alexander Yesayan’s scientific contributions

Background: Nowadays, the search for novel alternative antimicrobials has gained significant popularity. This surge is driven by the vast array of adverse effects of synthetic antimicrobials on human health and the environment. Consequently, the study of new natural sources of comparably ecologically safe and simultaneously effective antimicrobials is extremely important. In this context, the interest in wine by-products is growing due to their diverse beneficial properties. Traditionally considered industrial waste, wine by-products now offer promising opportunities. Notably, the unique climatic and geographical features of Armenian black grape varieties, such as Areni sev, make their by-products an attractive subject for study, with potential applications in agriculture. Objective: The study aims to investigate the antifungal and antibacterial properties of wine by-products obtained from the Areni sev grape variety. Methods: For the extraction of bioactive compounds, frozen and dry samples were homogenized. The maceration was performed in 70% hydroethanolic solution after incubation on a magnetic stirrer at room temperature. The obtained extracts were filtered through a 0.45 µm filter and evaluated for antifungal and antibacterial activity by disco-diffusion method. Results: Hydroethanolic extracts of wine by-products have exhibited antifungal and antibacterial activities. Specifically, the frozen samples demonstrated low antifungal activity against the Penicillium canescens with a 7.5 mm growth inhibition zone. In contrast, dried samples showed no antifungal activity. The highest antifungal activity was observed against Aspergillus niger with growth inhibition zones of 18 mm (frozen samples) and 15 mm (dried samples), respectively. Regarding antibacterial activity, wine by-product hydroethanolic extracts showed extremely low efficacy. Notably, frozen samples exhibited an 8 mm growth inhibition zone against Curtobacterium flaccumfaciens and 6.35 mm against Xanthomonas vesicatoria. Extracts from dried samples demonstrated a 6.35 mm inhibition zone against Curtobacterium flaccumfaciens and a 7 mm growth inhibition zone against Xanthomonas vesicatoria. Conclusion: Summarizing the results of the conducted experiments, it can be concluded that the used wine by-product derived from Areni sev grape has demonstrated notable antimicrobial activities, with a stronger emphasis on antifungal properties. The extracts obtained from frozen samples exhibited greater efficacy than those derived from dried samples. Future research plans include a more detailed investigation of Areni sev grape wine by-products. Keywords: wine by-product, grape pomace, Areni sev, bioactive compounds, antimicrobial properties

Background: For generations, vegetarian food products have been fundamental to the diets of rural Armenian communities. However, villages situated near territories near mines face severe chemical contamination of soil, air and water. This poses a significant problem in Syunik Region, Republic of Armenia (RA), where metal mines have operated for over 50 years. Notably, this region is one of Armenia’s most important agrarian areas ensuring food production for the entire country. Therefore, assessing potential chemical contamination risks in food products from this region is crucial. Objectives: This article assesses the risks associated with chemical contamination of traditional vegetarian food products commonly consumed in the villages of Artsvanik, Sevaqar, and Chapni in Syunik region of Republic of Armenia (RA). Specifically, this region has hosted both a thriving mining industry and agriculture for over 50 years. Results: According to the results obtained, there was no significant increase in the concentrations of most studied metals in the plant samples. Conclusions: Concentrations of most studied metals remained unchanged. However, copper (Cu) and molybdenum (Mo) levels were elevated in nettle samples. Long-term consumption of nettle-based foods, from this region may pose health risks. In contrast, consuming other plants is considered lower risk. Nevertheless, to minimize health risks ongoing monitoring of Cu and Mo concentration in this area is essential. Keywords: heavy metals, vegetarian food, Phaseolus vulgaris, Urtica dioica, Malus domestica, Solanum tuberosum.

Background: Food safety has been a concern since ancient times. In the 21st century, technogenic pollution from harmful natural and synthetic chemicals poses a significant threat to food safety. These substances can enter the various consumption chains and to be transmitted from organism to organism, ultimately reaching the human body through both animal-sourced and plant-sourced food products. Animal-sourced food is the main source of protein and essential compounds. Therefore, assessing the safety of animal-sourced food products, which are produced and consumed by populations in areas of technogenic pollution (such as factory surroundings and military conflict zones) is crucial. Objectives: The primary goal of this research was to study the contamination of animal-sourced foods (eggs and hen) produced in urban area of one of regions of Armenia’s regions, which has a heavy legacy of industrial pollution. Context and purpose of this study: This study aimed to assess and compare the concentrations of alkaline, alkaline-earth and transition elements, including heavy metals, in common animal-sourced food products produced in Kapan city, Armenia, and Syunik village, which borders Kapan city. To achieve this, poultry (hen) and egg samples were analyzed using inductively coupled plasma-mass spectrophotometry (ICP-MS) to detect the following heavy metals: Li; Na; Mg; Al; K; Ca; Ti; V; Cr; Fe; Mn; Co; Ni; Cu; Zn; As; Se; Sr; Mo; Cd; Sn; Sb; Ba and Pb. Results: The concentrations of heavy metals were elevated in all animal-sourced food samples from Syunik Village and Kaplan City. Similarly, general concentrations of alkaline and alkaline-earth metals were also increased. Comparative analysis revealed that concentrations of all studied elements were lower in Syunik Village than in Kaplan City. Notably, all detected levels were below the maximum permissible concentrations (MPC). Conclusions: Elevated concentrations of heavy metals were observed in all studied egg and hen samples from Syunik village and Kapan city. This increase is likely attributed to the mining industry development in the Syunik region. Although the detected levels are below the maximum permissible concentrations established by the World Health Organization (WHO), continuous monitoring of heavy metal concentrations in this area is recommended to mitigate potential health risks associated with chronic consumption of locally produced eggs. Keywords: food safety, animal-sourced food, heavy metals, technogenic pollution, remediation.

Background: Pursuing alternative starting materials has gained significant importance in the food and drug industries, driven by the global shift towards sustainable and renewable resources. Terpenes, naturally occurring hydrocarbons derived from plants, present a promising solution due to their abundant availability and range of physiological activities, including antioxidant, anti-inflammatory, antimicrobial, and anticancer properties. Objective: This study aims to develop a waste-free synthesis methodology for functionalizing limonene and myrcene, two notable terpenes, through Atom Transfer Radical Reactions (ATRR). The objective is to achieve high yields and purities while enhancing the therapeutic potential of these compounds and adhering to green chemistry principles. Methods: A catalytic complex of Cu(I)Br and dimethyl sulfoxide (DMSO) was used to facilitate the coupling of limonene and myrcene with various trichloroacetic acid derivatives. Reactions were performed at 80°C for 90 minutes, and products were purified by column chromatography. The synthesized compounds were characterized using Gas Chromatography-Mass Spectrometry (GC-MS) and Nuclear Magnetic Resonance (NMR). Microbiological analyses were conducted using the disk-diffusion method, and statistical analyses were performed to assess the reliability of the experiments. Results: The ATRR methodology enabled the efficient functionalization of limonene and myrcene, achieving high yields and purities. The best yield for limonene was 70%, and for myrcene, 82%, both using trichloroacetonitrile. The Cu(I) catalytic system showed dualistic biological effects, with 3% concentration exhibiting strong bactericidal and fungicidal activity, while 0.03% promoted growth. These results demonstrate the potential of the methodology and the catalytic system for bioactive compound synthesis and agricultural applications. Conclusion: This study demonstrates the viability of ATRR for efficiently functionalizing limonene and myrcene, achieving high yields and purities. The synthesized compounds show promise for pharmaceutical development. The dual antibacterial and antifungal activities of the Cu(I) catalytic system also suggest potential applications in wastewater reutilization. Future work should explore the biological effects and environmental impact of this process. Keywords: Terpenes, ATR reactions, Green Chemistry, Bioactive compounds, Therapeutic potential.

Background: Carnivorous fungi are commonly found inagricultural soils around the world, including RA. These fungi are trapping and eating microscopic nematode worms that reside in the soil and water. Phytopathogenic nematodes are harmful for agriculture, significantly decreasing the quality of vegetables and other crops. The classical pesticides are either ineffective or unsafe for human health and environment. Thus, an application of innovative biopreparations that address these safety and efficacy concerns are more preferable in terms of green agriculture and pesticide free food production. Objectives: This ecological and genetical study of Armenian carnivorous fungi, includingthe isolation, identification and in vitro study of nematicide activity against the local nematode pests, can be prospective for obtaining pesticide-free vegetables. Results: In this study, 50 strains of predatory fungi were isolated. According to the obtained data, local predatory fungi isolated from Armenian soils have demonstrated higher activity against both vinegar eel (Turbatrix aceti test object) and the local species of potato hookworm (Globodera rostochiensis) compared to the analogous trade preparations. Conclusions: The collected data demonstrated that different species of carnivorous fungi are present in Armenian soil. Particularly, the studied Orbilia oligospora (Fresen.) Baral and E. Weber (syn. Arthrobotrys oligospora (Fresen.) and Orbilia brochopaga Drechsler species of fungi had shown high activity against the potato hookworm. The identified fungal strains have demonstrated more efficiency, than the fungi-based trade biopesticides. Probably it is related to the features of source of pathogen and fungi isolation, which defines the strain-specificity of nematicide enzymes of the observed fungi. Keywords: nematophagous fungi, pesticide-free vegetables, nematode toxins, fungal nematicide enzymes, Orbilia oligospora, Orbilia brochopaga, potato hookworm

Background: The safety of agrarian preparations used for crop protection is a critical issue. In these regards, the minimization of usage of chemical pesticides containing artificial harmful substances is very important. Thus, the elaboration of innovative harmless biopesticides, based on biological enemies of pests, is very desirable. Microbe-based biopesticides can significantly increase the quality of agricultural production. Objectives: This research aims to develop ecologically safe, entomopathogenic microbe based biopesticides for use in green agriculture to improve agricultural production qualityIt includes the quality of vegetables, cereals, and fruits, as well as meat, milk, and eggs from animals that consume plant-based feed cultivated using recommended methodologies. Context and purpose of this study: This article was devoted to the consideration of bactericide effect of non-cellular extracts of entomopathogens against the various phytopathogens, as the potential prospective innovation for elaboration of plant protection safe biopesticides. Results: The majority of the studied entomopathogens can synthesize the compounds which inhibit the growth of phytopathogens. Entomopathogenic strains BT 2675, BL 200-4, and LS 2728 were found to significantly inhibit the growth of phytopathogens such as Pectobacterium, Xanthomonas, Rhodococcus, Curtobacterium, and Pseudomonas genera. According to spectroscopy the antiphytopathogenic effect is caused by an active component which is probably lipoprotein complex. Further detailed research on this is planned. Conclusions: Non-cellular extracts of entomopathogenic Bacillus are effective against the various plant pathogens. The identified antimicrobial properties of non-cellular extracts of entomopathogenic can be potentially used for the elaboration of plant protection safe biopesticides. Keywords: Bacillus thuringiensis (BT), Brevibacillus laterosporus (BL), Lysinibacillus sphaericus (LS), non-cellular extract, phytopathogen, entomopathogen, safe biopesticide