Picea sylvestris essential oil as a green corrosion inhibitor for mild steel in 1M HCl solution

With its superior mechanical and physical qualities, carbon steel finds extensive usage in several fields. Its primary flaw is that it easily corrodes, especially in acidic environments. Globally, scientists are researching green corrosion inhibitors, which are primarily defined as plant extracts and essential oils that are cheap, safe, non-toxic, and have a high corrosion inhibition efficiency. The study of Pinus Sylvestris essential oil as a green corrosion inhibitor of steel in 1M HCl serves as the foundation for our investigation. Through hydrodistillation with a Clevenger-style device, the essential oil of fresh, dried Pinus Sylvestris needles was recovered. Different inhibitor doses and immersion periods in HCl were used to calculate the internal efficiency (IE). Utilizing Polarization Measurements and Electrochemical Impedance Spectroscopy (EIS), the oil's inhibitory effects were estimated. Using electrochemical methods, it was determined that the optimal inhibitor concentration is 100 ppm. The effectiveness of the inhibition increases during the time of 1 to 4 hours of immersion. Also, this essential oil is a mixed corrosion inhibitor with dominant control of cathodic reaction

Black Pine (Pinus nigra) Essential Oil as a Green Corrosion Inhibitor for Carbon Steel

In this work, the essential oil of black pine (Pinus nigra J. F. Arnold) was used for the first time as a natural, ecological, and sustainable corrosion inhibitor for the acid cleaning of carbon steel. The essential oil was extracted by hydrodistillation using a Clevenger-type apparatus, and the oil was analyzed by gas chromatography–flame–ionization detection (GC–FID) and gas chromatography–mass spectrometry (GC–MS). The most abundant components in the essential oil were a-pinene, germacrene D, (E)-cariophyllene, and b-pinene. The inhibition efficiency was determined by electrochemical methods (electrochemical impedance spectroscopy and potentiodynamic polarization measurements). The results showed that the inhibitory efficiency of the black pine essential oil increases with time, reaching the highest values after 4 h of immersion for all inhibitor concentrations. It was also shown that black pine essential oil is a mixed-type inhibitor. The contact angle measurements confirmed that the black pine essential oil, as a new natural, environmentally safe inhibitor, is able to protect carbon steel from corrosion in a 1 M HCl solution

Flavonoidi iz cvetova Cephalaria pastricensis i njihova antiradikalska aktivnost

Two flavonoid glycosides 1 and 2 having the luteolin structure were isolated from flowers of the endemic plant species Cephalaria pastricensis. They were identified by (1)H and (13)C NMR, as well as UV/Vis spectroscopy. The structures of 1 and 2 were also confirmed by the spectral data of aglycones and TLC of the sugars obtained after acid hydrolysis. Flavones 1 and 2 showed significant antiradical activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay.Iz cvetova Cephalaria pastricensis izolovana su dva heterozidna flavonoida sa luteolinskim aglikonom (1 i 2). Wihova struktura je određena primenom 1H i 13C-NMR i UV spektroskopije. Strukture flavona 1 i 2 su potvrđene i spektrima aglikona, odnosno tankoslojnom hromatografijom oslobođenih šećera nakon kisele hidrolize. Jedinjenja 1 i 2 su pokazala značajnu antiradikalsku aktivnost u 1,1-difenil-2 pikrilhidrazil (DPPH) testu

Fitohemijsko ispitivanje biljne vrste Anthemis cotula

The investigation of roots of Anthemis cotula (Asteraceae) from cast Serbia revealed, in addition to polyacetylenes previously isolated from the same species, three prenylated 4-hydroxyacetophenones, detected for the first time in any Anthemis species. It is possible that they act as phytoalexins in the plant. From the aerial parts, six linear sesquiterpene lactones (four known and two new ones), as well as two known flavones, apigenin and hispidulin, were isolated.Novo ispitivanje korena biljke A. cotula (Asteraceae) pokazalo je, pored četiri već izolovana poliacetilena, i prisustvo tri prenilovana 4-hidroksiacetofenona koji do sada nisu bili izolovani iz ovog roda. Iz nadzemnog dela biljke izolovano je šest linearnih seskviterpenskih laktona, od koji su dva nova, dok su preostali ranije nađeni u istoj biljci. Takođe su u nadzemnom delu identifikovana dva poznata flavona, apigenin i hispidulin

Antifungalna aktivnost terpenoida davanonskog tipa izolovanih iz Artemisia lobelii Var. canescens

Five tetrahydrofuran sesquiterpenes, so-called davanones, and coumarin umbelliferone isolated from Artemisia lobelii All. var. canescens (DC.) Briqu, were tested for antifungal activity. All the compounds inhibited the growth of the applied fungi. The overall activity of one of them, 2-hydroxy-2,6,10-trimethyl-7,10-epoxy-dodeca-3,11-dien-5-on, was comparable to that of the antibiotic bifonazole.Pet tetrahidrofuranskih terpenoida davanonskog tipa i kumarin umbeliferon koji su prethodno izolovani iz biljne vrste Aretemisia lobelii var. conescens ispitivani su na antifungalnu aktivnost. Sva testirana jedinjenja inhibiraju rast primenjenih kultura gljiva. Najveću aktivnost, koja se može meriti sa aktivnošću komercijalnog antibiotika bifonazola, pokazuje 2-hidroksi-2,6,10-trimetil-7,10-epoksidodeka-3,11-dien-5-on

Antifungal activity of davanone-type sesquiterpenes from Artemisia lobelli var. conescens

Five tetrahydrofuran sesquiterpenes, so-called davanones, and coumarin umbelliferone isolated from Artemisia lobelii All. var. canescens (DC) Briqu, were tested for antifungal activity. All the compounds inhibited the growth of the applied fungi. The overall activity of one of them 2-hydroxy-2,6,10-trimethyl-7,10-epoxydodeca- 3,11-dien-5-on, was comparable to that of the antibiotic bifonazole.Pet tetrahidrofuranskih terpenoida davanonskog tipa i kumarin umbeliferon koji su prethodno izolovani iz biljne vrste Aretemisia lobelii var. conescens ispitivani su na antifungalnu aktivnost. Sva testirana jedinjenja inhibiraju rast primenjenih kultura gljiva. Najveću aktivnost, koja se može meriti sa aktivnošću komercijalnog antibiotika bifonazola, pokazuje 2-hidroksi-2,6,10-trimetil-7,10-epoksidodeka-3,11-dien-5-on.Projekat ministarstva br. 175

Supplementary data for the article: Pavlović, T.; Dimkić, I.; Andrić, S.; Milojković-Opsenica, D.; Stanković, S.; Janaćković, P.; Gavrilović, M.; Ristivojević, P. Linden Tea from Serbia – an Insight into the Phenolic Profile, Radical Scavenging and Antimicrobial Activities. Industrial Crops and Products 2020, 154, 112639. https://doi.org/10.1016/j.indcrop.2020.112639

Supplementary material for: [https://doi.org/10.1016/j.indcrop.2020.112639]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/4040

Picea omorika essential oil as a green corrosion inhibitor for mild steel in 1M HCl solution

Etarska ulja i ekstrakti biljaka spadaju u zelene inhibitore korozije jer su ekološki prihvatljivi, jeftini, netoksicni po ljude i poseduju veliku efikasnost inhibicije korozije. U našem istraživanju proucavali smo etarsko ulje Picea omorika (Pancic) Purk., kao zelenog inhibitora korozije na celiku u 1M HCl. Etarko ulje je dobijeno hidrodestilacijom svežih iglica korišcenjem aparature po Klevendžeru. Inhibitorska efikasnost je odre ena za razlicite koncentracije inhibitora, tokom razlicitog vremena delovanja agensa korozije. Koroziona stabilnost inhibitora je odre ena elektrohemijskim metodama, spektroskopijom elektrohemijske impedancije (EIS) i polarizacionim merenjima. Pokazano je da se optimalna efikasnost inhibicije korozije od 92% postiže sa 200 ppm ulja Panciceve omorike nakon cetiri sata.Essential oils and extracts of plants are green corrosion inhibitors because there are environmentally friendly, non-toxic, inexpensive, not harmful to human health, and they possessing high corrosion inhibition efficiency. In our research, we studied the essential oil of Picea omorika (Pancic) Purk. as a green corrosion inhibitor on steel in 1M HCl. Essential oil of fresh dried needles was obtained by hydrodistillation using the Clevengertype apparatus. IE was determined for different concentrations of inhibitors, as well as for different times of immersion in HCl. Electrochemical Impedance Spectroscopy (EIS) and Polarization Measurements were utilised to estimate the IE of the oil. Our results showed that the optimal concentration of 200 ppm P. omorika essential oil providing 92% inhibition efficiency after four hours

The activity concentrations 40-K, 137-Cs, 210-Pb and effective dose of ingestion of the radionuclides in selected medicinal herbs from the region of Majdanpek

Lekovite biljke imaju dugu istoriju upotrebe širom sveta u tradicionalnoj medicini. MeĎutim, njihova upotreba, kao i upotreba biljnih proizvoda mora se kontrolisati,kako bi se izbegla pojava neţeljenih efekata na zdravlje ljudi. Specifične aktivnosti radionuklida 40K, 137Cs i 210Pb u uzorcima lekovitih biljaka izmerenesu pomoću poluprovodničkog HPGe spektrometarskog sistema, na osnovu čega je odreĎena prosečna godišnja efektivna doza ingestije za odrasle koji piju dnevno 200 ml čaja pripremljenog od lekovitih biljaka. U radu je prikazana radiološka analiza 7 odabranih lekovitih biljaka sa područja Majdanpeka. Dobijene vrednosti za efektivnu dozu ingestije slične su vrednostima objavljenim u drugim studijama i manje su od 100 μSv, što upućuje na zaključak da svakodnevna upotreba čajeva od analiziranih lekovitih biljaka sa područja Majdanpeka ne predstavlja značajan radiološki rizik po zdravlje.Medicinal plants have a long history in traditional medicine worldwide. However, their use, as well as the use of plant products, must be controlled in order to avoid the occurrence of undesirable effects on human health. Specific activities of radionuclides 40K, 137Cs and 210Pb in samples of medicinal plants were measured using a semi-conductor HPGe spectrometer system. The average annual effective dose for adults due to daily ingestion of 200 ml herbal infusion prepared from medicinal plants is determined. In this paper a radiological analysis of 7 selected medicinal plants from the area of Majdanpekis presented. The values obtained for an effective dose of ingestion are similar to the values published in other studies and are less than 100 μSv, suggesting that the daily use of herbal infusions from analyzed medicinal plants from the Majdanpek area does not represent a significant radiological health riskProceedings: [http://vinar.vin.bg.ac.rs/handle/123456789/8681]XXX симпозијум ДЗЗСЦГ (Друштва за заштиту од зрачења Србије и Црне Горе), 2- 4. октобар 2019. године, Дивчибаре, Србиј

Fatty acid composition of the cypselae of two endemic Centaurea species (Asteraceae)

The fatty acid composition of cypselae of two endemic species from Macedonia, Centaurea galicicae and C. tomorosii, is analysed for the first time, using GC/MS (gas chromatography/mass spectrometry). In the cypselae of C. galicicae, 11 fatty acids were identified, palmitic (hexadecanoic) acid (32.5%) being the most dominant. Other fatty acids were elaidic [(E)-octadec-9-enoic] acid (13.9%), stearic (octadecanoic) acid (12.8%) and linoleic [(9Z,12Z)-9,12-octadecadienoic] acid (10.6%). Of the 11 identified fatty acids, seven were saturated fatty acids, which represented 41.5% of total fatty acids, while unsaturated fatty acids altogether constituted 58.5%. In the cypselae of C. tomorosii, five fatty acids were identified. The major fatty acid was linolelaidic [(9E,12E)-octadeca- 9,12-dienoic] acid (48.8%). The second most dominant fatty acid was oleic [(9Z)-octadec-9-enoic] acid (34.2%). Thus, unsaturated fatty acids were present with 83%. The other three fatty acids identified were saturated fatty acids, which represented 17% of total fatty acids. As a minor fatty acid, levulinic (4-oxopentanoic) acid was determined in both C. galicicae and C. tomorosii (0.3% and 3.2%, respectively). The obtained results differ from published data on dominant fatty acids in the cypselae of other species belonging to the same section as the species investigated in the present paper (section Arenariae, subgenus Acrolophus, genus Centaurea). They also, differ from published data referable to other genera belonging to the same tribe (Cardueae). The general chemotaxonomic significance of fatty acids is discussed. © 2017 Institute of Botany and Botanical Garden Jevremovac, Belgrade