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

Chemical composition, antibacterial and antifungal activity of the essential oils of Cotinus coggygria from Serbia

Essential oils from leaves with young branches of Cotinus coggygria Scop. from two localities in Serbia (Deliblatska peščara and Zemun), obtained by hydrodistillation, were analyzed by GC-MS. Thirty-one component were identified from both oils and among them monoterpenic hydrocarbons were the dominant class (87.4 and 93.1 %). The dominant constituent in both essential oils was limonene (47.0 and 39.2 %). Both oils were also tested for antibacterial and antifungal activities. In comparison to streptomycin, both oils showed slightly higher activity (against most Gram-positive bacteria) in the disc diffusion method and slightly lower activity when the microdilution method was employed. They also exhibited antifungal potential higher than that of the commercial fungicide bifonazole.Primenom GC-MS metode identifikovana je ukupno 31 komponenta u oba etarska ulja izolovana destilacijom vodenom parom iz lišća i mladih grančica biljne vrste Cotinus coggygria Scop. sa dva lokaliteta u Srbiji (Deliblatska peščara i Zemun). Takođe je ispitana antibakterijska i antifungalna aktivnost oba uzorka. U oba ulja najzastupljeniji su bili monoterpenski ugljovodonici (87,4 i 93,1 %), među kojima je dominantna komponenta limonen (47,0 i 39,2 %). Antibakterijska aktivnost je određena difuzionom i mikrodilucionom metodom, a antifungalna aktivnost modifikovanom mikrodilucionom metodom. Prema dufuzionoj metodi, oba ulja su pokazala nešto bolje antibakterijsko dejstvo (prvenstveno na gram-pozitivne bakterije) nego streptomicin, dok je na osnovu mikrodilucione metode njihova aktivnost bila nešto slabija. U poređenju sa bifonazolom, oba testirana ulja su pokazala nešto bolje antifungalno dejstvo.nul

Heavy Metals Content in Selected Medicinal Plants Produced and Consumed in Serbia and Their Daily Intake in Herbal Infusions

The heavy metals content (HMs) was investigated in 14 different medicinal plants collected from the three regions in Central Serbia, Zlatar, Sokobanja, and Kopaonik. The concentrations of Cd, Cr, Ni, Hg and Pb were determined: Cd (<0.03–2.72 mg/kg); Cr (<0.08–12.1 mg/kg); Ni (<0.08–12.2 mg/kg); Pb (0.6–49.0 mg/kg); the Hg concentration was below the detection limit of 0.06 mg/kg in all samples. The daily intake of HMs due to ingestion of 200 mL of herbal infusion was in all cases below the recommended limit prescribed by the World Health Organization. The estimated daily intake values were below the values for the oral reference dose regulated by the U.S. Environmental Protection Agency (USA EPA). The target hazard quotient and hazard index for Cd, Cr Ni, and Pb were below 1. Nevertheless, due to the tendency of heavy metals to accumulate in the organism, attention should be paid to the daily intake of herbal infusion during long-term usage. Specifically, it is recommended to consume not more than one cup (200 mL) of infusion per day made from thyme (Mt. Zlatar) and blueberry (Mt. Kopaonik), and not more than two cups per day for other herbs

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