scholarly journals Biological activity and structure of natural petroleum acids from Lower oil fractions of "Velebit" oil

2002 ◽  
pp. 135-142 ◽  
Author(s):  
Vera Cirin-Novta ◽  
Ksenija Kuhajda ◽  
Slavko Kevresan ◽  
Julijan Kandrac ◽  
Ljubica Radic

Natural petroleum acids of naphthenic type such as carboxylic acids from petroleum basins of Vojvodina are interesting because of diverse possibilities for their use, most importantly for their biological activity and the potential use as plant growth stimulators. The paper is concerned with biological activity of natural petroleum acids isolated form "Velebit", oil commercial fraction (168-290 ?C). Petroleum acids were isolated by alkaline extraction and turned into methylesters with diazomethane. Subsequently, group-structure n-d-M-analyses and GC-MS-analysis have been used to determine individual acid structures. Structures of aliphatic. mono and bicyclic acids of average molecular mass 144-326 have been determined. Biological activity of auxine type has been assessed in the K-naphthenate form, and distinct activity was detected in the solutions of 10-7 mol dm-3.


2003 ◽  
pp. 49-54 ◽  
Author(s):  
Vera Cirin-Novta ◽  
Slavko Kevresan ◽  
Ksenija Kuhajda ◽  
Julijan Kandrac ◽  
Ljubica Radic ◽  
...  

Petroleum acids can be obtained from oil and oil derivatives by alkaline extraction. The aim of this work was to optimize the process of alkaline extraction of petroleum acids from light commercial oil fractions of Vojvodina "Velebit" oil by changing the contact time of oil fraction with strong alkali and by changing the reaction temperature. Optimal conditions for isolation of petroleum acids have been determined to be 9 hours of contact time and reaction temperature of 90?C. Under these conditions the obtained petroleum acids yield was 88.38%. Identification of isolated acids was performed by GC-MS analysis.



2008 ◽  
Vol 59 (4) ◽  
Author(s):  
Gabriela Laura Almajan ◽  
Stefania Felicia Barbuceanu ◽  
Ioana Saramet ◽  
Mihaela Dinu ◽  
Cristian Vasile Doicin ◽  
...  

5-[4-(4X-phenylsulfonyl)phenyl]-1,3,4-oxadiazole-2-thiols, X=H, Cl, Br, reacted with ethyl chloroacetate to give S-alkylated compounds. Aminomethylation of the thione form of oxadiazoles yielded N(3)-derivatives. All the products have been characterized by elemental analysis, IR, 1H-NMR and 13C-NMR. The plant-growth regulating effects of the title compounds were examined. From the biological activity results, we found that most compounds showed weak stimulatory activities at low concentrations.



2020 ◽  
Vol 10 (3) ◽  
pp. 312-321
Author(s):  
Idin Sahidin ◽  
Carla W. Sabandar ◽  
Wahyuni ◽  
Rini Hamsidi ◽  
Sandra Aulia Mardikasari ◽  
...  

Background: Marine sponges provided a great source of natural products with promising biological activity. This study was aimed to investigate the chemical constituents of methanol extracts of selected Indonesian marine sponges (Callyspongia sp., Clathria sp., Melophlus sarasinorum, and Xestospongia sp.), collected from the Saponda Islands, Southeast Sulawesi, Indonesia as well as to evaluate their antimicrobial and antioxidant activities. Methods: LCMS/MS analysis used to identify the compounds. Agar well diffusion and DPPH assays were used to evaluate the antimicrobial and antioxidant activities. Results: Chemical screening reported alkaloids, terpenoids, steroids, and saponins from all investigated sponges. The LC-MS/MS analysis identified various compounds which mainly contained steroids. Antimicrobial activity (against Bacillus subtilis, Escherichia coli, Salmonella enterica, and Candida albicans) was only shown by the Xestospongia sp. extract. Meanwhile, extracts of M. sarasinorum, Xestospongia sp., and Callyspongia sp. exhibited potent radical scavenging activity. Conclusion: The study concluded that the selected sponges could provide various groups of compounds. Methanol extracts of these sponges could be used as sources of antimicrobial and antioxidant agents.



1990 ◽  
Vol 55 (8) ◽  
pp. 1959-1967 ◽  
Author(s):  
Petr Vaňura ◽  
Pavel Selucký

The extraction of polyethylene glycol of average molecular mass 400 (PEG 400) with dicarbolide solution in nitrobenzene and of longer-chain polyethylene glycol, of average molecular mass 1 500 (PEG 1 500), with chlorinated dicarbolide solution in nitrobenzene was studied. During the extraction of PEG 400, the polyethylene glycol solvates the Horg+ ion in the organic phase giving rise to the HLorg+ species (L is polyethylene glycol). The obtained value of the extraction constant Kex(HLorg+) = 933 is consistent with published data of metal extraction. Extraction of PEG 1 500 was treated applying the simplified assumption that the thermodynamic behaviour of PEG 1 500 is the same as that of n molecules of polyethylene glycol with relative molecular mass 1 500/n, each solvating one cation. For this model, the value of n = 3.2 ± 1.1 and the values of the extraction constants of the HL1/n,org+ and HL2/n,org+ species were obtained by using the adapted program LETAGROP. This value of n is consistent with published extraction data in the presence of polyethylene glycol with a relative molecular mass from 200 to 1 000.



Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1026 ◽  
Author(s):  
Laís G. Fregolente ◽  
João Vitor dos Santos ◽  
Giovanni Vinci ◽  
Alessandro Piccolo ◽  
Altair B. Moreira ◽  
...  

Hydrochar is a carbon-based material that can be used as soil amendment. Since the physical-chemical properties of hydrochar are mainly assigned to process parameters, we aimed at evaluating the organic fraction of different hydrochars through 13C-NMR and off-line TMAH-GC/MS. Four hydrochars produced with sugarcane bagasse, vinasse and sulfuric or phosphoric acids were analyzed to elucidate the main molecular features. Germination and initial growth of maize seedlings were assessed using hydrochar water-soluble fraction to evaluate their potential use as growth promoters. The hydrochars prepared with phosphoric acid showed larger amounts of bioavailable lignin-derived structures. Although no differences were shown about the percentage of maize seeds germination, the hydrochar produced with phosphoric acid promoted a better seedling growth. For this sample, the greatest relative percentage of benzene derivatives and phenolic compounds were associated to hormone-like effects, responsible for stimulating shoot and root elongation. The reactions parameters proved to be determinant for the organic composition of hydrochar, exerting a strict influence on molecular features and plant growth response.



Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3337
Author(s):  
Alberto Martín-Pérez ◽  
Daniel Ramos ◽  
Javier Tamayo ◽  
Montserrat Calleja

In this work we study the different phenomena taking place when a hydrostatic pressure is applied in the inner fluid of a suspended microchannel resonator. Additionally to pressure-induced stiffness terms, we have theoretically predicted and experimentally demonstrated that the pressure also induces mass effects which depend on both the applied pressure and the fluid properties. We have used these phenomena to characterize the frequency response of the device as a function of the fluid compressibility and molecular masses of different fluids ranging from liquids to gases. The proposed device in this work can measure the mass density of an unknown liquid sample with a resolution of 0.7 µg/mL and perform gas mixtures characterization by measuring its average molecular mass with a resolution of 0.01 atomic mass units.



2012 ◽  
Vol 67 (3-4) ◽  
pp. 123-128
Author(s):  
Anna Pachuta-Stec ◽  
Urszula Kosikowska ◽  
Anna Chodkowska ◽  
Monika Pitucha ◽  
Anna Malm ◽  
...  

N-Substituted amides of endo-3-(3-methylthio-1,2,4-triazol-5-yl)bicyclo[2.2.1]hept-5-ene- 2-carboxylic acid and 1-(5-methylthio-1,2,4-triazol-3-yl)cyclohexane-2-carboxylic acid were prepared by the condensation reaction of endo-S-methyl-N1-(bicyclo[2.2.1]hept-5-ene-2,3- dicarbonyl)isothiosemicarbazide and S-methyl-N1-(cyclohexane-2,3-dicarbonyl)isothiosemicarbazide with primary amines. The synthesized compounds were screened for their microbiological and pharmacological activities



OENO One ◽  
2021 ◽  
Vol 55 (4) ◽  
pp. 145-157
Author(s):  
Mónica Oyuela Aguilar ◽  
Florencia Álvarez ◽  
Daniela Medeot ◽  
Edgardo Jofré ◽  
Liliana Semorile ◽  
...  

The rhizosphere-associated microbiome has diverse functions that support plant growth and health, varying among plant species, vegetation growth stages and environmental habitats. This microbiome includes a group of bacteria denominated plant growth-promoting rhizobacteria (PGPR) which can colonize plant roots. Certain PGPR isolates improve the ability of plants to adapt to a stressful environment. In this study, we collected and characterised the rhizosphere-associated bacteria, or epiphytic rhizobacteria, from Malbec and Cabernet-Sauvignon vineyards from the main wine-producing provinces of Argentina to analyse their potential use as biologic fertilisers and/or as pathogen-control agents. A total of 170 bacterial isolates were obtained, distributed into eleven different genera and classified into three phyla, Proteobacteria, Actinobacteria and Firmicutes. The in vitro analysis for plant-growth-promoting (PGP) activities demonstrated that a significant number of bacterial isolates had one or more of these traits. The Pseudomonas was the genus with the highest number of isolates and PGP activities, followed by the Arthrobacter, Serratia, Bacillus andPantoea. We observed that bacterial isolates identified as Bacillus exhibited a remarkable production of hydrolytic enzymes related to biocontrol activities. Biocontrol trials from the Bacillus collection revealed that at least five isolates were able to inhibit the fungal growth of Botrytis cinerea and Alternaria alternata. The results obtained suggest the biological potential of each isolate and the relevance of proceeding to greenhouse and field assays to obtain long-term environmentally compatible bio-products for vineyard management.





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