scholarly journals Features of the Bioconversion of Pentacyclic Triterpenoid Oleanolic Acid Using Rhodococcus Actinobacteria

2022 ◽  
Author(s):  
Natalia A. Luchnikova ◽  
Polina Yu. Maltseva ◽  
Victoria V. Grishko ◽  
Irina B. Ivshina

The ability of actinobacteria of the genus Rhodococcus to transform oleanolic acid (OA), a plant pentacyclic triterpenoid, was shown for the first time using bioresources of the Regional Specialized Collection of AlkanotrophicMicroorganisms (IEGM; WDCM #768;www.iegmcol.ru). The most promising strains (R.opacus IEGM 488 and R.rhodochrousIEGM 285) were selected, and these catalyzed80% bioconversion of OA (0.5 g/L) in the presence of n-hexadecane (0.1% v/v) for seven days. The process of OA bioconversion was accompanied by a gradual decrease in the culture medium pH. Adaptive responses of bacterial cells to the OA effects included the formation of compact cellular aggregates, a marked change in the surface-to-volume ratio of cells, and a significant increase in the Zeta potential values. The results demonstrated that the process of OA bioconversion was catalyzed by membrane-bound enzyme complexes. Participation of cytochrome P450-dependent monooxygenases in the oxidation of the OA moleculewas confirmedusing specific inhibitors. The obtained data expand our knowledge on the catalytic activity of actinobacteria of the genus Rhodococcus and their possible use as biocatalysts for the bioconversion of complex hydrophobic compounds. The results can also be used inthe searchfor promising OA derivatives to be used in the synthesis of biologically active agents. Keywords: bioconversion, oleanolic acid, Rhodococcus, biologically active compounds

2019 ◽  
Vol 18 (10) ◽  
pp. 1405-1416 ◽  
Author(s):  
Isabel C.V. da Silva ◽  
Goran N. Kaluđerović ◽  
Pollyana F. de Oliveira ◽  
Denise O. Guimarães ◽  
Carla H. Quaresma ◽  
...  

Background: P. mucronata (Pm) comes from South America, Brazil and is characterized as “Maracujá de Restinga”. It is used in folk medicine for its soothing properties and in treating insomnia. Objective: The present study for the first time analyzed the antioxidant and cytotoxicity of the hydroalcoholic leaves extract and fractions from Pm. Method: The cytotoxicity test will be evaluated by different assays (MTT and CV) against human prostate cancer (PC3) and mouse malignant melanoma (B16F10) cell lines, and the antioxidant test by DPPH method. Results: β-Amyrin, oleanolic acid, β-sitosterol and stigmasterol were isolated of the most active, hexane fraction. These substances were tested against the tumor cell lines: β-sitosterol and stigmasterol showed the most relevant activity to PC3 in CV assay and, oleanolic acid to B16F10 by the MTT assay. In addition, it was possible to indicate that the mode of cell death for stigmasterol, presumably is apoptosis. In terms of antioxidant activity, the hydroalcoholic leaves extract presented higher activity (EC50 133.3 µg/mL) compared to the flower (EC50 152.3 µg/mL) and fruit (EC50 207.9 µg/mL) extracts. By the HPLC-MS, it was possible to identify the presence of flavones in the leaf extract (isoschaftoside, schaftoside, isovitexin, vitexin, isoorientin, orientin). Conclusions: P. mucronata hexane fraction showed promising cytotoxic effect against cancer cell lines, and stigmasterol contributes to this activity, inducing apoptosis of these cells. Furthermore, as other Passiflora species, Pm extract showed antioxidant activity and flavones are its major phenolic compounds.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Handuo Shi ◽  
Yan Hu ◽  
Pascal D. Odermatt ◽  
Carlos G. Gonzalez ◽  
Lichao Zhang ◽  
...  

AbstractThe steady-state size of bacterial cells correlates with nutrient-determined growth rate. Here, we explore how rod-shaped bacterial cells regulate their morphology during rapid environmental changes. We quantify cellular dimensions throughout passage cycles of stationary-phase cells diluted into fresh medium and grown back to saturation. We find that cells exhibit characteristic dynamics in surface area to volume ratio (SA/V), which are conserved across genetic and chemical perturbations as well as across species and growth temperatures. A mathematical model with a single fitting parameter (the time delay between surface and volume synthesis) is quantitatively consistent with our SA/V experimental observations. The model supports that this time delay is due to differential expression of volume and surface-related genes, and that the first division after dilution occurs at a tightly controlled SA/V. Our minimal model thus provides insight into the connections between bacterial growth rate and cell shape in dynamic environments.


Author(s):  
Maltseva E.M. ◽  
Egorova I.N. ◽  
Pinchuk L.G.

Pale-flowered licorice (Glycyrrhiza pallidiflora Maxim.) is the pea family (Fabaceae) perennial herb. It is a Russian Far East endemic. Pale-flowered licorice refers to the false (not sweet) licorice section (Pseudoglycyrrhiza Krug.), which do not accumulate glycyrrhizin derivatives. The G. pallidiflora successful introduction has been carried out over the past 5 years in the “Apothecary garden” territory, FRC UUH SB RAS, Kemerovo. Phytochemical studies screening biologically active compounds main classes of the plant aerial part confirmed the presence of a complex of phenolic compounds. The content of catechin derivatives and condensed-type tannins - proanthocyanidins (PAC) data in G. pallidiflora herb were obtained for the first time. In different years of cultivation, licorice herb accumulates phenolic compounds - up to 2.83 ± 0.22% in terms of gallic acid, flavonoids - up to 2.44 ± 0.03% in terms of rutin and PAC in terms of cyanidine chloride - up to 2.61 ± 0.11%. It was found that the maximum content of the phenolic compounds and PAC sum was observed in the herb for 4 years development. The greatest number of flavonoids accumulates in the herb harvested in the 3rd year of cultivation. A positive significant linear relation was found between antioxidant activity (AOA) and the total phenolic compounds and PAC content (r≥0.98). Considering that BAC with IC values ≤ 50 μg / ml in the DPPH assay refer to active antioxidant’s licorice herb can be classified as a plant with high antioxidant potential. It was found that the iron chelating activity of the G. pallidiflora herb is in direct dependence (r≥0.94) on the content of flavonoids. The obtained results demonstrate the importance of further study of this plant as a source of BAC, including plant antioxidants.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Hui Xu ◽  
Dongmei Han ◽  
Zhaohui Xu

The ability ofThermotogaspp. to degrade cellulose is limited due to a lack of exoglucanases. To address this deficiency, cellulase genes Csac_1076 (celA) and Csac_1078 (celB) fromCaldicellulosiruptor saccharolyticuswere cloned intoT.sp. strain RQ2 for heterologous overexpression. Coding regions of Csac_1076 and Csac_1078 were fused to the signal peptide of TM1840 (amyA) and TM0070 (xynB), resulting in three chimeric enzymes, namely, TM1840-Csac_1078, TM0070-Csac_1078, and TM0070-Csac_1076, which were carried byThermotoga-E. colishuttle vectors pHX02, pHX04, and pHX07, respectively. All three recombinant enzymes were successfully expressed inE. coliDH5αandT.sp. strain RQ2, rendering the hosts with increased endo- and/or exoglucanase activities. InE. coli, the recombinant enzymes were mainly bound to the bacterial cells, whereas inT.sp. strain RQ2, about half of the enzyme activities were observed in the culture supernatants. However, the cellulase activities were lost inT.sp. strain RQ2 after three consecutive transfers. Nevertheless, this is the first time heterologous genes bigger than 1 kb (up to 5.3 kb in this study) have ever been expressed inThermotoga, demonstrating the feasibility of using engineeredThermotogaspp. for efficient cellulose utilization.


eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Albert Lu ◽  
Paulina Wawro ◽  
David W Morgens ◽  
Fernando Portela ◽  
Michael C Bassik ◽  
...  

Extracellular vesicles mediate transfer of biologically active molecules between neighboring or distant cells, and these vesicles may play important roles in normal physiology and the pathogenesis of multiple disease states including cancer. However, the underlying molecular mechanisms of their biogenesis and release remain unknown. We designed artificially barcoded, exosomal microRNAs (bEXOmiRs) to monitor extracellular vesicle release quantitatively using deep sequencing. We then expressed distinct pairs of CRISPR guide RNAs and bEXOmiRs, enabling identification of genes influencing bEXOmiR secretion from Cas9-edited cells. This approach uncovered genes with unrecognized roles in multivesicular endosome exocytosis, including critical roles for Wnt signaling in extracellular vesicle release regulation. Coupling bEXOmiR reporter analysis with CRISPR-Cas9 screening provides a powerful and unbiased means to study extracellular vesicle biology and for the first time, to associate a nucleic acid tag with individual membrane vesicles.


Author(s):  
С. В. Шершова

Проведено експериментальне обґрунтування біо-конверсії відходів вирощування (полови) ехінацеїпурпурової (Echinacea purpurea (L.) Moench.) таехінацеї блідої (Echinacea pallida (Nutt) Nutt.).Доведена висока активність екстрактів полови зехінацеї пурпурової, що проявлялася у стимуляціїросту тест-культури. Встановлено, що найвищустимулюючу активність мають екстракти поло-ви ехінацеї пурпурової: водні за концентрації0,01 %, спиртові – 0,01–0,001 %; до того ж іззбільшенням концентрації спирту в екстрактахзнижувалась їх активність. Вперше встановлено,що полова ехінацеї містить специфічні білки –лектини, активність яких у відходах ехінацеї блі-дої значно перевищувала ехінацею пурпурову. Роз-роблено технологічні схеми отримання лектинівта екстрактів біологічно активних речовин із від-ходів вирощування (полови) для їх ефективноговикористовування. The experimental foundation bioconversion of waste product of growing (chaff), purple coneflower(Echinacea purpurea (L.) Moench.) and pale coneflower (Echinacea pallida (Nutt.) Nutt.) was to carriedout. The high activity of extracts of coneflower chaff, which had growth-stimulating effect to the testculture, was proved. Found that the highest stimulating activity has the extract of chaff purpleconeflowers: aqueous solution at concentrations of 0.01 %, alcohol-0.01 %-0.001 % and with increasingconcentration of alcohol in the extracts decreased their activity. For the first time it has been shown thatchaff of Echinacea contains specific proteins - lectins, and their activity in the waste product of paleconeflower significantly exceeded then activity in the waste product of purple coneflower. Technologicalschemes to get of lectins and extracts of biologically active substances from waste growing product(chaff), was worked out for their effective use.


2020 ◽  
Author(s):  
Sean L. Nguyen ◽  
Soo Hyun Ahn ◽  
Jacob W. Greenberg ◽  
Benjamin W. Collaer ◽  
Dalen W. Agnew ◽  
...  

ABSTRACTMembrane-bound extracellular vesicles (EVs) mediate intercellular communication in all organisms, and those produced by placental mammals have become increasingly recognized as significant mediators of fetal-maternal communication. Here, we aimed to identify maternal cells targeted by placental EVs and elucidate the mechanisms by which they traffic to these cells. Exogenously administered pregnancy-associated EVs traffic specifically to the lung; further, placental EVs associate with lung interstitial macrophages and liver Kupffer cells in an integrin-dependent manner. Localization of EV to maternal lungs was confirmed in unmanipulated pregnancy using a transgenic reporter mouse model, which also provided in situ and in vitro evidence that fetally-derived EVs, rarely, may cause genetic alteration of maternal cells. These results provide for the first time direct in vivo evidence for targeting of placental EVs to maternal immune cells, and further, evidence that EVs can alter cellular phenotype.


2019 ◽  
Vol 1 (1) ◽  
pp. 68-74
Author(s):  
Lenny Anwar

Pentacyclic triterpenoid, betulinic acid (1) and phenolic, p-hydroxybenzoic acid (2), had been isolated for the first time from the stem bark of Vitex pubescens Vahl. The structure of compounds 1 and 2 was determined based on the interpretation of spectroscopic data including UV, IR, NMR (1H-NMR, 13C-NMR, HMQC, HMBC, COSY) and MS, as well as by comparison with those reported data.


2021 ◽  
Vol 38 ◽  
pp. 00033
Author(s):  
Tatiana Fomina ◽  
Tatiana Kukushkina

The content of the major groups of biologically active substances in flowers of 7 Campanula species, cultivated in the forest-steppe of Western Siberia, were investigated for the first time. Freshly collected flowers were found to contain 0.06-0.15 % of catechins, 0.31-3.17 % of flavonols, 3.31-6.47 % of tannins, 3.10-15.57 % of pectic substances, and 0.66-16.4 mg% of carotenoids calculated per absolute dre weight of raw material. The amount of ascorbic acid was 36.9-114.0 mg% per wet weight. The data indicate that Campanula flowers are promising for the production of phenolic compounds, the development of food additives and fresh consumptions a seasoning.


2011 ◽  
Vol 278 (1723) ◽  
pp. 3437-3443 ◽  
Author(s):  
Colin E. Studds ◽  
Peter P. Marra

Climatic warming has intensified selection for earlier reproduction in many organisms, but potential constraints imposed by climate change outside the breeding period have received little attention. Migratory birds provide an ideal model for exploring such constraints because they face warming temperatures on temperate breeding grounds and declining rainfall on many tropical non-breeding areas. Here, we use longitudinal data on spring departure dates of American redstarts ( Setophaga ruticilla ) to show that annual variation in tropical rainfall and food resources are associated with marked change in the timing of spring departure of the same individuals among years. This finding challenges the idea that photoperiod alone regulates the onset of migration, providing evidence that intensifying drought in the tropical winter could hinder adaptive responses to climatic warming in the temperate zone.


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