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1.
Microbiol Res ; 286: 127827, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39002396

RESUMO

Drought is a major stressor that poses significant challenges for agricultural practices. It becomes difficult to meet the global demand for food crops and fodder. Plant physiology, physico-chemistry and morphology changes in plants like decreased photosynthesis and transpiration rate, overproduction of reactive oxygen species, repressed shoot and root shoot growth and modified stress signalling pathways by drought, lead to detrimental impacts on plant development and output. Coping with drought stress requires a variety of adaptations and mitigation techniques. Crop yields could be effectively increased by employing plant growth-promoting rhizobacteria (PGPR), which operate through many mechanisms. These vital microbes colonise the rhizosphere of crops and promote drought resistance by producing exopolysaccharides (EPS), 1-aminocyclopropane-1-carboxylate (ACC) deaminase and phytohormones including volatile compounds. The upregulation or downregulation of stress-responsive genes causes changes in root architecture due to acquiring drought resistance. Further, PGPR induces osmolyte and antioxidant accumulation. Another key feature of microbial communities associated with crops includes induced systemic tolerance and the production of free radical-scavenging enzymes. This review is focused on detailing the role of PGPR in assisting plants to adapt to drought stress.


Assuntos
Agricultura , Produtos Agrícolas , Secas , Desenvolvimento Vegetal , Reguladores de Crescimento de Plantas , Raízes de Plantas , Rizosfera , Microbiologia do Solo , Estresse Fisiológico , Produtos Agrícolas/microbiologia , Produtos Agrícolas/crescimento & desenvolvimento , Agricultura/métodos , Reguladores de Crescimento de Plantas/metabolismo , Raízes de Plantas/microbiologia , Raízes de Plantas/crescimento & desenvolvimento , Bactérias/genética , Bactérias/metabolismo , Carbono-Carbono Liases/metabolismo , Carbono-Carbono Liases/genética
2.
Cureus ; 14(7): e26995, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35989852

RESUMO

The purpose of this study is to review the published papers investigating maternal acetaminophen (AP) use during pregnancy and its effect on the offspring's neurodevelopment, particularly autism spectrum disorders (ASD). Acetaminophen is an over-the-counter analgesic and antipyretic considered safe in pregnancy. Recent studies have found an association between acetaminophen and immune system alterations like asthma and adverse neurodevelopmental outcomes. We used online databases (PubMed/Medline/PubMed Central, Science Direct, and Google Scholar) to search the studies relevant to our topic. We screened the papers by titles, abstracts, and then full-text availability. The screened articles were checked for eligibility using relevant quality assessment tools for each study design, extracting and analyzing the data. We finalized 30 studies after the screening; 14 were ineligible. Our final selection included 16 high-quality papers - 13 prospective cohort studies, two review articles, and one meta-analysis. We found a wide range of neurodevelopmental outcomes in our data collection. So, we included autism spectrum disorders, intelligent quotient (IQ), attention-deficit/hyperactivity disorder (ADHD), isolated language, attention and executive function, communication, behavior, and psychomotor development. All studies showed an association between acetaminophen use and listed neurodevelopmental outcomes. Long-term use, increased dose, and frequency were associated with a stronger association. We extracted collective evidence from 16 studies suggesting acetaminophen's role in developing adverse neurodevelopmental outcomes. It is urgent to do more research on this association before pregnant women can be cautioned about the precise use of acetaminophen.

4.
Commun Chem ; 4(1): 160, 2021 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-36697574

RESUMO

Polyamines play a major role in biosilicification reactions in diatoms and sponges. While the effects of polyamines on silicic acid oligomerization and precipitation are well known, the impact of polyamines chain length on silica particle growth is unclear. We studied the effects of polyamine chain length on silica particle growth and condensation in a known, simple, and salt-free biphasic reaction system; with tetraethyl orthosilicate as organic phase and polyamine dissolved in the aqueous phase. The particles at various growth stages were characterized by Cryo- Transmission Electron Microscopy, Scanning Electron Microscopy, Thermogravimetric Analysis, Zeta Potential, and solid-state NMR analysis. Polyamines were found co-localized within silica particles and the particle diameter increased with an increase in polyamine chain length, whereas silica condensation showed the opposite trend. Particle growth is proposed to progress via a coacervate intermediate while the final particles have a core shell structure with an amine-rich core and silica-rich shell. The results presented in this paper would of interest for researchers working in the field of bioinspired materials.

5.
Sci Rep ; 10(1): 19498, 2020 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-33177559

RESUMO

Diatoms are unicellular photosynthetic algae that produce a silica exoskeleton (frustule) which exposes a highly ordered nano to micro scale morphology. In recent years there has been a growing interest in modifying diatom frustules for technological applications. This is achieved by adding non-essential metals to the growth medium of diatoms which in turn modifies morphology, composition, and resulting properties of the frustule. Here, we investigate the frustule formation in diatom Pinnularia sp., including changes to overall morphology, silica thickness, and composition, in the presence of Al3+ ions at different concentrations. Our results show that in the presence of Al3+ the total silica uptake from the growth medium increases, although a decrease in the growth rate is observed. This leads to a higher inorganic content per diatom resulting in a decreased pore diameter and a thicker frustule as evidenced by electron microscopy. Furthermore, 27Al solid-state NMR, FIB-SEM, and EDS results confirm that Al3+ becomes incorporated into the frustule during the silicification process, thus, improving hydrolysis resistance. This approach may be extended to a broad range of elements and diatom species towards the scalable production of silica materials with tunable hierarchical morphology and chemical composition.


Assuntos
Diatomáceas/química , Diatomáceas/ultraestrutura , Alumínio/química , Cátions/química , Diatomáceas/efeitos dos fármacos , Diatomáceas/metabolismo , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Nanoestruturas/química , Dióxido de Silício/química , Dióxido de Silício/metabolismo , Espectrometria por Raios X , Termogravimetria
6.
Dalton Trans ; 47(10): 3258-3263, 2018 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-29442109

RESUMO

The self-assembly process of a Pd2L4 cage consisting of flexible ditopic ligands and Pd(ii) ions was revealed by QASAP (quantitative analysis of self-assembly process), which enables one to obtain information about the intermediates transiently produced during the self-assembly as the average composition of all the intermediates. It was found that the dominant pathway to the cage is the formation of a submicrometre-sized sheet structure, which was characterized by dynamic light scattering (DLS) and scanning transmission electron microscopy (STEM), followed by the addition of free ditopic ligands to the Pd(ii) centres of the sheet structure to trigger the cage formation. This assembly process is completely different from that of a Pd2L4 cage composed of rigid ditopic ligands, indicating that the flexibility of the components strongly affects the self-assembly process.

7.
Chem Sci ; 8(4): 2671-2676, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-28553503

RESUMO

Unique heterogeneous catalase-like activity was observed for metallosupramolecular ionic crystals [AuI4CoIII2(dppe)2(d-pen)4]X n ([1]X n ; dppe = 1,2-bis(diphenylphosphino)ethane; d-pen = d-penicillaminate; X n = (Cl-)2, (ClO4-)2, (NO3-)2 or SO42-) consisting of AuI4CoIII2 complex cations, [1]2+, and inorganic anions, X- or X2-. Treatment of the ionic crystals with an aqueous H2O2 solution led to considerable O2 evolution with a high turnover frequency of 1.4 × 105 h-1 for the heterogeneous cobalt complexes, which was dependent on their size and shape as well as the arrangement of cationic and anionic species. These dependencies were rationalized by the presence of cobalt(ii) centers on the crystal surface and their efficient exposure on the (111) plane rather than the (100) plane based on morphological and theoretical studies.

8.
Nat Prod Commun ; 10(9): 1521-3, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26594748

RESUMO

A systematic phytochemical study of the commercial extract of Luo Han Guo (Siraitia grosvenorii) resulted in the isolation of an additional minor new cucurbitane glycoside, mogroside V Al (1). The structure of the new compound was characterized on the basis of 1D (1H and 13C NMR) and 2D (COSY, HMQC, HMBC and NOESY) NMR and high resolution mass spectral (HRMS) data, as well as hydrolysis studies.


Assuntos
Cucurbitaceae/química , Triterpenos/química , Estrutura Molecular
9.
J Mater Chem B ; 3(29): 6057-6070, 2015 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-32262662

RESUMO

Intracellular protein (BSA) delivery by a phosphonate@mesoporous silica nanoparticle vehicle, PMSN, with high load capacity for the relatively large test protein BSA, is described. Wide pore (11.6 nm) PMSN nanoparticles were synthesised and loaded with a BSA cargo to give BSA#@PMSN*, where # and * signify Fluorescein and Rhodamine fluorescent labels respectively. Internalisation of BSA#@PMSN*s by HeLa cells was analysed from confocal microscopy and TEM images after dose and time dependent treatments. No evidence of cytotoxicity was observed after 24 h and in contrast to PMSN* no significant loss of BSA#@PMSN* was observed after 3 h incubation of the loaded cells in DMEM. Receptor blocking experiments showed caveolar uptake of PMSN* and folate receptor mediated uptake of BSA#@PMSN*s.

10.
Molecules ; 19(12): 20280-94, 2014 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-25486243

RESUMO

Four new minor diterpene glycosides with a rare α-glucosyl linkage were isolated from a cyclodextrin glycosyltransferase glucosylated stevia extract containing more than 98% steviol glycosides. The new compounds were identified as 13-[(2-O-ß-D-glucopyranosyl-3-O-(4-O-α-D-glucopyranosyl)-ß-D-glucopyranosyl-ß-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-[(4-O-α-D-glucopyranosyl-ß-D-glucopyranosyl) ester] (1), 13-[(2-O-ß-D-glucopyranosyl-ß-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-[(4-O-(4-O-(4-O-α-D-glucopyranosyl)-α-D-glucopyranosyl)-α-D-glucopyranosyl)-ß-D-glucopyranosyl ester] (2), 13-[(2-O-ß-D-glucopyranosyl-3-O-(4-O-(4-O-(4-O-α-D-glucopyranosyl)-α-D-glucopyranosyl)-α-D-glucopyranosyl)-ß-D-glucopyranosyl-ß-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid ß-D-glucopyranosyl ester (3), and 13-[(2-O-ß-D-glucopyranosyl-3-O-(4-O-(4-O-(4-O-α-D-glucopyranosyl)-α-D-glucopyranosyl)-α-D-glucopyranosyl)-ß-D-glucopyranosyl- ß-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-[(4-O-α-D-glucopyranosyl-ß-D-glucopyranosyl) ester] (4) on the basis of extensive NMR and mass spectral (MS) data as well as hydrolysis studies.


Assuntos
Diterpenos/química , Glicosídeos/química , Extratos Vegetais/química , Stevia/química , Glicosilação , Hidrólise , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular
11.
Molecules ; 19(3): 3669-80, 2014 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-24662081

RESUMO

Continuous phytochemical studies of the crude extract of Luo Han Guo (Siraitia grosvenorii) furnished three additional new cucurbitane triterpene glycosides, namely 11-deoxymogroside V, 11-deoxyisomogroside V, and 11-deoxymogroside VI. The structures of all the isolated compounds were characterized on the basis of extensive NMR and mass spectral data as well as hydrolysis studies. The complete ¹H- and ¹³C-NMR spectral assignments of the three unknown compounds are reported for the first time based on COSY, TOCSY, HSQC, and HMBC spectroscopic data.


Assuntos
Cucurbitaceae/química , Glicosídeos/química , Triterpenos/química , Estrutura Molecular , Extratos Vegetais/química
12.
Int J Mol Sci ; 15(1): 1014-25, 2014 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-24424316

RESUMO

Degradation of rebaudioside M, a minor sweet component of Stevia rebaudiana Bertoni, under conditions that simulated extreme pH and temperature conditions has been studied. Thus, rebaudioside M was treated with 0.1 M phosphoric acid solution (pH 2.0) and 80 °C temperature for 24 h. Experimental results indicated that rebaudioside M under low pH and higher temperature yielded three minor degradation compounds, whose structural characterization was performed on the basis of 1D (1H-, 13C-) & 2D (COSY, HSQC, HMBC) NMR, HRMS, MS/MS spectral data as well as enzymatic and acid hydrolysis studies.


Assuntos
Diterpenos do Tipo Caurano/química , Edulcorantes/química , Trissacarídeos/química , Ácidos/química , Diterpenos do Tipo Caurano/farmacologia , Concentração de Íons de Hidrogênio , Hidrólise , Temperatura , Trissacarídeos/farmacologia
13.
Nat Prod Commun ; 9(12): 1677-9, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25632456

RESUMO

From the commercial extract of the leaves of the sweet plant Stevia rebaudiana Bertoni obtained from Sinochem Qingdao Co. Ltd., a new diterpene glycoside having three ß-D-glucopyranosyl units of which two of them were connected in a relatively rare linkage of 3-ß-D-glucobiosyl substitution at C-19 position of the aglycone steviol. The structure of the new compound has been characterized as 13-ß-D-glucopyranosyloxy ent-kaur-16-en-19-oic acid-[(3-O-ß-D- glucopyranosyl-ß-D-glucopyranosyl) ester (1) on the basis of extensive 1D (1H and 13C) and 2D NMR (TOCSY, HMQC, and HMBC), and High Resolution mass spectroscopic data as well as hydrolysis studies.


Assuntos
Diterpenos/isolamento & purificação , Glicosídeos/isolamento & purificação , Stevia/química , Diterpenos/química , Glicosídeos/química , Espectroscopia de Ressonância Magnética , Folhas de Planta/química
14.
J Mater Chem B ; 2(7): 903-914, 2014 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-32261322

RESUMO

This paper reports the synthesis of large pore (11 nm) monodisperse raspberry textured phosphonate@silica nanoparticles (70-90 nm) with high capacity for protein immobilization. The raspberry nanoparticles denoted RNP_PME(2.5) with phosphonate loading 2.5 mmol g-1, formed using an organosilanephosphonate (MeO)3SiCH2CH2PO(OMe)2, as silica surface modifier and structure directing agent. Specific reaction conditions including temperature and concentration of phosphonate, base, surfactant and co-solvent were required for RNP_PME(2.5) formation. Rhodamine B labelled RNP_PME(2.5) was readily internalised by HeLa cells with no deficit of cell viability. Aqueous dispersions of RNP_PME(2.5) were stable over several months. In protein immobilization studies using BSA, bovine serum albumin, with RNP_PME(2.5), smaller pore (∼3 nm) phosphonate@silica nanoparticles NP_PME(1.0) and NP_PME(0.2) and mesoporous silica nanoparticles, MSN, the large pore RNP_PME(2.5) gave highest BSA loading 266 mg g-1, formed the most stable aqueous dispersions (BSA@MSN was unstable and precipitated) and gave the best protection against BSA structural distortion at pH 7.4.

15.
Molecules ; 18(11): 13510-9, 2013 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-24184820

RESUMO

Two additional novel minor diterpene glycosides were isolated from the commercial extract of the leaves of Stevia rebaudiana Bertoni. The structures of the new compounds were identified as 13-{ß-D-glucopyranosyl-(1 → 2)-O-[ß-D-glucopyranosyl-(1 → 3)-ß-D-glucopyranosyl-oxy} ent-kaur-16-en-19-oic acid {ß-D-xylopyranosyl-(1 → 2)-O-[ß-D-glucopyranosyl-(1 → 3)]-O-ß-D-glucupyranosyl-ester} (1), and 13-{ß-D-6-deoxy-glucopyranosyl-(1 → 2)-O-[ß-D-glucopyranosyl-(1 → 3)-ß-D-glucopyranosyl-oxy} ent-kaur-16-en-19-oic acid {ß-D-glucopyranosyl-(1 → 2)-O-[ß-D-glucopyranosyl-(1 → 3)-ß-D-gluco-pyranosyl-ester} (2), on the basis of extensive 1D (1H- and 13C-) 2D NMR (COSY, HSQC and HMBC) and MS spectroscopic data as well as chemical studies.


Assuntos
Asteraceae/química , Diterpenos/química , Glicosídeos/química , Stevia/química , Espectroscopia de Ressonância Magnética
16.
Int J Mol Sci ; 14(8): 15669-80, 2013 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-23896597

RESUMO

Catalytic hydrogenation of the exocyclic double bond present between C16 and C17 carbons of the four ent-kaurane diterpene glycosides namely rebaudioside A, rebaudioside B, rebaudioside C, and rebaudioside D isolated from Stevia rebaudiana has been carried out using Pt/C, Pd(OH)2, Rh/C, Raney Ni, PtO2, and 5% Pd/BaCO3 to their corresponding dihydro derivatives with 17α and 17ß methyl group isomers. Reactions were performed using the above-mentioned catalysts with the solvents methanol, water, and ethanol/water (8:2) under various conditions. Synthesis of reduced steviol glycosides was performed using straightforward chemistry and their structures were characterized on the basis of 1D and 2D NMR spectral data, including a comparison with reported spectral data.


Assuntos
Diterpenos do Tipo Caurano/química , Glicosídeos/química , Stevia/química , Catálise , Diterpenos do Tipo Caurano/isolamento & purificação , Glicosídeos/síntese química , Hidrogenação , Espectroscopia de Ressonância Magnética , Metais/química , Solventes/química
17.
J Contemp Dent Pract ; 14(2): 332-8, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-23811669

RESUMO

AIM: The present case report describes the importance of interdisciplinary approach and gives an understanding on management of an adolescent with unilateral cleft lip and palate. BACKGROUND: Failure of fusion between medial nasal process and maxillary process or between the palatal process leads to the formation of clefts. Clefts are result of genetic or environmental factors or a combination of both. Common dental problems associated with clefts includes anterior and posterior crossbites, hypodontia, malformation and abnormal eruption pattern. CASE REPORT: A girl, aged 15 years reported with a chief complaint of unesthetic appearance of her maxillary anterior teeth. She had unilateral cleft lip and palate and had received cheiloplasty and palatoplasty when she was in young age and rhinoplasty when she was 14 years of age. At pretreatment evaluation, she had concave profile with maxillary arch constriction and oroantral fistula and mesially tipped maxillary left canine. CONCLUSION: This patient's treatment was unconventional, but it was successful in significantly improving her masticatory function and smile, along with favorable dental and facial results. Generalized esthetics and function were significantly improved in this patient without orthognathic surgery, and treatment results were stable 3 years after the appliance removal. Clinical considerations, sequencing of treatment phases as shown in this case report can be utilized while treating an adolescent with cleft lip and palate. CLINICAL SIGNIFICANCE: If the skeletal discrepancy is mild and esthetic concerns are minimal, dental compensation by orthodontic treatment alone might be recommended. The cephalometric analysis and prediction tracings provide further information for deciding whether a patient can be treated by orthodontics alone, or by orthodontics and an orthognathic surgical procedure. A change in axial inclination of the teeth can camouflage the skeletal relationship adequately. However, one should be cautious in a growing patient, because he or she might outgrow the dental correction so that ultimately skeletal surgery would be indicated.


Assuntos
Fenda Labial/terapia , Fissura Palatina/terapia , Equipe de Assistência ao Paciente , Adolescente , Enxerto de Osso Alveolar/métodos , Cefalometria/métodos , Fenda Labial/cirurgia , Fissura Palatina/cirurgia , Dente Canino/patologia , Prótese Parcial Fixa , Estética Dentária , Assimetria Facial/terapia , Feminino , Seguimentos , Humanos , Má Oclusão Classe III de Angle/terapia , Mastigação/fisiologia , Fístula Bucoantral/terapia , Técnica de Expansão Palatina/instrumentação , Planejamento de Assistência ao Paciente , Retrognatismo/terapia , Rinoplastia/métodos , Sorriso
18.
Nat Prod Commun ; 8(11): 1523-6, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24427932

RESUMO

From the extract of the leaves of Stevia rebaudiana Bertoni, a diterpene glycoside was isolated which was identified as 13-[(2-O-beta-D-glucopyranosyl-3-O-beta-D-glucopyranosyl-beta-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-(2-O-beta-D-glucopyranosyl-3-O-beta-D-glucopyranosyl-D-glucopyranosyl) ester (1). The complete 1H and 13C NMR assignment of 1 is reported for the first time, from extensive NMR (1H and 13C, COSY, HSQC, and HMBC) and mass spectral data. Also, we report the sensory evaluation of 1 against sucrose for the sweetness property of this molecule.


Assuntos
Diterpenos/isolamento & purificação , Stevia/química , Diterpenos/química , Espectroscopia de Ressonância Magnética , Sacarose , Paladar
19.
Biomolecules ; 3(4): 733-40, 2013 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-24970189

RESUMO

From the commercial extract of the leaves of Stevia rebaudiana Bertoni, a minor steviol glycoside, 13-[(2-O-ß-D-glucopyranosyl-3-O-ß-D-glucopyranosyl-ß-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-[(2-O-(3-O-ß-D-glucopyranosyl-α-L-rhamnopyranosyl)-3-O-ß-D-glucopyranosyl-ß-D-glucopyranosyl) ester] (1); also known as rebaudioside O having seven sugar units has been isolated. Its structural characterization has been achieved by the extensive 1D (1H and 13C), and 2D NMR (COSY, HMQC, HMBC) as well as mass spectral data. Further, hydrolysis studies were performed on rebaudioside O using acid and enzymatic methods to identify aglycone and sugar residues in its structure as well as their configurations.

20.
Int J Mol Sci ; 13(11): 15126-36, 2012 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-23203115

RESUMO

Catalytic hydrogenation of rebaudioside B, rebaudioside C, and rebaudioside D; the three ent-kaurane diterpene glycosides isolated from Stevia rebaudiana was carried out using Pd(OH)(2). Reduction of steviol glycosides was performed using straightforward synthetic chemistry with the catalyst Pd(OH)(2) and structures of the corresponding dihydro derivatives were characterized on the basis of 1D and 2D nuclear magnetic resonance (NMR) spectral data indicating that all are novel compounds being reported for the first time. Also, the taste properties of all reduced compounds were evaluated against their corresponding original steviol glycosides and sucrose.


Assuntos
Diterpenos do Tipo Caurano/química , Stevia/química , Percepção Gustatória , Catálise , Diterpenos do Tipo Caurano/isolamento & purificação , Glicosídeos/química , Humanos , Hidrogenação , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Oligossacarídeos/química , Edulcorantes/química
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