17 research outputs found
Chemical composition and biological activities of the essential oil from <i>Rubus pungens</i> var. <i>oldhamii</i>
<p>This paper presents a study on chemical composition, antimicrobial, antioxidant and tyrosinase inhibitory properties of the essential oil from leaves of <i>Rubus pungens</i> var. <i>oldhamii</i> (REO). The major component of the REO is sesquiterpenes (36.04%), which consists of 1,5-Cyclooctadiene,3-(1-me thylallyl)-(8CI)(17.66%), 5,6-Diethenyl-1-methylcyclohexene (12%), (+) – γ-Elemene (10.48%) and β-Caryophyllene (8.39%).The REO is shown to be moderately active against <i>Staphylococcus</i> <i>aureus,</i> <i>Aspergillus</i> <i>niger</i> and <i>Penicillium</i> <i>glaucum</i>, and has weak antioxidant activity in 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Furthermore, tyrosinase inhibition was investigated against monophenolase (L-tyrosine). IC<sub>50</sub> values of REO and arbutin were found 0.923 and 0.657 mg/mL, respectively. The REO exerted potential antityrosinase activity. Our test results indicated that the REO was rich in sesquiterpenes, and also exhibited good antityrosinase activity, and moderate antimicrobial activity against pathogenic micro-organisms. The REO can be used as a natural source of promising antimicrobial and tyrosinase inhibiting agent.</p
Largely different carotenogenesis in two pummelo fruits with different flesh colors
<div><p>Carotenoids in citrus fruits have health benefits and make the fruits visually attractive. Red-fleshed ‘Chuhong’ (‘CH’) and pale green-fleshed ‘Feicui’ (‘FC’) pummelo (<i>Citrus maxima</i> (Burm) Merr.) fruits are interesting materials for studying the mechanisms of carotenoid accumulation. In this study, particularly high contents of linear carotenes were observed in the albedo tissue, segment membranes and juice sacs of ‘CH’. However, carotenoids, especially β-carotene and xanthophylls, accumulated more in the flavedo tissue of ‘FC’ than in that of ‘CH’. Additionally, the contents of other terpenoids such as limonin, nomilin and abscisic acid significantly differed in the juice sacs at 150 days postanthesis. A dramatic increase in carotenoid production was observed at 45 to 75 days postanthesis in the segment membranes and juice sacs of ‘CH’. Different expression levels of carotenogenesis genes, especially the ζ-carotene desaturase (<i>CmZDS</i>), β-carotenoid hydroxylase (<i>CmBCH</i>) and zeaxanthin epoxidase (<i>CmZEP</i>) genes, in combination are directly responsible for the largely different carotenoid profiles between these two pummelo fruits. The sequences of eleven genes involved in carotenoid synthesis were investigated; different alleles of seven of eleven genes might also explain the largely different carotenogenesis observed between ‘CH’ and ‘FC’. These results enhance our understanding of carotenogenesis in pummelo fruits.</p></div
Carotenoid profiles in the tissues of two pummelo fruits during development (μg/g DW).
<p>Note: Columns represent the means (μg/g DW, n = 3) of the profiles of each carotenoid in the flavedo (A), albedo (B), SMs (segment membranes; C) and JS (juice sacs; D) in ‘CH’ and ‘FC’. a, b, c, etc. above each column indicate significant differences in carotenoid contents at the <i>P</i><0.05 level among 5 stages of two pummelo fruits. DPA: days postanthesis. DW: dry weight.</p
Diagram of metabolic pathways involved in this study.
<p>Note: Acetyl-CoA: acetoacetyl-coenzyme A. <i>BCH</i>: β-carotene hydroxylase gene. <i>CCS</i>: chromoplast-specific lycopene β-cyclase gene. <i>CRTISO</i>: carotenoid isomerase gene. DXP: 1-deoxy-D-xylulose-5-phosphate. <i>CmDXR</i>: 1-deoxy-D-xylulose-5-phosphate reductoisomerase gene. <i>DXS</i>: 1-deoxy-D-xylulose-5-phosphate synthase gene. FPP: farnesyl pyrophosphate. GAP: D-glyceraldehyde-3-phosphate. GGPP: geranylgeranyl diphosphate. IAA: indole-3-acetic acid. IPP: isopentenyl pyrophosphate. JA: jasmonic acid. <i>LCYb</i>: lycopene β-cyclase gene. <i>LCYe</i>: lycopene ε-cyclase gene. Lipid: lipid (pathway). MVA: mevalonic acid (pathway). MEP: methylerythritol 4-phosphate (pathway). <i>NSY</i>: neoxanthin synthase gene. <i>PDS</i>: phytoene desaturase gene. PEP: phosphoenolpyruvate. <i>PSY</i>: phytoene synthase gene. SA: salicylic acid. <i>ZDS</i>: ζ-carotene desaturase gene. <i>ZEP</i>: zeaxanthin epoxidase gene. <i>ZISO</i>: 15-<i>cis</i>-ζ-carotene isomerase gene. The red and italic abbreviations denote genes investigated in this study. The green in the filled frames denote compounds detected in this study.</p
Alleles of carotenogenesis genes in different tissues of ‘Chuhong’ and ‘Feicui’ pummelo (<i>Citrus maxima</i>) fruits.
<p>Alleles of carotenogenesis genes in different tissues of ‘Chuhong’ and ‘Feicui’ pummelo (<i>Citrus maxima</i>) fruits.</p
Carotenogenesis gene expression profiles in four tissues of ‘Chuhong’ and ‘Feicui’ pummelo fruits during different developmental stages.
<p>Note: The data shown are the means±standard deviations (SDs) (n = 3). a, b, c, etc. above each column indicate significant differences at the <i>P</i><0.05 level. SM: segment membrane. JS: juice sacs.</p
Developmental stages of ‘Chuhong’ and ‘Feicui’ pummelo (<i>Citrus maxima</i>) fruits.
<p>Note: DPA: days postanthesis. The white ruler shown here is 5 cm in total length.</p
Limonin and nomilin contents (mg/g DW) in two pummelo fruits during development (A) as well as phytohormone contents (ng/g DW) at 150 DPA in two pummelo fruits (B).
<p>Note: A, the data shown are the means±standard deviations (SDs) (n = 3). * indicates a significance level of <i>P</i><0.05 between two pummelo fruits. B, the data shown are the means±SEs (n = 3). ABA: abscisic acid. DPA: days postanthesis. IAA: indole-3-acetic acid; JA: jasmonic acid; SA: salicylic acid. a, b above the columns indicate significant differences at the <i>P</i><0.05 level. SM: segment membrane. JS: juice sacs.</p
Distinct Carotenoid and Flavonoid Accumulation in a Spontaneous Mutant of Ponkan (Citrus reticulata Blanco) Results in Yellowish Fruit and Enhanced Postharvest Resistance
As
the most important fresh fruit worldwide, citrus is often subjected
to huge postharvest losses caused by abiotic and biotic stresses.
As a promising strategy to reduce postharvest losses, enhancing natural
defense by potential metabolism reprogramming in citrus mutants has
rarely been reported. The yellowish spontaneous mutant of Ponkan (Citrus reticulata Blanco) (YP) was used to investigate
the influence of metabolism reprogramming on postharvest performance.
Our results show that reduced xanthophyll accumulation is the cause
of yellowish coloring of YP and might be attributed to the reduced
carotenoid sequestration capacity and upregulated expression of carotenoid
cleavage dioxygenase genes. Constantly higher levels of polymethoxylated
flavones (PMFs) during the infection and the storage stage might make
significant contribution to the more strongly induced resistance against Penicillium digitatum and lower rotting rate. The
present study demonstrates the feasibility of applying bud mutants
to improve the postharvest performance of citrus fruits
Dimerization of TbPRMT6.
<p>(A) Two views of the TbPRMT6 dimer Monomer A is shown as a cartoon colored in magenta, and monomer B is colored in gray and shown through a surface presentation (B) Dimerization interactions The left image represents the hydrogen bond interactions on the dimeric interface, and the right image represents the hydrophobic interactions (C) SAXS results of TbPRMT6<sub>L</sub> The experimental SAXS curve of TbPRMT6 and the data points up to q  = 06 Å<sup>−1</sup> are plotted The top-right inset is the PDDF calculated by GNOM, and the bottom-left inset is the DR model with the crystal structure superimposed with a TbPRMT6 dimer The R<sub>g</sub> and D<sub>max</sub> of TbPRMT6 are 328±01 Å and 959 Å, respectively The DR models were generated by GASBOR using the final χ against the raw SAXS data of 063 The X-ray structure of the TbPRMT6 dimer can be superimposed onto the DR models quite well, with an NSD of 109.</p