Seasonal influence on volatile aroma constituents of two banana cultivars (Grand Naine and Nendran) under Kerala conditions

Banana is a tropical fruit with a pleasant flavour, widely consumed throughout the world. Volatile aroma compounds are responsible for olfactory flavor of banana. However, the development of aroma flavors is affected by the atmospheric temperatures during fruit growth period. In order to get good quality fruits in terms of aroma it is essential to understand the optimum temperature for maximum aroma production. The approach used in this study was to alter the dates of harvest to understand the optimum temperature required for maximum production of volatile compounds under Kerala conditions. The results revealed that with increased temperature volatile aroma compounds decreased in cvs. Grand Naine and Nendran. Total volatile compounds were higher in cv. Grand Naine compared to cv. Nendran. Cultivar Nendran recorded increased concentrations of esters, alcohols and decreased aldehydes, ketones, hydrocarbons and acids at high temperatures. Phenols and other constituents did not show much variation with respect to the temperature variation in both the cultivars. Among esters, Isoamyl butanoate and 3-Methylbutyl-3-methylbutyrate esters were the most abundant in both the cultivars. Ketones, especially 4-Methyl-1-penten-3-one was higher in cv. Nendran whereas esters were lower compared to cv. Grand Naine. Total area of aroma constituents in cultivars Grand Naine and Nendran were high in October followed by February with mean atmospheric temperature of 30.5ºC and 32.6ºC respectively. In case of cv. Nendran, total area of esters and alcohols were maximum at high temperature (34.5ºC) but in cv. Grand Naine, esters and alcohols decreased with high temperature. Results indicated that fruits harvested in October were better in terms of volatile aroma quantity in both the cultivars due to lower atmospheric temperature. Seasonal variations affected the two cultivars differentially in terms of percentage of groups of volatile compounds

Genotypic Variability in Tomato for Total Carotenoids and Lycopene Content during Summer and Response to Post Harvest Temperature

Lycopene is the major carotenoid responsible for fruit colour in tomato (Lycopersicon esculentum Mill.). However, colour of the fruit is greatly affected by high temperature prevailing during fruit growth in the summer crop. To select a genotype suitable for summer conditions that can maintain colour better, a set of 52 tomato genotypes were evaluated for lycopene, total carotenoids and for TSS during summer in Bengaluru. Among the genotypes screened, IIHR 2892 recorded very high lycopene content (328.4mg/100g dry weight) and IIHR 2866 recorded very low lycopene content (25.2mg/100g dry weight). TSS values ranged from 2.6° Brix in cv. Vybhav to 7.0° Brix in IIHR 2866. In addition, study was carried out to determine the effect of postharvest temperature on biosynthesis of lycopene in five selected tomato cultivars (Arka Rakshak, Arka Samrat, Arka Ananya, Lakshmi and Abhinava). Tomatoes harvested at breaker stage were stored at 27° C, 35° C and 40° C for ripening. High temperature reduced lycopene content in tomato fruits. Lycopene synthesis in fruits was completely inhibited above 35°C. In this study, mean lycopene content in tomatoes stored at 27° C was 3-4 times higher than that in tomatoes stored at 40° C. This indicates that in tomatoes, temperature at which the fruits are stored after harvest, is a more important factor for colour development

Changes in Fruit Quality and Carotenoid Profile in Tomato (Solanum lycopersicon L.) Genotypes under Elevated Temperature

Tomato (Solanum lycopersicon L.) is a rich source of carotenoids, especially lycopene, and is affected severely by high temperatures under tropical conditions. To study the effect of elevated temperature on lycopene content and other quality parameters, five tomato genotypes, viz., RF4A, Abhinava, Arka Saurabh, IIHR 2195 and Arka Vikas, were grown in a temperature gradient tunnel (TGT) facility under 33.4 and 35.4°C temperature conditions. Fruits were analyzed for total carotenoids, total phenols, total flavonoids, total sugars, TSS, acidity, Vitamin C besides carotenoids profile (β-carotene, lycopene, phytoene and luteoxanthin content). Results revealed that all the quality parameters studied were superior at 33.4°C, compared to 35.4°C in all the genotypes. 'IIHR 2195' recorded highest total phenols (479.28mg/100g dw), total flavonoids (70.27mg/100g dw), ferric reducing antioxidant potential (FRAP) (310.53mg/100g dw), diphenyl picryl hydrazyl (DPPH) radical (487.89mg/100g dw), Vitamin C content (292.25mg/ 100g dw) and total sugars (606.88mg/g dw) at 33.4°C and at 35.4°C. 'RF4A' and 'Arka Vikas' were found to have better total carotenoids content and lycopene at higher temperature than other genotypes. 'Arka Vikas' recorded highest total soluble solids (TSS) (8.9°Brix) and acidity (0.80%) at 35.4°C. Higher TSS and acidity were recorded at 35.4°C than at 33.4°C in all the five genotypes. Genotypic variation was observed in the above stated biochemical parameters in response to elevated temperatures

Metabolite Profiling for Six 'B' Vitamins Using LC-MS in Tomato Genotypes at Different Stages of Fruit Maturity

Vitamins are essential nutrients in food crucial for maintaining good health. Tomato, being a widely consumed vegetable, provides a good quantity of vitamins. Metabolite profiling of vitamins at different stages of fruit maturity in a crop helps identify the right stage for better quality. Based on preliminary screening for quality parameters, tomato lines rich in TSS, antioxidants, lycopene and beta-carotene were selected for the present study. Eight genotypes and a wild species were profiled for 'B' vitamins at three different stages of fruit maturity, viz., green, breaker and ripe stage. A simple and sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for simultaneous determination of six 'B' vitamins was developed and validated by us. Among the genotypes studied, IIHR-249-1 recorded higher niacin, pantothenic acid and biotin content. Pyridoxine content was higher in the hybrid, Arka Rakshak. The wild species, LA-1777(Solanum habrochaites) was found to be rich in pantothenic acid, riboflavin and thiamine. Content of most of the vitamins increased with ripening of the fruit. IIHR-249-1 and LA-1777 were found to be rich in 'B' vitamins, earlier reported to be also rich in antioxidants and lycopene. These genotypes can be used for improving the nutritive value of tomato under crop improvement programmes, through conventional breeding or biotechnological approaches

An MFS Transporter-Like ORF from MDR Acinetobacter baumannii AIIMS 7 Is Associated with Adherence and Biofilm Formation on Biotic/Abiotic Surface

A major facilitator superfamily (MFS) transporter-like open reading frame (ORF) of 453 bp was identified in a pathogenic strain Acinetobacter baumannii AIIMS 7, and its association with adherence and biofilm formation was investigated. Reverse transcription PCR (RT-PCR) showed differential expression in surface-attached biofilm cells than nonadherent cells. In vitro translation showed synthesis of a ~17 kDa protein, further confirmed by cloning and heterologous expression in E. coli DH5α. Up to 2.1-, 3.1-, and 4.1- fold biofilm augmentation was observed on abiotic (polystyrene) and biotic (S. cerevisiae/HeLa) surface, respectively. Scanning electron microscopy (SEM) and gfp-tagged fluorescence microscopy revealed increased adherence to abiotic (glass) and biotic (S. cerevisiae) surface. Extracellular DNA(eDNA) was found significantly during active growth; due to probable involvement of the protein in DNA export, strong sequence homology with MFS transporter proteins, and presence of transmembrane helices. In summary, our findings show that the putative MFS transporter-like ORF (pmt) is associated with adherence, biofilm formation, and probable eDNA release in A. baumannii AIIMS 7

GC-MS analysis of yellow pigmented Macrococcus equipercicus isolated from alfalfa rhizosphere soil fields of Coimbatore

The rhizosphere of plant possesses important microflora, which secretes wide chemical compounds including secondary metabolites necessary for plant growth and development. The microbial flora of alfalfa plant rhizosphere soil region was explored for functional activity and we found upto ten different pigmented colonies. Due to good functional diversity, this yellow pigmented colony was taken for further studies. Thus, the culture was molecularly characterized and identified for potent bioactive components responsible for antimicrobial activity. The selected culture mass was cultured and secondary metabolites were produced and extracted using ethyl acetate and subjected to GC-MS analysis. The antimicrobial study revealed selective activity against Streptococcus pneumonia, and Proteus sp with zone of inhibition to be 18 and 20 mm respectively.  Molecular identification of the isolate by 16S rRNA sequencing showed the isolate as Macrococcus equipercicus with 100 % similarity. Based on GC-MS analysis report 25bioactive compounds were identified and 13-docosenamide, hexadecanoic acid esters and quercetin were found in ethyl acetate extract. Conclusion: Thus the yellow pigmented gram positive cocci M.equipercicus isolated from Medicago sativa possessed wide antibacterial activity due to presence of quercetin. Through the studies, we were able to identify potent antibacterial compound producing bacteria from M. sativa plant rhizosphere soil

A CEP215-HSET complex links centrosomes with spindle poles and drives centrosome clustering in cancer.

Numerical centrosome aberrations underlie certain developmental abnormalities and may promote cancer. A cell maintains normal centrosome numbers by coupling centrosome duplication with segregation, which is achieved through sustained association of each centrosome with a mitotic spindle pole. Although the microcephaly- and primordial dwarfism-linked centrosomal protein CEP215 has been implicated in this process, the molecular mechanism responsible remains unclear. Here, using proteomic profiling, we identify the minus end-directed microtubule motor protein HSET as a direct binding partner of CEP215. Targeted deletion of the HSET-binding domain of CEP215 in vertebrate cells causes centrosome detachment and results in HSET depletion at centrosomes, a phenotype also observed in CEP215-deficient patient-derived cells. Moreover, in cancer cells with centrosome amplification, the CEP215-HSET complex promotes the clustering of extra centrosomes into pseudo-bipolar spindles, thereby ensuring viable cell division. Therefore, stabilization of the centrosome-spindle pole interface by the CEP215-HSET complex could promote survival of cancer cells containing supernumerary centrosomes.S.C. is supported by UK Medical Research Council (MC_U105185859). This work was made possible by funding from Cancer Research UK (C14303/A17197). We acknowledge the support of the University of Cambridge and Hutchison Whampoa Ltd.This is the final version of the article. It first appeared from Nature Publishing Group via https://doi.org/10.1038/ncomms1100

Cerebral malaria: insights from host-parasite protein-protein interactions

<p>Abstract</p> <p>Background</p> <p>Cerebral malaria is a form of human malaria wherein <it>Plasmodium falciparum</it>-infected red blood cells adhere to the blood capillaries in the brain, potentially leading to coma and death. Interactions between parasite and host proteins are important in understanding the pathogenesis of this deadly form of malaria. It is, therefore, necessary to study available protein-protein interactions to identify lesser known interactions that could throw light on key events of cerebral malaria.</p> <p>Methods</p> <p>Sequestration, haemostasis dysfunction, systemic inflammation and neuronal damage are key processes of cerebral malaria. Key events were identified from literature as being crucial to these processes. An integrated interactome was created using available experimental and predicted datasets as well as from literature. Interactions from this interactome were filtered based on Gene Ontology and tissue-specific annotations, and further analysed for relevance to the key events.</p> <p>Results</p> <p>PfEMP1 presentation, platelet activation and astrocyte dysfunction were identified as the key events influencing the disease. 48896 host-parasite along with other host-parasite, host-host and parasite-parasite protein-protein interactions obtained from a disease-specific corpus were combined to form an integrated interactome. Filtering of the interactome resulted in five host-parasite PPI, six parasite-parasite and two host-host PPI. The analysis of these interactions revealed the potential significance of apolipoproteins and temperature/Hsp expression on efficient PfEMP1 presentation; role of MSP-1 in platelet activation; effect of parasite proteins in TGF-β regulation and the role of albumin in astrocyte dysfunction.</p> <p>Conclusions</p> <p>This work links key host-parasite, parasite-parasite and host-host protein-protein interactions to key processes of cerebral malaria and generates hypotheses for disease pathogenesis based on a filtered interaction dataset. These hypotheses provide novel and significant insights to cerebral malaria.</p

Antimicrobial and antioxidant properties of methanol extract, fractions and compounds from the stem bark of Entada abyssinica Stend ex A. Satabie

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to evaluate the antimicrobial and antioxidant activities of the methanol extract, fractions and isolated compounds from <it>Entada abyssinica </it>stem bark, plant used traditionally against gastrointestinal infections.</p> <p>Methods</p> <p>The methanol extract of <it>E. abyssinica </it>stem bark was pre-dissolved in a mixture of methanol and water, and then partitioned between <it>n</it>-hexane, ethyl acetate and <it>n</it>-butanol. The ethyl acetate portion was fractionated by column chromatography and the structures of isolated compounds elucidated by analysis of spectroscopic data and comparison with literature data. Antimicrobial activity was assayed by broth microdilution techniques on bacteria and yeasts. The antioxidant activity was determined by DPPH radical scavenging method.</p> <p>Results</p> <p>Four known compounds [(5<it>S</it>,6<it>R</it>,8a<it>R</it>)-5-(carboxymethyl)-3,4,4a,5,6,7,8,8a-octahydro-5,6,8a-trimethylnaphthalenecarboxylic acid (<b>1</b>), methyl 3,4,5-trihydroxybenzoate (<b>2</b>), benzene-1,2,3-triol (<b>3</b>) and 2,3-dihydroxypropyltriacontanoate (<b>4</b>)] were isolated. Compared to the methanol extract, fractionation increased the antibacterial activities of the <it>n</it>-hexane and ethyl acetate fractions, while the antifungal activities increased in ethyl acetate, <it>n</it>-butanol and aqueous residue fractions. The isolated compounds were generally more active on bacteria (9.7 to 156.2 μg/ml) than yeasts (78.1 to 312.5 μg/ml). Apart from compound <b>1</b>, the three others displayed DPPH^·scavenging activity (RSa), with RSa₅₀values of 1.45 and 1.60 μg/ml.</p> <p>Conclusion</p> <p>The results obtained from this study support the ethnomedicinal use of <it>E. abyssinica </it>in the treatment of gastrointestinal infections and the isolated compounds could be useful in the standardisation of antimicrobial phytomedicine from this plant.</p

Computational Prediction of Host-Parasite Protein Interactions between P. falciparum and H. sapiens

To obtain candidates of interactions between proteins of the malaria parasite Plasmodium falciparum and the human host, homologous and conserved interactions were inferred from various sources of interaction data. Such candidate interactions were assessed by applying a machine learning approach and further filtered according to expression and molecular characteristics, enabling involved proteins to indeed interact. The analysis of predicted interactions indicated that parasite proteins predominantly target central proteins to take control of a human host cell. Furthermore, parasite proteins utilized their protein repertoire in a combinatorial manner, providing a broad connection to host cellular processes. In particular, several prominent pathways of signaling and regulation proteins were predicted to interact with parasite chaperones. Such a result suggests an important role of remodeling proteins in the interaction interface between the human host and the parasite. Identification of such molecular strategies that allow the parasite to take control of the host has the potential to deepen our understanding of the parasite specific remodeling processes of the host cell and illuminate new avenues of disease intervention