Antimicrobial and Antimycobacterial Activities of Methyl Caffeate Isolated from Solanum torvum Swartz. Fruit

Abstract

Solanum torvum Swartz. (Solanaceae) fruit is traditionally used for the treatment of bacterial and fungal infections. The methanolic extract was subjected to activity guided fractionation by column chromatography over silica gel. The structure of the compound was elucidated using physical and spectroscopic data. The antimicrobial activity was screened using five Gram-positive bacteria, six Gram-negative bacteria, seven clinical isolates and four fungi. Antimycobacterial activity was screened against two Mycobacterium strains. The zone of inhibition by methyl caffeate ranged from 0 to 22 mm. The lowest minimum inhibitory concentration (MIC) values of methyl caffeate were: 50 μg/ml against P. vulgaris, 25 μg/ml against K. pneumoniae (ESBL-3971), 8 μg/ml against M. tuberculosis (H³⁷Rv) and 8 μg/ml against M. tuberculosis (Rif^R). Methyl caffeate showed moderate antimicrobial and prominent antimycobacterial activities. Methyl caffeate can be evaluated further for drug development.     

Effects of extenders, cryoprotectants and freezing methods on sperm quality of the threatened Brazilian freshwater fish pirapitinga-do-sul Brycon opalinus (Characiformes)

The objective was to develop a suitable freezing method to cryopreserve Brycon opalinus (Characiformes) sperm. Extenders (NaCl and glucose at 325 and 365 mOsm/kg), cryoprotectants (dimethyl sulfoxide = dimethyl sulfoxide (DMSO) and methyl glycol = methyl glycol (MG)), equilibration times (15 and 30 min), thawing temperatures (30 and 60 °C), and straw sizes (0.5 and 4.0 mL) were tested. Sperm were frozen in a liquid nitrogen vapor vessel at −170 °C and subsequently stored in liquid nitrogen. Post-thaw sperm quality was always evaluated in terms of motility (expressed as percentage of motile sperm), duration of motility and vitality (eosin-nigrosin staining, expressed as percentage of intact sperm). The best freezing method was also tested for fertility and hatching (expressed as the percentage of fertilized eggs). Post-thaw sperm quality was highest when sperm were cryopreserved in Glucose 365 mOsm/kg and MG, after a 30-min equilibration and thawed at 60 °C for 8 s, of regardless straw size: 74 ± 7% motile sperm, 47 ± 4 s of motility duration, 69 ± 3% intact sperm, 64 ± 4% fertilization and 63 ± 3% hatching. The freezing method developed in the present study was efficient and can be used to maximize larvae production for both aquaculture purposes and for conservational programs, since B. opalinus is a threatened species.     

Gene cloning and molecular characterization of the Talaromyces thermophilus lipase catalyzed efficient hydrolysis and synthesis of esters

A genomic bank from Talaromyces thermophilus fungus was constructed and screened using a previously isolated fragment lipase gene as probe. From several clones isolated, the nucleotide sequence of the lipase gene (TTL gene) was completed and sequenced. The TTL coding gene consists of an open reading frame (ORF) of 1083 bp encoding a protein of 269 Aa with an estimated molecular mass of 30 kDa. The TTL belongs to the same gene family as Thermomyces lanuginosus lipase (TLL, Lipolase®), a well known lipase with multiple applications. The promoter sequence of the TTL gene showed the conservation of known consensus sequences PacC, CreA, Hap2-3-4 and the existence of a particular sequence like the binding sites of Oleate Response Element (ORE) and Fatty acids Responsis Element (FARE) which are similar to that already found to be specific of lipolytic genes in Candida and Fusarium, respectively. Northern blot analysis showed that the TTL expression was much higher on wheat bran than on olive oil as sole carbon source. Compared to the Lipolase®, this enzyme was found to be more efficient for the hydrolysis and the synthesis of esters; and its synthetic efficiency even reached 91.6% from Waste Cooking Oil triglycerides.     

Alkylating agent methyl methanesulfonate (MMS) induces a wave of global protein hyperacetylation: implications in cancer cell death

Protein acetylation modification has been implicated in many cellular processes but the direct evidence for the involvement of protein acetylation in signal transduction is very limited. In the present study, we found that an alkylating agent methyl methanesulfonate (MMS) induces a robust and reversible hyperacetylation of both cytoplasmic and nuclear proteins during the early phase of the cellular response to MMS. Notably, the acetylation level upon MMS treatment was strongly correlated with the susceptibility of cancer cells, and the enhancement of MMS-induced acetylation by histone deacetylase (HDAC) inhibitors was shown to increase the cellular susceptibility. These results suggest protein acetylation is important for the cell death signal transduction pathway and indicate that the use of HDAC inhibitors for the treatment of cancer is relevant.     

X-ray diffraction and high-resolution NMR spectroscopy of methyl 3,4-di-O-acetyl-1,5-anhydro-2-deoxy-D-arabino-hex-1-enopyranuronate

Single-crystal X-ray diffraction and high-resolution (1)H and (13)C NMR spectral data for methyl 3,4-di-O-acetyl-1,5-anhydro-2-deoxy-D-arabino-hex-1-enopyranuronate are reported. The (5)H(4) conformation was found to be the preferred form for this glycal, both in the crystal lattice and in solution. The factors determining the (4)H(5)<==>(5)H(4) conformational equilibrium for acetylated glycals are discussed.     

Simultaneous biodegradation of methyl parathion and carbofuran by a genetically engineered microorganism constructed by mini-Tn5 transposon

A genetically engineered microorganism (GEM) capable of simultaneous degrading methyl parathion (MP) and carbofuran was successfully constructed by random insertion of a methyl parathion hydrolase gene (mpd) into the chromosome of a carbofuran degrading Sphingomonas sp. CDS-1 with the mini-transposon system. The GEM constructed was relatively stable and cell viability and original degrading characteristic was not affected compared with the original recipient CDS-1. The effects of temperature, initial pH value, inoculum size and alternative carbon source on the biodegradation of MP and carbofuran were investigated. GEM cells could degrade MP and carbofuran efficiently in a relatively broad range of temperatures from 20 to 30°C, initial pH values from 6.0 to 9.0, and with all initial inoculation cell densities (10⁵–10⁷ CFU ml⁻¹), even if alternative glucose existed. The optimal temperature and initial pH value for GEM cells to simultaneously degrade MP and carbofuran was at 30°C and at pH 7.0. The removal of MP and carbofuran by GEM cells in sterile and non-sterile soil were also studied. In both soil samples, 50 mg kg⁻¹ MP and 25 mg kg⁻¹ carbofuran could be degraded to an undetectable level within 25 days even if there were indigenous microbial competition and carbon sources effect. In sterile soil, the biodegradation rates of MP and carbofuran were faster, and the decline of the inoculated GEM cells was slower compared with that in non-sterile soil. The GEM constructed in this study was potential useful for pesticides bioremediation in natural environment.     

Generation and relaxation of high rank coherences in AX<Subscript>3</Subscript> systems in a selectively methionine labelled SH2 domain

The usefulness of selective isotope labelling patterns is demonstrated using the C-terminal SH2 domain of PLC-γ1 selectively ¹³C labelled at methionine methyl groups. We demonstrate the generation and relaxation of coherences that are second rank in protons and first rank in carbons that derive from quadrupolar order in protons. The decay rates of second rank double quantum proton coherences are measured. These terms exhibit fewer channels for cross-correlated relaxation compared to single quantum coherences. Our results indicate the potential application of the measurement of high order proton coherences to the analysis of dynamics in methyl-bearing side chains.     

The chromatin remodeling complex imitation of switch controls stamen filament elongation by promoting jasmonic acid biosynthesis in Arabidopsis

Plant reproduction requires the coordinated development of both male and female reproductive organs.Jasmonic acid(JA) plays an essential role in stamen filament elongation. However, the mechanism by which the JA biosynthesis genes are regulated to promote stamen elongation remains unclear. Here, we show that the chromatin remodeling complex Imitation of Switch(ISWI) promotes stamen filament elongation by regulating JA biosynthesis. We show that AT-Rich Interacting Domain 5(ARID5) interacts with CHR11,CHR17, and RLT1, several known subunits of ISWI. Mutations in ARID5 and RLTs caused a reduced seed set due to greatly shortened stamen filaments. RNA-seq analyses reveal that the expression of key genes responsible for JA biosynthesis is significantly down-regulated in the arid5 and rlt mutants. Consistently, the JA levels are drastically decreased in both arid5 and rlt mutants. Chromatin immunoprecipitationquantitative PCR analyses further show that ARID5 is recruited to the chromatin of JA biosynthesis genes. Importantly, exogenous JA treatments can fully rescue the defects of stamen filament elongation in both arid5 and rlt mutants, leading to the partial recovery of fertility. Our results provide a clue how JA biosynthesisis positively regulated by the chromatin remodeling complex ISWI, thereby promoting stamen filament elongation in Arabidopsis.     

Methyl viologen responsive proteome dynamics of Anabaena sp. strain PCC7120

A proteomic approach was employed to elucidate the response of an agriculturally important microbe, Anabaena sp. strain PCC7120, to methyl viologen (MV). Exposure to 2 μM MV caused 50% lethality (LD₅₀) within 6 h and modified the cellular levels of several proteins. About 31 proteins increased in abundance and 24 proteins decreased in abundance, while 55 proteins showed only a minor change in abundance. Of these, 103 proteins were identified by MS. Levels of proteins involved in ROS detoxification and chaperoning activities were enhanced but that of crucial proteins involved in light and dark reactions of photosynthesis declined or constitutive. The abundance of proteins involved in carbon and energy biogenesis were altered. The study elaborated the oxidative stress defense mechanism deployed by Anabaena, identified carbon metabolism and energy biogenesis as possible major targets of MV sensitivity, and suggested potential biotechnological interventions for improved stress tolerance in Anabaena 7120.