scholarly journals Polyketide-Terpene Hybrid Metabolites from an Endolichenic Fungus Pestalotiopsis sp.

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Chao Yuan ◽  
Gang Ding ◽  
Hai-Ying Wang ◽  
Yu-Hua Guo ◽  
Hai Shang ◽  
...  

Five new polyketide-terpene hybrid metabolites (1–5) with highly functionalized groups, together with six known derivatives (6–11), were isolated from the endolichenic fungus Pestalotiopsis sp. Their structures were elucidated by extensive NMR experiments including 1H, 13C, HMQC, COSY, and HMBC. The relative configurations of the new compounds were determined by analysis of coupling constants and ROESY correlations. The absolute configurations especially the secondary alcohol at C-15 in 1 and secondary alcohol at C-14 in 5 were established via the CD experiments of the in situ formed [Rh2(OCOCF3)4] complex with the acetonide derivatives. These compounds were tested for their inhibition activity against six plant pathogens. Compounds 1 and 5 exhibited pronounced efficiency against Fusarium oxysporum, and compounds 5 and 6 potently inhibited Fusarium gramineum with MIC value of 8 µg/mL, which revealed the plausible ecological role of endolichenic fungus in providing chemical protection for its host lichen in the fungus-plant relationship. The biosynthetic pathway of compounds 1–11 was postulated for the first time, which paved the way for its further biosynthesis research.

2014 ◽  
Vol 9 (5) ◽  
pp. 1934578X1400900
Author(s):  
Henry IC Lowe ◽  
Ngeh J. Toyang ◽  
Charah T. Watson ◽  
Joseph Bryant

1,3-di-O-Cinnamoyl-glycerol is a natural compound isolated from a Jamaican medicinal plant commonly referred to as Ball moss (Tillandsia recurvata). The synthesis of this compound was achieved via a Wittig chemistry process. The synthetic approach started with acylation of a di-protected glycerol with cinnamoyl chloride, deprotection of the glycerol moiety, reaction of the primary alcohol with bromo acetylbromide followed by treatment with triphenyl phosphine to give the corresponding phosphonium bromide. The phosphonium bromide was then converted in situ to the Wittig reagent which is the basis for a novel route to 1,3-di-O-cinnamoyl glycerol. Four analogs were also synthesized, three of which are new and are being reported in this article for the first time. The new compounds include 3-(3,4-diemthoxy-phenyl)-acrylic acid 2-hydroxy-3-(3-ptolyl-acryloyloxy)-propyl ester (3), 2-acetoxy-5-((E)-3-(3-((E’)-3-(3,4-dimethoxyphenyl)acryloyloxy)-2-hydropropoxy)-3-oxoprop-1-enyl)benzoic acid (4) and 4-((E)-3-(3-((E)-3-(3,4-dimethoxyphenyl)acryloyloxy)-2-hydropropoxy)-3-oxoprop-1-enyl)benzoic acid (5). The compounds showed no activity in our anticancer assay.


2010 ◽  
Vol 72 ◽  
pp. 164-169 ◽  
Author(s):  
Daphiny Pottmaier ◽  
Sebastiano Garroni ◽  
Maria Dolors Barò ◽  
Marcello Baricco

Hydrogen storage in the solid state has shown increasing research and development, and recently an approach in mixing two hydride systems together by ball milling (reactive hydride composites) has been investigated in more detail, e.g. NaBH4 plus MgH2. Thermodynamic destabilization may occur by new compounds formation during dehydrogenation, e.g. MgB2. A study of the the role of O2/H2O contamination for the reaction 2NaBH4 + MgH2 ↔ 2NaH + MgB2 + 4H2 was conducted using in-situ X-ray powder diffraction. Desorption reaction is observed to begin by a competition of MgH2 and NaBH4 decomposition due to higher reactivity promoted by ball milling processing summed to O2/H2O contamination. Oxidation of NaBH4 into NaBO2 is observed to happen in higher degree than MgH2/Mg into MgO for the Na-Mg-B-H system.


1999 ◽  
Vol 23 (1) ◽  
pp. 57-66 ◽  
Author(s):  
C Keil ◽  
B Husen ◽  
J Giebel ◽  
G Rune ◽  
R Walther

In the present study we demonstrate for the first time the expression of glycodelin mRNA in the female and male genital tracts of rats using non-radioactive in situ hybridisation. Glycodelin fragment 1 (+41 to +141) shares 100% homology with the human gene sequence. In the ovary, glycodelin mRNA was restricted to granulosa cells. In the uterus, glycodelin mRNA was expressed in all epithelial cells of the endometrium. In the male reproductive tract, glycodelin mRNA was distributed in all epithelial cells of the epididymis, the prostate and the seminal vesicle. However, in the testis, glycodelin mRNA was predominantly found in spermatogonia and in spermatocytes of the seminiferous epithelium. The expression in several reproductive organs of rats offers an excellent tool to study further the physiological role of glycodelin, which is so far thought to act as an immunosuppressive factor.


2017 ◽  
Vol 5 (10) ◽  
pp. 4894-4903 ◽  
Author(s):  
Weiqiang Fan ◽  
Chunfa Li ◽  
Hongye Bai ◽  
Yanyan Zhao ◽  
Bifu Luo ◽  
...  

This paper presents for the first time a novel method of in situ depositing plasmonic Bi nanoparticles on BiOCl nanosheets (Bi/BiOCl) for PEC water splitting.


1981 ◽  
Vol 59 (4) ◽  
pp. 573-582 ◽  
Author(s):  
Anthony P. Russell

The role of the circulatory system in the functioning of the subdigital adhesive pads of geckoes has been the subject of much discussion. However, the morphology and configuration of the blood system in the foot has remained poorly understood, rendering functional interpretation of the blood sinuses simplistic. Here the major arterial vessels of the manus are described for the first time and a discussion of their geometry is presented. Due to the paucity of information concerning the arterial system of the appendages of lizards a description of the major vessels of the antebrachium is also given.The data presented are based on the study of material injected with low-viscosity silicone rubber and then cleared so that vessels may be studied in situ. The data are pertinent to subsequent discussions of the microvasculature of the subdigital lamellae and of reconsiderations of their structure and form.


PalZ ◽  
2021 ◽  
Author(s):  
Pablo Suarez-Gonzalez ◽  
Joachim Reitner

AbstractOoids (subspherical particles with a laminated cortex growing around a nucleus) are ubiquitous in the geological record since the Archean and have been widely studied for more than two centuries. However, various questions about them remain open, particularly about the role of microbial communities and organic matter in their formation and development. Although ooids typically occur rolling around in agitated waters, here, we describe for the first time aragonite ooids forming statically within microbial mats from hypersaline ponds of Kiritimati (Kiribati, central Pacific). Subspherical particles had been previously observed in these mats and classified as spherulites, but these particles grow around autochthonous micritic nuclei, and many of them have laminated cortices, with alternating radial fibrous laminae and micritic laminae. Thus, they are compatible with the definition of the term ‘ooid’ and are in fact very similar to many modern and fossil examples. Kiritimati ooids are more abundant and developed in some ponds and in some particular layers of the microbial mats, which leads to the discussion and interpretation of their formation processes as product of mat evolution, through a combination of organic and environmental factors. Radial fibrous laminae are formed during periods of increased supersaturation, either by metabolic or environmental processes. Micritic laminae are formed in closer association with the mat exopolymer (EPS) matrix, probably during periods of lower supersaturation and/or stronger EPS degradation. Therefore, this study represents a step forward in the understanding of ooid development as influenced by microbial communities, providing a useful analogue for explaining similar fossil ooids.


eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Florian Dunker ◽  
Adriana Trutzenberg ◽  
Jan S Rothenpieler ◽  
Sarah Kuhn ◽  
Reinhard Pröls ◽  
...  

The exchange of small RNAs (sRNAs) between hosts and pathogens can lead to gene silencing in the recipient organism, a mechanism termed cross-kingdom RNAi (ck-RNAi). While fungal sRNAs promoting virulence are established, the significance of ck-RNAi in distinct plant pathogens is not clear. Here, we describe that sRNAs of the pathogen Hyaloperonospora arabidopsidis, which represents the kingdom of oomycetes and is phylogenetically distant from fungi, employ the host plant’s Argonaute (AGO)/RNA-induced silencing complex for virulence. To demonstrate H. arabidopsidis sRNA (HpasRNA) functionality in ck-RNAi, we designed a novel CRISPR endoribonuclease Csy4/GUS reporter that enabled in situ visualization of HpasRNA-induced target suppression in Arabidopsis. The significant role of HpasRNAs together with AtAGO1 in virulence was revealed in plant atago1 mutants and by transgenic Arabidopsis expressing a short-tandem-target-mimic to block HpasRNAs, that both exhibited enhanced resistance. HpasRNA-targeted plant genes contributed to host immunity, as Arabidopsis gene knockout mutants displayed quantitatively enhanced susceptibility.


2006 ◽  
Vol 59 ◽  
pp. 132-136 ◽  
Author(s):  
M. Braithwaite ◽  
C.F. Hill ◽  
S. Ganev ◽  
J.M. Pay ◽  
H.G. Pearson ◽  
...  

During 2003 and 2004 fortyfive randomly selected wholesale and retail plant nurseries were surveyed for plant diseases The plant families Agavaceae Annonaceae Arecaceae Bromeliaceae Cycadaceae and Musaceae were targeted Plants were examined in situ for disease symptoms as well as samples being collected for laboratory analyses Fungi were identified using morphological characteristics and where necessary with molecular techniques The survey resulted in a range of fungi being identified from the target plants These fungi ranged from saprophytes to plant pathogens some of which may have undesirable effects on New Zealands biodiversity or economy Many new host/pathogen records were observed and several fungi were detected for the first time in New Zealand This paper presents and discusses the results of these findings


2019 ◽  
Author(s):  
Florian Dunker ◽  
Adriana Trutzenberg ◽  
Jan Samuel Rothenpieler ◽  
Sarah Kuhn ◽  
Reinhard Pröls ◽  
...  

AbstractFungal small RNAs (sRNAs) hijack the plant RNA silencing pathway to manipulate host gene expression, named cross-kingdom RNA interference (ckRNAi). It is currently unknown how conserved and significant ckRNAi is for microbial virulence. Here, we found for the first time that sRNAs of a pathogen representing the oomycete kingdom invade the host plant’s Argonaute (AGO)/RNA-induced silencing complex. To demonstrate the functionality of the plant-invading oomycete Hyaloperonospora arabidopsidis sRNAs (HpasRNAs), we designed a novel CRISPR endoribonuclease Csy4/GUS repressor reporter to visualize in situ pathogen-induced target suppression in Arabidopsis thaliana host plant. By using 5’ RACE-PCR we demonstrated HpasRNAs-directed cleavage of plant mRNAs. The significant role of HpasRNAs together with AtAGO1 in virulence was demonstrated by plant atago1 mutants and by transgenic Arabidopsis expressing a target mimic to block HpasRNAs, that both exhibited enhanced resistance. Individual HpasRNA plant targets contributed to host immunity, as Arabidopsis gene knockout or HpasRNA-resistant gene versions exhibited quantitative enhanced or reduced susceptibility, respectively. Together with previous reports, we found that ckRNAi is conserved among oomycete and fungal pathogens.


2021 ◽  
Author(s):  
Jesús Cases ◽  
Mónica Giménez-Marqués

Encapsulation of biomolecules using Metal-Organic Frameworks (MOFs) to form stable biocomposites has been demonstrated a valuable strategy for their preservation and controlled release, which has been however restricted to specific electrostatic surface conditions. We present a general in situ strategy that promotes the spontaneous MOF growth onto a broad variety of proteins, for the first time, regardless of their surface nature. We demonstrate that MOFs based on cations exhibiting considerable inherent acidity such as MIL-100(Fe) enable biomolecule encapsulation, including alkaline proteins previously inaccesible by the welldeveloped in situ encapsulation with azolate-based MOFs. In particular, MIL-100(Fe) scaffold permits effective encapsulation of proteins with very distinct surface nature, retaining their activity and allowing triggered release under biocompatible conditions. This general strategy will enable an ample use of biomolecules in desired biolotechnological applications.


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