Natural stilbenes and their derivatives as antifungals against rice blast

Among the fungal plant pathogens, Pyricularia oryzae poses a serious threat to sustainable agricultural pro- duction causing serious damage on rice and other crop plants. In rice, blast disease by P. oryzae causes annually 10-30% of harvest losses. Overreliance on fungicides, especially those with single-site mode of action, mono- culture cropping, and use of blast-susceptible rice varieties, have been favoring the development of resistance in pathogen populations increasing thus food insecurity. This in turn creates a strong demand for the develop- ment of novel fungicides for rice blast management with emphasis on their low environmental impact and circular economy. Here, we investigated the antifungal activity of natural stilbenes and their use as scaffolds for the development of novel biofungicides. Monomeric and dimeric stilbenoids were tested against wild-type (WT) and strobilurin-resistant (RES) strains of Pyricularia oryzae and several compounds showed inhibition higher than 40%, and in particular deoxyrhapontigenin inhibited mycelial growth of both WT and RES strains by 60-80%. Furthermore, a set of molecules based on methoxyacrylate stilbene (MOAS) were synthesized, merging a nature derived stilbene fragment with the β- methoxyacrylate moiety of strobilurin fungicides. We identified two molecules with activity comparable to the reference commercial fungicide azoxystrobin. How- ever, low mycelium growth inhibition of resistant strains indicates that these compounds most likely retain the strobilurin-like mechanism of action

Stilbenoids as antifungals to counteract rice blast pathogen Pyricularia oryzae

Fungi are among the greatest biotic threats to agricultural and food security. Intensive monoculture cropping and resistance to single-site fungicides in plant pathogens urge the discovery and development of novel compounds that possibly interfere with essential cellular processes in multiple ways. In this article, we describe our recent efforts addressed to the identification of natural compounds as multitarget biofungicides. A set of natural monomeric and dimeric compounds belonging to the class of stilbenoids were synthesized and tested against wild-type (WT) and strobilurin-resistant (RES) strains of Pyricularia oryzae, one of the most dangerous fungal phytopathogens. Monomers deoxyrhapontigenin, pinostilbene, and DMHS showed inhibitory activity higher than 40%, with deoxyrhapontigenin having the highest activity on mycelial growth (60−80% inhibition) on both WT and RES P. oryzae strains. Furthermore, we designed and synthesized a set of molecules having a nature-derived stilbene fragment merged with the pharmacophoric portion of strobilurins, namely, a β-methoxyacrylate moiety. We identified two molecules with activity comparable to the reference commercial fungicide azoxystrobin. However, low mycelium growth inhibition of resistant strains indicates that these compounds most likely retain the strobilurin-like mechanism of action. Overall, the results suggest that natural stilbenoids might be used as environmentally friendly biofungicides in rice blast management

Autoimmunity in gestational diabetes mellitus in Sardinia: a preliminary case-control report

<p>Abstract</p> <p>Background</p> <p>We previously reported a high prevalence (22.3%) of gestational diabetes mellitus (GDM) in a large group of Sardinian women, in contrast with the prevalence of Type 2 diabetes. Sardinia has an unusual distribution of haplotypes and genotypes, with the highest population frequency of HLA DR3 in the world, and after Finland, the highest prevalence of Type 1 diabetes and Autoimmune-related Diseases. In this study we preliminarily tested the prevalence of serological markers of Type 1 diabetes in a group of Sardinian GDM patients.</p> <p>Methods</p> <p>We determined glutamic decarboxylase antibodies (anti-GAD65), protein tyrosine phosphatase ICA 512 (IA2) antibodies (anti-IA2), and IAA in 62 GDM patients, and in 56 controls with matching age, gestational age and parity.</p> <p>Results</p> <p>We found a high prevalence and very unusual distribution of antibodies in GDM patients (38.8%), the anti-IA2 being the most frequent antibody. Out of all our GDM patients, 38.8% (24 of 62) were positive for at least one antibody. Anti-IA2 was present in 29.0 % (18 out of 62) vs. 7.1% (4 out of 56) in the controls (P < 0.001). IAA was present in 14.5% (9 out of 62) of our GDM patients, and absent in the control subjects (P < 0.001). Anti-GAD65 was also present in GDM patients, with a prevalence of 3.2% (2 out of 62) while it was absent in the control group (P = NS). Pre-gestational weight was significantly lower (57.78 ± 9.8 vs 65.9 ± 17.3 <it>P </it>= 0.04) in auto-antibodies- positive GDM patients.</p> <p>Conclusion</p> <p>These results are in contrast with the very low prevalence of all antibodies reported in Italy. If confirmed, they could indicate that a large proportion of GDM patients in Sardinia have an autoimmune origin, in accordance with the high prevalence of Type 1 diabetes.</p

On the connections between fresh state behavior, fiber dispersion and toughness properties of steel fiber reinforced concrete

The connections between fresh and hardened state properties of fiber reinforced concrete and issues related to fiber dispersion have been a research challenge in the very last years. The topic is addressed in this work with reference to “self compacting” concretes with three different types of steel fiber reinforcement. Fresh state properties have been measured through the slump flow, V funnel and L-box tests. Plate specimens 1000x500x70 mm have been cast in such a way that the concrete flow was parallel to their long side. Beams 150 mm wide and 600 mm long and disks with a 150 mm diameter were sawn from the plates and tested respectively in 4 point bending and splitting. Beams have been cut with their axis either parallel or normal to the flow direction of the fresh concrete in the plate and the same happened for the diameter axis of preferential fracture in split disks. The results show a strong correlation between the fresh state properties, the dispersion and orientation of fibers, as influenced by the casting process, and the mechanical properties of the composite. An omni-comprehensive approach to the problem is currently under development aiming at a “design” of the material and of the casting process tailored to the dedicated application and to the anticipated structural performance