Extraction and characterization of bio-effectors from agro-food processing by-products as plant growth promoters

Background Recently, a novel concept ‘bio-effectors’ rose on to describe a group of products that are able to improve plant performance rather than fertilizers. Agro-food processing residues and by-products potentially represent important sources of bio-effectors but they are currently not properly taken in consideration. To fulfill this gap, in these study, three food processing by-products: (i) brewers' spent grain, (ii) fennel processing residues, and (iii) lemon processing residues were chosen as bio-effector candidates. Raw materials were chemically characterized, and green extraction methodology was optimized by using water, ethanol, and their mixture based on the extraction yields. Aqueous extracts were used for seed germination bioassays on Lepidium sativum seeds to evaluate their potential bioactivities. Thereafter, the extracts were chemically characterized and metabolites were detected by 1D and 2D NMR spectroscopy. Results Results are summarized as follows: (i) raw materials showed an interesting nutritional content; (ii) aqueous extraction resulted higher yield more than other used solvent; (iii) at high solvent extraction ratio, aqueous extracts were not phytotoxic but enhanced seed germination and root elongation; (iv) all aqueous extracts are differently rich in nutrients, amino-acids, sugars, and other low molecular weight molecule compounds. Conclusions This study confirmed that efficient and simple recovery of bioactive compounds other than nutrients from agro-food processing by-products appear to be the new frontier in their valorization

Pentacoordinate [PtCl2(eta(2)-C2H4)(N-N')] complexes with asymmetrically hindered nitrogen donor chelates. Stereospecific synthesis of syn- and anti-[PtCl(eta(1)-CH2CH2OMe)(Mebpy)]

Synthesis and characterization of the new pentacoordinate [PtCl2(eta(2)-C2H4)(Mebpy)] and square planar [PtCl2(Mebpy)] complexes both containing the asymmetrically hindered nitrogen donor chelate Mebpy = 6-Methyl-2,2'-bipyridil are reported. By nucleophilic addition of MeO- to the coordinated ethene of [PtCl2(eta(2)-C2H4)(Mebpy)], syn-[PtCl(eta(1)-CH2CH2OMe)(Mebpy)] and anti-[PtCl(eta(1)-CH2CH2OMe)(Mebpy)] complexes have been obtained as the kinetic and thermodynamic product, respectively. The mechanism for selective formation of both stereoisomers is also reported. This synthetic route opens new perspectives for the stereospecific synthesis of syn- and anti-square planar organometallic complexes

First Insight on the Mucus of the Annelid Myxicola infundibulum (Polychaeta, Sabellidae) as a Potential Prospect for Drug Discovery

Many marine organisms, including invertebrates, produce mucosal matrices having different functions. Besides mechanical protection, the mucus of many invertebrates contains specific compounds to make the animal poisonous and/or distasteful or irritating. The presence of antibiotic molecules is more advantageous for some invertebrates to contrast bacterial attack. In the present study we investigated the mucus of the Mediterranean annelid species Myxicola infundibulum living in a gelatinous envelope made up of dense mucus. Antimicrobial lysozyme-like and antioxidant activities were investigated to highlight the potential interest of the worm mucus as a source of bioactive compounds for biotechnological applications. In order to understand which kind of compounds could be responsible for the detected activities, the mucus of M. infundibulum was chemically characterized in terms of elemental composition, protein, lipid and carbohydrate content. Further chemical characterization was achieved by the advanced analytical technique of multinuclear and multidimensional NMR spectroscopy. NMR spectroscopy revealed the scarcity of lipids which preferentially resulted of alcoholic origin, or otherwise hydroxylate and several aminoacids (valine, leucine and alanine) in the aqueous extract in relation to the protein nature of M. infundibulum mucus. The mucus indeed is mainly composed by water (94% ± 0.7%) whereas its dry weight is made of proteins (36% ± 2.3%) followed by lipids (2.9% ± 0.07%) and carbohydrates (2% ± 0.31%). The mucus exerted a natural antibacterial lysozyme-like activity corresponding to 1.14 mg mL−1 of hen egg-white lysozyme and an antioxidant activity corresponding to 483.00 ± 79.22 nmolTE (Trolox equivalent)/mL sample as Trolox Equivalent Antioxidant Capacity (TEAC) and 276.26 ± 50.76 nmolTE/mL sample as Oxygen Radical Absorbance Capacity (ORAC). Therefore, our findings have potential implications due to the ongoing explosion of antibiotic resistant infections and the need to discover antibacterial agents. Additionally, the observed antioxidant activity is intriguing taking into account the need to find natural antioxidants useful for human health