A Portable Photocollector for the Field Collection of Insects in Biodiversity Assessment.

Arthropod biodiversity research usually requires large sample collections. The efficient handling of these samples has always been a critical bottleneck. Sweep netting along transects is an effective and commonly used approach to sample diverse insects.

Revisiting the Determination of the Degree of Deacetylation Using Potentiometric Titration: A New Equation for Modified Chitosan.

Chitosan is a biopolymer that can be subjected to a variety of chemical modifications to generate new materials. The properties of modified chitosan are affected by its degree of deacetylation (), which corresponds to the percentage of D-glucosamine monomers in its polymeric structure. Potentiometric titration is amongst the simplest, most readily available, and most cost-effective methods of determining the .

A New and Rapid HPLC Method to Determine the Degree of Deacetylation of Glutaraldehyde-Cross-Linked Chitosan.

Chitosan is a linear biopolymer composed of D-glucosamine and N-acetylglucosamine units. The percentage of D-glucosamine in the polymeric chain can vary from one sample to another and is expressed as the degree of deacetylation (DDA). Since this parameter has an impact on many properties, its determination is often critical, and potentiometric titration is a common analytical technique to measure the DDA.

Convenient route to Fmoc-homotyrosine metallaphotoredox catalysis and its use in the total synthesis of anabaenopeptin cyclic peptides.

Herein, we report the first solid-phase total synthesis of the natural cyclic peptide anabaenopeptin F and the use of metallaphotoredox catalysis to overcome the key challenges associated with the preparation of the non-proteinogenic amino acid homotyrosine contained in these peptides. Starting from L-homoserine, enantiopure Fmoc-protected homotyrosine was prepared in a straightforward manner by metallaphotoredox catalysis with -Fmoc-()-2-amino-4-bromobutanoic acid and 4--butoxybromobenzene partners. The prepared protected amino acid was used in solid-phase peptide synthesis to achieve the total synthesis of anabaenopeptin F and establish the stereochemistry of the isoleucine residue.

Twenty-five new species of mining bees (Hymenoptera: Andrenidae: Andrena) from Israel and the Levant.

Andrena is one of the most diverse bee genera, comprising about 1,600 described species of ground-nesting solitary bees. Many Andrena species are plant specialists, and several taxa have been indicated to be important pollinators of wild and/or crop plants. The Eastern Mediterranean Basin and Israel in particular are one of the main world diversity hotspots of Andrena.