Residues of 165 pesticides in citrus fruits using LC-MS/MS: a study of the pesticides distribution from the peel to the pulp

Abstract A sensitive LC–ESI-MS/MS method was developed for the determination of 165 pesticides in 50 citrus fruit samples collected in Sicily. Moreover, an evaluation of pesticides levels in the citrus layers (peel, albedo, and pulp) was carried out. The method presented acceptable trueness, precision, and linearity with LOQ of 5 μg/kg. The results obtained showed a high frequency of fungicides class pesticides in all the citrus samples examined (>95%) with the highest concentrations in the peel (4468 µg/Kg). A significant difference of concentrations was found between the layers of the citrus fruits analysed (p < 0.05). In particular, the peel and albedo present higher pesticides significantly higher than the pulp. Our findings confirming the widespread use of these substances in citrus cultivation and suggesting the importance of pesticides analysis in all the citrus fruit layers separately, considering the different interactions between the physicochemical characteristics of the matrices and the pesticides

Novel 3,3-disubstituted oxindole derivatives. Synthesis and evaluation of the anti-proliferative activity

3,3-Disubstituted oxindole derivatives bearing a nitrogen atom at the C-3 position have been synthesized starting from 3-alkyl oxindole through a metal free pathway. These derivatives have been tested in five human tumor cell lines (PC3, MCF7, SW620, MiaPaca2 and A375) and on primary cells (PBMCs) from healthy donors providing compound 6d showing a strong anticancer effect in all cancer lines on the low micromolar range

An evaluative message fosters mathematics performance in male students but decreases intrinsic motivation in female students

This study contrasted the effects of two task messages, evaluative or non-evaluative, on mathematics performance, affect, and intrinsic task motivation. One hundred-twenty secondary-school students aged 17–21 years were delivered one of the two messages, or assigned to a control condition, before completing a mathematics task, measures of message appraisals (challenge and threat), affect (pleasantness, arousal, dominance), and a behavioural indication of intrinsic task motivation. The evaluative message raised performance only in males, while for females both messages decreased intrinsic motivation for the task, probably due to stereotype threat. Implications for future research and educational practices are discussed.HIGHLIGHTS In a low-value context, an evaluative message favoured male mathematics performance Males increased arousal after an evaluative message A challenge appraisal was linked with male performance Females decreased intrinsic motivation after evaluative and non-evaluative messages

Tetrahydro-4H-(pyrrolo[3,4-d]isoxazol-3-yl)methanamine : a bicyclic diamino scaffold stabilizing parallel turn conformations

Tetrahydro-4H-(pyrrolo[3,4-d]isoxazol-3-yl)methanamine scaffold was designed as diamino derivative to stabilize parallel turn conformations. Its synthesis took advantage of a [1,3]-dipolar cycloaddition reaction between the nitrile oxide derived from the inexpensive enantiopure L-phenylalanine, and N-benzyl-3-pyrroline. Two diastereoisomers were formed whose distribution depends on the selected base. 3aR,6aS-Isomer is favoured in organic bases which formation is driven by pi-interactions. On the other hand, the above interactions were significantly prevented using an inorganic base due to the chaotropic effect of the cation, decreasing the amount of the above isomer. Finally, we demonstrated that this isomer is able of stabilizing parallel turn conformations when inserted in short peptide sequences

Peptidomimetics containing a vinyl ketone warhead as falcipain-2 inhibitors

The design, chemical synthesis, and enzymatic activity evaluation of a set of falcipain-2 inhibitors are reported. These compounds contain a proven peptidomimetic recognition motif based on a benzo[1,4]diazepin-2-one (1,4-BDZ) framework built on a dipeptide sequence, and a Michael acceptor terminal moiety capable of deactivating the cysteine protease active site. Our goal is to modify the P3 site of this motif in order to identify the structural requirements for the interaction with the target