Detailed information about the relationships between structures and properties/activities of peptides as drugs and nutrients is useful in the development of drugs and functional foods containing peptides as active compounds. The bitterness of the peptides is an undesirable property which should be reduced during drug/nutrient production, and quantitative structure bitter taste relationship (QSBR) studies can help researchers to design less bitter peptides with higher target efficiency. Calculated structural parameters were used to develop three different QSBR models (i.e., multiple linear regression, support vector machine, and artificial neural network) to predict the bitterness of 229 peptides (containing 2–12 amino acids, obtained from the literature). The developed models were validated using internal and external validation methods, and the prediction errors were checked using mean percentage deviation and absolute average error values. All developed models predicted the activities successfully (with prediction errors less than experimental error values), whereas the prediction errors for nonlinear methods were less than those for linear methods. The selected structural descriptors successfully differentiated between bitter and nonbitter peptides.

Introduction: Beta-Boswellic acid (BBA) is a pentacyclic terpene which has been obtained from frankincense and its beneficial effects on neurodegenerative disorders such as Alzheimer's disease (AD) have been addressed. Methods: In the present study, thermodynamic and kinetic aspects of BBA interaction with Tau protein as one of the important proteins involved in AD in the absence and presence of glucose has been investigated using surface plasmon resonance (SPR) method. Tau protein was immobilized onto the carboxy methyl dextran chip and its binding interactions with BBA were studied at physiological pH at various temperatures. Glucose interference with these interactions was also investigated. Results: Results showed that BBA forms a stable complex with Tau (K D =8.45×10 -7 M) at 298 K. Molecular modeling analysis showed a hydrophobic interaction between BBA and HVPGGG segment of R 2 and R 4 repeated domains of Tau. Conclusion: The binding affinity increased by temperature enhancement, while it decreased significantly in the presence of glucose. Both association and dissociation of the BBA-Tau complex were accompanied with an entropic activation barrier; however, positive enthalpy and entropy changes revealed that hydrophobic bonding is the main force involved in the interaction.

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Biological activity of Boswellia extract (BE) has been attributed to its main active ingredients; i.e. Boswellic acids (BAs). BE/BAs possess a promising therapeutic potential in neurodegenerative disorders; including Alzheimer's disease (AD). The multifactorial nature of AD pathophysiology necessitates the development of the disease-modifying agents (DMA). Recent multi-targeting approaches for the DMAs development have brought more attention to the plant-derived compounds regarding their better human compatibility because of their biologic origin. This review addresses the current knowledge on the anti-AD activity of BE/BAs based on the available in silico, in vitro, in vivo studies and clinical trials. The contribution of BE/BAs in inflammatory pathways, Tau and β-amyloid proteins, microtubule functions, oxidative stress, cholinesterase and diabetes/insulin pathways involved in AD have been discussed. BAs efficacy in different AD-related pathways has been confirmed in vitro and in vivo. They can be considered as valuable scaffold/lead compounds for multi-targeted DMAs in anti-AD drug discovery and development.

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