Scaling the Andean Shilajit: A Novel Neuroprotective Agent for Alzheimer's Disease.

Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder without a cure, despite the enormous number of investigations and therapeutic approaches. AD is a consequence of microglial responses to "damage signals", such as aggregated tau oligomers, which trigger a neuro-inflammatory reaction, promoting the misfolding of cytoskeleton structure. Since AD is the most prevalent cause of dementia in the elderly (>60 years old), new treatments are essential to improve the well-being of affected subjects. The pharmaceutical industry has not developed new drugs with efficacy for controlling AD. In this context, major attention has been given to nutraceuticals and novel bioactive compounds, such as molecules from the Andean Shilajit (AnSh), obtained from the Andes of Chile. Primary cultures of rat hippocampal neurons and mouse neuroblastoma cells were evaluated to examine the functional and neuroprotective role of different AnSh fractions. Our findings show that AnSh fractions increase the number and length of neuronal processes at a differential dose. All fractions were viable in neurons. The AnSh fractions inhibit tau self-aggregation after 10 days of treatment. Finally, we identified two candidate molecules in M3 fractions assayed by UPLC/MS. Our research points to a novel AnSh-derived fraction that is helpful in AD. Intensive work toward elucidation of the molecular mechanisms is being carried out. AnSh is an alternative for AD treatment or as a coadjuvant for an effective treatment.

Synthesis, characterisation, crystal structure and antimicrobial evaluation of novel 6-alkoxyergosta-4,6,8(14),22-tetraen-3-one derived from natural ergosta-5,7,22-trien-3ß-ol.

In this study, we report a facile transformation starting from 5α-hydroxyergosta-7,22-dien-3,6-dione (1) to afford two novel compounds: 6-methoxyergosta-4,6,8(14),22-tetraen-3-one (2) and 6-ethoxyergosta-4,6,8(14),22-tetraen-3-one (3) using alcoholic acid catalysis. Their structures were elucidated using NMR experiments, FT-IR, MS and X-ray analysis. These compounds were evaluated for antibacterial activity using the disk and broth diffusion test. In those tests, compound 3 was found to be the most significant antibacterial agent. In general, compounds 1-3 showed inhibition zone in the range of 7.00-12.3 mm for S. aureus and S. mutans, meanwhile for Gram-negative bacteria E. coli and Pseudomonas sp. was found to be in the range of 7.00-8.00 mm. For the most active, compound 3, MIC was significantly lower than that reported for ergosterol, in a value of 160 µg/mL. Overall, these compounds were more active than their natural precursor.

A Medical Approach to the Monoamine Oxidase Inhibition by Using 7Hbenzo[ e]perimidin-7-one Derivatives.

BACKGROUND: A series of perimidinone derivatives (7H-benzo[e]perimidin-7-one) were synthesized and assessed by means of in vitro assays as human MAO inhibitors. These compounds inhibited reversibly the enzymes with inhibitory constants in the range of 2 to 20 µM. In addition, the selectivity of inhibition of the MAO isoforms seems to be significantly dependent of the presence either of heteroatom or electron donating and withdrawing groups on the perimidinone framework, which was verified by using molecular docking simulation with the crystallized MAO receptors. Most of these inhibitors were highly selective: 9 and 11 inhibited selectively the MAO-B isoform while 12 had 10-fold selectivity for MAO-A isoform. Moreover, the compound 12 was both the most selective and potent MAO-A inhibitor among perimidinones. RESULT: These results have important implications for the drug design of molecules targeting depression and movement-related disorders.

Molecular Docking Studies of the Antitumoral Activity and Characterization of New Chalcone.

Phytochemical investigation of Azorella madreporica led to the isolation of four known compounds and an unknown chalcone. The structure of the new compound was identified by spectroscopy, including two-dimensional NMR techniques and comparison with published spectral data. The antioxidant activity of chalcone (compound 1) was measured using the 1,2-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging assay, and the bioactivity was evaluated against five bacteria (Mycobacterium smegmatis ATCC 14468, clinical isolates of Staphylococcus aureus, Klebsiella granulomatis, Morganella morganii and Escherichia coli) and four cancer cell lines. Docking studies with the tested cancer related proteins revealed nearby values of energy between doxorubicin and compound 1. Besides, protein-ligand interactions correlate with these energy values.

Antimicrobial Diterpenes from Azorella Species Against Gram-Positive Bacteria.

The present study was aimed at evaluating the antibacterial activity of mulinane and azorellane diterpenes isolated from the Andean plants Azorella compacta and A. trifoliolata and semisynthetic derivatives against reference and multidrug-resistant strains. The results revealed that the semisynthetic compound 7-acetoxy-mulin-9,12-diene (5) exhibited antibacterial activity against reference and multidrug-resistant strains of Staphylococcus aureus and moderate antimycobacterial activity against Mycobacterium smegmatis ATCC 14468.