As acetylcholinesterase (AChE) inhibitors are an important therapeutic strategy in Alzheimer’s disease, efforts are being made in search of new molecules with anti-AChE activity. The fact that naturally-occurring compounds from plants are considered to be a potential source of new inhibitors has led to the discovery of an important number of secondary metabolites and plant extracts with the ability of inhibiting the enzyme AChE, which, according to the cholinergic hypothesis, increases the levels of the neurotransmitter acetylcholine in the brain, thus improving cholinergic functions in patients with Alzheimer’s disease and alleviating the symptoms of this neurological disorder. This review summarizes a total of 128 studies which correspond to the most relevant research work published during 2006-2012 (1st semester) on plant-derived compounds, plant extracts and essential oils found to elicit AChE inhibition.

Natural AChE Inhibitors from Plants and their Contribution to Alzheimer’s Disease Therapy

Food-derived bioactive peptides, as potential ingredients in health-promoting functional foods targeting diet-related chronic diseases, have attracted increasing attention because of their high biological activities, low toxicity, and easy of metabolism in human body. However, conventional methods for analyzing the bioactive peptides are not only expensive but also time-consuming; these drawbacks limited detailed studies and rapid development of bioactive peptides. Emerging bioinformatics approaches may overcome these problems to enable bioactive peptide research. The aim of this review is to provide an overview of research progress in the bioinformatics methods used for identifying, characterizing, elaborating bioactive mechanisms of, and producing food-derived bioactive peptides, and also to present an effective workflow. The workflow has been integrated in silico and traditional methods to predict, validate, and modify bioactive peptides.

Advancement and prospects of bioinformatics analysis for studying bioactive peptides from food-derived protein: Sequence, structure, and functions

Comparison of analytical techniques for the identification of bioactive compounds from natural products

Nine new monoterpenoid indole alkaloids, ervatamines A–I (1–9), and five known ones (10–14), were isolated from Ervatamia hainanensis. The new structures were elucidated by extensive spectroscopic analysis and comparison to known compounds. Their absolute configurations were determined by various methods including computational methods, X-ray diffraction analysis, and electronic circular dichroism spectroscopy, as well as chemical transformations. Ervatamine A (1) is a ring-C-contracted ibogan-type monoterpenoid indole alkaloid with an unusual 6/5/6/6/6 pentacyclic rearranged ring system. Ervatamines B–E (2–5) display a nitrogen-containing 9/6 ring system, which is rarely observed in nature. The epimeric ervatamines B (2) and C (3) possess a 22-nor-monoterpenoid indole alkaloid carbon skeleton, which was only found in deformylstemmadenine. Compounds 10 and 14 exhibited significant anti-inflammatory activities, with IC50 values of 25.5 and 41.5 μM, respectively, while the IC50 value of indomethacin as a po...

Ervatamines A-I, Anti-inflammatory Monoterpenoid Indole Alkaloids with Diverse Skeletons from Ervatamia hainanensis.

The green alga Caulerpa racemosa var. cylindracea has invaded Mediterranean seabed including marine reserves, modifying the structure of habitats and altering the distributional patterns of associated organisms. However, the understanding of how such invasion can potentially affect functional properties of Mediterranean subtidal systems is yet to be determined. In this study, we show that C. racemosa changes foraging habit of the native white seabream, Diplodus sargus. In invaded areas, we found a high frequency of occurrence of C. racemosa in the stomach contents of this omnivorous fish (72.7 and 85.7%), while the alga was not detected in fish from a control area. We also found a significant accumulation of caulerpin, one of the main secondary metabolites of C. racemosa, in fish tissues. The level of caulerpin in fish tissues was used here as an indicator of the trophic exposure to the invasive pest and related with observed cellular and physiological alterations. Such effects included activation of some enzymatic pathways (catalase, glutathione peroxidases, glutathione S-transferases, total glutathione and the total oxyradical scavenging capacity, 7-ethoxy resorufin O-deethylase), the inhibition of others (acetylcholinesterase and acylCoA oxidase), an increase of hepatosomatic index and decrease of gonadosomatic index. The observed alterations might lead to a detrimental health status and altered behaviours, potentially preventing the reproductive success of fish populations. Results of this study revealed that the entering of alien species in subtidal systems can alter trophic webs and can represent an important, indirect mechanism which might contribute to influence fluctuations of fish stocks and, also, the effectiveness of protection regimes.

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Qi Yu

Papers

Indole alkaloids from Ervatamia hainanensis with potent acetylcholinesterase inhibition activities.