A new lignan and a new alkaloid, and α -glucosidase inhibitory compounds from the grains of Echinochloa utilis Ohwi & Yabuno

The Influence of Hop Phenolic Compounds on Dry Hopping Beer Quality

Background: The article considers the phenolic hop compounds’ effect on the quality indicators of finished beer. The topic under consideration is relevant since it touches on the beer matrix colloidal stability when compounds with potential destabilizing activity are introduced into it from the outside. Methods: The industrial beer samples’ quality was assessed by industry-accepted methods and using instrumental analysis methods (high-performance liquid chromatography methods—HPLC). The obtained statistical data were processed by the Statistics program (Microsoft Corporation, Redmond, WA, USA, 2006). Results: The study made it possible to make assumptions about the functional dependence of the iso-α-bitter resins and isoxanthohumol content in beer samples. Mathematical analysis indicate interactions between protein molecules and different malted grain and hop compounds are involved in beer structure, in contrast to dry hopped beer, where iso-a-bitter resins, protein, and coloring compounds were significant, with a lower coefficient of determination. The main role of rutin in the descriptor hop bitterness has been established in kettle beer hopping technology, and catechin in dry beer hopping technology, respectively. The important role of soluble nitrogen and β-glucan dextrins in the perception of sensory descriptors of various technologies’ beers, as well as phenolic compounds in relation to the formation of bitterness and astringency of beer of classical technology and cold hopping, has been shown. Conclusions: The obtained mathematical relationships allow predicting the resulting beer quality and also make it possible to create the desired flavor profiles.

Natural Alkaloids and Diabetes Mellitus: A Review

BACKGROUND

The use of herbal therapies for treatment and management of diabetes mellitus and complications associated with this chronic condition is increasing. Plants contain a bounty of phytochemicals that have been proven to be protective by reducing the risk of various ailments and diseases, including alkaloids. Moreover, alkaloids are known to be among the oldest natural products used by humans for highlighting drugs that play crucial roles as therapeutic agents. The reason for this expanding interest and uses of alkaloids as a part of plant natural compounds-based treatments is that a significant proportion of diabetic patients do not respond very well to conventional therapeutic medication. Furthermore, other explanations to this fact are the cost of medication, side-effects, accessibility, and availability of health facilities and drugs and the inefficiency of these medicines in certain cases.

OBJECTIVE

In this study we aimed to review the literature on the valuable effects of herbs and plants and their isolated alkaloids compounds as medication for management of diabetes, a prevalent risk factor for several other disorders and illnesses.

METHODS

In the current review, PubMed, ScienceDirect, Springer and google scholar databases were used and the criterion for inclusion was based on the following keywords and phrases: diabetes, hyperglycemia, complications of diabetes, alkaloids, antidiabetic alkaloids, hypoglycemic alkaloids, alkaloids and complications of diabetes mellitus, mechanisms of action and alkaloids.

RESULTS

In the current review, we demonstrate that alkaloids in the form of extracts and isolated molecules obtained from a large variety of species demonstrated their efficiency for improving raises in blood glucose either in animal models via experimental studies or in human subjects via clinical trials. Medicinal species as chillies (Capsicum annuum), turmeric (Curcuma longa), barberry (Berberis vulgaris) and cress (Lepidium sativum) are among the most common and therapeutic plants used for controlling diabetes that were the subject of several experimental and clinical investigations. Whereas, isolated alkaloids such as berberine, capsaicin and trigonelline have received more interest in this field. Interestingly, the therapeutic impact of alkaloids against blood glucose pathogenesis is mediated through a variety of signaling cascades and pathways, via inhibiting or stimulating diversity of systems such as inhibition of α-glucosidase enzyme, blockade of PTP- 1B, deactivation of DPP-IV, increasing insulin sensitivity and modulating the oxidative stress.

CONCLUSION

Based on the findings of the present review, alkaloids could be used as preventive and curative agents in the case of endocrine disorders, particularly diabetes and could play a promoting function for the discovery of new antidiabetic agents.

Patulignans A-C, three structurally unique lignans from the leaves of Melicope patulinervia

(±)-Patulignans A-C (1-3), three unique pairs of lignan enantiomers were isolated from the leaves of Melicope patulinervia. Patulignan A (1) possesses an unprecedented dimethyloxonane moiety in nature, meanwhile patulignans B (2) and C (3) are epimers carrying a novel dimethyl-1,6-dioxaspiro[4.5]decane skeleton. Their structures were established by spectroscopy methods and electronic circular dichroism (ECD) calculations. Compounds 1-3 showed significant inhibitory activity against α-glucosidase.

Lignans and Neolignans: Plant secondary metabolites as a reservoir of biologically active substances

Lignans and neolignans are plant secondary metabolites derived from the oxidative coupling of phenylpropanoids. Biological activity of these phenolic compounds ranges from antioxidant, antitumor (terminaloside P, IC₅₀ = 10 nM), anti-inflammatory, anti-neurodegenerative (schibitubin B, IC₅₀ = 3.2 nM) and antiviral (patentiflorin A, IC₅₀ = 14-23 nM) to antimicrobial. In addition, it was observed that several members of this group, namely enterolactone and its biochemical precursors also known as phytoestrogens, possess important protective properties. Most of these lignans and neolignans are presented in reasonable amounts in one's diet and thus the protection they provide against the colon and breast cancer, to name a few, is even more important to note. Similarly, neuroprotective properties were observed (schisanwilsonin G, IC₅₀ = 3.2 nM) These structural motives also serve as an important starting point in the development of anticancer drugs. Presumably the most famous members of this family, etoposide and teniposide, synthetic derivatives of podophyllotoxin, are used in the clinical treatment of lymphocytic leukemia, certain brain tumors, and lung tumors already for nearly 20 years. This review describes 413 lignans and neolignans which have been isolated between 2016 and mid-2018 being reported in more than 300 peer-reviewed articles. It covers their source, structure elucidation, and bioactivity. Within the review, the structure-based overview of compounds as well as the bioactivity-based overview of compounds are described.

Functional Properties of Polyphenols in Grains and Effects of Physicochemical Processing on Polyphenols

Phenolic compounds are important products of secondary metabolism in plants. They cannot be synthesized in the human body and are mainly taken from food. Cereals, especially whole grains, are important sources of dietary polyphenols. Compared with vegetables and fruits, the content and biological activities of polyphenols in cereals have long been underestimated. Polyphenols in whole grains are non-nutritive compounds, which are distributed in all structural areas of cereal substances, mainly phenolic acids, flavonoids, and lignans. In recent years, the health effects of whole grains are closely related to their phenolic compounds and their antioxidant activities. Now, different physicochemical processing treatments and their effects have been summarized in order to provide the basis for promoting the development and utilization of food. The various functions of whole grains are closely related to the antioxidant effect of polyphenols. As the basic research on evaluating the antioxidant effect of active substances, in vitro antioxidant tests are faster and more convenient.