Phloroglucinol compounds of natural origin

Publisher Summary This chapter explains the decomposition of saccharides by heat devoted to the caramelization of saccharides and their pyrolysis above 250°. Caramelization belongs to the group of so-called “browning reactions.” Caramel has a brown color and it originates from various sugars when they are heated, either dry, or in concentrated solutions. The quality of a caramel depends on its source as well as on the parameters of the process of its manufacture. Caramel is manufactured to change and improve the appearance (color) of many food products; the enhancement of the flavor of food is also important. The chemical nature of caramel depends on the conditions of the caramelization and the source, at least in the terminal period of their processing. Ever since it was suspected that caramels are biologically active, the daily uptake levels for them have been calculated and announced. The pyrolysis of sugars has been studied because carbohydrates could be considered as a source of technically important products. Moreover, these studies were intended to contribute to the knowledge of the chemistry of caramelization.

The Thermal Decomposition of Carbohydrates. Part I. The Decomposition of Mono-, Di-, and Oligo-Saccharides

Photocatalytic ammonia synthesis is another important reaction to mimic natural nitrogen fixation, which has attracted more and more attention. In recent reports, sacrificial agents are often used to promote charge separation, and high-activity photocatalysts are discovered by using Nessler’s reagent method as a detection technique of ammonia production. However, there is an open question on the rationality and accuracy of the ammonia production amount in the presence of the sacrificial agent and Nessler’s reagent detection method. In this report, P25 TiO2 is employed as a model photocatalyst and alcohol as sacrificial agent, and both Nessler’s reagent and cation exchange chromatography are employed as ammonia detection methods. The different ammonia production amount was found by the different detection method. HPLC and 1H NMR results indicate that carbonyl compounds (formaldehyde, acetaldehyde, and acetone) are produced in the reaction. When the carbonyl compound was added to the ammonia standard soluti...

Interference Effect of Alcohol on Nessler’s Reagent in Photocatalytic Nitrogen Fixation

Chrysophanol is a unique anthraquinone having broad-spectrum therapeutic potential along with ecological importance. It is the first polyketide that has been reported to be biosynthesized in an organism-specific manner. The traditional Chinese and Korean medicinal systems provide evidence of the beneficial effects of chrysophanol on human health. The global distribution of chrysophanol encountered in two domains of life (bacteria and eukaryota) has motivated researchers to critically evaluate the properties of this compound. A plethora of literature is available on the pharmacological properties of chrysophanol, which include anticancer, hepatoprotective, neuroprotective, anti-inflammatory, antiulcer, and antimicrobial activities. However, the pharmacokinetics and toxicity studies on chrysophanol demand further investigations for it to be used as a drug. This is the first comprehensive review on the natural sources, biosynthetic pathways, and pharmacology of chrysophanol. Here we reviewed recent advancements made on the pharmacokinetics of the chrysophanol. Additionally, we have highlighted the knowledge gaps of its mechanism of action against diseases and toxicity aspects.

https://www.mdpi.com/2218-273X/9/2/68/pdf

Chrysophanol: A Natural Anthraquinone with Multifaceted Biotherapeutic Potential.

Summary
1A review of the published theories which seek to account for the activity of purgative drugs containing anthracene derivatives is given.
2The relative activity of anthracene derivatives occurring as (a) glycosides, (b) anthranols and (c) anthraquinones, in certain crude drugs has been determined by biological means.
3A similar investigation of isolated glycosides, anthranols and anthraquinones has been carried out.
4The results show that the anthracene derivatives are highly active as anthranol glycosides; less active as free anthranols and much less active as free anthraquinones.
5The more complex aglycone (dianthranol) of sennoside A is more active than the simple anthranol of aloe emodin.
6The theory is advanced that the sugar moiety of the glycoside not only acts as a “transporter” of the active aglycone, enabling it to reach the large intestine, but is also a “protector” which prevents oxidation of the aglycone to the relatively (orally) inactive anthraquinone.
7The experiments also show that a determination of “total anthraquinones” irrespective of their form of occurrence will be no guide to biological activity.
8Further work on the glycoside fraction of these crude drugs is being carried out.I would like especially to thank Mr. T. C. Lou for performing all the bio-assays included in this paper, for preparing the pure anthracene compounds and for much valuable assistance and many useful suggestions during the course of the work. I am also grateful to the Pharmacology Department of this School for facilities for carrying out the bio-assays; and to the Department of Physical Chemistry for the loan of certain spectrophotometric equipment necessary for the colorimetric assays. Acknowledgments are made to Sandoz Products Ltd.*** for the gift of sennosides A and B, and to Mr. A. H. Fenton for the preliminary biological work.

George D. Beal

Papers

The Oil of Pongamia Glabra1 2

The behavior of iodine solutions at liquid-solid interfaces. II. The importance thereof in the preparation of new iodine antiseptics

The Preparation of Pure Sucrose and Dextrose Caramels

Constituents in Cascara Sagrada extract. IV. Aloe‐emodin, chrysophanic acid and emodin

The preparation, properties, and uses of silicoduodecitungstic acid*: I. The Preparation of the Acid and its Salts1