China
Africa
Explore chapters and articles related to this topic
Synthesis And Transformations Of 2,3-Secotriterpene Derivatives Of Betulin
Published in Alexander V. Kutchin, Lyudmila N. Shishkina, Larissa I. Weisfeld, Gennady E. Zaikov, Ilya N. Kurochkin, Alexander N. Goloshchapov, Chemistry and Technology of Plant Substances, 2017
Irina A. Tolmacheva, Natalia V. Galaiko, Ekaterina V. Igosheva, Anastasiya V. Konysheva, Alexey V. Nazarov, Gulnaz F. Krainova, Marina N. Gorbunova, Eugene I. Boreko, Vladimir F. Eremin, Victoria V. Grishko
Pentacyclic triterpenoids of natural and semisynthetic origin are characterized by their high biological activity as a result of the fact that these compounds can be obtained from readily available sources. Typical representatives of this group of triterpenoids are betulin, a major component of birch bark Betula, and its derivatives betulinic and betulonic acids. These compounds are perspective candidates for synthesis of therapeutically active agents [1–6]. The majority of the known reactions of betulin, and its derivatives are carried out at C-3, C-28, and C-30 carbon atoms which occur without affecting the carbon skeleton. Examples of rearrangement of the carbon skeleton of lupane triterpenoids are less common, in particular the A-ring fragmentation with the A-secoderivatives formation by chemical [7–10], photochemical [11, 12], and microbiological [13] transformations. The production of various ring-A-secoderivatives which are characterized by different biological activity [8, 14, 15] and modification of secoderivatives via the introduction of various pharmacophoric groups usually results in the enhancement or variation of biological activity of the obtained compounds [2, 16].
Encapsulation of antioxidant compounds in biopolymer micelles
Published in Chemical Engineering Communications, 2020
Jolanta Pulit-Prociak, Małgorzata Kabat, Ewelina Węgrzyn, Michał Zielina, Marcin Banach
Birch leaves are one of the natural sources of polyphenol compounds. Birch extract contains, among other compounds: catechin, coumaric acid, quercetin, kaempferol, apigenin, isoramnetin, and triterpenoids, whose main constituents are betulin, lupeol, betulinic acid, and oleanolic acid (Germanò et al. 2012; Malinowska et al. 2014). These compounds are considered valuable active substances. Thus, extracts from birch leaves may be an important source of effective compounds in the treatment of numerous diseases (Dehelean et al. 2007, 2012). Gallic acid (3,4,5-trihydroxybenzoic acid) is a secondary metabolite present in birch leaf extract. This metabolite has antioxidant, antimicrobial, anti-inflammatory, and antitumor properties. It has been shown to have prophylactic and therapeutic effects in many diseases caused by oxidative stress, including cardiovascular diseases, cancer, neurodegenerative disorders, and aging. Gallic acid can also be found in birch leaf extract (Nayeem et al. 2009; Piazzon et al. 2012; Hugo et al. 2016). The solubility values of active compounds that are contained in birch leaf extract are provided in Table 1.