A new triterpenoid from Teucrium viscidum

A review of the phytochemistry, ethnopharmacology and biological activities of Teucrium genus (Germander)

Teucrium L (Lamiaceae) is mainly distributed in the Mediterranean area. A comprehensive survey in the electronic databases (during 2000-2020 years) with keywords of 'Teucrium' and 'Germander' showed that chemical analyses are available for 27 species, with sesquiterpenoids, iridoids, di and triterpenoids, and phenolic compounds as identified structures. The neo-clerodane diterpenoids as potential chemotaxonomic markers were the main compounds of this genus. As a result, Italy and Turkey have good attempts at phytochemical analysis. The pharmacological activities of different species including antioxidant, cytotoxic activity, antidiabetic, antimicrobial, anti-inflammatory and anti-insect have been summarized. Teucrium polium and Teucrium chamaedrys mainly have been used in digestive problems and diabetes in traditional medicine. Evidence-based clinical trials are needed to confirm the therapeutic properties of this genus. As well to the popularity of Asian and Anatolian species as ingredients in contemporary medicines and products, further research is required in comparison to European species.

Triterpenoids

Covering: 2013. Previous review: Nat. Prod. Rep., 2015, 29, 1028-1065This review covers the isolation and structure determination of triterpenoids reported during 2013 including squalene derivatives, lanostanes, holostanes, cycloartanes, cucurbitanes, dammaranes, euphanes, tirucallanes, tetranortriterpenoids, quassinoids, lupanes, oleananes, friedelanes, ursanes, hopanes, serratanes, isomalabaricanes and saponins; 350 references are cited.

A novel spirocyclic triterpenoid and a new taraxerane triterpenoid from Teucrium viscidum

Two new triterpenoids, teuviscins A (1) and B (2), were isolated from the whole plants of Teucrium viscidum. Compound 2 showed anti-AD bioactivity which delayed animals paralysis of transgenic AD C. elegans.

neo-Clerodane diterpenoids from the aerial parts of Teucrium fruticans cultivated in China

Seven neo-clerodane diterpenes, teufruintins A-G (1-7), together with eight known compounds (8-15) were isolated from the CHCl3-soluble fraction of the aerial parts of Teucrium fruticans cultivated in China. The chemical structures of the isolated compounds were elucidated using different spectroscopic methods. All of the isolated diterpenes were evaluated for their cytotoxic activities on three human cancer cell lines, and for their ability to inhibit LPS-induced nitric oxide production in RAW 264.7 macrophages. None of the compounds displayed cytotoxic activities on the cancer cell lines, and only 15 showed weak NO inhibitory activity.

Dimeric Abietane Diterpenoids and Sesquiterpenoid Lactones from Teucrium viscidum

A new abietane diterpenoid, teuvisone (2), a pair of new dimeric abietane diterpenoid stereoisomers, biteuvisones A (3) and B (4), and three new sesquiterpenoid lactones, teuvislactones A-C (6, 7, and 10), were isolated from the whole plants of Teucrium viscidum, along with four known terpenoids (1, 5, 8, and 9). The structures of the new compounds were elucidated by spectroscopic analysis, and the absolute configurations of 5-10 were determined by electronic circular dichroism analysis. The isolated compounds were evaluated for their cytotoxic effects against five human cancer cell lines and for their α-glucosidase inhibitory effects.

Antimicrobial activity of oleanolic and ursolic acids: an update

Triterpenoids are the most representative group of phytochemicals, as they comprise more than 20,000 recognized molecules. These compounds are biosynthesized in plants via squalene cyclization, a C30 hydrocarbon that is considered to be the precursor of all steroids. Due to their low hydrophilicity, triterpenes were considered to be inactive for a long period of time; however, evidence regarding their wide range of pharmacological activities is emerging, and elegant studies have highlighted these activities. Several triterpenic skeletons have been described, including some that have presented with pentacyclic features, such as oleanolic and ursolic acids. These compounds have displayed incontestable biological activity, such as antibacterial, antiviral, and antiprotozoal effects, which were not included in a single review until now. Thus, the present review investigates the potential use of these triterpenes against human pathogens, including their mechanisms of action, via in vivo studies, and the future perspectives about the use of compounds for human or even animal health are also discussed.

Teucvisins A-E, five new neo-clerodane diterpenes from Teucrium viscidum

Two new neo-clerodane diterpenoids, teucvisins A and B (1, 2), and three new 19-nor-neoclerodane diterpenoids, teucvisins C-E (3-5), together with ten known constituents (6-15) were isolated from the whole plants of Teucrium viscidum. All the isolates were evaluated for their inhibitory activities of lipopolysaccharide (LPS)-induced nitric oxide production in RAW264.7 macrophages. The results indicated that compounds 11 and 15 showed moderate inhibition with an IC50 value of 21.9 and 22.4 µM, respectively.

Dammarane-type triterpenoids as 11β-HSD1 inhibitors from Homonoia riparia

An exploration for 11β-HSD1 inhibitors from Homonoia riparia returned eight new dammarane-type triterpenoids, horipenoids A–H (1–8), and a known oleanane-type triterpenoid (9). Their structures were elucidated on the basis of comprehensive analysis of spectroscopic data, and the absolute configuration of horipenoid E (5) was established by single crystal X-ray crystallography. Compounds 1–4 represent a rare class of octanortriterpenoids. Horipenoids C (3) and E (5) showed potent inhibition against mouse 11β-HSD1 with IC50 values of 0.810 ± 0.058 and 0.898 ± 0.215 μM, respectively.

Antihyperglycemic glucosylated coumaroyltyramine derivatives from Teucrium viscidum

Eight new glucosylated coumaroyltyramine derivatives, teuvissides A-H (1-8), were isolated from whole plants of Teucrium viscidum. Their structures were elucidated using spectroscopic data and chemical methods. The antihyperglycemic activities of these compounds were evaluated in HepG2 cells and 3T3-L1 adipocytes, and all of the isolates elicited different levels of glucose consumption at a concentration of 2.0 μM. Teuvissides A (1), B (2), and F (6) induced 2.2-, 2.1-, and 2.2-fold changes, respectively, in the levels of glucose consumption in HepG2 cells and 2.5-, 2.1-, and 2.3-fold changes, respectively, in 3T3-L1 adipocytes relative to the basal levels.