Triterpene saponins from the aerial parts of Trifolium medium L. var. sarosiense

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2013-2014

This review is the eighth update of the original article published in 1999 on the application of Matrix-assisted laser desorption/ionization mass spectrometry (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2014. Topics covered in the first part of the review include general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation, and arrays. The second part of the review is devoted to applications to various structural types such as oligo- and poly- saccharides, glycoproteins, glycolipids, glycosides, and biopharmaceuticals. Much of this material is presented in tabular form. The third part of the review covers medical and industrial applications of the technique, studies of enzyme reactions, and applications to chemical synthesis. © 2018 Wiley Periodicals, Inc. Mass Spec Rev 37:353-491, 2018.

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.

Trifolium species - the latest findings on chemical profile, ethnomedicinal use and pharmacological properties

OBJECTIVES

Clovers (Trifolium, Fabaceae) have a long history of use in folk medicine. Furthermore, during last 3 years, a considerable growth in scientific interest in these plants has been observed. This article summarizes and critically reviews an over 3-year progress of knowledge of ethnomedicinal use, phytochemical profile, physiological effects and possible therapeutic action of various clover species. It contains the latest literature (over 80 papers), originated from international databases (MEDLINE/PubMed, Science Direct/Elsevier, Springer Link, Wiley Online Library) and reports from other international and local scientific periodicals.

KEY FINDINGS

Traditional uses of T. pratense and T. repens have been confirmed, while the folk medicine recommendations for administration of other clovers such as T. burchellianum, T. fragiferum, T. hybridum, T. minus and T. purpureum were reported for the first time. Furthermore, several other clover species were also investigated in terms of their antioxidant, antimicrobial and phytoestrogenic effects for the first time. Only T. alexandrinum, T. pratense and T. medium were examined in animal studies.

SUMMARY

Besides T. pratense, other clovers may be a rich source of bioactive phytochemicals. However, in contradiction to red clover, the therapeutic use of other clovers is still limited by the lack of in-vivo evidence.

Discovery of a potent anti-yeast triterpenoid saponin, clematoside-S from Urena lobata L

Urena lobata has been used as a traditional medicinal plant in India and China. In this study, we investigated the antimicrobial activity and isolated the active compound from the leaves of U. lobata. The 80% ethanol extract from U. lobata leaves showed an effective anti-yeast activity against Saccharomyces cerevisiae (S. cerevisiae) strains. Using a combination of chromatographic methods, (−)-trachelogenin (1) and clematoside-S (2) were isolated from this plant for the first time, and their chemical structure was identified by mass spectrometry (MS) and extensive nuclear magnetic resonance (NMR) data analysis. In addition, 1 was found to be inactive against all of the test microorganisms in the antimicrobial assay, whereas 2 exhibits a specific anti-yeast activity against S. cerevisiae strains with diameter of inhibition zones in the range from 11 to 20 mm. Furthermore, the MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) values of 2 against S. cerevisiae strains were detected to be in the ranges of 0.61 to 9.8 μg/mL and 2.42 to 9.8 μg/mL, respectively. This is the first report of 2 with a specific anti-yeast activity. The above result suggests the potential application of U. lobata to be used as a natural anti-yeast agent in food preservation.

Saponins of Trifolium spp. aerial parts as modulators of Candida albicans virulence attributes

The aim was to provide the insight into the biology of C. albicans influenced by undescribed yet properties of saponin-rich (80%–98%) fractions (SAPFs), isolated from extracts of Trifolium alexandrinum, T. incarnatum, T. resupinatum var. resupinatum aerial parts. Their concentrations below 0.5 mg/mL were arbitrarily considered as subMICs for C. albicans ATCC 10231 and were further used. SAPFs affected yeast enzymatic activity, lowered tolerance to the oxidative stress, to the osmotic stress and to the action of the cell wall disrupting agent. In their presence, germ tubes formation was significantly and irreversibly inhibited, as well as Candida invasive capacity. The evaluation of SAPFs interactions with anti-mycotics showed synergistic activity, mainly with azoles. Fluconazole MIC was lowered—susceptible C. albicans ATCC 10231 was more susceptible, and resistant C. glabrata (clinical strain) become more susceptible (eightfold). Moreover, the tested samples showed no hemolytic activity and at the concentrations up to 0.5 mg/mL did not reduce viability of fibroblasts L929. This study provided the original evidence that SAPFs of Trifolium spp. aerial part exhibit significant antimicrobial activity, by reduce the expression/quantity of important Candida virulence factors and have good potential for the development of novel antifungal products supporting classic drugs.