Triterpenoidal lupin saponins from the Chilean legume Lupinus oreophilus Phil

Genus Lupinus (Fabaceae): a review of ethnobotanical, phytochemical and biological studies

OBJECTIVES

Lupinus is a large and diverse genus comprising approximately 200 species, belonging to the family Fabaceae. Lupinus plants have been used for heart stimulants, nerves, urinary tract infections, skin disorders, and psoriasis in folk medicine. This review aims to recap the traditional medicinal uses, nutritional value, phytochemical profile, and biological activities of Lupinus species.

KEY FINDINGS

From the literature survey, Lupinus is considered as a factory of various phytochemicals like flavonoids, iso-flavonoids, alkaloids, triterpenoids. The presence of proteins, essential fatty acids, and amino acids, as well as alkaloids, minerals, and dietary fibers, indicated that the plants in this genus had a high nutritional value. The Lupinus extracts displayed promising antidiabetic, anticancer, antimicrobial, antidiabetic, antihypertensive, antioxidant, anti-inflammatory, and antimicrobial activities.

CONCLUSIONS

The current review provides updated information that could drive the researchers for further studies. The in vitro and in vivo experiments have demonstrated various pharmacological properties. Some pharmacokinetic and toxicological investigations are warranted to ensure its safety and validity for human use.

Rapid Characterization of Triterpene Saponins from Zornia brasiliensis by HPLC-ESI-MS/MS

Zornia brasiliensis Vogel (Leguminosae) is a species popularly known in Brazil as “urinária”, “urinana”, and “carrapicho”, it is popularly used as a diuretic and in the treatment of venereal diseases. A specific methodology to obtain a saponin-enriched fraction and high-performance liquid chromatography coupled with diode array detection, ion trap mass spectrometry, and TOF-MS (HPLC-DAD-ESI-MS/MS) was applied for the analysis of triterpene saponins. The MS and MS/MS experiments were carried out by ionization in negative mode. Molecular mass and fragmentation data were used to support the structural characterization of the saponins. Based on retention times, high-resolution mass determination and fragmentation, 35 oleanane-triterpene saponins were tentatively identified in Z. brasiliensis.

Saponins in pulses and their health promoting activities: A review

Saponins are a class of natural compounds present in pulses having surface active properties. These compounds show variation in type, structure and composition of their aglycone moiety and oligosaccharide chains. Saponins have plasma cholesterol lowering effect in humans and are important in reducing the risk of many chronic diseases. Moreover, they have shown strong cytotoxic effects against cancer cell lines. However, more epidemiological and clinical studies are required for the proper validation of these health promoting activities. Processing and cooking promotes the loss of saponins from foods. The effect of soaking, sprouting and cooking on the stability and bioavailability of saponins in pulses is an important area which should be thoroughly worked out for achieving desirable health benefits. In the present review, the structures, contents and health benefits of saponins present in pulses are discussed. Moreover, the effect of processing (of pulses) on the saponins is also highlighted.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2003-2004

This review is the third update of the original review, published in 1999, on the application of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings the topic to the end of 2004. Both fundamental studies and applications are covered. The main topics include methodological developments, matrices, fragmentation of carbohydrates and applications to large polymeric carbohydrates from plants, glycans from glycoproteins and those from various glycolipids. Other topics include the use of MALDI MS to study enzymes related to carbohydrate biosynthesis and degradation, its use in industrial processes, particularly biopharmaceuticals and its use to monitor products of chemical synthesis where glycodendrimers and carbohydrate-protein complexes are highlighted.

Phytochemicals for health, the role of pulses

Pulses are the seeds of legumes that are used for human consumption and include peas, beans, lentils, chickpeas, and fava beans. Pulses are an important source of macronutrients, containing almost twice the amount of protein compared to cereal grains. In addition to being a source of macronutrients and minerals, pulses also contain plant secondary metabolites that are increasingly being recognised for their potential benefits for human health. The best-studied legume is the soybean, traditionally regarded as an oilseed crop rather than a pulse. The potential health benefits of soy, particularly with respect to isoflavone content, have been the subject of much research and the focus of several reviews. By comparison, less is known about pulses. This review investigates the health potential of pulses, examining the bioactivity of pulse isoflavones, phytosterols, resistant starch, bioactive carbohydrates, alkaloids and saponins. The evidence for health properties is considered, as is the effect of processing and cooking on these potentially beneficial phytochemicals.

Saponins, classification and occurrence in the plant kingdom

Saponins are a structurally diverse class of compounds occurring in many plant species, which are characterized by a skeleton derived of the 30-carbon precursor oxidosqualene to which glycosyl residues are attached. Traditionally, they are subdivided into triterpenoid and steroid glycosides, or into triterpenoid, spirostanol, and furostanol saponins. In this study, the structures of saponins are reviewed and classified based on their carbon skeletons, the formation of which follows the main pathways for the biosynthesis of triterpenes and steroids. In this way, 11 main classes of saponins were distinguished: dammaranes, tirucallanes, lupanes, hopanes, oleananes, taraxasteranes, ursanes, cycloartanes, lanostanes, cucurbitanes, and steroids. The dammaranes, lupanes, hopanes, oleananes, ursanes, and steroids are further divided into 16 subclasses, because their carbon skeletons are subjected to fragmentation, homologation, and degradation reactions. With this systematic classification, the relationship between the type of skeleton and the plant origin was investigated. Up to five main classes of skeletons could exist within one plant order, but the distribution of skeletons in the plant kingdom did not seem to be order- or subclass-specific. The oleanane skeleton was the most common skeleton and is present in most orders of the plant kingdom. For oleanane type saponins, the kind of substituents (e.g. -OH, =O, monosaccharide residues, etc.) and their position of attachment to the skeleton were reviewed. Carbohydrate chains of 18 monosaccharide residues can be attached to the oleanane skeleton, most commonly at the C3 and/or C17 atom. The kind and positions of the substituents did not seem to be plant order-specific.

Chromatographic determination of plant saponins—An update (2002–2005)

The developments during 2002-2005 in the methods used for saponin analyses in plant material are presented. There were number of papers published on isolation and identification of new saponins by chromatographic techniques. Some new developments can be found in separation techniques or solid and mobiles phases used. Separation of individual saponins is still complicated and time consuming. This is due to the fact that in most of the plant species saponins occur as a multi-component mixture of compounds of very similar polarities. Thus, to isolate single compound for structure elucidation or biological activity testing, a combination of different chromatographic techniques has to be used, e.g. first separation of the mixture to simpler sub-fractions on reversed phase C18 has to be followed by further purification on normal phase Silica gel column. Especially difficult is determination of saponins in plant material as these compounds do not possess chromophores and their profiles cannot be registered in UV. Most HPLC methods apply not only specific registration at 200-210 nm, but these methods are not applicable for determination of many saponins in plant material at levels lower than 200-300 mg/kg. Some new or improved techniques for quantification of saponins in plant material were published in reviewed period. These include further progress in the application of evaporative light scattering detection (ELSD) for saponin profiling and quantification, which is also not only specific but also more sensitive in comparison to 200-210 nm detection. Some progress in development of new applications for liquid chromatography-electrospray mass spectrometry (LC/ESI/MS) for saponin determination has also been done. This method gives highest sensitivity and on line identification of separated saponins and should be recommended for specialized analyses of extracts and pharmaceutical formulas like the validation of a new assay. From non-chromatographic techniques for saponin determination, a sensitive and compound specific ELISA tests for some saponins were developed.

Biological activities and distribution of plant saponins

Plant saponins are widely distributed amongst plants and have a wide range of biological properties. The more recent investigations and findings into their biological activities were summarized. Isolation studies of saponins were examined to determine which are the more commonly studied plant families and in which families saponins have been identified.