New pregnane and steroidal glycosides from Tribulus terrestris L

Study on steroidal saponins in crude and stir-fried Fructus Tribuli by ultra-high-performance liquid chromatography-mass spectrometry coupled with multivariate statistical analysis

Fructus Tribuli is a traditional Chinese medicine used clinically for many years. Crude Fructus Tribuli and stir-fried Fructus Tribuli are recorded in the Pharmacopoeia of the People's Republic of China. However, the differences between steroidal saponins in crude Fructus Tribuli and stir-fried Fructus Tribuli have not been compared. In this study, ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry along with multivariate statistical analysis was developed to discriminate the chemical profiles and identify the steroidal saponins of crude Fructus Tribuli and stir-fried Fructus Tribuli. Additionally, an ultra-high-performance liquid chromatography triple-quadrupole mass spectrometer was used for the simultaneous quantification of nine major steroidal saponins to analyze the variations between crude Fructus Tribuli and stir-fried Fructus Tribuli. Finally, a total of 30 steroidal saponins whose structures or contents changed significantly after processing were found and identified. The mechanism of structural transformations deduced indicated that during the stir-frying of Fructus Tribuli, C-22 hydroxy furostanol saponins were converted to the corresponding furostanol saponins containing C-20-C-22 double bonds by dehydroxylation and deglycosylation reactions that occurred in the spirostanol saponins causing the generation of steroidal sapogenins. This study was successfully applied to the global analysis of crude Fructus Tribuli and stir-fried Fructus Tribuli. The results of this research will be beneficial to explore the processing mechanism of Fructus Tribuli.

Chemical Constituents, Biological Properties, and Uses of Tribulus terrestris: A Review

Tribulus terrestris L. (TT) (puncturevine) is a common weed that grows in many countries worldwide and in some places is considered as a noxious weed. The plant has been used in traditional Chinese and Indian medicines and is now considered as one of the most popular aphrodisiacs. It is known for its healing properties for sexual difficulties, impotence, and human and animal hormonal imbalance. It is also used as a sexual booster. Because of the plant’s active substances that can be used for curing sexual and other disorders, interest in it is increasing, and it is currently one of the most studied medicinal plants. The products and preparations manufactured from the aboveground plant parts are especially popular among athletes and people with health issues and diseases such as hormonal imbalance, sexual problems, heart problems, and various kidney and skin diseases. The aim of this review is a comprehensive and critical assessment of the scientific publications involving TT, with special reference to its chemical constituents and biological properties that may facilitate current understanding and future studies of this fascinating plant species. The objectives of this review were (1) to find knowledge gaps, (2) to discuss critically relevant publications and issues with materials and methods that may be prerequisites for contradictory results, and (3) to identify research and development areas. It was found that some of the studies on TT extracts as aphrodisiacs are controversial. A significant number of research publications claim that TT extracts and nutritional supplements containing TT improve muscle tone, have a common biostimulating effect, and improve spermogenesis. However, there are a growing number of publications that dispute these claims, as there are no empirical data on commonly accepted mechanisms of action. The main biologically active substances in TT are steroidal saponins, flavonoids, alkaloids, and lignan amides, the most studied being the steroidal saponins. Multiyear data on the metabolic profile of the species are generally lacking. There are a variety of methods used for extracting plant material, differences in methodologies and saponin analyses, and scientific instruments that were used. Lack of common standards could be a reason for differences in the pharmacological activity and composition of the TT preparations. Development of standard procedures and methods for collection of plant material and analyses are recommended. Selection and breeding efforts and agronomic studies of promising clones of TT would need to be conducted in order to develop TT as a new crop. This will provide consistency of supply and quality of the feedstock for the pharmaceutical industry and could provide a new cash crop for growers.

Recent advances in steroidal saponins biosynthesis and in vitro production

Steroidal saponins exhibited numerous pharmacological activities due to the modification of their backbone by different cytochrome P450s (P450) and UDP glycosyltransferases (UGTs). Plant-derived steroidal saponins are not sufficient for utilizing them for commercial purpose so in vitro production of saponin by tissue culture, root culture, embryo culture, etc, is necessary for its large-scale production. Saponin glycosides are the important class of plant secondary metabolites, which consists of either steroidal or terpenoidal backbone. Due to the existence of a wide range of medicinal properties, saponin glycosides are pharmacologically very important. This review is focused on important medicinal properties of steroidal saponin, its occurrence, and biosynthesis. In addition to this, some recently identified plants containing steroidal saponins in different parts were summarized. The high throughput transcriptome sequencing approach elaborates our understanding related to the secondary metabolic pathway and its regulation even in the absence of adequate genomic information of non-model plants. The aim of this review is to encapsulate the information related to applications of steroidal saponin and its biosynthetic enzymes specially P450s and UGTs that are involved at later stage modifications of saponin backbone. Lastly, we discussed the in vitro production of steroidal saponin as the plant-based production of saponin is time-consuming and yield a limited amount of saponins. A large amount of plant material has been used to increase the production of steroidal saponin by employing in vitro culture technique, which has received a lot of attention in past two decades and provides a way to conserve medicinal plants as well as to escape them for being endangered.

Rapid Characterization of Constituents in Tribulus terrestris from Different Habitats by UHPLC/Q-TOF MS

A strategy for rapid identification of the chemical constituents from crude extracts of Tribulus terrestris was proposed using an informatics platform for the UHPLC/Q-TOF MS^E data analyses. This strategy mainly utilizes neutral losses, characteristic fragments, and in-house library to rapidly identify the structure of the compounds. With this strategy, rapid characterization of the chemical components of T. terrestris from Beijing, China was successfully achieved. A total of 82 steroidal saponins and nine flavonoids were identified or tentatively identified from T. terrestris. Among them, 15 new components were deduced based on retention times and characteristic MS fragmentation patterns. Furthermore, the chemical components of T. terrestris, including the other two samples from Xinjiang Uygur Autonomous region, China, and Rome, Italy, were also identified with this strategy. Altogether, 141 chemical components were identified from these three samples, of which 39 components were identified or tentatively identified as new compounds, including 35 groups of isomers. It demonstrated that this strategy provided an efficient protocol for the rapid identification of chemical constituents in complex samples such as traditional Chinese medicines (TCMs) by UHPLC/Q-TOF MS^E with informatics platform. Graphical Abstract ᅟ.

Steroidal saponins from Tribulus terrestris

Sixteen steroidal saponins, including seven previously unreported compounds, were isolated from Tribulus terrestris. The structures of the saponins were established using 1D and 2D NMR spectroscopy, mass spectrometry, and chemical methods. They were identified as: 26-O-β-d-glucopyranosyl-(25R)-furost-4-en-2α,3β,22α,26-tetrol-12-one (terrestrinin C), 26-O-β-d-glucopyranosyl-(25R)-furost-4-en-22α,26-diol-3,12-dione (terrestrinin D), 26-O-β-d-glucopyranosyl-(25S)-furost-4-en-22α,26-diol-3,6,12-trione (terrestrinin E), 26-O-β-d-glucopyranosyl-(25R)-5α-furostan-3β,22α,26-triol-12-one (terrestrinin F), 26-O-β-d-glucopyranosyl-(25R)-furost-4-en-12β,22α,26-triol-3-one (terrestrinin G), 26-O-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl-(25R)-furost-4-en-22α,26-diol-3,12-dione (terrestrinin H), and 24-O-β-d-glucopyranosyl-(25S)-5α-spirostan-3β,24β-diol-12-one-3-O-β-d-glucopyranosyl-(1→4)-β-d-galactopyranoside (terrestrinin I). The isolated compounds were evaluated for their platelet aggregation activities. Three of the known saponins exhibited strong effects on the induction of platelet aggregation.