Previously undescribed pyridyl-steroidal glycoalkaloids and 23S,26R-hydroxylated spirostanoid saponin from the fruits of Solanum violaceum ortega and their bioactivities

The Therapeutic Value of Solanum Steroidal (Glyco)Alkaloids: A 10-Year Comprehensive Review

Steroidal (glycol)alkaloids S(G)As are secondary metabolites made of a nitrogen-containing steroidal skeleton linked to a (poly)saccharide, naturally occurring in the members of the Solanaceae and Liliaceae plant families. The genus Solanum is familiar to all of us as a food source (tomato, potato, eggplant), but a few populations have also made it part of their ethnobotany for their medicinal properties. The recent development of the isolation, purification and analysis techniques have shed light on the structural diversity among the SGAs family, thus attracting scientists to investigate their various pharmacological properties. This review aims to overview the recent literature (2012-2022) on the pharmacological benefits displayed by the SGAs family. Over 17 different potential therapeutic applications (antibiotic, antiviral, anti-inflammatory, etc.) were reported over the past ten years, and this unique review analyzes each pharmacological effect independently without discrimination of either the SGA's chemical identity or their sources. A strong emphasis is placed on the discovery of their biological targets and the subsequent cellular mechanisms, discussing in vitro to in vivo biological data. The therapeutic value and the challenges of the solanum steroidal glycoalkaloid family is debated to provide new insights for future research towards clinical development.

An overview of the traditional use, phytochemistry, and biological activity of the genus Homalanthus

Homalanthus species are native to tropical Asia and the Pacific region. This genus, comprising 23 accepted species, received less scientific attention compared to other genera of the Euphorbiaceae family. Seven Homalanthus species, such as H. giganteus, H. macradenius, H. nutans, H. nervosus, N. novoguineensis, H. populneus, and H. populifolius, have been reported to treat various health problems in traditional medicine. Only a few Homalanthus species have been investigated for their biological activities, including antibacterial, anti-HIV, anti-protozoal, estrogenic, and wound-healing activities. From a phytochemical point of view ent-atisane, ent-kaurane, and tigliane diterpenoids, triterpenoids, coumarins, and flavonol glycosides were found to be characteristic metabolites of the genus. The most promising compound is prostratin, isolated from H. nutans, with anti-HIV activity and the ability to eradicate the HIV reservoir in infected patients by mechanism of protein kinase C (PKC) agonist. This review provides information on traditional usage, phytochemistry, and biological activity of the genus Homalanthus with the aim to delineate future research directions.

Unusual ring B-seco isosteroidal alkaloid, yibeiglycoalkaloids A-E from Fritillaria pallidiflora schrenk

Five previously undescribed steroidal glycoalkaloids(SGAs)and a rare ring B-seco isosteroidal alkaloid, were isolated from Fritillaria pallidiflora Schrenk, along with six known alkaloids. The structures of these alkaloids were established by comprehensive analyses of the 1D, 2D-NMR and HR-ESI-MS data. Configurations of sugar moieties were resolved by chemical derivations. The isolated compounds showed nitric oxide (NO) inhibitory activities in lipopolysaccharide (LPS) induced RAW264.7 cells, and yibeinone exhibited the strongest inhibitory effects among them. This study revealed that the alkaloids from F. pallidiflora might have significant anti-inflammatory potentials.

Eight undescribed steroidal saponins including an unprecedented 16, 26-epoxy-furostanol saponin from Solanum xanthocarpum and their cytotoxic activities

Eight undescribed steroidal saponins named solasaponins A-H were isolated from the fruits of Solanum xanthocarpum, including an unusual 16,26-epoxy-furostanol saponin, two furostanol saponins, three isospirostanol saponins, two pseudo-spirostanol saponins. The structures of all compounds were elucidated by extensive spectroscopic data analyses (1D, 2D NMR, and HRESIMS) combined with physico-chemical analysis methods (acid hydrolysis, optical rotation, and IR). The cytotoxicities of all compounds in vitro against two human cancer cell lines (A-549 and HepG2) were evaluated by CCK-8 assay.

Effect of Microwave-Assisted Aqueous Two-Phase Extraction of α-Solanine from S. retroflexum and Analysis on UHPLC-qTOF-MS

A new, fast and efficient method, hyphenated microwave-assisted aqueous two-phase extraction (MA-ATPE) was applied in the extraction of α-solanine from Solanum retroflexum. This environmentally friendly extraction method applied water and ethanol as extraction solvents. Central composite design (CCD) was performed which included numerical parameters such as time, mass of plant powder and microwave power. The categorical factors included the chaotrope — NaCl or the kosmotrope — Na2CO3. Fitting the central composite design response surface model to the data generated a quadratic model with a good fit (R2 = 0.920). The statistically significant (p < 0.05) parameters such as time and mass of plant powder were influential in the extraction of α-solanine. Quantification of α-solanine was achieved using a robust and sensitive feature of the ultra-high performance quadrupole time of flight mass spectrometer (UHPLC-qTOF-MS), multiple reaction monitoring (MRM). The optimized condition for the extraction of α-solanine in the presence of NaCl and Na2CO3 was a period of 1 min at a mass of 1.2 g using a microwave power of 40%. Maximal extraction of α-solanine was 93.50 mg kg−1 and 72.16 mg kg−1 for Na2CO3 and NaCl, respectively. The synergistic effect of salting-out and microwave extraction was influential in extraction of α-solanine. Furthermore, the higher negative charge density of the kosmotrope (Na2CO3) was responsible for its greater extraction of α-solanine than chaotrope (NaCl). The shorter optimal extraction times of MA-ATPE make it a potential technique that could meet market demand as it is a quick, green and efficient method for removal of toxic metabolites in nutraceuticals.