Cytotoxic steroidal saponins from Panicum turgidum Forssk

Cytotoxic steroidal saponins from the rhizomes of Paris fargesii var. Petiolata

Phytochemical investigation on the rhizomes of Paris fargesii var. petiolata (Baker ex C. H. Wright) Wang et Tang led to the isolation of five previously undescribed steroidal saponins, parpetiosides A-E (1-5), and six known analogs (6-11). Their structures were established by extensive spectroscopic data analysis and chemical methods. Compound 5 was a rare steroidal saponin with disaccharide moiety linked at C-26 of dehydrokryptogenin that was hardly seen in the genus Paris. The cytotoxicities of the isolated compounds against three human cancer cell lines (U87, HepG2 and SGC-7901) were evaluated, and compound 1 displayed certain inhibitory effect with IC₅₀ values of 8.02 ± 0.45, 8.24 ± 0.57 and 6.20 ± 0.79 μM, respectively. Moreover, the preliminary mechanism of 1 inhibiting the proliferation of the three cancer cell lines might be related to cell cycle distribution and the induction of S phase arrest.

Eupatorin 3'-O-glucopyranoside, a trimethoxyflavonoid glucoside from the aerial parts of Salvia mellifera

Salvia mellifera, native to California, Baja California, and Mexico, is a medicinal herb traditionally used to relieve pain, body aches, including chronic pain. A detailed phytochemical investigation of aerial parts of S. mellifera was accomplished to find species-specific markers and to differentiate the closely related, often (un)intentionally substituted with S. apiana. A total of 22 metabolites, including flavonoids (1-14), triterpenoids (15-18), diterpenoids (19-21), and phenylpropanoid (22), were isolated and characterized thoroughly. Among the isolates, eupatorin 3'-O-glucopyranoside (1) was identified as undescribed phytochemical and detailed structure elucidation was achieved through extensive NMR and mass spectral data analysis.

Chemical Composition of Reichardia tingitana Methanolic Extract and Its Potential Antioxidant, Antimicrobial, Cytotoxic and Larvicidal Activity

The biggest challenges are locating effective, reasonably priced, and eco-friendly compounds to treat diseases caused by insects and microbes. The aim of this study was to employ GC-MS to assess the biological potency and chemical composition of the aerial parts of Reichardia tingitana (L.) Roth. Using this technique, 17 components were interpreted from the extracted plant, accounting for around 100% of total volatile compounds. Commonly, 6,10,14-trimethylpentadecan-2-one (21.98%) and methyl oleate (27.26%) were positioned as the major components, which were ascertained after 19.25, and 23.34 min, respectively. The major components were classified as hydrocarbons (23.82%), fatty acids, esters of fatty acids (57.46%), steroids (17.26%), and terpenes (1.48%). The DPPH antioxidant activity of the R. tingitana extracted components revealed that the shoot extract is the most powerful, with an IC50 value of 30.77 mg L−1 and a radical scavenging activity percentage of 71.91%. According to the current result, methanolic extract of R. tingitana had the maximum zone of inhibition against Salmonella typhimurium and Bacillus cereus (25.71 ± 1.63 and 24.42 ± 0.81 mm, respectively), while Clostridium tetani and Staphylococcus xylosus were the main resistant species. In addition, the 50% methanol crude shoot extract of R. tingitana showed greater potential anticancer activity with high cytotoxicity for two tumor cells HepG-2 and PC3 cells (IC50 = 29.977 and 40.479 µg mL−1, respectively) and noncytotoxic activity for WI-38 normal cells (IC50 = >100 µg mL−1). The MeOH extract of plant sample was more effective against Aedes aegypti larvae with LC50 of extract being 46.85, 35.75, and 29.38 mg L−1, whereas the LC90 is 82.66, 63.82, and 53.30 mg L−1 for the various time periods of 24, 48, and 72 h, respectively. R. tingitana is a possible biologically active plant. Future study will include pure chemical isolation and individual component bioactivity evaluation.

Two new cytotoxic tetralin derivatives from Panicum turgidum

Two new tetralin compounds were isolated from the aerial parts of Panicum turgidum Forssk. Their structures were elucidated by comprehensive 1 D and 2 D NMR experiments as well as high resolution ESI mass spectrometry. In addition, these two compounds have been tested for in vitro cytotoxicity against SKOV3 (Ovarian Carcinoma) and BT-549 (Breast Carcinoma). Compound 1 showed good cytotoxic activities against SKOV3 and BT 549 with IC₅₀ value of 5.65 ± 0.31 and 10.3 ± 0.56 µg/mL, respectively.

Investigation and Biological Assessment of Rumex vesicarius L. Extract: Characterization of the Chemical Components and Antioxidant, Antimicrobial, Cytotoxic, and Anti-Dengue Vector Activity

The objective of this study was to assess the biological potency and chemical composition of Rumex vesicarius aboveground parts using GC-MS. In this approach, 44 components were investigated, comprising 99.99% of the total volatile compounds. The major components were classified as fatty acids and lipids (51.36%), oxygenated hydrocarbons (33.59%), amines (7.35%), carbohydrates (6.06%), steroids (1.21%), and alkaloids (0.42%). The major components were interpreted as 1,3-dihydroxypropan-2-yl oleate (oxygenated hydrocarbons, 18.96%), ethyl 2-hydroxycyclohexane-1-carboxylate (ester of fatty acid, 17.56%), and 2-propyltetrahydro-2H-pyran-3-ol (oxygenated hydrocarbons, 11.18%). The DPPH antioxidant activity of the extracted components of R. vesicarius verified that the shoot extract was the most potent with IC₅₀ = 28.89 mg/L, with the percentages of radical scavenging activity at 74.28% ± 3.51%. The extracted plant, on the other hand, showed substantial antibacterial activity against the diverse bacterial species, namely, Salmonella typhi (23.46 ± 1.69), Bacillus cereus (22.91 ± 0.96), E. coli (21.07 ± 0.80), and Staphylococcus aureus (17.83 ± 0.67). In addition, the extracted plant was in vitro assessed as a considerable anticancer agent on HepG2 cells, in which MTT, cell proliferation cycle, and DNA fragmentation assessments were applied on culture and treated cells. The larvicidal efficacy of the extracted plant was also evaluated against Aedes aegypti, the dengue disease vector. As a result, we may infer that R. vesicarius extract increased cytocompatibility and cell migratory capabilities, and that it may be effective in mosquito control without causing harm.

Unravelling the antifungal and antiprotozoal activities and LC-MS/MS quantification of steroidal saponins isolated from Panicum turgidum

Bioassay-guided investigation of Panicum turgidum extract resulted in the identification of seven steroidal saponins (Turgidosterones 1–7). They were evaluated for their in vitro antifungal, antileishmanial, and antitrypanosomal activities. Turgidosterone 6 was the most active antifungal against Candida albicans and Candida neoformans (IC₅₀ values of 2.84 and 1.08 μg mL⁻¹, respectively). Turgidosterones 4–7 displayed antileishmanial activity against Leishmania donovani promastigotes with IC₅₀ values ranging from 4.95 to 8.03 μg mL⁻¹ and against Leishmania donovani amastigote/THP with IC₅₀ values range of 4.50–9.29 μg mL⁻¹. Activity against Trypanosoma brucei was also observed for Turgidosterones 4–7 with an IC₅₀ values range of 1.26–3.77 μg mL⁻¹. Turgidosterones 1–3 did not display any activity against the tested pathogens. The study of structure–activity relationships of the isolated saponins indicated that the antifungal, antileishmanial, and antitrypanosomal activities are markedly affected by the presence of spirostane-type saponins and the elongation of the sugar residue at C-3. To quantitatively determine the most abundant active ingredient in Panicum turgidum extract, a single run, sensitive, and highly selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been applied under positive and negative modes. The obtained results showed that compound 5 was the most abundant (95.93 ± 1.10 mg per gram of dry Panicum turgidum extract), followed by 6 (52.51 ± 1.05 mg gm⁻¹), 4 (32.71 ± 0.48 mg gm⁻¹), and 7 (13.19 ± 0.50 mg gm⁻¹). Docking of these saponins against the Candida albicans oxidoreductases and Leishmania infantum trypanothione reductase active sites revealed their potential to effectively bind with a number of key residues in both receptor targets.

Bioassay-guided investigation of Panicum turgidum extract resulted in the identification of seven steroidal saponins (Turgidosterones 1–7).

Chemical characterization of Cassia fistula polysaccharide (CFP) and its potential application as a prebiotic in synbiotic preparation

Prebiotics are non-digestible food ingredients that are selectively fermented by probiotics. The aim of this study was to investigate the chemical properties of a polysaccharide extracted from Cassia fistula mature fruit pulp and to evaluate its effects on probiotic strains: L. casei, L. rhamnosus, E. coli Nissle 1917 (EcN), and E. faecalis. These strains were compared for their growth behavior in culture media supplemented with different Cassia fistula polysaccharide (CFP) concentrations. The molecular weight of CFP was approximately 8.707 × 105 Da. The recovered polysaccharide contained a low percentage of crude protein (4.4%). Aspartic acid, glutamic acid, and proline were the most abundant amino acids. Glucose and mannose were the predominant sugars followed by arabinose and rhamnose. L. casei grew faster at high CFP concentrations (2%) compared with the lower concentrations of CFP. The highest values for the prebiotic index and prebiotic activity score were observed for L. casei treated with 2% CFP, and it may be considered a prebiotic due to its high resistance against α-amylase and acidic conditions. CFP provides two ways to adjust nitric oxide (NO) synthesis in macrophages. Finally, the use of 1.5 and 2% CFP for cultured milk production significantly shortened the fermentation period from 210 min to 180 min and 150 min, respectively.

Nutritional Value, Mineral Composition, Secondary Metabolites, and Antioxidant Activity of Some Wild Geophyte Sedges and Grasses

Geophytes are plants with underground storage organs including bulbs, corms, tubers, and rhizomes, often physiologically active and able to survive during harsh environmental conditions. This study is conducted to assess the nutritive value, mineral composition, bioactive metabolites, and antioxidant activity of five wild geophytes (Cyperus capitatus, C. conglomeratus, Elymus farctus, Lasiurus scindicus, and Panicum turgidum) collected from the Nile Delta coast and inland desert. The proximate composition including dry matter, moisture content, ash content, fiber, fat, protein, sucrose, and glucose were determined. Also, total carbohydrates, total digestible nutrients (TDN), and nutritive values were calculated. Macro- and micro-minerals were also determined in the studied geophytes. Total phenolics, total flavonoids, alkaloids, saponins, and tannins were determined. Antioxidant activity was evaluated based on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicle scavenging. Based on the nutritive value, the studied geophytes are ranked as follows: E. farctus > C. conglomeratus > L. scindicus > P. turgidum > C. capitatus. The mineral analysis reveals a sufficient amount of macro- and micro-elements in the studied geophytes while the microelements levels in the studied wild plants exist as Fe > Mn > Zn > Cu. Cyperus conglomeratus attained the highest concentrations of all determined secondary metabolites. On the other hand, C. conglomeratus, C. capitatus, and P. turgidum extracts showed strong scavenging activity (EC₅₀ < 1 mg mL^-1), while extracts of E. farctus and L. scindicus exhibited moderate scavenging activity (1 ≤ EC₅₀ ≤ 2 mg mL^-1). The present data reveal that geophytes under investigation could be used as good forage plants, especially in arid habitats. In addition, C. conglomeratus could be a potentially important candidate for natural antioxidants as it attained high contents of the bioactive constituents.

Synthesis of Ergosterol Peroxide Conjugates as Mitochondria Targeting Probes for Enhanced Anticancer Activity

Inspired by the significant bioactivity of ergosterol peroxide, we designed and synthesized four fluorescent coumarin and ergosterol peroxide conjugates 8a–d through the combination of ergosterol peroxide with 7-N,N-diethylamino coumarins fluorophore. The cytotoxicity of synthesized conjugates against three human cancer cells (HepG2, SK-Hep1, and MCF-7) was evaluated. The results of fluorescent imaging showed that the synthesized conjugates 8a–d localized and enriched mainly in mitochondria, leading to significantly enhanced cytotoxicity over ergosterol peroxide. Furthermore, the results of biological functions of 8d showed that it could suppress cell colony formation, invasion, and migration; induce G2/M phase arrest of HepG2 cells, and increase the intracellular ROS level.

Two new bioactive steroids from a mangrove-derived fungus Aspergillus sp

Two unusual naturally Diels-Alder additive steroids, ergosterdiacids A and B (1 and 2), constructing a 6/6/6/6/5 pentacyclic steroidal system, together with three known compounds (3-5) were obtained from the mangrove-derived fungus Aspergillus sp. Their structures were elucidated based on the comprehensive spectroscopic analysis, including 1D, 2D NMR and HRESIMS, as well as the quantum chemical ECD calculations. The plausible biosynthetic pathways of 1 and 2 were discussed. In the bioactivity assays, 1 and 2 exhibited potential in vitro inhibition activity against Mycobacterium tuberculosis protein tyrosine phosphatase B (MptpB) with an IC₅₀ value of 15.1 and 30.1 μM, respectively. The inhibitory kinetic experiments indicated that both of them acted via a noncompetitive inhibition mechanism. Moreover, 1 and 2 showed strong in vitro anti-inflammatory effects by suppressing the NO production at 4.5 and 3.6 μM, respectively.

New Steroidal Saponins from the Rhizomes of Paris vietnamensis and Their Cytotoxicity

Four new spirostanol saponins, named pavitnosides A–D (1–4), with six known steroidal saponins 5–10 were isolated from the rhizomes of Paris vietnamensis. Their chemical structures were determined based on extensive spectroscopic studies and chemical methods. The aglycones of pavitnoside B and pavitnoside C were not reported in previous work. The cytotoxicity of all saponins was evaluated against human glioblastoma U87MG and U251 cell lines. The new spirostanol saponin 1 displayed weak anti-proliferative activity against U87MG cell line and the known saponins 8 and 9 exhibited significant cytotoxicity against the two tumor cell lines, with IC₅₀ values of 2.16 to 3.14 μM, but did not affect the growth of primary cultures of human astrocytes.