A review on triterpenoid and triterpenoid saponins from Xanthoceras sorbifolium Bung.

Xanthoceras sorbifolium Bunge, also known as Tu-Mu-Gua and Wen-Dan-Ge-Zi, has several applications. Clinical data and experimental studies have shown anti-tumor, anti-inflammatory, anti-bacterial, and anti-oxidant properties of Xanthoceras sorbifolium Bunge that inhibits prostate hyperplasia, lowers blood pressure and lipid level, and treats enuresis and urinary incontinence. It also has neuroprotective effects and can treat Alzheimer's disease and Parkinson's syndrome. The research on the chemical composition and pharmacological effects of Xanthoceras sorbifolium Bunge has been increasing. Triterpenoid and triterpenoid saponins are the main constituents in Xanthoceras sorbifolium Bunge and exhibit biological activities. In this review, we summarized the research progress on triterpenoids and their glycosides in Xanthoceras sorbifolia, including the chemical constituents, pharmacological activities, and biogenic pathways of triterpenoid mother nucleus. The results would provide a reference for further research and development of triterpenoids and their glycosides in Xanthoceras sorbifolia.

10-Secocycloartane (=9,19-cyclo-9,10-secolanostane) triterpenoid saponins: Huangqiyenins M-X from Astragalus membranaceus (Fisch.) Bge.

Phytochemical investigations of the leaves of Astragalus membranaceus (Fisch.) Bge. have led to the isolation of 12 undescribed triterpenoid saponins named huangqiyenins M-X. The structures of the undescribed compounds were determined using NMR and HRESIMS data. The cytotoxicity of these compounds against the RKO and HT-29 colon cancer cell lines was evaluated. Among these compounds, huangqiyenin W exhibited the highest cytotoxic activity against RKO colon cancer cells, whereas huangqiyenin Q and W showed moderate cytotoxic activity against HT-29 colon cancer cells. The network pharmacology results indicated that STAT3, IL-2 and CXCR1 are the correlated targets of huangqiyenin W against colon cancer, with AGE-RAGE and Th17 cell differentiation as the key signaling pathways.

Triterpenoids and triterpenoid saponins from Vitex negundo and their anti-inflammatory activities.

Seven undescribed polyoxygenated ursane-type triterpenoids (vitnegundins A-G), three undescribed triterpenoid saponins (vitnegundins H-J), and 17 known ones were isolated from an EtOH extract of the aerial parts of Vitex negundo L. The structures of the undescribed compounds were established by extensive spectroscopic analysis. The absolute configurations of vitnegundins A, B, and E were determined by single-crystal X-ray diffraction data. Vitnegundins B-D are pentacyclic triterpenoids possessing rare cis-fused C/D rings and vitnegundins C-H represent undescribed ursane-type triterpenoids with 12,19-epoxy moiety. In the biological activity assay, vitnegundin A, vitnegundin E, and swinhoeic acid displayed inhibitory effects against LPS-induced NO release in BV-2 microglial cells, with IC50 values of 11.8, 44.2, and 19.6 µM, respectively.

A new flavonolignan from milk thistle (Silybum marianum).

A new flavonolignan, sonyamandin (1), along with other known compounds was isolated from the aerial parts and seeds extracts of Silybum marianum (milk thistle) collected from Jordan. The known ones are ursolic acid (2), oleanolic acid (3), maslinic acid (4), oleic acid (5), ß-sitosterol (6), ß-, sitosteryl glucoside (7), apigenin (8), kaempferol-3-O-rhamnoside (9), apigenin-7-O-ß-D-glycoside (10), isosylibin A (11), isosylibin B (12), and silybin B (13). The absolute stereochemistry of 1 was confirmed by 2D NMR and CD analysis.

Triterpenoids from the hook-bearing stems of Uncaria rhynchophylla.

An unprescribed nortriterpenoid with an aromatic E ring, uncanortriterpenoid A (1), together with fourteen known triterpenoids (2-15), were isolated from the hook-bearing stems of Uncaria rhynchophylla Miq. Based on extensive spectroscopic analyses, the NMR data of 2, 5, and 10 in CD3OD were assigned for the first time, and the wrongly assigned δC of C-27 and C-29 of 2 were revised. Among the known compounds, 7, 13, and 15 were isolated from this species for the first time, and 15 represents the first lanostane triterpenoid bearing an extra methylidene at C-24 for the Rubiaceae family. Additionally, compounds 6 and 14 exhibited moderate ferroptosis inhibitory activity, with an EC50 value of 14.74 ± 0.20 µM for 6 and 23.11 ± 1.31 µM for 14.

Response surface methodology optimization of extraction and enrichment conditions of total triterpenoid saponins from Celosiae Semen and evaluation of its lipid-lowering activity.

The saponin-enriched extract from Celosiae Semen is a promising resource owing to its lipid-lowering activity. However, triterpenoid saponins are difficult to extract owing to their high molecular weight and strong water solubility. The aim of this paper was to explore an eco-friendly and effective technology of extraction and enrichment of total triterpenoid saponins to obtain high lipid-lowering fractions. Initially, Box-Behnken design experiments were employed to optimize the heat reflux extraction process on the basic of mono-factor experiments. Afterwards, the crude extract was further purified using D-101 resin, and the purification parameters were investigated based on adsorption/desorption experiments and biological activity assay. Under optimal conditions, the purity of the finally obtained total triterpenoid saponins was increased by 7.28-fold. The lipid-lowering activities of the six main triterpenoid saponins were evaluated in HepG2 cells induced by palmitic acid. The results of Oil Red O staining showed that the compounds all exhibited potential lipid-lowering activity. The structure-activity relationship analysis suggested that the oligosaccharide chain at C-28 played an essential role in their lipid-lowering activity and the substituent group at C-23 site also showed important effects. The optimal extraction and purification methods may facilitate the utilization of Celosiae Semen for the industrial production as a functional food and drug.

Modified ent-Abietane Diterpenoids from the Leaves of Suregada zanzibariensis.

The leaf extract of Suregada zanzibariensis gave two new modified ent-abietane diterpenoids, zanzibariolides A (1) and B (2), and two known triterpenoids, simiarenol (3) and ß-amyrin (4). The structures of the isolated compounds were elucidated based on NMR and MS data analysis. Single-crystal X-ray diffraction was used to establish the absolute configurations of compounds 1 and 2. The crude leaf extract inhibited the infectivity of herpes simplex virus 2 (HSV-2, IC50 11.5 µg/mL) and showed toxicity on African green monkey kidney (GMK AH1) cells at CC50 52 µg/mL. The isolated compounds 1-3 showed no anti-HSV-2 activity and exhibited insignificant toxicity against GMK AH1 cells at ≥100 µM.

Good Practices in Sponge Natural Product Studies: Revising Vouchers with Isomalabaricane Triterpenes.

Species misidentification in the field of natural products is an acknowledged problem. These errors are especially widespread in sponge studies, albeit rarely assessed and documented. As a case study, we aim to revisit reports of isomalabaricane triterpenes, isolated from four demosponge genera: Jaspis, Geodia, Stelletta and Rhabdastrella. From a total of 44 articles (1981-2022), 27 unique vouchers were listed, 21 of which were accessed and re-examined here: 11 (52.4%) of these were misidentified. Overall, 65.9% of the studies published an incorrect species name: previously identified Jaspis and Stelletta species were all in fact Rhabdastrella globostellata. We conclude that isomalabaricane triterpenes were isolated from only two Rhabdastrella species and possibly one Geodia species. In addition to shedding a new light on the distribution of isomalabaricane triterpenes, this study is an opportunity to highlight the crucial importance of vouchers in natural product studies. Doing so, we discuss the impact of species misidentification and poor accessibility of vouchers in the field of sponge natural products. We advocate for stricter voucher guidelines in natural product journals and propose a common protocol of good practice, in the hope of reducing misidentifications in sponge studies, ensure reproducibility of studies, and facilitate follow-up work on the original material.

In Vitro Anticancer and Cancer-Preventive Activity of New Triterpene Glycosides from the Far Eastern Starfish Solaster pacificus.

Sea stars or starfish (class Asteroidea) and holothurians or sea cucumbers (class Holothuroidea), belonging to the phylum Echinodermata (echinoderms), are characterized by different sets of glycosidic metabolites: the steroid type in starfish and the triterpene type in holothurians. However, herein we report the isolation of eight new triterpene glycosides, pacificusosides D−K (1−3, 5−9) along with the known cucumarioside D (4), from the alcoholic extract of the Far Eastern starfish Solaster pacificus. The isolated new compounds are closely related to the metabolites of sea cucumbers, and their structures of 1−3 and 5−9 were determined by extensive NMR and ESIMS techniques. Compounds 2, 5, and 8 have a new type of tetrasaccharide chain with a terminal non-methylated monosaccharide unit. Compounds 3, 6, and 9 contain another new type of tetrasaccharide chain, having 6-O-SO3-Glc as one of the sugar units. The cytotoxic activity of 1−9 against non-cancerous mouse epidermal cells JB6 Cl41 and human melanoma cell lines SK-MEL-2, SK-MEL-28, and RPMI-7951 was determined by MTS assay. Compounds 1, 3, 4, 6, and 9 showed potent cytotoxicity against these cell lines, but the cancer selectivity (SI > 9) was observed only against the SK-MEL-2 cell line. Compounds 1, 3, 4, 6, and 9 at the non-toxic concentration of 0.1 µM significantly inhibited neoplastic cell transformation of JB6 Cl41 cells induced by chemical carcinogens (EGF, TPA) or ionizing radiation (X-rays and UVB). Moreover, compounds 1 and 4 at the non-toxic concentration of 0.1 µM possessed the highest inhibiting activity on colony formation among the investigated compounds and decreased the colonies number of SK-MEL-2 cells by 64% and 70%, respectively. Thus, triterpene glycosides 1 and 4 can be considered as prospective cancer-preventive and anticancer-compound leaders.

Chemical Components in Hedera rhombea Leaves and Their Cytotoxicity.

Two novel triterpene glycosides (1 and 2), 17 known triterpene glycosides (3-19), two known flavonoid glycosides (20 and 21), and two known norsesquiterpene glucosides (22 and 23) were isolated from Hedera rhombea (Araliaceae) leaves. The structures of 1 and 2 were determined by spectroscopic analysis, including two-dimensional NMR spectroscopy, and chromatographic analysis of the hydrolyzed products. The cytotoxicity of the isolated triterpene glycosides (1-19) against HL-60 human promyelocytic leukemia cells was evaluated. Compounds 9, 10, and 11 were cytotoxic to HL-60 cells with IC50 values of 7.2, 21.9, and 32.8 µM, respectively. Other compounds isolated from the leaves were not cytotoxic at sample concentrations of 50 µM.

The Role of Cyclodextrins in the Design and Development of Triterpene-Based Therapeutic Agents.

Triterpenic compounds stand as a widely investigated class of natural compounds due to their remarkable therapeutic potential. However, their use is currently being hampered by their low solubility and, subsequently, bioavailability. In order to overcome this drawback and increase the therapeutic use of triterpenes, cyclodextrins have been introduced as water solubility enhancers; cyclodextrins are starch derivatives that possess hydrophobic internal cavities that can incorporate lipophilic molecules and exterior surfaces that can be subjected to various derivatizations in order to improve their biological behavior. This review aims to summarize the most recent achievements in terms of triterpene:cyclodextrin inclusion complexes and bioconjugates, emphasizing their practical applications including the development of new isolation and bioproduction protocols, the elucidation of their underlying mechanism of action, the optimization of triterpenes' therapeutic effects and the development of new topical formulations.

Commikuanoids A-C: New cycloartane triterpenoids with exploration of carbonic anhydrase-II inhibition from the resins of Commiphora kua by in vitro and in silico molecular docking.

Three new cycloartane triterpenoids, commikuanoids A-C (1-3), together with four known compounds 4-7, were isolated from the resin of Commiphora kua. Their structures were confirmed by advanced NMR techniques such as 1D (1H and 13C) and 2D (HMBC, HSQC, COSY, NOESY and NOE) and high-resolution mass spectrometry (HRMS). Five compounds (1-5) were screened for in vitro carbonic anhydrase II (CA II) inhibitory activity. All the tested compounds demonstrated significant activity against CA II with IC50 values ranging from 4.9-19.6 µM. Moreover, the binding pattern of each compound in the binding site of CA-II was predicted through in silico molecular docking approach. It was observed that compounds 2, 4, and 5 binds with the Zn ion present in the active site of CA II, while compounds 1 and 3 mediated hydrogen bonding with Thr199 of CA-II, and all the compounds showed good binding score (> - 5 kcal/mol).

Wound healing, anti-inflammatory and anti-melanogenic activities of ursane-type triterpenes from Semialarium mexicanum (Miers) Mennega.

ETHNO-PHARMACOLOGICAL RELEVANCE: The bark of Semialarium mexicanum commonly known as 'Cancerina' is used as an infusion in Central America and Mexico to treat various wound infections, as well as skin and vaginal ulcers. AIM OF THE STUDY: This study aimed to determine the wound healing, anti-inflammatory and anti-melanogenic activities of the aqueous extract of Semialarium mexicanum and to identify the compounds related to these activities. MATERIALS AND METHODS: A bio-guided isolation of the active compounds of Semialarium mexicanum was carried out, selecting the sub-extracts and fractions depending on their wound healing, anti-inflammatory and anti-melanogenic activities in the RAW 264.7, NIH/3T3 and B16-F10 cells. RESULTS: Three compounds were obtained and characterised by nuclear magnetic resonance and mass spectrometry. These compounds are (3ß)-3-Hydroxy-urs-12-en-28-oic acid (1), (3ß)-Urs-12-ene-3,28-diol (2) and (2α, 19α)-2,19-Dihydroxy-3-oxo-urs-12-en-28-oic acid (3). Regarding the anti-inflammatory activity, the three compounds inhibited the production of NF-κB and NO, however, compound 3 was the most active with IC50 values of 8.15-8.19 µM and 8.94-9.14 µM, respectively, in all cell lines. The anti-melanogenic activity of these compounds was evaluated by the inhibition of tyrosinase and melanin in the B16-F10 cell line. The three compounds showed anti-melanogenic activity, however, compound 3 was the most active with an IC50 of 8.03 µM for the inhibition of tyrosinase production, and an IC50 of 8.53 µM for the inhibition of melanin production. Finally, concerning the wound healing activity, the three compounds presented proliferative activity in all the tested cell lines, however, compound 3 showed higher cell proliferation percentages than compounds 1 and 2 (88.89-89.60% compared to 64.92-65.71% and 71.53-71.99%, respectively). CONCLUSION: The wound healing, anti-inflammatory and anti-melanogenic activity of the aqueous extract of Semialarium mexicanum was tested and analysed in the present study, after having isolated three ursane-type triterpenes.

Intestinal absorption mechanism of rotundic acid: Involvement of P-gp and OATP2B1.

ETHNOPHARMACOLOGICAL RELEVANCE: Ilicis Rotundae Cortex (IRC), the dried barks of Ilex rotunda Thunb. (Aquifoliaceae), has been used for the prevention or treatment of colds, tonsillitis, dysentery, and gastrointestinal diseases in folk medicine due to its antibacterial and anti-inflammatory effects. However, there is no report about the intestinal absorption of major compounds that support traditional usage. AIM OF STUDY: Considering the potential of rotundic acid (RA) - major biologically active pentacyclic triterpenes found in the IRC, this study was purposed to uncover the oral absorption mechanism of RA using in situ single-pass intestinal perfusion (SPIP) model, in vitro cell models (Caco-2, MDCKII-WT, MDCKII-MDR1, MDCKII-BCRP, and HEK293-OATP2B1 cells) and in vivo pharmacokinetics studies in rats. MATERIALS AND METHODS: The molecular properties (solubility, lipophilicity, and chemical stability) and the effects of principal parameters (time, compound concentrations, pH, paracellular pathway, and the different intestinal segments) were analyzed by liquid chromatography-tandem mass spectrometry. The susceptibility of RA to various inhibitors, such as P-gp inhibitor verapamil, BCRP inhibitor Ko143, OATP 2B1 inhibitor rifampicin, and absorption enhancer EGTA were assessed. RESULTS: RA was a compound with low water solubility (12.89 µg/mL) and strong lipophilicity (LogP = 4.1). RA was considered stable in all media during the SPIP and transport studies. The SPIP and cell experiments showed RA was moderate absorbed in the intestines and exhibited time, concentration, pH, and segment-dependent permeability. In addition, results from the cell model, in situ SPIP model as well as the in vivo pharmacokinetics studies consistently showed that verapamil, rifampicin, and EGTA might have significant effect on the intestinal absorption of RA. CONCLUSION: The mechanisms of intestinal absorption of RA might involve multiple transport pathways, including passive diffusion, the participation of efflux (i.e., P-gp) and influx (i.e., OATP2B1) transporters, and paracellular pathways.

The chemical composition of different leaf extracts of Lantana fucata Lindl. influences its cytotoxic potential: A study using the Allium cepa model.

ETHNOPHARMACOLOGICAL RELEVANCE: One of the most popular plants used to treat diseases in Brazil is Lantana fucata. Like most herbal medicines, its consumption is based on popular knowledge, which, despite being considered effective, may cause side effects. AIM OF THE STUDY: Since the scientific data on the pharmacological properties of L. fucata are still incipient, this research aimed to evaluate the cytotoxic and genotoxic potential of different types of extracts (infusion, aqueous and hydroalcoholic), characterizing them chemically. MATERIALS AND METHODS: The cytotoxicity assay was performed by the A. cepa model. The cytotoxicity parameters studied were number of dividing cells and percentage mitotic index (%MI). RESULTS: The result of the A. cepa assay showed that there was a decrease in the number of dividing cells and the percentage mitotic index as concentrations increased, for all extracts, indicating cytotoxicity. However, the hydroalcoholic extract was the most cytotoxic. Chromatography analysis allowed the characterization of secondary metabolites in the extracts, which were very similar. However, a greater abundance of flavonoids and triterpenoids was observed in the hydroalcoholic extract, suggesting that these compounds are responsible for its greater toxicity. CONCLUSIONS: Since the highest doses of extracts showed to have a cytotoxic effect, it is suggested that the ingestion of this species occurs in a moderate way.

A new 26-norlanostane from Phlogacanthus turgidus growing in Vietnam.

Chemical investigation on chloroform extract of Phlogacanthus turgidus led to the isolation of one new compound namely turgidol, together with five known triterpenoids, lupeol, lupenone, betulin, betulinic acid, and taraxerol. Their structures and stereochemistry have been determined by 1 D and 2 D NMR analysis, high resolution mass spectrometry, and compared with those in literatures. The relative configuration of turgidol was defined using DFT-NMR chemical shift calculations and subsequent DP4+ probability method. Turgidol, betulin, and betulinic acid were evaluated for cytotoxic activity toward K562 cancer cell line and the alpha-glucosidase inhibition.

21,24-Cyclolanostanes revisited: Structural revision and biological evaluation.

Chemical fractionation of the EtOH extract of a medicinal macro fungus, Inonotus obliquus, afforded an array of lanostane-type triterpenoids (1-11) including two new ones (1 and 8). The structures of these compounds were determined on the basis of spectroscopic analyses, single crystal X-ray crystallography of 3-6 and biosynthetic considerations. With the confirmatory structural information provided by X-ray diffraction analysis in hand, several previously reported 21,24-cyclolanostanes, such as inonotsutriols A-C and (20R,21S,24S)-21,24-cyclopenta-3ß,21,25-trihydroxylanosta-8-ene, were structurally corrected. In addition, the NMR data of other types of 21,24-cyclo triterpenoids were also re-examined and structural revisions were thus suggested. Compounds 2, 6 and 8 showed significant cytostatic effects against a panel of tumor cell lines with IC50 values ranging from 7.80 to 18.5 µM. Further assays established that compound 2 exerted promising in vitro anti-breast cancer potential by inhibiting the proliferation and migration of 4T1 cells.

The triterpenoids and sesquiterpenoids from the plant of Agrimonia pilosa.

A phytochemistry of the whole plant of Agrimonia pilosa led to the discovery of two new nortriterpenoids, agrimonorterpenes A and B (1 and 2), together with one known triterpenoid fupenzic acid (3) and seven known sesquiterpenoids (4-10). The new structures were determined as 19α-hydroxy-2-oxo-nor-A (3)-urs-11,12-dien-28-oic acid (1) and 2, 19ß-dihydroxy-3-oxo-23-noroleana-1, 4, 12-trien-28-oic acid (2) by the spectroscopic data of UV, IR, HR-ESI-MS, and NMR. Notably, the structure of 1 possessed a rare five-membered A- ring. And this is the first time to discover the sesquiterpenoids (4-10) from A. pilosa. Compound 3 displayed the selective cytotoxicity against HCT116, BGC823, and HepG2 cell lines with the IC50 values of 16.31 µM, 21.94 µM, and 23.40 µM, respectively.

The protective effect of Centella asiatica and its constituent, araliadiol on neuronal cell damage and cognitive impairment.

Alzheimer's disease (AD) is characterized by progressive cognitive decline, and the number of affected individuals has increased worldwide. However, there are no effective treatments for AD. Therefore, it is important to prevent the onset of dementia. Oxidative stress and endoplasmic reticulum (ER) stress are increased in the brains of AD patients, and are postulated to induce neuronal cell death and cognitive dysfunction. In this study, Centella asiatica, a traditional Indian medicinal herb, were fractionated and compared for their protective effects against glutamate and tunicamycin damage. Araliadiol was identified as a component from the fraction with the highest activity. Further, murine hippocampal cells (HT22) were damaged by glutamate, an oxidative stress inducer. C. asiatica and araliadiol suppressed cell death and reactive oxygen species production. HT22 cells were also injured by tunicamycin, an ER stress inducer. C. asiatica and araliadiol prevented cell death by mainly inhibiting PERK phosphorylation; additionally, C. asiatica also suppressed the expression levels of GRP94 and BiP. In Y-maze test, oral administration of araliadiol (10 mg/kg/day) for 7 days ameliorated the arm alternation ratio in mice with scopolamine-induced cognitive impairment. These results suggest that C. asiatica and its active component, araliadiol, have neuroprotective effects, which may prevent cognitive dysfunction.

New iridal-type triterpenoid analogues with 6/5/6-fused carbon skeleton from the rhizomes of Belamcanda chinensis.

Five new iridal-type triterpenoid derivatives with 6/5/6 tricyclic ring skeleton (1-5) were obtained from the rhizomes of Belamcanda chinensis. Their structures were determined on the basis of detailed spectroscopic data and ECD calculation. Compounds 1-5 possessed the same 6/5/6-fused carbon skeleton as Belamchinenin A, which further enriched this kind of iridals. In vitro bioassay, compounds 2 and 3 exhibited 51.95 and 54.52% inhibitory activities, respectively, against Fe2+/cysteine-induced liver microsomal lipid peroxidation at a concentration of 10 µM. A putative biogenetic pathway for compounds 1-5 was proposed.