Saponins from Barringtonia acutangula

Isoryanodane diterpene derivatives from Barringtonia macrocarpa

From the MeOH residue of Barringtonia macrocarpa branches and leaves, one new isoryanodane diterpene, barringisol (1), and two new isoryanodane diterpene glucosides, barringisosides A and B (2 and 3), were obtained using various chromatographic isolations. The structural characterization was confirmed by spectroscopic methods including 1D, 2D NMR and HR-ESI-QTOF-MS. This is the first isolation of isoryanodane diterpene derivatives from Barringtonia species. Moreover, the in vitro cytotoxicity of 1-3 on three human cancer cell lines (HepG2, LNCaP and MCF7) was also accessed using SRB assays.

Phytochemical profile and ethnopharmacological applications of Lecythidaceae: An overview

ETHNOPHARMACOLOGICAL RELEVANCE

The family Lecythidaceae has about 25 genera and 400 identified species, which are distributed especially in the pantropical region, mostly found in the tropics of Central and South America, Southeast Asia and Africa. The third most abundant family in Amazonian forests and the genus Eschweilera, with the large number of species in Lecythidaceae.

AIM OF THE REVIEW

The present review compiles information since the 1934s about of ethnopharmacology, and chemical constituents of species of Lecythidaceae, as well as a summary of the bioactivities shown by the extracts, fractions, and secondary metabolites.

MATERIALS AND METHODS

All relevant information on ethnopharmacology, and chemical constituents of species of Lecythidaceae were gathered from electronic databases including Web of Science, Science Direct, Elsevier, ResearchGate, and Google Scholar. Information was also obtained from local books, PhD. and MSc. Dissertations.

RESULTS

The phytochemical diversity of the family was demonstrated with 180 different metabolites that have been reported from 25 species, most of them being triterpenes or flavonoids. The pharmacological studies carried out with the extracts, fractions and compounds showed promising antibacterial, antifungal, anti-inflammatory, antinociceptive, cytotoxic and antioxidant activities.

CONCLUSION

The present review provides an insight into ethnopharmacology, phytochemistry and pharmacology of species of Lecythidaceae. Based on the pharmacological studies it has been found that different plant species of Lecythidaceae possess a wide range of bioactivities such as anti-arthritic, anti-inflammatory, antileishmanial, antibacterial and antifungal. These activities are due to the presence of bioactive compounds including triterpenoids and their glycosides derivatives, flavonoids, steroids, sesquiterpenoids, alkaloids, and other compounds. However, there are many plants, which have not been assessed pharmacologically and hence warrant further studies.

Triterpene saponins from Barringtonia acutangula (L.) Gaertn as a potent inhibitor of 11β-HSD1 for type 2 diabetes mellitus, obesity, and metabolic syndrome

Background

Barringtonia acutangula (L.) Gaertn, Garcinia indica (Thouars) Choisy, and Feronia limonia (L.) Swingle is widely utilized in traditional folk medicine against diabetes, obesity, and metabolic syndrome but lacks the evidence of compound-protein interaction for the treatment.

Methods

Phytocompounds were retrieved from herbs databases and public repositories. Probable protein targets were predicted using BindingDB (p ≥ 0.7). The pathways modulated by compounds were analyzed using the STRING and KEGG pathways. The compound-protein-pathway network was constructed using Cytoscape v3.6.1. Druglikeness was predicted by Molsoft. Docking was performed by AutoDock vina by PyRx 0.8v.

Results

Among three plants, eleven triterpene saponins from B. acutangula showed druggable characteristics and identified to inhibit the 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1/HSD11B1) as a key protein target and also inhibit/modulate other 27 protein molecules involved in the 3 major pathways i.e. Metabolic syndrome, cGMP-PKG signaling, and insulin resistance pathways and also these compounds showed interactions with the active site amino acid residues of 11β-HSD1. Among eleven compounds Barringtogenol B scored the highest binding affinity by forming a hydrogen bond with Ile218 active site residue of 11β-HSD1.

Conclusion

Triterpene saponins contained in B. acutangula bark and seed inhibits 11Β-HSD1 and this multi-compound contained enriched fraction could be the potent treatment regimen for T2DM, obesity, and MetS.

Role of Saponins in Plant Defense Against Specialist Herbivores

The diamondback moth (DBM), Plutella xylostella (Lepidoptera: Plutellidae) is a very destructive crucifer-specialized pest that has resulted in significant crop losses worldwide. DBM is well attracted to glucosinolates (which act as fingerprints and essential for herbivores in host plant recognition) containing crucifers such as wintercress, Barbarea vulgaris (Brassicaceae) despite poor larval survival on it due to high-to-low concentration of saponins and generally to other plants in the genus Barbarea. B. vulgaris build up resistance against DBM and other herbivorous insects using glucosinulates which are used in plant defense. Aside glucosinolates, Barbarea genus also contains triterpenoid saponins, which are toxic to insects and act as feeding deterrents for plant specialist herbivores (such as DBM). Previous studies have found interesting relationship between the host plant and secondary metabolite contents, which indicate that attraction or resistance to specialist herbivore DBM, is due to higher concentrations of glucosinolates and saponins in younger leaves in contrast to the older leaves of Barbarea genus. As a response to this phenomenon, herbivores as DBM has developed a strategy of defense against these plant biochemicals. Because there is a lack of full knowledge in understanding bioactive molecules (such as saponins) role in plant defense against plant herbivores. Thus, in this review, we discuss the role of secondary plant metabolites in plant defense mechanisms against the specialist herbivores. In the future, trials by plant breeders could aim at transferring these bioactive molecules against herbivore to cash crops.

Oleanane-type glycosides from Pittosporum tenuifolium "variegatum" and P. tenuifolium "gold star"

The phytochemical study of two cultivars of Pittosporum tenuifolium Banks & Sol. ex Gaertn, "variegatum" and "gold star", led to the isolation of eight oleanane-type glycosides: seven previously undescribed and a known one. Their aglycons are oxygenated oleanane derivatives as barringtogenol C, camelliagenin A, hederagenin, and 22α-hydroxyoleanolic acid. Their structures were established by 2D NMR spectroscopic techniques and mass spectrometry as 3-O-β-D-galactopyranosyl-(1 → 2)-[α-L-arabinopyranosyl-(1 → 3)]-β-D-glucuronopyranosyl-21-O-angeloyl-22-O-acetylbarringtogenol C, 3-O-β-D-galactopyranosyl-(1 → 2)-[α-L-arabinopyranosyl-(1 → 3)]-β-D-glucuronopyranosyl-21,22-di-O-angeloylbarringtogenol C, 3-O-β-D-galactopyranosyl-(1 → 2)-[α-L-arabinopyranosyl-(1 → 3)]-β-D-glucuronopyranosyl-22-O-angeloylcamelliagenin A, 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-glucopyranosyl-(1 → 6)]-β-D-glucopyranosyl-22-O-[(6-O-acetyl)-β-D-glucopyranosyl]camelliagenin A, 3-O-β-D-galactopyranosyl-(1 → 2)-[α-L-arabinofuranosyl-(1 → 4)]-β-D-glucuronopyranosylhederagenin 28-O-β-D-glucopyranosyl ester, 3-O-α-L-arabinofuranosyl-(1 → 4)-β-D-glucuronopyranosylhederagenin 28-O-β-D-glucopyranosyl ester, 3-O-β-D-galactopyranosyl-(1 → 2)-[α-L-arabinofuranosyl-(1 → 4)]-β-D-glucuronopyranosyl-22α-hydroxyoleanolic acid 28-O-β-D-glucopyranosyl ester, and the known ilexoside XLIX. These results represent a significative contribution to the chemotaxonomy of the genus Pittosporum, highlighting hederagenin-type saponins as chemotaxonomic markers of P. tenuifolium cultivars.

Triterpene saponins from Eryngium kotschyi

Four new oleanane-type saponins 3-O-α-L-rhamnopyranosyl-(1 → 4)-β-D-glucuronopyranosyl-22-O-β,β-dimethylacryloylA1-barrigenol (1), 3-O-α-L-rhamnopyranosyl-(1 → 4)-β-D-glucuronopyranosyl-22-O-angeloylA1-barrigenol (2), 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-glucopyranosyl-(1 → 6)]-β-D-glucopyranosyl-21,22,28-O-triacetyl-(3β,21β,22α)-olean-12-en-16-one (3), and 3-O-β-D-glucopyranosyl-(1 → 2)-glucopyranosyl-22-O-β-D-glucopyranosylsteganogenin (4), along with the known 3-O-β-D-galactopyranosyl-(1 → 2)-[α-L-arabinopyranosyl-(1 → 3)]-β-D-glucuronopyranosyl-22-O-angeloylA1-barrigenol and 3-O-α-L-rhamnopyranosyl-(1 → 4)-β-D-glucuronopyranosyloleanolic acid, were isolated from a methanol extract of the roots of Eryngium kotschyi by multiple chromatographic steps. Saponins 3 and 4 are unusual by the original structure of their aglycon. Compound 3 possessed an oleanane-type skeleton with a 21,22,28-triacetylation and a ketone function at the C-16 position. For compound 4, the 17,22-seco-oleanolic acid skeleton is rarely found in natural saponins.

Scorpion anti-venom activity of botanicals: a pharmacological approach

Scorpion bite is considered as one of the common and dangerous phenomenon throughout the world. The clinical manifestations include pulmonary edema, myocardial damage, intracerebral haemorrhage, brachial plexopathy, renal failure etc. which sometimes leads to mortality. The common antivenin therapy includes anti-scorpion venom serum or prazosin. In the vast rural areas of the third world countries phytotherapy is considered as an alternative system of medicine and scorpion sting is treated with the help of medicinal botanicals. As the safety and efficacy are considered as important aspects of anti venin therapy, conventional treatment can be supported by the herbal remedy. The present review compiles a number of medicinal plants pharmacologically evaluated in vitro and/or in vivo for scorpion antivenin properties. Considering the aspects like cost effectiveness, availability, lesser side effects and development of drug resistance, plant based anti venin therapy may be considered as a possible remedy against scorpion envenomation.

Oleanane-type isomeric triterpenoids from Barringtonia racemosa

Two new isomeric acylated oleanane-type triterpenoids along with three known compounds were isolated from the MeOH extract of the dried fruits of Barringtonia racemosa. On the basis of spectroscopic methods, with special emphasis on 1D and 2D NMR techniques as well as chemical methods, the structures were characterized as racemosol A (1) [22alpha-acetoxy-3beta,15alpha,16alpha,21beta-tetrahydroxy-28-(2-methylbutyryl)olean-12-ene] and isoracemosol A (2) [21beta-acetoxy-3beta,15alpha,16alpha,28-tetrahydroxy-22alpha-(2-methylbutyryl)olean-12-ene]. The isolated compounds (1-5) were not active against HeLa and P388 D1 carcinoma cell lines.

New terpenoids from Stachys parviflora Benth

Two new triterpenoidal saponins were isolated from the n-butanolic extract of Stachys parviflora (Lamiaceae). Their structures were elucidated on the basis of spectral data as stachyssaponin A; 3beta, 15alpha, 19alpha, 21beta, 22alpha-pentahydroxyolean-12-ene-28-oic acid 3-O-{alpha-L-rhamnopyranosyl-(1 --> 3)-beta-D-glucopyranoside}-22-O-{alpha-L-arabinofuranosyl-(1 --> 3)-beta-D-glucopyranoside} (1) and stachyssaponin B; 2beta, 3beta, 15alpha, 21beta-tetrahydroxyolean-12-ene-28-oic acid 2-O-[alpha-L-arabinofuranoside]-3, 21-bis-O-[beta-D-glucopyranoside] (2).

Cytotoxic acylated triterpene saponins from the husks of Xanthoceras sorbifolia

Four new oleanane-type triterpene saponins, xanifolia-Y0 (1), xanifolia-Y2 (2), xanifolia-Y3 (3), and xanifolia-Y7 (4), were isolated from the husks of Xanthoceras sorbifolia along with two known analogues, xanifolia-Y8 (5) and xanifolia-Y10 (6). The structures of 1-4 were determined by spectroscopic data interpretation and chemical degradation. Compounds 1-6 were evaluated for their cell-growth inhibition activity toward human ovarian cancer cells (OVCAR3) by a MTT assay, and the IC50 values ranged from 4 to 13 microM. On the basis of the results obtained, it is concluded that a C-3 trisaccharide with a galactose and acylation with an angeloyl group at both C-21 and C-22 are important for cell inhibition activity for this class of compounds.

Antibacterial compounds from Planchonia careya leaf extracts

AIM OF THE STUDY

The leaves of Planchonia careya (F. Muell.) R. Knuth (Lecythidaceae) have been traditionally implemented in the treatment of wounds by the indigenous people of northern Australia, although the compounds responsible for the medicinal properties have not been identified. In this study, antibacterial compounds from the leaf extracts were isolated and characterized, and the biological activity of each compound was assessed.

MATERIALS AND METHODS

Compounds were isolated from the leaf extracts using HPLC-piloted activity-guided fractionation. The minimum inhibitory concentrations (MICs) were assessed with plate-hole diffusion assays, and the cytotoxicity was determined with MTT assays using monkey kidney epithelial (MA104) cells.

RESULTS

Six known compounds were isolated from the leaf extracts and were identified as 1, (+)-gallocatechin; 2, gallocatechin-(4alpha-->8)-gallocatechin; 3, 9(S)-hydroxy-10E,12Z-octadecadienoic acid (alpha-dimorphecolic acid); 4, 2alpha,3beta,24-trihydroxyolean-12-en-28-oic acid (hyptatic acid-A); 5, 3beta-O-cis-p-coumaroyltormentic acid; and 6, 3beta-O-trans-p-coumaroyltormentic acid. Compounds 5 and 6 were weakly selective for vancomycin-resistant Enterococcus (VRE) compared with eukaryotic cells, with an MIC of 59.4microg/mL and a 50% inhibitory concentration (IC(50)) of 72.0microg/mL for MA104 cells.

CONCLUSIONS

The isolation of six antibacterial compounds from the leaves of Planchonia careya validates the use of this species as a topical wound-healing remedy.

A triterpenoid saponin possessing antileishmanial activity from the leaves of Careya arborea

Bioguided-fractionation of the methanol extract of the leaves of Careya arborea led to isolation of a triterpenoid saponin, designated arborenin, and characterized as 3-O-beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl-2 alpha,3beta-dihydroxy-taraxast-20-en-28-oic acid (1), together with desacylescin III (2). The structures were determined on the basis of extensive 2D NMR spectroscopic analysis. The saponin showed in vitro antileishmanial activity against Leishmania donovani (strain AG 83).

Trypanocidal activity of extracts and fractions of Bertholletia excelsa

Crude extracts and fractions of Bertholletia excelsa stem barks were tested for trypanocidal activity. Acetone and methanol extracts showed significant in vitro trypanocidal activity against trypomastigote form of Trypanosoma cruzi since in the concentration of 500 microg/ml, the parasites were reduced in 100% and 90.3% respectively, whereas the triterpene betulinic acid pure isolated from hexane extract presented 75.4%.

A triterpenoid saponin from Maesa ramentacea

The structure of a piscicidal triterpenoid saponin (saponin A) isolated from the leaves of Maesa ramentacea has been shown to be 3-O-[[(alpha-rhamnopyranosyl (1-->2)-alpha-L-rhamnopyranosyl(1-->2)-beta-D-galactopyranosyl (1-->3)]-[beta-D-glucopyranosyl(1-->2)]-beta-D-glucuronopyranosyl] barringtogenol C21, 22-O-diangeloate. Extensive use was made of homo- and heteronuclear 2D NMR techniques.