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From the root barks of a Central African tree Millettia dubia De Wild. (Fabaceae), ten previously undescribed oleanane-type glycosides were isolated by various chromatographic protocols. Their structures were elucidated by spectroscopic methods, mainly 2D NMR experiments and mass spectrometry, as mono- and bidesmosidic glycosides of mesembryanthemoidigenic acid, hederagenin and oleanolic acid. The stimulation of the sweet taste receptor TAS1R2/TAS1R3 by these glycosides was evaluated, and structure/activity relationships were proposed. Two of them showed an agonist effect on TAS1R2/TAS1R3., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Here we report for the first time the entire 13 C-NMR spectral assignments of 119 (out of 127) triterpenoids from the oleo-gum resins of the medicinally important genus Boswellia, which includes the culturally highly valuable Frankincense species. The complete 13 C-NMR resonances of these triterpenoids isolated between 1998 and 2024 and their biological activities are presented. 13 C-NMR spectroscopy is a highly powerful tool for the characterization of these bioactive natural products. The compounds are arranged according to their skeletons, i.e., ursane, oleanane, lupane, dammarane, and tirucallane triterpenes. This review will be a future reference for the identification of these compounds, which have key medicinal properties in the areas of cytotoxicity and inflammation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Medicinal plants have been used to treat different diseases throughout the human history namely in traditional medicine. Most of the plants mentioned in this review article belong among them, including those that are widely spread in the nature, counted frequently to be food and nutrition plants and producing pharmacologically important secondary metabolites. Triterpenoids represent an important group of plant secondary metabolites displaying emerging pharmacological importance. This review article sheds light on four selected triterpenoids, oleanolic, ursolic, betulinic and platanic acid, and on their amide derivatives as important natural or semisynthetic agents in cancer treatment, and, in part, in pathogenic microbe treatment. A literature search was made in the Web of Science for the given key words covering the required area of secondary plant metabolites and their amide derivatives. The most recently published findings on the biological activity of the selected triterpenoids, and on the structures and biological activity of their relevant amide derivatives have been summarized therein. Mainly anti-cancer effects, and, in part, antimicrobial and other effects of the four selected triterpenoids and their amide derivatives have also been reviewed. A comparison of the effects of the parent plant products and those of their amide derivatives has been made., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Oleanolic acid (OA), a ubiquitous pentacyclic oleanane-type triterpene isolated from edible and medicinal plants, exhibits a wide spectrum of pharmacological activities and tremendous therapeutic potential. However, the undesirable pharmacokinetic properties limit its application and development. Numerous researches on structural modifications of OA have been carried out to overcome this limitation and improve its pharmacokinetic and therapeutic properties. This review aims to compile and summarize the recent progresses in the medicinal chemistry of OA derivatives, especially on structure-activity relationship in the last few years (2010-2021). It gives insights into the rational design of bioactive derivatives from OA scaffold as promising therapeutic agents., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Gymnema sylvestre (Retz.) R. Br. ex Schult. has a long history to be used as an antidiabetic herbal medicine. Various varieties of G. sylvestre, have been studied intensively on their 3β-hydroxy oleanane triterpenoid composition for hypoglycemic effects. It is also well-known that most species belonging to the same genus have similar chemical composition and biological activity. Thus, an extract of the Gymnema latifolium Wall. ex Wight, which showed considerable protein tyrosine phosphatase 1B (PTP1B) inhibitory activity (>70% inhibition at 30 μg/mL), was studied intensively. Extensive chemical investigation on the 70% EtOH of G. latifolium led to the isolation of four previously undescribed oleanane hemiacetal glycosides, gymlatinosides GL1-GL4, three previously undescribed oleanane glycosides, gymlatinosides GL5-GL7, and two known 3β-hydroxy oleanane analogs. The structures of the previously undescribed compounds were elucidated using diverse spectroscopic methods. The hemiacetal structure of the glycoside portion was further elaborated precisely by HMBC and J resolved proton NMR. Gymlatinosides GL2 and GL3 showed considerable PTP1B inhibitory effect., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

A phytochemical investigation of Blighia unijugata led to the isolation of eleven hederagenin glycosides. Among these compounds, six are previously undescribed, two are described in their native forms for the first time and three are known whereas firstly isolated from Blighia unijugata. The structure of the undescribed compounds was elucidated on the basis of 2D NMR and mass spectrometry analyses as 3-O-β-D-xylopyranosyl-(1 → 3)-α-L-arabinopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin, 3-O-β-D-xylopyranosyl-(1 → 3)-α-L-arabinopyranosyl-(1 → 4)-3-O-acetyl-β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin, 3-O-β-D-glucopyranosyl-(1 → 3)-α-L-arabinopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin, 3-O-β-D-xylopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin, 3-O-β-D-xylopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-3-O-acetyl-β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin, 3-O-α-L-arabinopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin 28-O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranosyl ester, 3-O-α-L-arabinopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin 28-O-β-D-glucopyranosyl ester and 3-O-β-D-xylopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin 28-O-β-D-glucopyranosyl ester. These results revealed the existence of several conserved structural features that could be used as chemotaxonomic markers for the Blighia genus such as the glycosidic sequence 3-O-α-L-arabinopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyl, the occurrence of 3-O-acetylated β-D-glucopyranosyl units and the systematic presence of hederagenin as aglycone., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Gymnema sylvestre (Retz.) R.Br. ex Sm. (Asclepiadaceae) is a well-known Ayurvedic anti-sweet plant for the treatment of type 2 diabetes mellitus. Although it was previously proposed that G. sylvestre exhibits chemical variation based on geography, most research on G. sylvestre has used material originating from India. Morphological and anatomical descriptions, ITS1-5.8S-ITS2 DNA sequencing, and acid hydrolysis analyses showed that G. sylvestre samples from Vietnam are distinguishable from those of Indian origin and thus suggest a dissimilarity among G. sylvestre samples with different geographic distributions. An LC-MS-guided strategy targeting 3β-glucuronide oleane-triterpenes in the Vietnamese G. sylvestre variety led to the isolation of four known compounds and nine previously undescribed compounds, named gymnemosides ND1-ND9. None of the isolated compounds were reported in the Indian sample, further supporting the geo-diversity of G. sylvestre. Three compounds, gymnemosides ND7-9, exerted significant stimulatory effects on the uptake of 2-NBDG in 3T3-L1 adipocyte cells and thus have potential as lead molecules for anti-diabetes agents., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Eight undescribed triterpenoid saponins, scabiostellatosides A-H, together with three known compounds were isolated from the whole plant of Scabiosa stellata L. Their structures were established by spectroscopic analyses (1D, 2D-NMR and HRESIMS) and chemical methods. Scabiostellatosides A-H were evaluated for their cytotoxicity against human fibrosarcoma cell line (HT1080). Scabiostellatoside F, a heptasaccharide derivative of oleanolic acid, exhibited moderate cytotoxicity against HT1080 cell line with IC 50 value of 12.0 μM., (Copyright © 2018. Published by Elsevier Ltd.)

Camellia seeds have been traditionally used as oil raw materials in Asia, and are known for a wide spectrum of applications. Oleanane-type triterpene saponins are the major specialised metabolites in Camellia seeds, and more than seventy saponins have been isolated and characterized. These natural compounds have caught much attention due to their various biological and pharmacological activities, including modulation of gastrointestinal system, anti-cancer, anti-inflammation, anti-microorganism, antioxidation, neuroprotection, hypolipidemic effects, foaming and detergence, as well as helping the accumulation of pollutants by plants. These compounds have a promising application in medicine, agriculture, industry and environmental protection. The present paper summarized the information from current publications on Camellia seed saponins, with a focus on the advances made in chemical structures, determination methods, bioactivities and toxicity. We hope this article will stimulate further investigations on these compounds., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Six previously undescribed oleanane-type triterpenoid saponins, fortunosides A-F, together with six known ones, were isolated from the aerial parts of Lysimachia fortunei Maxim. Their structures were established by spectroscopic data analyses (1D, 2D-NMR and HRESIMS) and chemical methods. All isolated triterpenoid saponins were evaluated for their cytotoxicity against four human liver cancer cell lines (SMMC-7721, Hep3B, HuH7, and SK-Hep-1). Three saponins with the aglycone protoprimulagenin A exhibited moderate cytotoxicity against all of the tested human cancer cell lines, with IC 50 values ranging from 4.76 to 15.12 μM., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Five previously undescribed bisdesmosidic triterpenoid saponins named calendustellatosides A-E, along with fifteen known compounds were isolated from the 70% ethanol whole plant extract of Calendula stellata Cav. (Asteraceae). Their structures were determined by 1D- and 2D-NMR spectroscopy as well as high resolution mass spectrometry and acid hydrolysis. The saponins comprised oleanolic acid, echinocystic acid, morolic acid or mesembryanthemoidigenic acid as the aglycones and saccharide moieties at C-3 and C-28. Like most Calendula saponins, the sugar moiety linked at C-3 was either β-d-glucose or β-d-glucuronic acid which could be substituted at C-3 by a β-d-galactose and/or C-2 by a supplementary β-d-galactose or a β-d-glucose. The sugar moiety linked to C-28 was determined as β-d-glucose. The antibacterial evaluation of compounds 1-20 by bioautography on Staphylococcus aureus followed by the determination of MIC values of active compounds by serial dilution technique against 5 bacteria revealed that; calendustellatoside D was the most active against Enterococcus faecalis with an antibacterial effect comparable to antibiotics. The cytotoxic activities of isolated compounds were evaluated against fibrosarcoma cell line (HT1080) and human lung cancer cell line (A549). Calendustellatosides B and D exhibited a low cytotoxic activity against HT1080 cell line with IC 50 values of 47 ± 0.6 and 39 ± 0.5 μM, respectively., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

During the search for new protein tyrosine phosphatase (PTP) 1B inhibitors, EtOH extracts from the aerial parts of Lantana camara L. (lantana) collected at Manado (Indonesia) and two subtropical islands in Japan (Ishigaki and Iriomote Islands, Okinawa) exhibited potent inhibitory activities against PTP1B in an enzyme assay. Four previously undescribed oleanane triterpenes were isolated together with known triterpenes and flavones from the Indonesian lantana. The EtOH extracts of lantana collected in Ishigaki and Iriomote Islands exhibited different phytochemical profiles from each other and the Indonesian lantana. Triterpenes with a 24-OH group were isolated from the Indonesian lantana only. Five known triterpene compounds were detected in the Ishigaki lantana, and two oleanane triterpenes with an ether linkage between 3β and 25 were the main components together with five known triterpenes as minor components in the Iriomote lantana. The structures of previously undescribed compounds were assigned on the basis of their spectroscopic data. Among the compounds obtained in this study, oleanolic acid exhibited the most potent activity against PTP1B, and is used as a positive control in studies on PTP1B., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

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., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Phytochemical investigations of the roots of Spergularia marginata had led to the isolation of four previously undescribed triterpenoid saponins, a known one and one spinasterol glycoside. Their structures were established by extensive NMR and mass spectroscopic techniques as 3-O-β-D-glucuronopyranosyl echinocystic acid 28-O-α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-α-L- arabinopyranosyl ester, 3-O-β-D-glucopyranosyl-(1 → 3)-β-D-glucuronopyranosyl echinocystic acid 28-O-α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)- α-L-arabinopyranosyl ester, 3-O-β-D-glucopyranosyl-(1 → 4)-3-O-sulfate-β-D-glucuronopyranosyl echinocystic acid 28-O-α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyl ester, and 3-O-β-D-glucopyranosyl-(1 → 4)-β-D-glucuronopyranosyl 21-O-acetyl acacic acid. Their cytotoxicity was evaluated against two human cancer cell lines SW480 and MCF-7. The most active compound showed a cytotoxicity with IC 50 14.2 ± 0.8 μM (SW480), and 18.7 ± 0.8 μM (MCF-7), respectively., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Artefact compounds obtained during acid hydrolysis of saponins from Medicago spp. (Fabaceae), have been monitored and evaluated by GC-FID. Their identification has been performed by GC-MS and 1 H and 13 C NMR. Saponins with different substituents on the triterpenic pentacyclic aglycones were considered, and their hydrolysis products were detected and quantified during 10 h of time course reaction. From soyasapogenol B glycoside the well known soyasapogenols B, C, D and F were obtained together with a previously undescribed sapogenol artefact identified as 3β,22β,24-trihydroxyolean-18(19)-en and named soyasapogenol H. From a zanhic acid saponin two major artefact compounds identified as 2β,3β,16α-trihydroxyolean-13(18)-en-23,28-dioic acid and 2β,3β,16α-trihydroxyolean-28,13β-olide-23-oic acid were obtained, together with some zanhic acid. Other compounds, detected in very small amount in the reaction mixture, were also tentatively identified based on their GC-MS and UV spectra. The other most characteristic saponins in Medicago spp., hederagenin, bayogenin and medicagenic acid glycosides, under acidic condition of hydrolysis, released instead the correspondent aglycones and generated a negligible amount of artefacts. Nature of artefacts and mechanism of their formation, involving a stable tertiary carbocation, is here proposed and discussed for the first time., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Eleven oleanane-type triterpenoid saponins, foegraecumosides A-K, and eight known ones, were isolated from the aerial parts of Lysimachia foenum-graecum. Their structures were elucidated by spectroscopic data analyses and chemical methods. All isolated saponins were evaluated for their cytotoxicity against four human cancer cell lines (NCI-H460, MGC-803, HepG2, and T24). Seven saponins containing the aglycone cyclamiretin A exhibited moderate cytotoxicity against all tested human cancer cell lines, with IC 50 values of 9.3-24.5 μM. Simultaneously, the cytotoxic activities of foegraecumosides A and B, lysichriside A, ardisiacrispins A and B, cyclaminorin, and 3-O-α-L-rhamnopyranosyl-(1 → 2)-β-d-glucopyranosyl-(1 → 4)-α-l-arabinopyranosyl-cyclamiretin A were tested on drug-resistant lung cancer cell lines (A549 and A549/CDDP, respectively). Ardisiacrispin B displayed moderate cytotoxicity against A549/CDDP, with an IC 50 value of 8.7 μM and a resistant factor (RF) of 0.9., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Seven previously undescribed bidesmosidic triterpenoid saponins named albidosides A - G, were isolated from a methanol extract of the roots of Acacia albida. Their structures were elucidated using 1D and 2D NMR spectroscopy and mass spectrometry and determined to be bidesmosides of oleanolic acid and of 16α-hydroxyoleanolic acid. Albidosides B - G were assayed for their cytotoxicity against HeLa and HL60 cells using MTT method and microscopic observation., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Twelve oleanane saponins, zebiriosides A-L, were isolated from the roots of Dendrobangia boliviana Rusby, together with two known saponins, talunùmoside I and 3-O-β-d-glucuronopyranosyl serjanic acid. These saponins are glycosides of serjanic or phytolaccinic acid. Their structures were established on two basis: first, their spectral data, mainly HR-TOFESIMS, 1D-NMR ((1)H, (13)C, DEPT) and 2D-NMR ((1)H(1)H COSY, TOCSY, HSQC, HMBC, and ROESY), and second by comparison with literature data. These compounds were evaluated for their cytotoxic, antileishmanial and hemolytic activities. No antileishmanial or hemolytic activities were revealed, however zebirioside C and zebirioside I showed cytotoxicity against fibroblasts with IC50 of 6.4 and 5.6 μM, respectively., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Eight previously undescribed oleanane-type triterpenoid saponins, clematangoticosides A-H, together with eight known saponins, were isolated from the whole plants of Clematis tangutica (Maxim.) Korsh. Their structures were elucidated by extensive spectroscopic analysis, in combination with chemical methods (acid hydrolysis and mild alkaline hydrolysis). Clematangoticosides D-G were found to be unusual 23, 28-bidesmosidic glycosides. The cytotoxic activities of all of the isolated saponins were evaluated against the four human cancer cell lines SGC-7901, HepG2, HL-60 and U251MG. Clematoside S, sapindoside B, kalopanax saponin A, and koelreuteria saponin A exhibited cytotoxicity against all of the test cancer cell lines with IC50 values in the range of 1.88-27.20 μM, while clematangoticoside D and F showed selective cytotoxicity against SGC-7901 with IC50 values of 24.22 and 21.35 μM, respectively., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Twelve triterpenoid saponins, including seven compounds (i.e., armerosides A-G) hitherto unknown, were isolated from whole plants of Silene armeria. Their structures were established based on extensive spectroscopic analyses and chemical methods. From a biosynthetic perspective, C-23 oxidation of the sapogenin appears to be a key factor in the glycosylation pathway., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Twenty polyoxygenated triterpenes, including nineteen ursanes and one oleanane, were characterized from the stem material of Siphonodon celastrineus (Celastraceae) through the application of spectroscopic techniques and chemical transformation. Three of the ursane-type triterpenoids possessed the rare 13,27-cyclopropane ring skeleton., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Four previously undescribed and one known oleanolic acid glycosides were isolated from the roots of Weigela stelzneri, and one previously undescribed and three known hederagenin glycosides were isolated from the leaves. Their structures were elucidated mainly by 2D NMR spectroscopic analysis and mass spectrometry as 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyloleanolic acid, 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-β-D-xylopyranosyloleanolic acid, 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-glucopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-β-D-xylopyranosyloleanolic acid, 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyloleanolic acid 28-O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranosyl ester, and 3-O-β-D-glucopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin 28-O-β-D-xylopyranosyl-(1 → 6)-[α-L-rhamnopyranosyl-(1 → 2)]-β-D-glucopyranosyl ester. The majority of the isolated compounds were evaluated for their cytotoxicity against two tumor cell lines (SW480 and EMT-6), and for their anti-inflammatory activity. The compounds 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyloleanolic acid and 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-β-D-xylopyranosyloleanolic acid exhibited the strongest cytotoxicity on both cancer cell lines. They revealed a 50% significant inhibitory effect of the IL-1β production by PBMCs stimulated with LPS at a concentration inducing a very low toxicity of 23% and 28%, respectively., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Eight oleanane-type saponins, glomerulosides A-H, were isolated from leaves of Glochidion glomerulatum. All isolated compounds were evaluated for cytotoxic activity on four human cancer cell lines, A-549, HT-29, OVCAR, and MCF-7. Glomerulosides C and E, which contain a benzoyloxy group at C-22, showed significant cytotoxic activities against the A-549, HT-29, and OVCAR cancer cell lines with IC50 values ranging from 5.9 to 9.8μM. Glomeruloside A showed cytotoxicity on HT-29 and OVCAR cell lines with IC50 values of 7.3 and 6.6μM, respectively. Moreover, glomeruloside B exhibited significant activity on A-549 and HT-29 cancer cell lines with IC50 values of 9.7 and 7.5μM. In contrast, glomerulosides F-H, lacking a benzoyloxy group, showed only moderate cytotoxic activity., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The methanol extract from Bellis perennis (Asteraceae) flowers was found to promote collagen synthesis in normal human dermal fibroblasts (NHDFs). Seven oleanane-type triterpene saponins, perennisosides XIII-XIX, and two known saponins, bellissaponins BS5 and BS9, were isolated from the methanol extract. The structures were determined based on chemical and physicochemical data, and confirmed using previously isolated related compounds as references. Among the isolates, including 19 previously reported saponins, perennisosides XVIII, I, II, VII, IX, and XI, asterbatanoside D, bernardioside B2, and bellissaponins BS5 and BS9 significantly promoted collagen synthesis at 3-30μM without cytotoxicity., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The neotropical lianas Souroubea gilgii and Souroubea sympetala (Marcgraviaceae) were chosen for study as part of a phytochemical discovery strategy focusing on rare plant families in Central America. In participatory research, Q'eqchi' healers in Belize reported the use of these plants to reverse psychological symptoms inflicted by witchcraft. Extracts of two Souroubea species showed significant anti-anxiety activity in the elevated plus maze, a standardized test paradigm. Bioassay guided isolation led to the active principle, the pentacyclic triterpene, betulinic acid, which had activity in the elevated plus maze at 0.5mg/kg. Other phytochemicals isolated included α- and β-amyrin, 2-hydroxyursolic acid, taraxenyl trans-4-hydroxy-cinnamate, naringenin, methyl ursolate, eriodytiol, methyl 2-α-hydroxyursolate, methyl 2-α-hydroxymaslinate, methyl betulinate, and condrilla sterol., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Nine quillaic acid and five gypsogenin bisdesmosides were isolated from roots of Saponaria officinalis L. (Caryophyllaceae). Seven of the quillaic acid saponins possessed a 3-O-β-D-galactopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 3)]-β-D-glucuronopyranosyl unit, but differed from each other in oligosaccharide units linked to the C-28 ester. The five gypsogenin saponins isolated from the roots all possessed the 3-O-β-D-galactopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 3)]-β-D-glucuronopyranosyl unit, with their oligosaccharide units linked to the C-28 ester differing. Structures were elucidated by extensive 1D and 2D NMR spectroscopy and mass spectrometry. The saponins were evaluated for growth inhibitory activity in two human cancer cell lines and hemolytic activity in sheep red blood cells., (Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.)

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., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Camelina sativa (L.) Crantz is an emerging low input, stress tolerant crop with seed oil composition suitable for biofuel and bioproduct production. The chemical compositions and ultrastructural features of surface waxes from C. sativa aerial cuticles, seeds, and roots were analyzed using gas chromatography and microscopy. Alkanes, primary fatty alcohols, and free fatty acids were common components of all analyzed organs. A particular feature of leaf waxes was the presence of alkyl esters of long-chain fatty acids and very long-chain fatty alcohols, ranging from C38 to C50 and dominated by C42, C44 and C46 homologues. Stem waxes were mainly composed of non-sterol pentacyclic triterpenes. Flowers accumulated significant amounts of methyl-branched iso-alkanes (C29 and C31 total carbon number) in addition to straight-chain alkanes. Seed waxes were mostly primary fatty alcohols of up to 32 carbons in length and unbranched C29 and C31 alkanes. The total amount of identified wax components extracted by rapid chloroform dipping of roots was 280μgg(-1) (fresh weight), and included alkyl hydroxycinnamates, predominantly alkyl coumarates and alkyl caffeates. This study provides qualitative and quantitative information on the waxes of C. sativa root, shoot, and seed boundary tissues, allowing the relative activities of wax biosynthetic pathways in each respective plant organ to be assessed. This detailed description of the protective surface waxes of C. sativa may provide insights into its drought-tolerant and pathogen-resistant properties, and also identifies C. sativa as a potential source of renewable high-value natural products., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Protein tyrosine phosphatase 1B (PTP1B) plays a key role in metabolic signaling, thereby making it an exciting drug target for type 2 diabetes and obesity. Besides, there is substantial evidence that shows its overexpression is involved in breast cancer, which suggests that selective PTP1B inhibition might be effective in breast cancer treatment. As part of our continuous research on PTP1B inhibitors from medicinal plants, four oleanane-type triterpenes were isolated from an EtOAc-soluble extract of fruit peels of Camellia japonica (Theaceae), together with 6 previously known compounds of this class. Their structures were determined on the basis of spectroscopic data analysis (UV, IR, (1)H and (13)CNMR, HMBC, HSQC, NOESY, and MS). All isolates were evaluated for their inhibitory effects on PTP1B, as well as their cytotoxic effects against human breast cancer cell lines MCF7, MCF7/ADR, and MDA-MB-231. Several compounds with OH-3 or/and COOH-28 functionalities showed strong PTP1B inhibitory activity (IC50 values ranging from 3.77±0.11 to 6.40±0.81 μM) as well as significant cytotoxicity (IC50 values ranging from 0.51±0.05 to 13.55±1.44 μM)., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Five oleanane-type saponins, 3-O-β-D-glucuronopyranosylzanhic acid 28-O-β-D-xylopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-(4-O-acetyl)-β-D-fucopyranosyl ester (1), 3-O-β-D-glucopyranosylzanhic acid 28-O-β-D-xylopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-(4-O-acetyl)-β-D-fucopyranosyl ester (2), zanhic acid 28-O-β-D-xylopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-(4-O-acetyl)-β-D-fucopyranosyl ester (3), zanhic acid 28-O-α-L-rhamnopyranosyl-(1→2)-4-O-[(3'-hydroxy-2'-methyl-butyroyloxy)-3-hydroxy-2-methyl-butyroyloxy]-β-D-fucopyranosyl ester (4), medicagenic acid 28-O-α-L-rhamnopyranosyl-(1→2)-4-O-[(3'-hydroxy-2'-methyl-butyroyloxy)-3-hydroxy-2-methyl-butyroyloxy]-β-D-fucopyranosyl ester (5), were isolated from the root barks of Ganophyllum giganteum. Compounds 4 and 5 possessed an unusual substitution of the C-4 position of the β-D-fucopyranosyl moiety by a C10 ester group formed by two symmetrical C5 nilic acid. From a chemotaxonomic point of view, their structures are in accordance with the previous saponins isolated from the Doratoxyleae tribe of the Sapindaceae family. Their cytotoxicity and anti-inflammatory activity were also evaluated., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Silphium asteriscus L., commonly known as starry rosinweed, is a plant found in prairies, glades, woodlands and savannas of the southeastern United States. The phytochemical investigation of the methanolic extract of S. asteriscus leaves led to the isolation of eighteen saponins with highly hydroxylated oleanane-type aglycones never reported before. Their structures were elucidated by extensive spectroscopic methods including 1D- ((1)H and (13)C) and 2D-NMR (DQF-COSY, HSQC, HMBC, TOCSY and ROESY) experiments as well as ESIMS analysis. The antiproliferative activity of the isolated compounds was evaluated against three cancer cell lines including Hela (human epitheloid cervix carcinoma), Jurkat cells (leukaemic T-cell line) and DLD-1 (colorectal adenocarcinoma). Compounds 1, 5 and 17 displayed weak activity with IC50 values ranging from 50 to 75 μM., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Microbial transformation of oleanolic acid by Rhizomucor miehei produced three metabolites. A known compound, a 30-hydroxyl derivative (queretaroic acid), and two 7β,30- and 1β,30-dihydroxylated metabolites, respectively. The action of the same fungus (R. miehei) on maslinic acid produced an olean-11-en-28,13β-olide derivative, a metabolite hydroxylated at C-30, an 11-oxo derivative, and two metabolites with an 11α,12α-epoxy group, hydroxylated or not at C-30. Their structures were elucidated by extensive analyses of their spectroscopic data, and also by chemical correlations., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

As a part of our ongoing research for bioactive compounds from Turkish Astragalus species, the investigation of Astragalus tauricolus has been carried out. An approach based on HPLC-ESIMS(n) experiments has been used to profile the triterpene glycosides occurring in the butanol extract of the whole plant. On the basis of the results of the online screening by HPLC-ESIMS(n), 22 oleanane-type triterpene glycosides, including ten compounds never reported before, were isolated, and their structures were established by the extensive use of 1D and 2D-NMR experiments along with ESIMS and HRMS analysis. Noteworthy, cycloartane-type triterpene glycosides, the main constituents of Astragalus spp., were not found. This peculiar feature characterizes a very limited group of Astragalus spp. The antiproliferative activity of the isolated compounds 1-12, 15, 17-19 was evaluated against a small panel of cancer cell lines. Only compound 11 showed an IC(50) of 22 μM against human leukemia cell line (U937). The other tested compounds, in a range of concentrations between 1 and 50 μM, did not cause any significant reduction of the cell number., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Six oleanane saponins were isolated for the first time from leaves of Bellis sylvestris Cyr., the southern daisy. Their structures were established by the extensive use of 2D-NMR experiments, including COSY, TOCSY, NOESY, HSQC, HMBC, CIGAR, H2BC, and HSQC-TOCSY, along with Q-TOF HRMS² analysis. All of the compounds are constituted by bayogenin as aglycone, and characterized by the presence of an oligosaccharide moiety, consisting of two to four sugar unities esterified at the C-28 carboxyl carbon. One of the isolated compounds is a bisdesmoside containing an additional sugar moiety at the C-3 carbon. The phytotoxic activity assayed against Aegilops geniculata Roth., a coexisting test species, has been evaluated revealing that all the compounds, at the highest concentrations, showed strong phytotoxicity against the leaf development., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Oleanolic acid (3β-hydroxyolean-12-en-28-oic acid) is a pentacyclic triterpenoid compound with a widespread occurrence throughout the plant kingdom. In nature, the compound exists either as a free acid or as an aglycone precursor for triterpenoid saponins, in which it can be linked to one or more sugar chains. Oleanolic acid and its derivatives possess several promising pharmacological activities, such as hepatoprotective effects, and anti-inflammatory, antioxidant, or anticancer activities. With the recent elucidation of its biosynthesis and the imminent commercialization of the first oleanolic acid-derived drug, the compound promises to remain important for various studies. In this review, the recent progress in understanding the oleanolic acid biosynthesis and its pharmacology are discussed. Furthermore, the importance and potential application of synthetic oleanolic acid derivatives are highlighted, and research perspectives on oleanolic acid are given., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Eleven oleanane-type saponins (1-11) have been isolated from Microsechium helleri and Sicyos bulbosus roots and were evaluated for their antifeedant, nematicidal and phytotoxic activities. Saponins {3-O-β-D-glucopyranosyl (1→3)-β-D-glucopyranosyl-2β,3β,16α,23-tetrahydroxyolean-12-en-28-oic acid 28-O-α-L-rhamnopyranosyl-(1→3)-β-D-xylopyranosyl-(1→4)-[β-D-xylopyranosyl-(1→3)]-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranoside} (1), and {3-O-β-D-glucopyranosyl-2β,3β,16α,23-tetrahydroxyolean-12-en-28-oic acid 28-O-α-L-rhamnopyranosyl-(1→3)-β-D-xylopyranosyl-(1→4)-[β-D-xylopyranosyl-(1→3)]-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranoside} (2) were also isolated from M. helleri roots together with the two known compounds 3 and 4. Seven known structurally related saponins (5-11) were isolated from S. bulbosus roots. The structures of these compounds were established as bayogenin and polygalacic glycosides using one- and two-dimensional NMR spectroscopy and mass spectrometry. Compounds 7, 10, bayogenin (12) and polygalacic acid (13) showed significant (p<0.05) postingestive effects on Spodoptera littoralis larvae, compounds 5-11 and 12 showed variable nematicidal effects on Meloydogyne javanica and all tested saponins had variable phytotoxic effects on several plant species (Lycopersicum esculentum, Lolium perenne and Lactuca sativa). These are promising results in the search for natural pesticides from the Cucurbitaceae family., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Three oleanane-type saponins, 3-O-β-d-glucopyranosylechinocystic acid 28-O-β-d-xylopyranosyl-(1→4)-[α-l-rhamnopyranosyl-(1→2)]-α-l-rhamnopyranosyl ester (1), 3-O-β-d-glucopyranosylechinocystic acid 28-O-α-l-arabinopyranosyl-(1→3)-β-d-xylopyranosyl-(1→4)-[α-l-rhamnopyranosyl-(1→2)]-α-l-rhamnopyranosyl ester (2), 3-O-β-d-glucopyranosylcaulophyllogenin 28-O-β-d-apiofuranosyl-(1→3)-β-d-xylopyranosyl-(1→4)-[β-d-apiofuranosyl-(1→3)]-α-l-rhamnopyranosyl-(1→2)-α-l-rhamnopyranosyl ester (3) were isolated from the whole plant of Arenaria montana. Their unusual structures for the Caryophyllaceae family were established mainly by 2D NMR techniques and mass spectrometry., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

The investigation of the ethanol extract of fresh aerial parts of the Patagonian shrub Nardophyllum bryoides collected in the province of Chubut, Argentina, yielded eleven terpenoids. These include: three seco-ent-halimane diterpenoids (1-3), two ent-halimanes (4-5) and six pentacyclic oleanane and ursane triterpenoids (6-11). Four of these compounds (2, 6, 8 and 11) are hitherto unknown, while two others (1 and 4) have been previously reported but only as synthetic products. Several of these compounds showed moderate cytotoxicity against a human pancreatic adenocarcinoma cell line while compounds 4 and 5 were active at micromolar concentrations. The main component, seco-chiliolidic acid (1), could be isolated from this extract in large amounts, turning N. bryoides into a sustainable source of this bioactive compound., (Copyright 2010 Elsevier Ltd. All rights reserved.)

Three triterpene glycosides and two known ones were isolated from the bark of Albizia procera by using chromatographic techniques. The structures of the compounds were determined to be 3-O-beta-D-xylopyranosyl-(1-->2)-beta-D-galactopyranosyl-(1-->6)-2-acetamido-2-deoxy-beta-D-glucopyranosyl echinocystic acid 16-O-beta-D-glucopyranoside, 3-O-beta-D-xylopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)-2-acetamido-2-deoxy-beta-D-glucopyranosyl echinocystic acid 16-O-beta-D-glucopyranoside and 3-O-alpha-L-arabinopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)-2-acetamido-2-deoxy-beta-D-glucopyranosyl echinocystic acid 16-O-beta-D-glucopyranoside. Their structures were determined by NMR techniques including HOHAHA, (1)H-(1)H COSY, ROE, HMQC and HMBC experiments together with FABMS as well as acid hydrolysis. To the best of our knowledge, the new compounds are considered the first examples of echinocystic acid 3,16-O-bisglycosides. In contrast to other cytotoxic echinocystic acid glycosides with N-acetyl glucosamine unit, the new glycosides were found inactive when assayed by MTT method for their cytotoxicities against the human tumor cell lines HEPG2, A549, HT29 and MCF7. The results showed the importance of the free hydroxyl group at the aglycone C-16 for exhibiting cytotoxic properties., (Copyright 2010 Elsevier Ltd. All rights reserved.)

Four triterpene saponins, agrostemmosides A-D were isolated from the methanol extract of Agrostemma gracilis. The structures of the compounds were determined as 3-O-beta-D-xylopyranosyloleanolic acid 28-O-beta-D-glucopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->6)]-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester, 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-xylopyranosyloleanolic acid 28-O-beta-D-glucopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->6)]-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester, 3-O-beta-D-xylopyranosylechinocystic acid 28-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester, 3-O-beta-D-xylopyranosylechinocystic acid 28-O-beta-D-glucopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->6)]-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester by a combination of one- and two-dimensional NMR techniques, and mass spectrometry. To the best of our knowledge this is the first phytochemical report on A. gracilis, and echinocystic acid saponins were encountered for the first time in Caryophyllaceae family., (Copyright 2009 Elsevier Ltd. All rights reserved.)

A study of an EtOH extract obtained from the roots of the Madagascan plant Terminalia tropophylla H. Perrier (Combretaceae) led to isolation of the oleanane-type triterpenoid saponin 1, the lignan derivative 2, and the two known saponins arjunglucoside I (3) and sericoside (4). The structures of compounds 1 (terminaliaside A) and 2 (4'-O-cinnamoyl cleomiscosin A) were elucidated using 1D and 2D NMR experiments and mass spectrometry. Compound 1 showed antiproliferative activity against the A2780 human ovarian cancer cell line with an IC(50) value of 1.2 microM., (2009 Elsevier Ltd. All rights reserved.)

The methanolic extract from the pericarps of Sapindus rarak DC. was found to show pancreatic lipase inhibitory activity (IC50=ca. 614 microg/mL). From the extract, oleanane-type triterpene oligoglycosides, rarasaponins I-III (1-3), and raraoside A (4), were isolated together with 13 known saponins and four known sesquiterpene glycosides. Among them, several saponin constituents including rarasaponins I (1, IC50=131microM) and II (2, 172microM), and raraoside A (4, 151microM) inhibited pancreatic lipase activity, which were stronger than that of theasaponin E(1) (270microM).

Hydroponically cultivated Nigella sativa L. plants treated with methyl jasmonate (MeJA) showed a twelve-fold increase in levels of the monodesmosidic triterpene saponins alpha-hederin and kalopanaxsaponin I (KsI) in the leaves. We will demonstrate that these two saponins accounted for approximately 10% of the dry plant matter, of which 93% was KsI and 7% alpha-hederin. To address the molecular basis of saponin induction by MeJA, we cloned and characterized the beta-amyrin synthase gene (NsbetaAS1) encoding one of the key enzymes in triterpene saponin biosynthesis. As expected, NsbetaAS1 transcription was induced by MeJA and led to the production of beta-amyrin when over-expressed in yeast.

Oleanane-type triterpenoidal saponins, hydrocosisaponins A-F (1-6), along with a known saponin, hydrocotyloside VII (7), were isolated from Hydrocotyle sibthorpioides. Their structures were established on the basis of spectroscopic analyses including NMR spectroscopic techniques ((13)C, (1)H, COSY, HMQC, HMBC, TOCSY and NOESY). Biological evaluation established that saponins possessing four sugar units (three d-glucoses and one l-arabinose) (4-7) exhibited moderate cytotoxicity against KB, Daoy and WiDr human tumor cell lines.

Stem bark of Hippocratea excelsa afforded six pentacyclic triterpenes, five oleanane and one ursane types. They were identified as 11beta,21beta-dihydroxy-olean-12-ene-3-one (2), 3alpha,11alpha,21beta-trihydroxy-olean-12-ene (3), 3alpha,21beta-dihydroxy-11alpha-methoxy-olean-12-ene (4), 3alpha,21beta-dihydroxy-olean-9(11),12-diene (5), 3alpha,21beta-dihydroxy-olean-12-ene (6) and 3alpha,21beta-dihydroxy-11alpha-methoxy-urs-12-ene, isolated as its diacetate derivative (7), as well as 3alpha,21beta-dihydroxy-olean-12-ene (1) previously isolated from the root bark. The known alpha- and beta-amyrin, oleanoic and ursolic acids, trans-polyisoprene, and the ubiquitous beta-sitosterol were also isolated. Structures were elucidated on the basis of spectroscopic analyses, including homo- and heteronuclear correlation NMR experiments (COSY, ROESY, HSQC and HMBC) and comparison with literature data. The antigiardial activity of compounds 2-5 was not significant.

Betulinic acid (1), a triterpenoid found in many plant species, has attracted attention due to its important pharmacological properties, such as anti-cancer and anti-HIV activities. The closely related, betulonic acid (2) also has similar properties. In order to obtain derivatives potentially useful for detailed pharmacological studies, both compounds were submitted to incubations with selected microorganisms. In this work, both were individually metabolized by the fungi Arthrobotrys, Chaetophoma and Dematium, isolated from the bark of Platanus orientalis as well as with Colletotrichum, obtained from corn leaves; such fungal transformations are quite rare in the scientific literature. Biotransformations with Arthrobotrys converted betulonic acid (2) into 3-oxo-7beta-hydroxylup-20(29)-en-28-oic acid (3), 3-oxo-7beta,15alpha-dihydroxylup-20(29)-en-28-oic acid (4) and 3-oxo-7beta,30-dihydroxylup-20(29)-en-28-oic acid (5); Colletotrichum converted betulinic acid (1) into 3-oxo-15alpha-hydroxylup-20(29)-en-28-oic (6) acid whereas betulonic acid (2) was converted into the same product and 3-oxo-7beta,15alpha-dihydroxylup-20(29)-en-28-oic acid (4); Chaetophoma converted betulonic acid (2) into 3-oxo-25-hydroxylup-20(29)-en-28-oic acid (7) and both Chaetophoma and Dematium converted betulinic acid (1) into betulonic acid (2). Those fungi, therefore, are useful for mild, selective oxidations of lupane substrates at positions C-3, C-7, C-15, C-25 and C-30.

Four oleanane-type triterpenes, 3alpha,21beta,22alpha-trihydroxy-11,13(18)-oleanadien-28-oic acid (1), 3-epi-papyriogenin C (2), 21-O-acetyl-21-hydroxy-3-oxo-11,13(18)-oleanadien-28-oic acid (3) and 3beta-hydroxy-21-oxo-11,13(18)-oleanadien-28-oic acid methyl ester (4), together with four known triterpenes, were isolated from Tetrapanax papyriferus (Hook) K. Koch. Papyriogenin A (8) exhibited anti-HIV activity and low cytotoxicity in acutely infected H9 lymphocytes. Their structures were determined by analysis of spectroscopic data, including by 1D and 2D NMR.

An investigation of an ethyl acetate extract of Embelia schimperi leaves has led to the isolation of 10 oleanane-type triterpenes characterized as 3beta,16alpha-di-O-acetyl-13beta, 28-epoxyoleanane (1), 3beta-acetyl-16-oxo-13beta, 28-epoxyoleanane (2), 3beta-acetyl-16alpha-hydroxy-13beta, 28-epoxyoleanane (3), 3beta-acetyl-16alpha-hydroxyoleanane-13beta, 28-olide (4), 3beta-acetyl-28-hydroxy-16-oxo-12-oleanene (5), 3beta, 28-di-O-acetyl-16alpha-hydroxy-12-oleanene (6), 3beta-acetyl-11alpha, 28-dihydroxy-16-oxo-12-oleanene (7), 3beta, 11alpha, 16alpha, 28-tetrahydroxy-12-oleanene (8), 3beta-acetyl-16alpha, 28alpha-dihydroxy-13beta, 28-oxydooleanane (9) and 3beta, 28alpha-dihydroxy-16-oxo-13beta, 28-oxydooleanane (10). The known compounds isolated from the same extract included 3beta, 16alpha-dihydroxy-13beta, 28-epoxyoleanane (protoprimulagenin A) (11), 3beta-hydroxy-16-oxo-13beta, 28-epoxyoxyoleanane (aegicerin) (12), 3, 16-dioxo-13beta, 28-epoxyoleanane (embilionone) (13), 3beta, 28-dihydroxy-16-oxo-12-oleanene (schimperinone) (14), taraxerone (15), taraxerol (16) and stigmasterol (17). Structure elucidations were carried out spectroscopically.

Five triterpenoid saponins, caryocarosides II-22 (3), III-22 (4), II-23 (5), III-23 (6), and II-24 (7), have been isolated from the methanol extract of the stem bark of Caryocar villosum, along with two known saponins (1-2). The seven saponins are glucuronides of hederagenin (II) or bayogenin (III). Caryocaroside II-24 (7) is an unusual galloyl ester saponin acylated on the sugar chain attached to C-28, the 3-O-alpha-L-rhamnopyranosyl-(1-->3)-beta-D-galactopyranosyl-(1-->3)-beta-D-glucuronopyranosyl hederagenin-28-O-[2-O-galloyl-beta-D-glucopyranosyl] ester. The structures of the saponins were established on the basis of extensive NMR ((13)C, (1)H, COSY, TOCSY, HSQC, HMBC and ROESY) and ESI-MS studies. The cytotoxic activity of saponins 2 and 3 was evaluated in vitro against human keratinocytes. The DOPA-oxidase inhibition and the lipolytic activities were evaluated ex vivo using an explant of human adipose tissue.

A xanthone derivative, named gaboxanthone (1), has been isolated from the seed shells of Symphonia globulifera, together with known compounds, symphonin (2), globuliferin (3), guttiferone A (4), sistosterol, oleanolic acid and methyl citrate. The structure of the compound was assigned as 5,10-dihydroxy-8,9-dimethoxy-2,2-dimethyl-12-(3-methylbut-2-enyl) pyrano [3,2-b]xanthen-6(2H)-one, by means of spectroscopic analysis. The anti-plasmodial and antioxidant activities of the phenolic compounds were evaluated, respectively, in culture against W2 strain of Plasmodium falciparum and using the free radical scavenging activity of the DPPH radical, respectively. Compounds 1-4 were found to be active against the Plasmodium parasites (IC(50) of 3.53, 1.29, 3.86 and 3.17 microM, respectively). Guttiferone A (4) showed a potent free radical scavenging activity compared to the well-known antioxidant caffeic acid.