Biomarkers for Ilex pubescens under anti-platelet activity-oriented isolation

In the present study, eleven ursane triterpenoids (1—11), seven oleanane triterpenoids (12—18), one lupine sapogenin (19) as well as two sterols (20 and 21) were obtained from Ilex pubescens under the anti-platelet activity-oriented isolation. Among them, compounds 2 and 4 were isolated from I. pubescens for the first time, while the isolation of the compounds 12, 15, 16 and 17 was a new finding in the Aquifoliaceae family. Our present study exhibited the taxonomic relationships (similarities and differences) between I. pubescens and some other species of genus Ilex. The result also suggested that triterpenoids are the anti-platelet components which may be fingerprints and serve as biomarkers for seeking alternative sources for I. pubescens.     

Chemical constituents from the leaves of Ilex urceolatus

Eighteen compounds, including four hemiterpene glycosides (1–4), three triterpenoid saponins (5–7), four triterpenes (8–11), five sterols (12-16) and two monoterpene glucosides (17 and 18), were isolated from the leaves of Ilex urceolatus C. B. Shang, K. S. Tang et D. Q. Du, which was identified as a new species belonging to the genus Ilex. Among them, compounds 14–18 were firstly isolated from the genus Ilex, others were obtained from I. urceolatus for the first time. This work represented the initially phytochemical study on this plant. The isolated compounds have significant chemotaxonomic characteristics with the other species from this genus.     

Chemical constituents from Ilex urceolatus

Twenty-four compounds were obtained from the extract of the leaves of I. urceolatus, which were divided into saturated fatty alcohols (1 and 2), triterpenoids (3–8 and 14–16), lignanoids (9, 20 and 22), coumarins (10 and 19), flavonoids (11–13, 21, 23 and 24) and others (17 and 18). Among them, compounds 1, 2, 17 and 18 were firstly obtained from the genus Ilex, others were isolated from this species for the first time. The chemotaxonomic relationships between I. urceolatus and other species of genus Ilex were also discussed. As a result, the isolated compounds closely matched the ones obtained in other species of the genus.     

The triterpenes and steroids from the fruiting body Ganoderma duripora

Two new triterpenes (1–2) and seven steroids (3–9) were isolated from the fruiting bodies of Ganoderma duripora. Structure elucidation of these compounds was generated by a combination of spectroscopic means (HRTOFMS, ¹H and ¹³C NMR). There are significant differences between the compounds isolated from Ganoderma duripora and from the other Ganoderma species, suggesting that we need to reconsider the classification of G. duripora according to the taxonomy of chemistry.     

Chemical constituents of Medinilla septentrionalis (W. W. Sm.) H. L. Li (Melastomataceae)

Our phytochemical investigation of the whole plants of Medinilla septentrionalis (W. W. Sm.) H. L. Li led to the isolation of five tannins (1–5), five phenolic acids and phenolic acid derivatives (6–10), four flavonoids (11–14), two triterpenes (15 and 16), and one hydantoin derivative (17). The structures of the obtained compounds were identified using spectrometric methods (¹H NMR, ¹³C NMR and MS). This is the first study reporting on the chemical constituent of M. septentrionalis and the chemotaxonomic relationships between Medinilla and other genera of Melastomataceae.     

Nitric oxide inhibitory constituents from Siegesbeckia pubescens

Two new sesquiterpenoids (1 and 2) and a new ent-pimarane type diterpenoid (3), together with eighteen known compounds (4–21), were isolated from the whole plants of Siegesbeckia pubescens. The structures of the new compounds were determined on the basis of 1D-, 2D NMR and HRESIMS data. All compounds were evaluated for their inhibitory effects on LPS-induced nitric oxide production in RAW 264.7 macrophages. Of these, highly oxygenated germacrane type sesquiterpenoids (1–2 and 13–14) showed significant inhibitory effects with IC₅₀ values ranging from 3.9 to 16.8 μM.     

Chemical constituents from the roots of Euphorbia nematocypha Hand.-Mazz.

A new myrsinol-type diterpene (1), three myrsinol-type diterpenes (2–4), three ent-abietane-type diterpenes (5–7), one tigliane-type diterpene (8), two cycloartane-type triterpenes (9–10), and two tirucallane-type triterpenes (11–12) were isolated from the roots of Euphorbia nematocypha Hand.-Mazz. Their structures were identified by spectroscopic analyses and by comparison of their spectral data with those reported in the literature. Compound 12 was isolated and reported from plants for the first time. All compounds were isolated from E. nematocypha for the first time.     

Chemical constituents from leaves of Lagerstroemia speciosa L.

This work describes the isolation and characterization of fourteen compounds from Lagerstroemia speciosa (L.) Pers, including four triterpenes (1–4), eight ellagic acids (5–12), one coumarin (13) and one neolignan (14). Their structures were elucidated on the basis of various spectroscopic methods (UV, IV and NMR, including 2D experiments). It was the first report of compounds 14 from the genus Lagerstroemia and the first report of compounds 9–12 from the family Lythraceae.     

Fatty acid derivatives and dammarane triterpenes from the glandular trichome exudates of Ibicella lutea and Proboscidea louisiana

Ibicella lutea and Proboscidea louisiana, both of the Martyniaceae family, are known for rich glandular trichomes on their leaves and stems. Chemical investigations of the glandular trichome exudates on leaves of the two plants furnished three types of secondary metabolites, glycosylated fatty acids, glycerides (2-O-(3,6-diacetyloxyfattyacyl)glycerols and 2-O-(3-acetyloxyfattyacyl)glycerols) and dammarane triterpenes. The glycosylated fatty acids from I. lutea were determined to be 6(S)-(6-O-acetyl-β-d-glucopyranosyloxy)-octadecanoic acid (1A), -eicosanoic acid (1B) and -docosanoic acid (1C), as well as their respective deacetyl congeners (2A, 2B and 2C), whereas P. louisiana furnished 8(S)-(6-O-acetyl-β-d-glucopyranosyloxy)-eicosanoic acid (3A) and -docosanoic acid (3B) and their respective deacetyl congeners (4A and 4B), together with 2B. Both plants contained 12 identical 2-O-[(3R,6S)-3,6-diacetyloxyfattyacyl]glycerols (5A-L), in which the fatty acyl moieties contained between 17 and 21 carbon atoms. The corresponding mono-acetyloxy compounds, 2-O-[(3R)-3-acetyloxyfattyacyl]glycerols (6A–L) were detected in both plants. Among these glycerides, ten compounds (5A, 5C, 5F, 5H, 5K, 6A, 6C, 6F, 6H and 6K) had iso-fattyacyl structures and four (5E, 5J, 6E and 6J) had anteiso-fattyacyl structures. A previously unknown dammarane triterpene, betulatriterpene C 3-acetate (7), was isolated together with three known dammarane triterpenes, 24-epi-polacandrin 1,3-diacetate (8), betulatriterpene C (9) and 24-epi-polacandrin 3-acetate (10) from I. lutea, whereas 12 dammarane triterpenes, named probosciderols A–L (12–23), and the known compound betulafolienetriol (11) were isolated from P. louisiana. The structures of these compounds were elucidated by spectroscopic analysis including 2D-NMR techniques and chemical transformations. The 6-O-acetylglucosyloxy-fatty acids 1A–C (42%) and the dammarane triterpenes 7–10 (31%) were the two most abundant constituents in the glandular trichome exudate of I. lutea, whereas the dammarane triterpenes 11–23 (47%) and the glucosyloxy-fatty acids (4A, 4B and 2B) (38%) were the most abundant constituents in the glandular trichome exudate of P. louisiana.     

Chemical constituents from Polygonum capitatum Buch-Ham. ex D. Don

This work describes the isolation and characterization of thirty-one compounds from Polygonum capitatum Buch-Ham. ex D. Don, including two triterpenes (1–2), ten flavonoids (7–16), nine lignans (17–25), nine phenolic compounds (4–7, 26–31) and one anthraquinones (3). Their structures were elucidated on the basis of various spectroscopic methods (UV, IV and NMR, including 2D experiments). It was the first report of compounds 13, 15, 17, 24, 25, 28, 29, 30, 31 from the genus Ploygonum, and the first report of compounds 13, 15, 17, 24, 25 from the family Polygonaceae.     

Studies of naturally occurring friedelane triterpenoids as insulin sensitizers in the treatment type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a rapidly expanding public epidemic and frequently results in severe vascular complications. In an attempt to find anti-diabetic agents, we report herein on the isolation, structural elucidation and bioactivity of nine friedelane-type triterpenes (1–9) and twenty two known ones (10–31) from the root barks of Celastrus vulcanicola and Maytenus jelskii. Their structures were elucidated on the basis of spectroscopic analysis, including 1D and 2D NMR techniques. Two compounds from this series (1 and 3) exhibited increased insulin-mediated signalling, which suggests these friedelane triterpenes have potential therapeutic use in insulin resistant states.     

Carbazole alkaloids with antiangiogenic activities from Clausena sanki

Two new carbazole alkaloids 1 and 2, and eleven known congeners 3–13 were isolated and identified from Clausena sanki for the first time. Their structures were elucidated on the basis of extensive UV, IR, MS, NMR spectroscopic data and comparison with literatures. The compounds 1–13 were evaluated by MTT assay to determine whether they decreased VEGF-mediated cell proliferation in HUVECs with Axitinib as positive control. Among them, compounds 1, 2, 6, 8, and 13 (μM) exhibited moderate antiangiogenic activities, which inhibited VEGF-induced HUVEC proliferation in vitro with IC₅₀ values of 12.1 (C.I. 8.2–15.2), 58.1 (C.I. 56.3–63.4), 13.7 (C.I. 9.2–15.4), 16.0 (C.I. 9.5–16.4), and 63.2 (C.I. 57.8–65.7) μM, respectively. Moreover, the antiangiogenic activities of compounds 1–13 were evidenced in vivo in the zebrafish embryo model. As a result, compounds 1, 2, 6, 8, and 13 showed effectively suppress angiogenesis. These research results may guide the search for new natural products with antiangiogenic attributes.     

Cytotoxic triterpenes with diverse skeletons from Amoora tsangii

Two new 29-nor-cycloartane triterpenes, amooratsanols A and B (1, 2) along with nine known compounds including two 29-nor-cycloartane triterpenes (3, 9), two lupane triterpenes (4, 5), two cycloartane triterpenes (6, 10), two dammarane triterpenes (7, 8), as well as one dinorcycloartane triterpene (11) were isolated from the leaves and twigs of Amoora tsangii (Merr.) X. M. Their structures were established by spectroscopic methods (IR, HRESIMS, and NMR). The cytotoxicity of 1–11 was evaluated against the human fibro sarcoma HT1080, esophageal cancer TE, and non-small cell lung cancer A549 cell lines by the CCK8 assay. Cycloartanes (1–3, 6, and 9–11) displayed significant cytotoxic activity with IC₅₀ values ranging from 2.56 to 19.05 μM. Among these triterpenes, mooratsanol A (1) showed the most potent cytotoxic activity, with IC₅₀ values ranging from 2.56 to 5.10 μM.     

Chemical constituents from Picrasma quassioides (D.Don) Benn. and their network analysis of chemotaxonomic significance

A phytochemical investigation of Picrasma quassioides (D.Don) Benn led to the isolation of seventeen compounds including five coumarins (1–5), six lignans (6–11), two alkaloids (12–13), two phenolic compounds (14–15), one megastigman glycoside (16) and one phenylpropanoid (17). The structures of those compounds were determined by spectroscopy data of NMR spectra. All of the compounds were isolated from P. quassioides for the first time. In this study, in order to discuss the chemotaxonomic significance of those compounds from P. quassioides, network analysis was carried out to determine the chemotaxonomic relationships among the Simaroubaceae family and the other families. The result showed that the Simaroubaceae family and the Rutaceae family, together with the Asteraceae family have some chemotaxonomic relationships.     

Chemical constituents from Ficus natalensis hochst (Moraceae) and their chemophenetic significance

Phytochemical investigation of the stem bark of Ficus natalensis afforded eleven compounds including one ceramide (1), two anthraquinones (2, 3), four triterpenes (4–7), two polyols (8, 9) and two steroids (10, 11). The structures of the compounds were determined by spectroscopic analyses including IR, UV, MS, 1D- and 2D- NMR (¹H, ¹³C, ¹H–¹H COSY, HMQC, HMBC and NOESY), as well as by comparison with literature data. The antibacterial activity and the cytotoxicity of the extract, fractions and some isolated compounds (3, 5, 8 and 9) were evaluated. Some fractions and sub-fractions from various column chromatography displayed moderate antibacterial activity with diameter zone of inhibition (DZI) ranging from 7 to 10 mm. None of the compounds tested had activity. In the present study, all the compounds are isolated for the first time from the species F. natalensis. Compounds 2, 4–7, 10 and 11 were previously reported from the genus Ficus. The chemophenetic significance of the isolated compounds is discussed.     

Chemical constituents from Hovenia dulcis Thunb. And their chemotaxonomic significance

Phytochemical investigations on the fruit stalks and seeds of the plant Hovenia dulcis Thunb. led to the isolation of twenty-one compounds, including three triterpenes (1–3), two sterols (4–5), five flavonoids (6–10), two sesquiterpenes (11–12), one lignan (13), two phenylpropanoids (14–15), four benzoic acid derivatives (16–19), one acid amide (20) and one cerebroside (21). The structures of these compounds were elucidated on the basis of spectroscopic analysis and comparison with previous literatures. Among them, ten compounds (4, 11–12, 14–20) were isolated from familiy Rhamnaceae, two (13, 21) from the genus Hovenia, and three (5, 8, 10) from the species Hovenia dulcis Thunb. for the first time, respectively. The chemotaxonomic significance of these isolates was also discussed.     

Chemical constituents of the Piper crocatum leaves and their chemotaxonomic significance

Chemical study of Piper crocatum leaves has led to isolation of a new megastigmane glucoside isomer (18), along with 23 known compounds including fifteen phenolic compounds (1–15), two monoterpenes (16 and 17), three sesquiterpenes (19–21), a phenolic amide glycoside (22), a neolignan (23), and a flavonoid C-glycoside (24). Structures of these compounds were identified via spectroscopic methods and compared with those reported in the literature. Seven compounds (7, 11, 13, 14, 17, 20, and 24) from the P. crocatum species and 17 others (1–6, 8–10, 12, 15–16, 18–19, and 21–23) from the Piper genus and Piperaceae family were isolated and reported for the first time. Furthermore, this study discusses chemotaxonomic relations between P. crocatum and other Piper species.     

Semisynthesis of epoxy-pimarane diterpenoids from kirenol and their FXa inhibition activities

Kirenol is one of the biologically active diterpenoids from Siegesbeckia pubescens. In terms of the high content and typical structure, many ent-diterpenoids separated from S. pubescens were presumed to be biologically related to kirenol. Among them, epoxy-pimarane diterpenoids are belonging to a special family of naturally occurring compounds that attracted our attentions on their putative biosynthesis pathway and biological activities. Here, we designed and synthesized two known 14,16-epoxy-pimarane diterpenoids (2 and 3) and five 8,15-epoxy-pimarane diterpenoids (4–8) from kirenol. Their absolute structures were determined by 1D and 2D NMR data and the absolute configurations of 4 were confirmed by X-ray crystallographic data. Their inhibition effects on factor Xa (FXa) were evaluated to assess the potentiality of epoxy-pimarane diterpenoids as FXa inhibitor agents.     

Isolation of hopane triterpenes and other constituents from Machaerium brasiliense vogel (Fabaceae)

Phytochemical study of Machaerium brasiliense leaves extract afforded three hopane triterpenes 3,4-seco-21β-H-hop-22 (29)-en-3-oic acid (1), hopenone B (2), hopene B (3). In addition, lupeol (4), stigmasterol (5), β-sitosterol (6), daucosterol (7), uracil (8), allantoin (9) and trans-4-hydroxy-N-methylproline (10) were isolated. The structures of these compounds were established based on spectroscopic data in comparison to those described in literature. Considering the chemotaxonomic relevance of the isolated compounds, this is the first report of triterpenes 1, 2 and 3 in Fabaceae family and compounds 7, 8 and 9 in the genus Machaerium. Besides, preliminary screening on antiproliferative and antioxidant activities was performed for MBEB and its fractions.     

Chemical constituents from the roots of Pteroxygonum giraldii Damme et Diels

Twenty-four compounds were obtained from Pteroxygonum giraldii and were classified as five triterpenes (1–5), two sterols (6 and 7), two quinones (8 and 11), three stilbenes (9, 10 and 18) and twelve flavonoids (12–17, 19–24). Seventeen of these compounds were obtained from the genus Pteroxygonum for the first time. The chemotaxonomic significance of this plant was also discussed. Compounds 10, 12 and 23 can serve as the fingerprints for P. giraldii, and compounds 12, 13, 17 and 22–24 are recognized as typical metabolites of P. giraldii. Both Pteroxygonum and Polygonum might have the same origin and could be classified into the same tribe among Polygonaceae. Furthermore, due to the presence of stilbenes, Pteroxygonum may have some taxonomic relationships with Fallopia, Rumex and Reynoutria.