New 2-arylbenzofurans with selective cytotoxicity from Morus wittiorum

Four new 2-arylbenzofuran derivatives wittifurans O, N, K and L (1–4) were isolated from the stem bark of Morus wittiorum. Their structures were elucidated on the basis of spectroscopic analysis. Compounds 1–3 were evaluated for their cytotoxicity against five human cancer cell lines. Compounds 1 and 2 exhibited selective cytotoxicity against human ovarian cancer cell line A2780 with IC₅₀ (μM) values of 1.80 and 1.32, respectively.     

New formylated phloroglucinol compounds from Eucalyptus globulus foliage

Two new acylphloroglucinols were isolated from the leaves of Eucalyptus globulus Labill and identified as macrocarpals P (1) and Q (2). Structural elucidations were carried out using conventional 1D and 2D NMR and mass spectrometry together with complementary techniques (UV and IR). Macrocarpal Q was a diastereoisomer of macrocarpal E (3), configuration of which was not precised. Simultaneous isolation of macrocarpals E and Q allowed to determine the configurations of both compounds. The diformylphloroglucinol (4) was also isolated as well as already known compounds grandinol, macrocarpals D, I, L, N, O and am-1.     

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.     

Manzamenones L–N,new dimeric fatty-acid derivatives from an Okinawan marine sponge Plakortis sp.

Three new polyketides, manzamenones L–N (1–3), have been isolated from an Okinawan marine sponge of the genus Plakortis. The structures of 1–3 were elucidated on the basis of spectroscopic data. Manzamenones L–N (1–3) were new dimeric fatty-acid derivatives consisting of a tetrahydroindenone with three carboxy groups and two hexadecanyl chains. Manzamenones M (2) and N (3) showed antimicrobial activity against several bacteria and fungi.     

Sterostreins F–O,illudalanes and norilludalanes from cultures of the Basidiomycete Stereum ostrea BCC 22955

Sterostreins F–O (1–10), 10 illudalanes and norilludalanes, were isolated from cultures of the Basidiomycete Stereum ostrea BCC 22955. Their structures were elucidated by analyses of the NMR spectroscopic and mass spectrometry data. Sterostreins M (8), N (9), and O (10) are pyridine-containing illudalanes.     

Five new degraded diterpenoids from Trigonostemon xyphophylloides

Five new degraded diterpenoids trigoxyphins J–N (1–5), among them trigoxyphins K and L have a novel carbon skeleton, together with four known analogues (6–9) have been obtained from the ethanol extract of the twigs of Trigonostemon xyphophylloides. Compounds 1?5 were evaluated for their cytotoxic activity in vitro against three human tumor cell lines by MTT assay. The results exhibited that Trigoxyphin N (5) showed moderate cytotoxicities against SPC-A-1 and SGC-7901 cancer cell lines.     

Baculiferins A–O,O-sulfated pyrrole alkaloids with anti-HIV-1 activity,from the Chinese marine sponge Iotrochota baculifera

Fifteen new DOPA-derived pyrrole alkaloids, named baculiferins A–O (2–16), were isolated from the Chinese marine sponge Iotrochota baculifera, together with the known alkaloids purpurone (1) and ningalin A (17). Most of the new compounds contain one to three O-sulfate units. Their structures were determined by extensive spectroscopic analysis including ¹H and ¹³C NMR (COSY, HMQC, HMBC) and ESIMS data. A possible pathway for the biosynthetic origin of the isolated alkaloids is proposed, in which DOPA is assumed to be a joint biogenetic precursor. Baculiferins C, E–H, and K–N (4, 6–9, 12–15) were found to be potent inhibitors against the HIV-1 IIIB virus in both, MT4 and MAGI cells. Additional bioassay revealed that baculiferins could dramatically bind to the HIV-1 target proteins Vif, APOBEC3G, and gp41, for which structure–activity relationships are discussed.     

Three new terpenoids from Trigonostemon xyphophylloides (Croiz.) L.K. Dai and T.L. Wu

Two new daphnane diterpenoids, trigoxyphins J and K (1 and 2), and one new friedelane triterpene derivative, 3-O-benzoylpluricostatic acid (3), together with thirteen known terpenoids (4–16) were isolated from Trigonostemon xyphophylloides (Croiz.) L.K. Dai and T.L. Wu. Their structures were identified on the basis of physicochemical properties and spectroscopic data. All compounds were evaluated for their cytotoxicity against K562, SGC-7901, and BEL-7402 tumor cell lines, respectively.     

Chemical constituents isolated from Valeriana officinalis L

Phytochemical investigations on the leaves of Valeriana officinalis L. led to the isolation of 18 compounds, including eight lignans (1–8), three sesquiterpenoids (9–11), five iridoids (12–16), and two aldehydes (17–18) The structure elucidation of isolated compounds was achieved on the basis of NMR and mass spectral data. Among them, three compounds (9–16, 18) are reported from V. officinalis for the first time and one compound (5) was isolated from the genus Valeriana for the first time. In addition, six compounds (2, 4, 6–8, 17) are isolated for the first time from Valerianaceae family. The chemotaxonomic significance of these isolated compounds has also been discussed.     

Bioactive monoterpene indole alkaloids from Nauclea officinalis

Two new monoterpene indole alkaloids, naucleaoffines A (1) and B (2), together with six known alkaloids (3–8), were isolated from the stems and leaves of Nauclea officinalis. The structures of 1 and 2 were elucidated by extensive spectroscopic methods and the known compounds were identified by comparisons with the data reported in literature. All isolated compounds were evaluated for their anti-inflammatory activities and anti-HIV-1 activities. Compounds 1–8 exhibited significant inhibitory activities on nitric oxide (NO) production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells in vitro with IC₅₀ values comparable to that of hydrocortisone. In addition, compounds 1–8 showed significant anti-HIV-1 activities with EC₅₀ ranged from 0.06 to 2.08 µM. These findings suggest that the discoveries of these indole alkaloids with significant anti-inflammatory activities and anti-HIV-1 activities isolated from N. officinalis could be of great importance to the development of new anti-inflammatory and anti-HIV agents.     

Chemical constituents from Cyclocarya paliurus (Batal.) Iljinsk

A novel triterpenoid, cyclocarioside K, together with fifteen known compounds, including seven triterpenoids (2–8), five flavonoids (9–13), three phenolic derivatives (14–16), was obtained from the leaves of Cyclocarya paliurus (Batal.) Iljinsk (Juglandaceae). Their structures were elucidated by spectroscopic methods, including two-dimensional NMR experiments (HSQC DEPT and HMBC). The chemotaxonomic relationships were also discussed. As a result, 3, 4-secodammarane triterpenoids and kaempferol glycosides may represent phytochemical fingerprints for C. paliurus, and C. paliurus has close relationships with other species of Juglandaceae.     

Cytosporones,coumarins, and an alkaloid from the endophytic fungus Pestalotiopsis sp. isolated from the Chinese mangrove plant Rhizophora mucronata

Chemical examination of the endophytic fungus Pestalotiopsis sp., isolated from the leaves of the Chinese mangrove Rhizophora mucronata, yielded 11 new compounds including cytosporones J–N (1–3, 5–6), five new coumarins pestalasins A–E (8–12), and a new alkaloid named pestalotiopsoid A (14), along with the known compounds cytosporone C (4), dothiorelone B (7), and 3-hydroxymethyl-6,8-dimethoxycoumarin (13). The structures of the new compounds were unambiguously elucidated on the basis of extensive spectroscopic data analysis.     

Limonoids from the leaves of Toona ciliata var. yunnanensis

Twelve limonoids, toonayunnanins A–L (1–12) and eleven known compounds (13–23) were isolated from the leaves of Toona ciliata var. yunnanensis, and their structures were elucidated by means of extensive spectroscopic analyses, particularly 1D and 2D NMR techniques. The inhibitory effects of all the isolated compounds were evaluated on human tumor cell lines, such as HL-60, SMMC-7721, A-549, MCF-7 and SW480. Cedrelone (13) and dysobinin (18) showed significant cytotoxicity, and toonayunnanin B (2) and epoxyazadiradione (14), were found to be slightly cytotoxic against the above cell lines. Furthermore, this study provides valuable information for the chemotaxonomy of T. ciliata varieties.     

NGF-potentiating vibsane-type diterpenoids from Viburnum sieboldii

Six new vibsane-type diterpenoids, named neovibsanin O (1), neovibsanin M (2), neovibsanin L (3), (8Z)-neovibsanin M (4), 15-O-methylvibsanin H (5), and 5-epi-15-O-methylvibsanin H (6), were isolated from the leaves of Viburnum sieboldii by bioassay-guided fractionation using NGF-differentiated PC12 cells. The structures of 1–6 were established by analyzing their spectroscopic data and comparing their NMR data with those of previously reported vibsane-type diterpenoids. Compounds 3 and 4, and the known vibsane-type diterpenoids neovibsanins A (7) and B (8) significantly enhanced the neurite outgrowth of NGF-mediated PC12 cells at concentrations ranging from 20 to 40 μM.     

Naphthoquinone and flavonoid constituents from the carnivorous plant Nepenthes mirabilis and their anti-osteoporotic and antioxidant activities

The methanolic extract of Nepenthes mirabilis (Nepenthaceae) showed significant in vitro antioxidant (peroxyl radical-scavenging and reducing effects) and anti-osteoporotic (pre-osteoclastic RAW 264.7 cells) activities. Phytochemical investigation of chloroform and ethyl acetate partitions of N. mirabilis branches and leaves allowed to isolate 13 compounds (1–13), including two new naphthoquinones, nepenthones F (1) and G (2), together with 11 known compounds. The structures of the isolated compounds were established mainly by extensive analysis of the 1D and 2D NMR, as well as HRMS data. The isolated compounds also were further evaluated for in vitro antioxidant and anti-osteoclast activities. Among them, compounds 10 and 11 showed potent antioxidant effects. While compounds 4 and 12 showed significant inhibition on receptor activation for nuclear factor κB ligand (RANκL)-induced osteoclast formation in murine bone-marrow macrophages.     

Two new polyhydroxylated steroidal glycosides from Paris polyphylla var. yunnanensis

Chemical investigation of Paris polyphylla smith var. yunnanensis afforded two new polyhydroxylated steroidal glycosides, named Parisyunnanosides K and L (1–2), together with nine known ones. The chemical structures of the new compounds were elucidated by 1D, 2D NMR and HR-ESI-MS techniques, together with chemical methods. Parisyunnanosides K and L (1–2) are rare C₂₇ steroidal glycosides with two double bonds located at C-5, 6 and C-25, 26 of the aglycone, respectively. The cytotoxic activities of the isolated compounds were evaluated against Caco-2 cells by CCK-8 assay. Among them, compounds 5–11 exhibited potent cytotoxic activity with IC₅₀ values ranging from 1.10 to 14.14 μM compared with the positive control oxaliplatin (1.38 μM).     

Chemical constituents of Callistemon citrinus from Egypt and their antiausterity activity against PANC-1 human pancreatic cancer cell line

Human pancreatic cancer is resistant to almost all conventional chemotherapeutic agents. It is known to proliferate aggressively within hypovascular tumor microenvironment by exhibiting remarkable tolerance to nutrition starvation,  a phenomenon termed as “austerity”. Search for the new agents that eliminate the tolerance of cancer cells to nutrition starvation is a promising strategy in anticancer drug discovery. In this study, two new meroterpenoids named callistrilones O and P (1 and 2) together with eight known triterpenes (3–10) were isolated from the active dichloromethane extract of Callistemon citrinus leaves. The structure elucidation of the new compounds was achieved by HRFABMS, 1D, 2D NMR, and ECD quantum calculations. All isolated compounds were tested for their preferential cytotoxicity against PANC-1 human pancreatic cancer cells. Among these, callistrilone O (1) exhibited the most potent preferential cytotoxicity with a PC₅₀ value of 0.3 nM, the strongest activity with over 2000 times potent than the positive control arctigenin. Callistrilone O (1) induced dramatic alterations in PANC-1 cell morphology leading to cell death under nutrient-deprived conditions. Compound 1 also inhibited PANC-1 cell migration and -PANC-1 colony formation under the nutrient-rich condition.     

Flavonoids from the leaves and twigs of Knema elegans

Knema elegans, a tropical evergreen plant, belongs to Myristicaceae family. Phytochemical investigation on the leaves and twigs of K. elegans led to the isolation and identification of two new flavonoids knemavones A and B (1 and 2), along with fifteen known analogues (3–17). These compounds belong to four subtypes of flavonoids, including chalcones, flavanes, flavones, and isoflavones. The structures of 1 and 2 were elucidated by means of spectroscopic techniques, including HRESIMS, 1D, and 2D NMR experiments. Compounds 3–17 are isolated from the title plant for the first time. Moreover, the new chalcones 1 and 2 could serve as chemotaxonomic markers of K. elegans.     

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.     

Grayanane diterpenoids from the leaves of Rhododendron dauricum

Phytochemical investigations on the leaves of Rhododendron dauricum L. (Ericaceae) resulted in the isolation of thirteen known grayanane diterpenoids (1–13). Their structures were determined by spectroscopic data analysis and comparison with the literature. The structure and absolute configuration of grayanotoxin VI (1) was determined by single-crystal X-ray diffraction analysis for the first time. This is the first time to report the isolation of grayanane diterpenoids 1–10, 12, and 13 from Rhododendron dauricum. Grayanotoxin VI (1) was isolated from the genus of Rhododendron for the first time. The chemotaxonomic significance of grayanane diterpenoids (1–13) was discussed.