Two Unusual Rearranged Flavan Derivatives from Narcissus tazetta var. chinensis

Two unusual rearranged flavan derivatives with a rare bicyclo[3.3.1]non‐3‐ene‐2,9‐dione ring, tazettone A ( 1 ) and tazettone B ( 2 ), together with five known flavans, 3 – 7 , were isolated from the bulbs of Narcissus tazetta var. chinensis Roem . The structures of two new compounds were elucidated by spectroscopic analyses, including 1D‐ and 2D‐NMR spectroscopy. All of the isolated compounds were evaluated for their cytotoxicities against four human tumor cell lines A549, HCT116, SK‐BR‐3, and HepG2. Compounds 1 and 2 were almost inactive against all tested cell lines, while compounds 3 – 7 exhibited moderate or weak cytotoxicities against the tested cell lines.     

New Triterpenoid Saponins from the Roots of Gypsophila paniculata L.

The seven new triterpenoid saponins 1 – 7 were isolated from the roots of Gypsophila paniculata L. Their structures were established by 1D ‐ and 2D‐NMR techniques, HR‐MS, and acid hydrolysis. The isolated compounds include 3,28‐O‐bidesmosides with or without a 4‐methoxycinnamoyl group (see 1 vs. 2 and 3 ), and 3‐O‐monoglucosides 4 – 7 . All isolated saponins 1 – 7 and their aglycones were evaluated for their α‐glucosidase inhibition activity. Compound 1 showed inhibitory activity against yeast α‐glucosidase with an IC₅₀ value of 100.9±3.3 μM , whereas compounds 2 – 7 were inactive.     

Paeonenoides D and E: Two New Nortriterpenoids from Paeonia lactiflora and Their Inhibitory Activities on NO Production

Two new nortriterpenoids, paeonenoides D and E ( 1 and 2 , resp.), together with seven known compounds, were isolated from the roots of Paeonia lactiflora. Their structures were elucidated on the basis of spectroscopic evidence. Compounds 1 – 7 were screened for inhibitory effects against NO production in LPS‐induced RAW246.7 macrophages and for cytotoxic activities against HL‐60, Hep‐G2, and SK‐OV‐3 cell lines. Compounds 1 – 3 and 5 – 7 exhibited inhibitory activities with IC₅₀ values in the range of 9.6–32.2 μM . Triterpenoids with an epoxide ring and a free COOH function, 1 – 3 , showed effectively increased activities compared with other pentacyclic triterpenoids. Compounds 1 – 6 showed significant cytotoxic activities against the Hep‐G2 cell line and modest cytotoxic activities against HL‐60 and SK‐OV‐3 cell lines.     

Three New Lignan Derivatives from Lindera glauca (Siebold et Zucc.) Blume

Two new aryl‐tetralin lignan glycosides, linderanosides A and B ( 1 and 2 , resp.), and a new dihydrobenzofuran neolignan glycoside, linderanoside C ( 3 ), together with five known lignan derivatives ( 4 – 8 ) were isolated from the trunk of Lindera glauca. The structures of these new compounds were determined through spectroscopic analyses, including extensive 2D‐NMR data and acid hydrolysis. The absolute configurations of the compounds were clarified by circular dichroism (CD) spectroscopic studies. Compounds 1 – 8 were evaluated for their cytotoxicity against A549 (non‐small cell lung adenocarcinoma), SK‐OV‐3 (ovarian cancer cells), A498 (human kidney epithelial cells), and HCT‐15 (colon cancer cells) human tumor cell lines using sulforhodamine B assays in vitro.     

Secondary Metabolites from the Stem Bark of Litsea akoensis and Their Cytotoxic Activity

Six new butanolides, litseadioxanins A and B ( 1 and 2 , resp.) bearing a 1,2‐dioxane moiety, litseatrinolides A and B ( 3 and 4 , resp.), and litseakolides D₁ and D₂ ( 5 and 6 , resp.), were isolated from the stem bark of Litsea akoensis, together with six known compounds. The structures of the new compounds were characterized by in‐depth NMR‐spectroscopic and mass‐spectrometric analyses. Butanolides 1 – 4 , and a mixture of 6 and litsenolide E₂, and litsenolide B₁ were tested against human tumor cells, including MCF‐7 (human breast adenocarcinoma), NCI‐H460 (non‐small‐cell lung cancer), and SF‐268 (glioblastoma) cell lines. Among the tested compounds, litsenolide B₁ exhibited marginal cytotoxic activity against MCF‐7, NCI‐H460, and SF‐268 cell lines in vitro.     

Two New Prenylated Xanthones from the Pericarp of Garcinia mangostana (Mangosteen)

Two new prenylated xanthones (=9H‐xanthen‐9‐ones), garcimangosxanthones D ( 1 ) and E ( 2 ), together with the six known xanthones 3 – 8 , were isolated from the pericarp of Garcinia mangostana. Their structures were determined by analysis of their spectroscopic data. All of the isolated compounds were biologically evaluated for their in vitro cytotoxic activity against A549, Hep‐G2, and MCF‐7 human‐cancer cell lines and antioxidant activity. Compound 1 exhibited moderate cytotoxicity against Hep‐G2 (IC₅₀=19.2 μM ) and weak cytotoxicity against MCF‐7 (IC₅₀=62.8 μM ) cell lines, and compound 2 showed moderate cytotoxicity against A549, Hep‐G2, and MCF‐7 cell lines with IC₅₀ values of 12.5–20.0 μM (Table 2). Both compounds 1 and 2 demonstrated a weak antioxidant activity with ferric reducing antioxidant power (FRAP) values of 41±7 and 130±4 μmol/g, respectively (Table 3).     

Polyoxygenated Sterols from Freshwater Clam

Two new biologically active polyoxygenated sterols, 3,5,9‐trihydroxycholest‐7‐en‐6‐one ( 1 ) and cholest‐7‐ene‐3,6,9‐triol ( 3 ), together with one known sterone, topsentisterol D3 ( 2 ), were isolated from freshwater clam (Corbicula fluminea Muller ; an important cultured edible shellfish in Taiwan). The structure elucidation of sterols 1 – 3 were accomplished by ¹H‐ and ¹³C‐NMR, HMQC, and HMBC, and MS analyses. The sterols 1 – 3 displayed cytotoxicities against the human hepatoma Hep G2 cells (IC₅₀: 6.04±0.07, 40.78±4.28, and 10.57±0.51 μg/ml, resp.).     

New Triterpenoid Glycosides from the Roots of Camellia oleifera Abel

Five new triterpenoid saponins, oleiferosides I–M ( 1 – 5 , resp.) were isolated from the roots of Camellia oleifera Abel . Their structures were elucidated by a combination of 1D‐ and 2D‐NMR spectroscopy, mass spectrometry, and chemical methods. All the compounds were identified as oleanane‐type saponins with sugar moieties linked to C(3) of the aglycone. In addition, cytotoxic activities of these saponins were evaluated against four human tumor cell lines (A549, B16, BEL‐7402, and MCF‐7) by using the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) in vitro assay. All of the compounds showed significant cytotoxic activities against the tested cell lines.     

Phenolic Compounds from Scorzonera tomentosa L.

From the subaerial parts of S. tomentosa L. (Asteraceae), two new dihydroisocoumarins, compounds 1 and 2 , a new phthalide, 3 , and a new stilbene derivative, 4 , were isolated, together with four known compounds, (±)‐hydrangenol ( 5 ), (?)‐hydrangenol 4′‐O‐β‐glucoside ( 6 ), (±)‐hydramacrophyllol A ( 7 ), and (±)‐hydramacrophyllol B ( 8 ). All secondary metabolites were identified on the basis of physicochemical, spectroscopic, and mass‐spectrometric data. The known compounds 5 – 8 were isolated for the first time from this species.     

Six New Sesquiterpenes from Eupatorium lindleyanum

The six new germacrane‐type sesquiterpenoid lactones 1 – 6 were isolated from the CHCl₃ extract of Eupatorium lindleyanum DC. The structures of these compounds were determined by spectroscopic analyses, including interpretation of 1D‐ and 2D‐NMR spectra. Compounds 1 – 6 were tested for cytotoxicity against NB4 and K562 leukemia cell lines, showing that 2 and 5 possess potent cytotoxicity (Table 3).     

Neolignans from the Fruits of Magnolia obovata Inhibit NO Production and Have Neuroprotective Effects

One new sesquineolignan, obovatalignan A ( 1 ), and one new neolignan, obovatalignan B ( 2 ), were isolated from the Magnolia obovata fruits. Their chemical structure, including absolute configuration, was determined based on various spectroscopic methods, such as HR‐EI‐MS, 1D‐NMR (¹H, ¹³C, DEPT), 2D‐NMR (gCOSY, gHSQC, gHMBC, NOESY), and CD spectroscopy. The compounds were evaluated for protective effects against glutamate‐induced oxidative stress in HT22‐immortalized hippocampal cells and inhibitory activity against NO production in LPS‐induced RAW 264.7 cells. Compounds 1 and 2 exhibited protective effects against glutamate‐induced oxidative stress with EC₅₀ values of 18.1 ± 1.23 and 7.10 ± 0.78 μm , respectively, as well as inhibitory effects on NO production with IC₅₀ values of > 30.0 and 8.22 ± 2.01 μm , respectively.     

Eleven New Triterpenes from Eurycorymbus cavaleriei

Eleven new triterpenes, cavalerols A–K ( 1 – 11 , resp.), ten of which were derivatives of hopane and one was derivative of dammarane, were isolated from the twigs of Eurycorymbus cavaleriei. Their structures were elucidated by spectroscopic methods including 2D‐NMR analysis. Cavalerol D ( 4 ) and cavalerol F ( 6 ), cavalerol B ( 2 ), and cavalerol G ( 7 ) were two pairs of isomers, and silver ion was introduced for their differentiation by multi‐stage tandem mass spectrometry. And nine compounds, except 5 and 10 , were tested for quinone reductase (QR) induction activities in vitro, and results showed that compounds 2, 4 , and 7 exhibited moderate induction activities with CD values of 8.62, 9.13, and 2.56 μg/ml, respectively, and compounds 6 and 8 showed cytotoxicity against hepa 1c1c7 cell line with IC₅₀ values of no more than 1 μg/ml.     

A New Prenylated Isoflavone and a New Flavonol Glycoside from Flemingia philippinensis

A new prenylated isoflavonoid, flemiphilippinin G ( 1 ), and a new flavonol glycoside, flemiphilippininside ( 2 ), along with eleven known isoflavonoids were obtained from the roots of Flemingia philippinensis (Merr. et Rolfe) Li . Their structures were elucidated on the basis of spectroscopic data. The in vitro cytotoxicities of compounds 1 – 13 against MCF‐7, A549, and Hep‐G2 cell lines were determined by using the MTT (=3‐(4,5‐dimethylthazol‐2‐yl)‐2,5‐diphenyl‐2H‐tetrazolium bromide) colorimetric assay, and their antioxidant activities were evaluated by ferric‐reducing antioxidant power (FRAP) method. Compound 1 exhibited significant cytotoxicity against all the tested cell lines with IC₅₀ values of 4.8–7.3 μM , and compound 2 was found to be inactive. Both compounds 1 and 2 showed weak antioxidant activities with FRAP values of 110±15 and 124±16 μmol/g, respectively.     

Cytotoxic triterpene saponins from the mangrove Aegiceras corniculatum

Using various chromatographic separations, sixteen compounds, including one new triterpene saponin named aegicoroside A (1), were isolated from the leaves of the Vietnamese mangrove Aegiceras corniculatum. Their structures were determined by spectroscopic methods such as 1D and 2D NMR and HR-ESI-MS. The cytotoxic activities of the isolated compounds against MCF7 (breast), HCT116 (colon), B16F10 (melanoma), and A549 (adenocarcinoma) cancer cell lines were also evaluated. Strong cytotoxicity was observed for sakurasosaponin (2) against all four cancer cell lines and for sakurasosaponin methyl ester (3) against MCF7, A549, and HCT116 cell lines with IC₅₀ values ranging from 2.89 ± 0.02 to 9.86 ± 0.21 μM.     

Kadsufolins A – D and Related Cytotoxic Lignans from Kadsura oblongifolia

Kadsufolins A–D ( 1 – 4 , resp.), four new dibenzocyclooctane‐type lignans, were isolated from the roots and stems of Kadsura oblongifolia, together with eleven known lignans. Their structures and configurations were elucidated by spectroscopic methods including 2D‐NMR techniques. The compounds were also evaluated for cytotoxic activity against human tumor cell lines A549 (lung carcinoma), DU145 (prostate carcinoma), KB (epidermoid carcinoma of the nasopharynx), and HCT‐8 (ileocecal carcinoma). Kadsufolin A ( 1 ), kadsufolin D ( 4 ), angeloylbinankadsurin A, and heteroclitin B were found to show cytotoxic activities against A549, DU145, KB and HCT‐8 with GI₅₀ values of 5.1–20.0 μg/ml.     

Indoloquinazoline Alkaloids from Araliopsis tabouensis

Three new indoloquinazolidine‐type alkaloids, 8,13‐dihydro‐2‐methoxyindolo[2′,3′: 3,4]pyrido[2,1‐b]quinazolin‐5(7H)‐one ( 1 ), 8,13‐dihydro‐2‐methoxy‐13‐methylindolo[2′,3′: 3,4]pyrido[2,1‐b]quinazolin‐5(7H)‐one ( 2 ), and 5,8,13,14‐tetrahydro‐2‐methoxy‐14‐methyl‐5‐oxo‐7H‐indolo[2′,3′: 3,4]pyrido[2,1‐b]quinazolim‐6‐iun chloride ( 3 ) were isolated from Araliopsis tabouensis, together with three known compounds. The structures of the new compounds were determined primarily from 1D‐ and 2D‐NMR analysis. The antimalarial activities of compounds 1 – 5 were evaluated against Plasmodium falciparum D6 and W2 clones. The IC₅₀ values in antimalarial bioassay for compounds 2 – 5 varied from 1.8 to 4.7 μg/ml.     

Two New Flavonoids from Retama raetam

Two new furanoflavonoids, retamasins A and B ( 1 and 2 , resp.), along with five known flavonoids, 3 – 7 , were isolated from the aerial parts of Retama raetam. Their structures were determined on the basis of extensive spectroscopic (IR, MS, and 1D‐ and 2D‐NMR) analyses and by comparison with the literature data. This is the first report of the isolation of new furanoflavonoids 1 and 2 from Retama genus, while compounds 3, 5 , and 6 were found for the first time from R. raetam. Antioxidant and anti‐inflammatory activities of the isolated compounds were also evaluated. Compounds 2, 3 , and 5 – 7 exhibited potent inhibitions of iNOS activity with IC₅₀ values of 2.9, 5.0, 3.1, 1.2, and 4.8 μg/ml, respectively. All compounds inhibited NF‐κB except 1 and 5 . Compound 6 was most active in inhibiting iNOS and NF‐κB activity, as well as in decreasing oxidative stress.     

Triterpene Saponins from Entada phaseoloides

Four oleanane‐type triterpene saponins, phaseoloideside A–D ( 1 – 4 ), were isolated from the seed kernels of Entada phaseoloides, along with rheediinoside B. The structures of the four new compounds were established by 2D‐NMR spectroscopic methods, HR‐ESI‐MS analysis, and chemical degradation. Phaseoloideside D ( 4 ) showed cytotoxic activity against the Eca‐109 cell line with an IC₅₀ value of 28.0 μM .     

New Cytotoxic Myrsinane‐Type Diterpenes from Euphorbia prolifera

Four new myrsinol diterpenes, proliferins A–D ( 1 – 4 , resp.) were isolated from the EtOH extracts of the roots of Euphorbia prolifera, along with four known compounds, euphorprolitherin B ( 5 ), euphorprolitherin D ( 6 ), SPr5 ( 7 ), and 14‐desoxo‐3‐O‐propionyl‐5,15‐di‐O‐acetyl‐7‐O‐nicotinoylmyrsinol‐14β‐acetate ( 8 ). Their structures were established on the basis of spectroscopic methods, including HR‐ESI‐MS, and 1D‐ and 2D‐NMR techniques. The cytotoxicity of compounds 1, 3 , and 4 against cancer cells was evaluated, with compound 1 being active against A2780 cancer cells.     

Tricycloalternarenes A – E: Five New Mixed Terpenoids from the Endophytic Fungal Strain Alternaria alternata Ly83

Five new mixed terpenoids, tricycloalternarenes (TCAs) A–E ( 1 – 5 ), together with two known compounds, TCA 1b ( 6 ) and TCA 2b ( 7 ), were isolated from the solid‐state‐cultured endophytic fungus Alternaria alternata of Maytenus hookeri. Their structures were identified by extensive spectroscopic (especially 2D‐NMR) experiments. Compound 7 showed weak activity against human tumor cell lines by MTT assay.