New Limonoids from the Seeds of Xylocarpus granatum

Three novel limonoids, 2,3‐dideacetylxyloccensin S ( 1 ), 30‐deacetylxyloccensin W ( 2 ), and 7‐hydroxy‐21β‐methoxy‐3‐oxo‐24,25,26,27‐tetranortirucalla‐1,14‐diene‐23(21)‐lactone ( 3 ), were isolated from the seeds of the Chinese mangrove, Xylocarpus granatum. The structures were elucidated on the basis of 1D‐ and 2D‐NMR (including ¹H‐ and ¹³C‐NMR, DEPT, ¹H,¹H‐COSY, HSQC, HMBC, and NOESY) data and confirmed by HR‐MS.     

Meliarachins A–K: Eleven Limonoids from the Twigs and Leaves of Melia azedarach

Eleven new limonoids, meliarachins A–K ( 1 – 11 , resp.), together with five known ones, were isolated from the twigs and leaves of Melia azedarach. The structures of the new compounds were elucidated on the basis of spectroscopic analysis. Compounds 4 and 8 exhibited moderate antibacterial activities against Gram‐positive bacteria.     

Limonoids from the Twigs and Leaves of Chukrasia tabularis

Seven new limonoids, tabularisins J–P ( 1 – 7 , resp.), together with eight known compounds, were isolated from the twigs and leaves of Chukrasia tabularis. Their structures were determined primarily by spectroscopic methods. The potassium channel blocking activities of some of these isolates were evaluated, and a few of them exerted significant activities on the delayed rectifier (I_K) K⁺ current.     

Three New Limonoids from the Leaves of Cipadessa cinerascens

Three new limonoids, cipadesins G–I ( 1 – 3 ), together with four known ones, were isolated from the leaves of Cipadessa cinerascens. Their structures were elucidated on the basis of 1D‐ and 2D‐NMR data.     

Bioactive Cytochalasins from Aspergillus flavipes,an Endophytic Fungus Associated with the Mangrove Plant Acanthus ilicifolius

Five new cytochalasins, Z₁₆–Z₂₀ ( 1 – 5 ), and three known ones, 6 – 8 , were isolated from Aspergillus flavipes, an endophytic fungus associated with Acanthus ilicifolius. Their structures were elucidated on the basis of comprehensive spectral analysis. Cytochalasin Z₁₇ ( 2 ) and rosellichalasin ( 8 ) showed cytotoxic activities against A‐549 cell lines with IC₅₀ values of 5.6 and 7.9 μM , respectively.     

Aphagranols D – H: Five New Limonoids from the Fruits of Aphanamixis grandifolia

Five new limonoids, aphagranols D–H ( 1 – 5 , resp.), were isolated from the EtOH extract of the fruits of Aphanamixis grandifolia by chromatographic methods. Their structures were established on the basis of extensive spectroscopic analyses. The absolute configuration of 1 was determined by comparison the experimental and calculated electronic circular dichroism (ECD) spectra. All of the isolates were evaluated for insecticidal activities.     

Dimeric Diterpenes from the Roots of the Mangrove Plant Ceriops tagal

Three new dimeric diterpenes, tagalsin L ( 1 ), tagalsin M ( 2 ), and tagalsin N ( 3 ) were isolated from the roots of the mangrove plant Ceriops tagal. Their structures and relative configurations were elucidated by means of extensive IR, NMR, and MS analyses.     

Trichodermates A–F,New Cytotoxic Trichothecenes from the Plant Pathogenic Fungus Trichoderma sp.

Trichodermates A – F ( 1 – 6 , resp.), six new trichothecene polyunsaturated octadioic acid esters, and (?)‐harzianum B ( 7 ) were isolated from the fermentation extract of Trichoderma sp., a plant pathogenic fungus isolated from stem rot of an unidentified tree in Thailand. The structures of 1 – 7 were elucidated by NMR experiments. The absolute configuration at C(12) in 3 was assigned by in situ dimolybdenum circular dichroism method, whereas that in 7 was deduced after hydrolysis of 7 to 8 via modified Mosher's method. Compounds 1 and 2 showed modest cytotoxic activities against the K562 (human myelogenous leukemia) cell line with IC₅₀ values of 12.12 and 13.08 μM , respectively.     

Cytotoxic Diterpenes from the Root Tuber of Curcuma wenyujin

Bioassay‐guided fractionation of ethanolic extract from the root tuber of Curcuma wenyujin afforded three new diterpenes, curcumrinols A–C ( 1 – 3 ), where 2 is the (14S)‐epimer of 1 . The structures of 1 – 3 were established on the basis of spectroscopic analysis, mainly NMR and MS. 1 – 3 were tested in vitro for their cytotoxic activity against the HL‐60 and K562 cancer cells. Among the compounds tested, 1 exhibited medium cytotoxicity against K‐562 and HL60 human cancer cells with IC₅₀ values of 11.2 and 3.2 μg/ml, respectively. However, 2 showed only weak activity against the above cancers cells, which suggested that C(14) may be an important position for cytotoxic activity.     

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.     

Isolation and Characterization of Bioactive Cyclotides from Viola labridorica

Many Violaceae plants contain cyclotides, which are plant cyclopeptides distinguished by a cyclic cystine knot motif with 28–37 amino acid residues. In the current study, four new cyclotides, vila A–D ( 1 – 4 , resp.), together with a known cyclotide, varv D ( 5 ), were isolated from Viola labridorica (Violaceae). A chromatography‐based method was used to isolate the cyclotides, which were characterized using tandem mass spectrometry and 2D‐NMR spectroscopy. Several of the cyclotides showed cytotoxic activities against five cancer cell lines, i.e., U251, MDA‐MB‐231, A549, DU145, and BEL‐7402, with vila A and B ( 1 and 2 , resp.) being the most cytotoxic. The isolated cyclotides showed no antibacterial activity against Staphyloccocus aureus and Candida albicans. Homology modeling of the cyclotide structures was used to analyze structure–activity relationships.     

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.     

Unusual Spirodecane Sesquiterpenes and a Fumagillol Analogue from Cordyceps ophioglossoides

Investigation of the cultured mycelia of Cordyceps ophioglossoides resulted in the isolation and characterization of three new unusual spiro[4.5]decane sesquiterpenes, cordycepol A ( 1 ), cordycepol B ( 2 ), and cordycepol C ( 3 ), and a new fumagillol analogue, cordycol ( 4 ). Their structures were established by spectroscopic means. The cytotoxic activities were also evaluated, compounds 3 and 4 showing their IC₅₀ values in the range of 12–33 μg/ml against HeLa and HepG2 (Table 3). In addition, 3 and 4 were not obviously harmful towards normal liver cell lines LO2, showing IC₅₀ values above 80 μg/ml.     

Two new diterpenoids from the endophytic fungus Trichoderma sp. Xy24 isolated from mangrove plant Xylocarpus granatum

Two new harziane diterpenoids, named(9R,10R)-dihydro-harzianone(1) and harzianelactone(2), were isolated from the endophytic fungus Trichoderma sp. Xy24 by using various column chromatography techniques. Their structures were determined on the basis of extensive spectroscopic(HR-ESI-MS, 1D NMR, 2D NMR and CD) analyses. Among them, 1 was the reductive product of harzianone and 2 was the Baeyer–Villiger monooxygenase catalyzed oxidation product of harzianone. Compound 1 exhibited cytotoxic activity against He La and MCF-7 cell lines with IC_(50) values of 30.1 μmol/L and 30.7 μmol/L,respectively.     

Three New 3,6‐Dioxygenated Diketopiperazines from the Basidiomycete Lepista sordida

Three new 3,6‐dioxygenated diketopiperazines, lepistamides A–C ( 1 – 3 ), along with a known compound, diatretol ( 4 ), were isolated from the mycelial solid cultures of the basidiomycete Lepista sordida. Their structures were elucidated by spectroscopic means. The isolated diketopiperazines were evaluated for the cytotoxic activity against Astc‐a‐1, Bel 7402, and HeLa cell lines, and their biogenetic pathway was discussed.     

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 .     

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.     

Triterpenoids from the Edible Leaves of Photinia serrulata

Five new triterpenoids, serrulatins A–E ( 1 – 5 ), including two new artifacts, together with ten known serrulatins, were isolated from the edible leaves of Photinia serrulata after extraction and purification. Their structures were identified on the basis of spectroscopic methods including 2D NMR experiments. Compounds 1 and 3 are unusual ursolic triterpenoids characterized by the occurrence of a C(13)?C(18) bond.     

Four New Pregnane Steroids from Aglaia abbreviata and Their Cytotoxic Activities

Four new pregnane steroids, aglaiasterols A–D ( 1 – 4 ), have been isolated from the EtOH extract of stems of Aglaia abbreviata. They were identified as (3α,5α,17Z)‐3‐hydroxypregn‐17‐en‐16‐one ( 1 ), (3β,5α,17E)‐3‐hydroxypregn‐17‐en‐16‐one ( 2 ), (3β,5α,17Z)‐3‐hydroxypregn‐17‐en‐16‐one ( 3 ), and (3α,5α,20S*)‐3‐hydroxy‐16‐oxopregnan‐20‐yl acetate ( 4 ) on the basis of spectroscopic methods, including 1D‐ and 2D‐NMR techniques. Compounds 1 – 4 were evaluated for their cytotoxic activities against K562 (human leukemia), MCF‐7 (human breast cancer), and KB (human oral epithelium cancer) cells, and drug‐resistant cells of K562/A02, MCF‐7/ADM, and KB/VCR. These isolates showed weak to moderate inhibitory effects on the growth of the tested cell lines.