New Ophiobolins from the Deep-Sea Derived Fungus Aspergillus sp. WHU0154 and Their Anti-Inflammatory Effects.

Deep-sea fungi have become a new arsenal for the discovery of leading compounds. Here five new ophiobolins 1-5, together with six known analogues 6-11, obtained from a deep-sea derived fungus WHU0154. Their structures were determined by analyses of IR, HR-ESI-MS, and NMR spectra, along with experimental and calculated electronic circular dichroism (ECD) analysis. Pharmacological studies showed that compounds 4 and 6 exhibited obvious inhibitory effects on nitric oxide (NO) production induced by lipopolysaccharide (LPS) in murine macrophage RAW264.7 cells. Mechanical study revealed that compound 6 could inhibit the inducible nitric oxide synthase (iNOS) level in LPS-stimulated RAW264.7 cells. In addition, compounds 6, 9, and 10 could significantly inhibit the expression of cyclooxygenase 2 (COX 2) in LPS-induced RAW264.7 cells. Preliminary structure-activity relationship (SAR) analyses revealed that the aldehyde group at C-21 and the α, ß-unsaturated ketone functionality at A ring in ophiobolins were vital for their anti-inflammatory effects. Together, the results demonstrated that ophiobolins, especially for compound 6, exhibited strong anti-inflammatory effects and shed light on the discovery of ophiobolins as new anti-inflammatory agents.

Glaucumolides A and B, Biscembranoids with New Structural Type from a Cultured Soft Coral Sarcophyton glaucum.

Glaucumolides A (1) and B (2), novel biscembranes composed of an unprecedented α,ß-unsaturated ε-lactone, along with the known metabolites ximaolide A (3) and isosarcophytonolide D (4), were isolated from the cultured soft coral Sarcophyton glaucum. The structures of the new metabolites were determined by extensive spectroscopic analyses. Compounds 1 and 2 were shown to exhibit cytotoxicity against a limited panel of cancer cell lines. In anti-inflammation assay, compounds 1 and 2 displayed strong inhibition of superoxide anion generation and elastase release in human neutrophils stimulated by fMLP/CB. Furthermore, both 1 and 2 were shown to significantly inhibit the accumulation of the pro-inflammatory inducible nitric oxide synthase protein, and compounds 1-3 were found to effectively reduce the expression of cyclooxygenase-2 protein, in lipopolysaccharide-stimulated RAW264.7 macrophage cells.

Eunicellin-Based Diterpenoids, Hirsutalins S-V, from the Formosan Soft Coral Cladiella hirsuta.

Four new eunicellin-type hirsutalins S-V (1-4), along with a known compound (-)-6α-hydroxy polyanthellin A (5), were isolated from the soft coral Cladiella hirsuta. The structures of the metabolites were determined by extensive spectroscopic analysis. Cytotoxity of compounds 1-5 against the proliferation of a limited panel of cancer cell lines was measured. Anti-inflammatory activity of compounds 1-5 was evaluated by measuring their ability in suppressing superoxide anion generation and elastase release in fMLP/ CB-induced human neutrophils.

A new DNA-intercalative cytotoxic allylic xanthone from Swertia corymbosa.

Phytochemical investigation of the CHCl3 fraction of Swertia corymbosa resulted in the isolation of a new 3-allyl-2,8-dihydroxy-1,6-dimethoxy-9H-xanthen-9-one (1), along with four known xanthones, gentiacaulein (3), norswertianin (4), 1,3,6,8-tetrahydroxyxanthone (5), and 1,3-dihydroxyxanthone (6). Structure of compound 1 was elucidated with the aid of IR, UV, NMR, and MS data, and chemical transformation via new allyloxy xanthone derivative (2). Compounds 1-6 exhibited various levels of antioxidant and anti-α-glucosidase activities. Absorption and fluorescence spectroscopic studies on 1-6 indicated that these compounds could interact with calf thymus DNA (CT-DNA) through intercalation and with bovine serum albumin (BSA) in a static quenching process. Compound 1 was found to be significantly cytotoxic against human cancer cell lines HeLa, HCT116, and AGS, and weakly active against normal NIH 3T3 cell line.

Natural occurrence of organofluorine and other constituents from Streptomyces sp. TC1.

Antioxidant-directed fractionation of an ethyl acetate extract of Streptomyces sp. TC1 resulted in the isolation of a novel secondary metabolite with an aromatic organofluorine scaffold (1), an atypical tripod-type triallyl phenol (2), and a leucine residue comprised polyamine (3). Their structures were established by comprehensive spectroscopic analysis of 1D and 2D NMR data, and compound 1 was confirmed by (19)F NMR and single-crystal X-ray diffraction studies. The absolute configuration of compound 3 was assigned by comparison of its ECD spectra and quantum chemical ECD calculations. Of these, compound 1 displayed antioxidant and DNA and protein binding properties.

Axially chiral biscarbazoles and biological evaluation of the constituents from Murraya koenigii.

Chemical investigation of the fruit pulp of Murraya koenigii resulted in the identification of two new dimeric carbazole alkaloids, bisgerayafoline D (1) and bismahanimbinol (2) along with four known alkaloids, bispyrayafoline (3), O-methyl mahanine (4), O-methyl mukonal (5), and mahanine (6). Structures of 1-6 were determined with the aid of UV, IR, Mass and extensive NMR spectroscopic studies. Absolute configurations of biaryls in 1 and 2 were assigned using a combination of computational Circular Dichroism (CD) and experimental electronic CD spectroscopic data. Compounds 1-6 were evaluated for anti-oxidant, anti-α-glucosidase, DNA binding, protein interactions and cytotoxic activities. Among all the isolates, mahanine (6) was found to exhibit significant radical scavenging and α-glucosidase inhibitory activities. Compound 6 was also found to be active in cytotoxicity assay against three human cancer cell lines HeLa, HCT116, AGS and this compound was weakly active against normal mouse embryonic fibroblasts (NIH3T3).

A regioselective multicomponent protocol for the synthesis of novel bioactive 4-hydroxyquinolin-2(1H)-one grafted monospiropyrrolidine and thiapyrrolizidine hybrids.

An expedient route toward the synthesis of 4-hydroxyquinolone grafted spiropyrrolidines or pyrrolizidines has been accomplished through 1,3-dipolar cycloaddition reaction of various azomethine ylides derived from isatin or acenaphthalene and sarcosine with 4-hydroxyquinolone derivatives as dipolarophile. The regio and stereo chemical outcome of the cycloaddition reaction is ascertained by X-ray crystallographic studies and spectroscopic techniques of the cycloadducts. Furthermore, cytotoxicity evaluation of selected compounds showed significant inhibition of cell proliferation against cervical as well as colon cancer cell lines.

Bioactive dimeric carbazole alkaloids from Murraya koenigii.

Phytochemical studies on the CHCl3 extract of the fruit pulp of Murraya koenigii afforded three new dimeric carbazole alkaloids, bisgerayafolines A-C (1-3). Bisgerayafolines A-C (1-3) are structurally unique dimeric carbazole alkaloids comprising geranyl moieties incorporated in their structures. Compounds 1-3 exhibited various levels of antioxidant, anti-α-glucosidase, DNA binding, and cytotoxic activities and protein interactions.