Bisabolane type sesquiterpenes from a marine Didiscus sponge

Two bisabolane type sesquiterpene phenols, (+)-curcuphenol (1) and (+)-curcudiol (2), were isolated from a Philippine marine sponge, Didiscus sp., in addition to b -sitosterol (3) and phenethylamine (4). The structures of the metabolites were established on the basis of spectral evidence (1D- and 2D NMR, [a]D, EIMS). (+)-Curcuphenol (1) showed cytotoxicity, which is indicative of a p53 independent mechanism

Cytotoxic bromoindole derivatives and terpenes from the Philippine marine sponge Smenospongia sp.

A detailed chemical analysis of a Philippine marine sponge Smenospongia sp. has been performed. This study yielded four new metabolites, 5-bromo-l-tryptophan (1), 5-bromoabrine (2), 5,6-dibromoabrine (3) and 5-bromoindole-3-acetic acid (4). The pyrroloiminoquinone alkaloid, makaluvamine O (5) as well as 5,6-dibromotryptamine (6), aureol (7) and furospinulosin 1 (8) were also isolated. Although 1 and 4 have been synthesized previously, this is the first report on the isolation of these compounds from a natural source. The furanosesterterpene furospinulosin 1 (8) was obtained for the first time from the genus Smenospongia. The structures of all compounds were established by spectroscopic methods (UV, IR, 1D and 2D NMR, MS, [α]D). The cytotoxic potential of 1Ð8 was evaluated in a panel of isogenic HCT-116 human colon tumor cell lines

Evaluation of Pyridoacridine Alkaloids in a Zebrafish Phenotypic Assay

Three new minor components, the pyridoacridine alkaloids 1-hydroxy-deoxyamphimedine (1), 3-hydroxy-deoxyamphimedine (2), debromopetrosamine (3), and three known compounds, amphimedine (4), neoamphimedine (5) and deoxyamphimedine (6), have been isolated from the sponge Xestospongia cf. carbonaria, collected in Palau. Structures were assigned on the basis of extensive 1D and 2D NMR studies as well as analysis by HRESIMS. Compounds 1–6 were evaluated in a zebrafish phenotype-based assay. Amphimedine (4) was the only compound that caused a phenotype in zebrafish embryos at 30 μM. No phenotype other than death was observed for compounds 1–3, 5, 6

Ribosomally synthesized and post-translationally modified peptide natural products: overview and recommendations for a universal nomenclature

This review presents recommended nomenclature for the biosynthesis of ribosomally synthesized and post-translationally modified peptides (RiPPs), a rapidly growing class of natural products. The current knowledge regarding the biosynthesis of the \u3e20 distinct compound classes is also reviewed, and commonalities are discussed

Microtermolides A and B from Termite-Associated Streptomyces sp. and Structural Revision of Vinylamycin

Microtermolides A (1) and B (2) were isolated from a Streptomyces sp. strain associated with fungus-growing termites. The structures of 1 and 2 were determined by 1D- and 2D-NMR spectroscopy and high-resolution mass spectrometry. Structural elucidation of 1 led to the re-examination of the structure originally proposed for vinylamycin (3). Based on a comparison of predicted and experimental $^1$H and $^{13}$C NMR chemical shifts, we propose that vinylamycin’s structure be revised from 3 to 4

An agonist sensitive, quick and simple cell-based signaling assay for determination of ligands mimicking prostaglandin E2 or E1 activity through subtype EP1 receptor: Suitable for high throughput screening

<p>Abstract</p> <p>Background</p> <p>Conventionally the active ingredients in herbal extracts are separated into individual components, by fractionation, desalting, and followed by high-performance liquid chromatography (HPLC). In this study we have tried to directly screen water-soluble fractions of herbs with potential active ingredients before purification or extraction. We propose that the herbal extracts mimicking prostaglandin E₁(PGE₁) and E₂(PGE₂) can be identified in the water-soluble non-purified fraction. PGE₁is a potent anti-inflammatory molecule used for treating peripheral vascular diseases while PGE₂is an inflammatory molecule.</p> <p>Methods</p> <p>We used cell-based assays (CytoFluor multi-well plate reader and fluorescence microscopy) in which a calcium signal was generated by the recombinant EP₁receptor stably expressed in HEK293 cells (human embryonic kidney). PGE₁and PGE₂were tested for their ability to generate a calcium signal. Ninety-six water soluble fractions of Treasures of the east (single Chinese herb dietary supplements) were screened.</p> <p>Results</p> <p>After screening, the top ten stimulators were identified. The identified herbs were then desalted and the calcium fluorescent signal reconfirmed using fluorescence microscopy. Among these top ten agonists identified, seven stimulated the calcium signaling (1-40 μM concentration) using fluorescence microscopy.</p> <p>Conclusions</p> <p>Fluorescence microscopy and multi-well plate readers can be used as a target specific method for screening water soluble fractions with active ingredients at a very early stage, before purification. Our future work consists of purifying and separating the active ingredients and repeating fluorescence microscopy. Under ordinary circumstances we would have to purify the compounds first and then test all the extracts from 96 herbs. Conventionally, for screening natural product libraries, the procedure followed is the automated separation of all constituents into individual components using fractionation and high performance liquid chromatography. We, however, demonstrated that the active ingredients of the herbal extracts can be tested before purification using an agonist sensitive, quick and simple cell-based signaling assay for ligands mimicking the agonists, PGE₁and PGE₂.</p