New Sesquiterpene Formamides from the Marine Sponge Axinyssa sp.

Chemical investigation of an extract of the marine sponge Axinyssa sp., collected from the South China Sea, led to the isolation and identification of two new sesquiterpene formamides, (4R*,5R*,10R*)‐4‐formamidoeudesm‐7‐ene ( 1 ) and (4R*,5R*,7S*,10R*)‐4‐formamidoeudesman‐11‐ol ( 2 ), together with the known 4α‐formamidogorgon‐11‐ene ( 3 ). Their structures were elucidated by spectroscopic methods, including 1D‐ and 2D‐NMR spectroscopy, high‐resolution ESI‐TOF mass spectrometry, as well as X‐ray single‐crystal diffraction experiments. Possible biosynthetic pathways for 1 – 3 were also proposed. The human nasopharyngeal cancer cell line CNE‐2, human cervical cancer cell line HeLa, and human normal liver cell line L02 were used to examine the cytotoxic activities of 1 – 3 in vitro. As the results, 1 showed significant cytotoxic activity against CNE‐2, HeLa, and L02 cell lines with the IC₅₀ values of 13.8, 7.5, and 38.0 μg/ml, resp.     

Two Phaeophytin Type Analogues from Marine Sponge Dysidea sp.

A new compound named 13b (S)-hydroxy-17c-ethoxypheaophorbide a (2) together with a known compound 17c-ethoxypheaophorbide a (1) were isolated from marine sponge Dysidea spcollected in South China sea. The structures were elucidated by spectroscopic analysis as well as comparison with those reported in literatures.     

Stellatolide H,a cytotoxic peptide lactone from a deep-sea sponge Discodermia sp.

Stellatolide H (1) was isolated from a deep-sea sponge Discodermia sp. as the cytotoxic constituent. The planar structure of 1 was elucidated on the basis of the NMR spectroscopic and mass spectrometric data. The absolute configurations of the constituent amino acid residues were determined by the Marfey’s method. Stellatolide H (1) is a peptide lactone of the callipeltin class with its N-terminus blocked by 3-hydroxy-6,8-dimethyldeca-(4Z,6E)-dienoic acid (Hdda).     

A New Isomalabaricane Triterpenoid from Sponge Jaspis sp.

From the marine sponge Jaspis sp., a new isomalabaricane triterpenoid 22, 23-dihydrostellettin D (1) was isolated, and its structure was established on the basis of IR, MS and extensive 2D NMR spectroscopic analysis. It is a unique skeleton compound rarely obtained from Chinese marine organisms.     

Cytotoxic aromatic polyketides from an insect derived Streptomyces sp. NA4286

Chemical study of the insect-derived bacterium, Streptomyces sp. NA4286, led to the discovery of four new polyketides, murayaquinones B-E (1–4), together with a known compound, murayaquinone (5). The structures of new compounds (1–4) were determined by extensive analysis of their NMR and HRESIMS data. The absolute configuration of (+)-1 and (?)-1 was assigned through comparison of experimental and calculated ECD spectra. Murayaquinone D (3) exhibited potent cytotoxic activities against six human cancer cell lines with IC₅₀ values ranging from 1.03 to 9.99 μM.     

Poecillastrin E,F, and G,cytotoxic chondropsin-type macrolides from a marine sponge Poecillastra sp.

Poecillastrin E (1), F (2), and G (3) were isolated from a marine sponge Poecillastra sp. as the cytotoxic constituents. Their planar structures were determined by analyzing the MS and NMR spectra. They are closely related to the known poecillastrin C (4). The absolute configuration of the β-hydroxyaspartic acid (OHAsp) residue was determined to be D-threo by Marfey's analysis of the hydrolysate. The mode of lactone ring formation of OHAsp residue in 1–3 was determined by selective reduction of the ester linkage followed by acid hydrolysis.     

Isolation and Identification of Two New Polyhydroxylated Sterols from Soft Coral Sinularia sp.

Two new polyhydroxysteroids, 12β,16β,20-trihydroxycholesta-1,4-dien-3-one 16-acetate(1) and 24- methyl-12β,16β,20-trihydroxycholesta-1,4-dien-3-one(2) were isolated from octocoral Sinularia sp. Their structures were elucidated primarily on the basis of 1D and 2D NMR and the mass spectroscopic studies. The cytotoxicity of these compounds against three tumor cell lines was also reported.     

New Sesterterpenoids from the Marine Sponge Phyllospongia papyracea

Chemical investigation of an extract of the marine sponge Phyllospongia papyracea, collected from the South China Sea, led to the isolation and identification of three new scalarane‐type sesterterpenoids, compounds 1 – 3 . Their structures were elucidated by spectroscopic methods, including 1D‐ and 2D‐NMR as well as high‐resolution ESI‐MS experiments. (12α,16β)‐12‐Acetoxy‐16‐hydroxy‐20,24‐dimethyl‐25‐norscalar‐17‐en‐24‐one ( 1 ) was cytotoxic against the leukemia P388 cancer cell line, with an IC₅₀ value of 5 μg/ml.     

Xestospongienols A–L,Brominated Acetylenic Acids from the Chinese Marine Sponge Xestospongia testudinaria

Chemical examination of the Chinese marine sponge Xestospongia testudinaria resulted in the isolation and characterization of twelve new brominated acetylenic acids, namely xestospongienols A–L ( 1a – 1d, 2a – 2d , and 3a – 3d ), together with the known analog 4 . The structures of xestospongienols A–L were determined on the basis of 1D‐ and 2D‐NMR, IR, and MS analysis in association with the modified Mosher method. The structural patterns are characteristic of brominated unbranched C₁₆‐alkyl chains containing polyene and acetylene moieties.     

Anti-MRSA actinomycins D1-D4 from the marine sponge-associated Streptomyces sp. LHW52447

Actinomycins D₁?D₄ (1–4), four new D-type actinomycin analogues, were isolated from the fermentation broth of a strain of marine sponge-associated Streptomyces sp. LHW52447, together with actinomycin D (5). The structures of 1?4 were determined by a combination analysis of HRMS and NMR spectroscopic methods, and their absolute configurations of amino acids were determined by Marfey's analysis. Actinomycins D₁ (1) and D₂ (2) are the first two naturally occurring actinomycins with incorporation an oxazole unit into the central phenoxazinone chromophore. Both 1 and 2 showed more potent antibacterial activities against three strains of pathogenic methicillin-resistant Staphylococcus aureus (MRSA) with MIC values of 0.125–0.25?μg/mL than those of 3?5 with MIC values of 0.5–1.0?μg/mL, which suggested that the anti-MRSA activity might be enhanced by the incorporation of an additional oxazole unit. In addition, the cytotoxicity evaluation against WI-38 human diploid lung fibroblasts revealed that the incorporation of oxazole unit could decrease the cytotoxicity of actinomycins on human normal cells.     

红树植物内生真菌Penicillium sp.中一个醌类化学成分的研究

利用各种层析手段(反相ODS健合硅胶、葡聚糖凝胶LH-20柱层析等),从红树植物内生真菌Penicil-liumsp.的发酵液中分离纯化了1个醌类化合物,通过各种波谱实验(1D-NMR,2D-NMR以及ESIMS)确定其结构为:5-甲氧基-11,12,18,19-四羟基蒽醌(1)。     

Studies on the Steroids of Marine Sponge

Sterols are essential components of all eukaryotic cells and were the first group of marine sponge natural products used in the taxonomic characterization of marine sponges. Thus, in the past decade there has been an increasing interest in sterols of marine sponge, which has led to the discovery of a large number of novel compounds. The use of a variety of separation techniques has demonstrated the complexity of the sterol components of marine extracts, up to 50 sterols from one species of organism. However, the quantity of each sterol     

New Cytotoxic Metabolites from the Marine‐Derived Fungus Penicillium sp. ZLN29

One new penicillide derivative, prenpenicillide ( 1 ), and one new xanthone derivative, prenxanthone ( 2 ), were isolated from the culture extract of the marine‐derived fungus Penicillium sp. ZLN29, together with six known polyketide compounds, 3 – 8 . Their structures were elucidated on the basis of spectroscopic and spectrometric analyses. The cytotoxicities of these eight compounds were evaluated on four tumor‐cell lines by SRB (=sulforhodamine B) or MTT (=3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide) methods. Compounds 1 and 3 exhibited weak cytotoxicities against HepG2 cell line with IC₅₀ values of 9.9 and 9.7 μM , respectively.     

海绵Ircinia selaginea中一种罕见的长共轭二萜烯酮

海绵的代谢产物中含有多种多样结构新异的生理活性物质[1～ 4 ] ,从中发现了不少抗肿瘤、抗病毒的活性物质 .我们在系统地研究海绵次生代谢产物的生理活性物质中 ,从海绵 Ircinia selagineaL amarck(Dictyoceratida目 ,Thorectidae科 )中分离出一种结构罕见的长共轭二萜烯酮 (1 ) . 1是新化合物 ,命名为 irciniketene,采用波谱方法测定了其化学结构 (Scheme 1 ) .生物活性试验表明 ,化合物 1对肿瘤细胞具有较强的抑制作用 .1 21 31 4 1 5 011 11 92 01 89871 7654 31 6C2 C1 OScheme1　Structure of irciniketene( 1 )1　实验部分1 .1　…     

Novel Chromone Derivatives from Marine Fungus Aspergillus versicolor Isolated from the Sponge Xestospongia exigua

In the continuation of our research for the bioactive secondary metabolites from the sponge-associated fungi, the bioassay guiding fractionation led to the isolation of six new secondary metabolites with unusual skeleton based on chromone ring system from the inoculated fungus Aspergillus versicolor, that had been isolated from fresh samples of marine sponge Xestospongia exigua, collected along coast line of Bali, Indonesia in 1997. The basic skeleton of those compounds possessed an oxohexacy…     

Two new diterpene alkaloids from the South China Sea Sponge Agelas aff. Nemoechinata

Two new N-methyladenine-containing diterpenes,nemoechines F(l)and G(2),were isolated from the South China Sea sponge Agelas aff.nemoechinata.The structures were assigned on the basis of spectroscopic date.Compound 2 showed weak activity against Jurkat cell lines with IC_(50) of 17.1 μmol/L     

New borrelidin derivatives from an endophytic Streptomyces sp.

Three new borrelidin-type macrolactones, designated as borrelidins J?L (4–6), together with borrelidin A (1), borrelidin E (2), and 12-desnitrile-12-carboxyl-borrelidin (3) were isolated from a plant endophytic Streptomyces sp. NA06554. Their structures were determined by extensive spectroscopic analysis including HRESIMS, 1D and 2D NMR data. The antibacterial activities for compounds 1–6 were examined. Borrelidins A (1) and L (6) showed potent and moderate antibacterial activity against Micrococcus luteus, respectively, whereas other derivatives (2–5) are almost inactive, which allows us to propose a plausible structure-activity relationship.     

Isolation and identification of two new compounds from the Penicillium sp. SYPF7381

Abstract

Two new compounds, (7R, 2E, 5E)-3,5,7-trimethyl-2,5-octadienedioic-8-methyl ester (1) and neovasipyridone G (3), together with a new natural product compound (7R,2E,5E)-3,5,7-trimethyl-2,5-octadienedioic acid (2), and six known compounds (4–9) were isolated from Penicillium sp. SYPF7381. Their structures were elucidated on the basis of extensive spectroscopic analysis, and the absolute configurations of compounds 1 and 2 were determined by optical rotation. The absolute configuration of compound 3 was determined by means of electronic circular dichroism (ECD) calculation. In addition, the in vitro anti-inflammatory activities of all compounds were assayed in RAW 264.7 cells by assessing LPS-induced NO production. Furthermore, the structure-antiinflammation activity relationships for these isolated compounds were summarized based on the experimental as well as the docking results.     

New Sesquiterpenes from a Taiwanese Marine Sponge of the Genus Parahigginsia

An undescribed Taiwanese marine sponge of the genus Parahigginsia yielded two new sesquiterpene hydrocarbons-parahigginine ( 1 ) and parahigginone ( 2 ). The structures of the new compounds were established on the basis of NMR spectroscopic and mass spectrometric data. Compounds 1 and 2 exhibited moderate cytotoxicity against murine P-388 and human KB-16, A-549, and HT-29 tumor cells.     

New bromopyrrole alkaloids from the marine sponge Agelas sp.

Chemical investigation of the marine sponge Agelas sp. collected from the South China Sea resulted in the isolation of four new dimeric bromopyrrole alkaloids, including hexazosceptrin (1) with a rare cyclohexane-fused-cyclobutane skeleton, agelestes A and B (2–3), the sceptrin analogues without any aminoimidazole substitution, and (9S, 10R, 9′S, 10′R)-nakamuric acid (4), of which the absolute configuration was confirmed for the first time. The structure elucidation and absolute configuration assignments were unambiguously determined via extensive spectroscopic analyses and the comparison of experimental and calculated electronic circular dichroic spectra. Compounds 1 and 4 exhibited moderate antimicrobial activity.