Salicylaldehyde and dihydroisobenzofuran derivatives from the marine fungus Zopfiella marina

Two salicylaldehyde derivatives (1 and 2), a hydroxymethylphenol (3), five dihydroisobenzofuran (4–8) derivatives, and a 5-chloro-3-deoxyisoochracinic acid (9), together with a known 3-deoxyisoochracinic acid (10) were isolated from the marine fungus Zopfiella marina BCC 18240 (or NBRC 30420). The structures of these compounds were elucidated by extensive spectroscopic analysis. Compound 1 showed weak antituberculous activity against Mycobacterium tuberculosis H37Ra, and antibacterial activity against Bacillus cereus with MIC values of 25 and 12.5 μg/mL, respectively.     

Antioxidative sulphated polygalactans from marine macroalgae as angiotensin-I converting enzyme inhibitors

Antioxidant and antihypertensive potential of the sulphated polygalactans isolated from the marine macroalgae Kappaphycus alvarezii and Gracilaria opuntia were assessed by utilising different in vitro systems. The galactans isolated from K. alvarezii possessed significantly greater antioxidative properties as determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH IC₉₀ 0.97 mg/mL) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS^.+ IC₉₀ 0.72 mg/mL) scavenging activities than those isolated from G. opuntia (DPPH IC₉₀ 1.2 mg/mL and ABTS 0.86 mg/mL). The sulphated polygalactan →4)-4-O-sulphonato-(2-O-methyl)-β-D-galactopyranosyl-(1→4)-3,6-anhydro-(2-O-methyl)-α-D-galactopyranan from K. alvarezii showed greater angiotensin-I-converting enzyme (ACE) inhibitory activity (IC₅₀ 0.02 μg/mL) than →3)-4-O-sulphonato-(6-O-acetyl)-β-D-galactopyranosyl-(1→4)-3,6-anhydro-(2-O-sulphonato)-α-D-galactopyranosyl-(1→3)-4-O-sulphonato-(6-O-acetyl)-β-D-xylosyl-(1→3)-4-O-sulphonato-(6-O-acetyl)-β-D-galactopyranosyl-(1→4)-3,6-anhydro-(2-O-sulphonato)-α-D-galactopyranan motif extracted from G. opuntia (IC₅₀ 0.70 μg/mL). Structure activity correlation studies displayed that the ACE inhibitory properties of titled polygalactans were directly proportional to their electronic properties and inversely with the steric and hydrophobic characteristics. Putative ACE inhibitory mechanism of action of sulphated galactans from marine macroalgae corroborated the structure bioactivity correlation analysis.     

Metabolites from the marine fungus <Emphasis Type="Italic">Eurotium repens</Emphasis>

1,8-Dihydroxy-6-methoxy-3-methyl-9,10-anthracenedione (physcion, 1), 3,4-dihydro-3,6,9-trihydroxy-8-methoxy-3-methyl-1(2H)-anthraceneone (asperflavin, 2), and 2,5-dihydroxy-3-(3-methyl-2-butenyl)-6-[(1E)-1-heptenyl]-benzaldehyde (tetrahydroauroglaucin, 3) were shown to be the main pigments of the marine isolate of the fungus Eurotium repens. In addition to the pigments, the fungal metabolites included the diketopiperazine alkaloid echinulin (4). The structures of the compounds were identified using NMR spectroscopy and mass spectrometry. The cytotoxic activity of 1–3 toward sex cells of the sea urchin Strongylocentrotus intermedius was determined. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 327–329, July–August, 2007.     

Accreditation of GMO detection laboratories: Improving the reliability of GMO detection

Reliable and efficient methods for detecting genetically modified organisms (GMOs) are essential for establishing an effective system for traceability all along the supply chain from seed producers to final consumers. The latter is especially meaningful in European Union and other countries where strict legislations on GMOs were set up. Performance of the methods used in laboratories around the world should be uniform, in order to obtain reliable and comparable results. Accreditation is a suitable system for harmonising procedures in each testing laboratory. In this paper, key elements for the accreditation of molecular biology methods for GMO detection according to ISO/IEC 17025 are described. The procedures described are also valuable for the accreditation of molecular methods for all laboratory diagnostics where qualitative and quantitative characterisation of nucleic acids is needed.     

New cerebrosides from the marine sponge Oceanapia sp.

New cerebrosides containing N-acetylglucosamine were isolated from the marine sponge Oceanapia sp. Some of them contain n-and iso-C₁₈-and iso-C₁₉-phytosphingosines N-acylated by n-C_16:0, n-C_17:0, and n-C_18:0 fatty acids, some other are derivatives of iso-and anteiso-C₁₇-,-C₁₈-, and-C₁₉-phytosphingosines N-acylated by long-chain (C₂₄-C²⁸) α-hydroxy acids. The structures of these compounds were determined by NMR spectroscopy, MALDI-TOF mass spectrometry, and by chemical transformations. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 895–899, May, 2006.     

蕨藻红素（Caulerpin）的结构分析

蕨藻红素分子的化学计量式为Ｃ_（２４）Ｈ_（１８）Ｎ_２Ｏ_４，用Ｘ－ｒａｙ法确定其晶体结构。该结晶呈紫红色，属单斜晶系，空间群为Ｃｃ。晶胞参数：ａ＝１９．６１２（４），ｂ＝４．７６３（１），ｃ＝２０．４３４（５）Ａ，β＝８１．８３（２）°，Ｚ＝４，Ｖ＝１８８９．４（７）Ａ~３，Ｄ_ｃ＝１．４１５ｇ·ｃｍ~（－３），Ｆ（０００）＝８３２。应用直接法解析分子结构。以最小二乘法修正结构参数。最终可靠因子Ｒ＝０．０５４，Ｒ_ω＝０．０６３。结果表明蕨藻红素分子是具有非晶体学Ｃ_２对称性的吲哚生物碱。     

海洋生物毒素

本文对河豚毒素、石房蛤毒素和沙群海葵毒素作了简要的综述。     

Liquid chromatographic assay for the cyclic depsipeptide aplidine, a new marine antitumor drug, in whole blood using derivatization with trans-4'-hydrazino-2-stilbazole

A sensitive bio-analytical assay for the depsipeptide aplidine in plasma has been modified and tested for human whole blood samples. The adapted method is based on reversed-phase liquid chromatography and fluorescence detection of the trans-4'-hydrazino-2-stilbazole derivative of the analyte. Aplidine is isolated from the matrix by solid-phase extraction on an octadecyl modified silica stationary phase. After evaporation of the acetone eluate, the derivatization with the hydrazino reagent is performed in a water-acetonitrile mixture at pH = 4. The reaction mixture is injected directly into the chromatograph and the analyte is quantified by fluorescence detection at 410 and 560 nm for excitation and emission, respectively. The method has been validated in the 2-100 ng/mL range, with 2 ng/mL being the lower limit of quantification. Precision and accuracy both meet the current requirements for a bioanalytical assay. The stability of aplidine in whole blood at ambient temperature and at 37 degrees C is limited; recoveries in the range 60-85% were observed after 7 h. Further, adequate stability of aplidine in plasma at -80 and -20 degrees C for 35 months could now be demonstrated.     

催化褪色光度法测定海洋生物中痕量硒

在pH =3的HCl KHC8H4O4缓冲介质中 ,硒 能催化溴酸钾氧化甲基紫的褪色反应 ,据此建立了催化动力学光度测定痕量硒的新方法。优化了动力学反应条件 ,并对海洋生物样品测定的前处理过程进行了研究。该方法对硒的检出限为 0 .14μg L ,线性范围为 0～ 8μg L ,精密度和准确度良好 ,对牡蛎等海洋生物样品中总硒含量测定的RSD <10 %,回收率为 96 %～ 10 7%,与DAN荧光光度法测定结果的相对偏差 <± 6 %。     

南海短足软珊瑚Cladiella sp.的化学成分

神经酰胺;烷醇孕甾酮;南海短足软珊瑚Cladiella sp.的化学成分