13-Epi-9-deacetoxyxenicin,a Cytotoxic Diterpene from the Soft Coral Asterospicularia laurae (Alcyonacea)

An investigation of the soft coral Asterospicularia laurae collected on the Great Barrier Reef, Australia, afforded the cytotoxic diterpene 13-epi-9-deacetoxyxenicin (1) in addition to the known metabolites 13-epi-9-deacetylxenicin (2) and gorgosterol. 13-Epi-9-deacetoxyxenicin readily underwent an autoxidation reaction in solution to afford a single product, the hydroperoxide 3. Structures, stereochemistry, and NMR assignments were established by high resolution NMR spectroscopy and by comparison with published data for known compounds.     

籼稻矮化多分蘖突变体gsor23的基因克隆与表达分析

 矮化多分蘖突变体gsor23是籼稻品种Indica9经γ射线辐射后获得的。遗传分析表明其矮化多分蘖表型受一个隐性基因控制,并将突变基因定位在第1染色体长臂上InDel标记C1 WT2与C1 WT4之间。这两个标记之间物理距离为386 kb,其间包含一个抑制植物分枝的基因D10。对gsor23中的D10基因测序发现编码区第404位的碱基C缺失,导致从第135位氨基酸开始移码突变。gsor23的突变位点与已报道的粳稻背景的d10 1和d10 2突变体不一样,是D10基因一个新的等位突变体。D10编码的类胡萝卜素裂解双加氧酶8 (carotenoid cleaving dioxygenase, CCD8),是抑制分枝的新型植物激素独脚金内酯(strigolactones, SLs)合成途径中的关键酶之一。用SLs人工合成类似物GR24处理gsor23,其多分蘖表型受到抑制。实时 RT PCR结果显示D10在水稻根部表达量较高,叶片较低。在突变体gsor23中,参与 SLs合成的基因D10上调表达,而可能参与SLs信号转导的基因D3和D14表达下调。     

A New Spatane Diterpenoid from the Cultured Soft Coral Sinularia leptoclados

A new spatane diterpenoid, leptoclalin A (1), along with two previously reported known norcembranoid diterpenes (2 and 3), were isolated from a cultured soft coral Sinularia leptoclados. The structures were determined by extensive spectroscopic analyses and by comparison with the spectral data of related known compounds. Metabolite 1 is rarely found in spatane skeletons reported from soft corals. In addition, compound 1 exhibited weak cytotoxicity towards human tumor cell lines T-47 D and K-562.     

Polyhydroxylated Steroids from the South China Sea Soft Coral Sarcophyton sp. and Their Cytotoxic and Antiviral Activities

Chemical investigation on the soft coral Sarcophyton sp. collected from the South China Sea yielded three new polyhydroxylated steroids, compounds (1–3), together with seven known ones (4–10). Their structures were established by extensive spectroscopic methods and comparison of their data with those of the related known compounds. All the isolates possessed the 3β,5α,6β-trihydroxylated steroidal nucleus. The cytotoxicities against selected HL-60, HeLa and K562 tumor cell lines and anti-H1N1 (Influenza A virus (IAV)) activities for the isolates were evaluated. Compounds 2, 3 and 5–8 exhibited potent activities against K562 cell lines with IC₅₀ values ranging from 6.4 to 10.3 μM. Compounds 1, 6–8 potently inhibited the growth of HL-60 tumor cell lines, and 6 also showed cytotoxicity towards HeLa cell lines. In addition, preliminary structure-activity relationships for the isolates are discussed. The OAc group at C-11 is proposed to be an important pharmacophore for their cytotoxicities in the 3β,5α,6β-triol steroids. Compounds 4 and 9 exhibited significant anti-H1N1 IAV activity with IC₅₀ values of 19.6 and 36.7 μg/mL, respectively.     

Sarcophyolides B–E,New Cembranoids from the Soft Coral Sarcophyton elegans

Four new cembrane-type diterpenoids, sarcophyolides B–E (1–4), along with 11 known analogues were isolated from the soft coral Sarcophyton elegans. The structures of new compounds 1–4 were established on the basis of spectroscopic analysis and chemical conversion. The new cembranoids sarcophyolides B (1) and lobocrasol were found to exhibit potent inhibition against A2780 human ovarian tumor cells.     

Cytotoxic Polyketide Metabolites from a Marine Mesophotic Zone Chalinidae Sponge-Associated Fungus Pleosporales sp. NBUF144

Two new polyketide natural products, globosuxanthone F (1), and 2′-hydroxy bisdechlorogeodin (2), were isolated from the fungus Pleosporales sp. NBUF144, which was derived from a 62 m deep Chalinidae family sponge together with four known metabolites, 3,4-dihydroglobosuxanthone A (3), 8-hydroxy-3-methylxanthone-1-carboxylate (4), crosphaeropsone C (5), and 4-megastigmen-3,9-dione (6). The structures of these compounds were elucidated on the basis of extensive spectroscopic analysis, including 1D and 2D NMR and high-resolution electrospray ionization mass spectra (HRESIMS) data. The absolute configuration of 1 was further established by single-crystal X-ray diffraction studies. Compounds 1–5 were evaluated for cytotoxicity towards CCRF-CEM human acute lymphatic leukemia cells, and it was found that 1 had an IC₅₀ value of 0.46 µM.     

Sea cucumbers in the Seychelles: effects of marine protected areas on high‐value species

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Snake bite: coral snakes

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不同经营模式下新银合欢的枝系特征差异分析

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