Ascidians (tunicates) are widely recognized as one of the most prolific producers of bioactivenatural products in the marine environment. This present study reviewed the chemical diversityof marine ascidians from the Aplidium genus and their pharmacological applications since Jan 2005.The resources of this genus from China Seas, including the changes of their names in the family Polydinidaewere also summarized in this paper. In addition, a concise outlook on their chemical andpharmaceutical investigation is made to support further development.

南极因其独特的自然环境成为潜在、重要的微生物资源库,是产生新型生物活性物质和先导化合物菌株的潜在种源地,南极微生物正在成为创新药物研究新的重要资源.虽然近年来对南极微生物次级代谢产物的研究逐渐增加,但与温带和热带微生物研究相比仍处于初级阶段.对从南极普里兹湾海洋沉积物中获得的两株枝孢霉属真菌Cladosporium sp.NJF4和NJF6进行次级代谢产物分离及结构鉴定,获得20个化合物.化合物结构类型包括甾醇(1)、倍半萜类(7—8)、生物碱类(9—14)、二酮哌嗪(2—5、15—17)、芳香酸(6、18—19)等,其中倍半萜类(7—8)为首次从枝孢霉属真菌中分离得到,以上研究将为丰富南极微生物次级代谢产物库奠定一定的研究基础.

为进一步研究我国南海真菌活性次级代谢产物,对从中国南海表层海水中获得的2株真菌Aspergillus aculeatus 1-P1和Paraconiothyrium cyclothyrioides 1-I2进行鉴定和分析,通过ITS序列分析并构建系统发育树来鉴定菌株,综合运用硅胶柱层析、Sephadex LH-20凝胶柱层析及半制备高效液相等色谱学方法对其发酵产物进行分离纯化,获得17个化合物,化合物结构类型包括三萜(1～2)、甾醇(3～4,12)、二酮哌嗪(5～7)、甘油酯(14～17)等.研究结果有助于为我国南海丰富的海洋微生物资源及其次级代谢产物结构多样性研究提供参考.此外,对发现其中可能含有的结构新颖的化学物质以开发抗菌、抗病毒及抗肿瘤新药等也具有十分重要的理论意义和潜在的应用价值.

通过对2017年第34次“雪龙号”南极考察采集的南极大磷虾(Euphausia superba)共复生微生物进行分离,并对有价值菌株的次级代谢产物进行了研究.采用在3种选择性培养基中添加不同抗生素的稀释平板涂布法,从南极大磷虾中分离出一株有价值的真菌进行扩大培养,运用TLC、柱色谱(正相硅胶、C18硅胶、MCI、Sephadex LH-20凝胶)和半制备型HPLC等色谱方法对其代谢产物进行高效快速地分离纯化,结合现代波谱学手段(ESI HR MS、1H-NMR),鉴定次级代谢产物结构.首先经过形态学、18S rDNA-ITS序列分析,鉴定分离到一株真菌为曲霉Aspergillus sp.NJF7;从曲霉NJF7中分离到13个代谢产物,分别鉴定为环(脯氨酸-酪氨酸)(1)、环(色氨酸-酪氨酸)(2)、环(脯氨酸-苯丙氨酸)(3)、环(缬氨酸-脯氨酸)(4)、环(缬氨酸-色氨酸)(5)、环(异亮氨酸-色氨酸)(6)、环(谷氨酰胺-色氨酸)(7)、对羟基肉桂酸甲酯(8)、尿嘧啶(9)、对羟基苯乙胺(10)、苯乙胺(11)、N-甲基酪胺(12)、大麦芽碱(13),其中化合物7为新的天然产物.

The marine phytoplankton Prorocentrum lima is one of the toxic and harmful microalgae which can cause red tides. In chemical investigation on cultured strain P. lima PL11, seven compounds were isolated and identified by spectroscopic data, including three typical shellfish toxins okadaic acid (OA, 1), OA methyl ester (2), and prorocentrolide (3), three terpenoids (4–6), and one polyketide (7). Compounds 5 and 6 should be derived from carotenoid fucoxanthin. Compounds 4–7 were isolated from this genus of microalgae for the first time.

为揭示产腹泻性贝类毒素(diarrheic shellfish poisoning,DSP)典型赤潮甲藻-利玛原甲藻(Prorocentrum lima)PL11的共附生菌群多样性信息,通过Illumina MiSeq高通量测序分析了PL11的共附生菌群种类及相对丰度,并且对其可培养共附生菌株进行了选择性分离及其16S rRNA基因序列扩增与系统发育的分析.利玛原甲藻PL11高通量测序结果显示:样品共附生细菌包括5门,14纲,26目,38科及54属.其中优势门(>5％)为3个,包括变形菌门(Proteobacteria,75.5％)、拟杆菌门(Bacteriodetes,11.5％)以及浮霉菌门(Planctomycetex,8.5％);优势纲(>5％)为4个,包括α-变形菌纲(Alphaproteobacteria,51.7％)、δ-变形菌纲(Deltaproteobacteria,31.8％)、鞘脂杆菌纲(Sphingobacteria,9.9％)以及OM190纲(8.9％);优势属(>5％)为6个,侏囊菌科下未知属(norank Nannocystaceae,21.8％)、Pyruvatibacte属(11.6％)、Phaeodactylibacter属(9.4％)、生丝单胞菌科下未知属(norank Hyphomonadaceae,8.5％)、OM190纲下未知属(8.1％)以及Roseovarius属(7.9％).从利玛原甲藻PL11培养物中分离获得可培养微生物菌株9株,分属于8个属,包括Ochrobactrum sp.(2株)及Microbacterium sp.、Algoriphagus sp.、Ponticoccus sp.、Hoeflea sp.、Labrenzia sp.、Sphingopyxis sp.、Erythrobacter sp.各1株.其中PL11-1为Ponticoccus属潜在新种.

Aristoyunnolins G (1) and H (2), two new diastereoisomeric sesquiterpenes featuring a rare aristophyllene skeleton, were isolated from the traditional Chinese medicine Aristolochia yunnanensis. Their absolute stereochemistry involving three chiral centers was determined by combined chemical, spectral, and Density Functional Theory (DFT) calculation methods.

大量结构新颖的活性代谢产物来源于物种多样性丰富的海绵类海洋生物资源.本文首次对柑桔荔枝海绵(Tethya aurantium)进行化学成分研究,利用半制备高效液相色谱(HPLC)、正相硅胶柱、反相硅胶柱及凝胶LH-20柱等多种色谱手段从柑桔荔枝海绵中分离得到8个化合物,经波谱数据分析鉴定为环(脯氨酸-亮氨酸)(1)、环(苯丙氨酸-脯氨酸)(2)、环(脯氨酸-酪氨酸)(3)、3-吲哚乙醛酸(4)、胸苷(5)、钓樟奠(6)、反式4-甲基肉桂酸(7)、对羟基苯甲酸(8).所得化合物均测试对革兰氏阳性菌株金黄色葡萄球菌(Staphylococcus aureus ATCC 25923)、革兰氏阴性菌株大肠杆菌(Escherichia coli ATCC 25922)以及真菌菌株白色念珠菌(Candida albicans ATCC 60193)的抑菌活性,测试结果表明无明显的抑菌活性.

Ten new prostaglandin derivatives (PGs), sarcoehrendins A-J (1-10), together with five known analogues (11-15) were isolated from the soft coral Sarcophyton ehrenbergi. Compounds 4-8 represented the first examples of PGs featuring an 18-ketone group. The structures including the absolute configurations were elucidated on the basis of spectroscopic analysis and chemical evidence. All of the isolates and six synthetic analogues (3a, 3b, 4a, and 11a-11c) were screened for inhibitory activity against phosphodiesterase-4 (PDE4), which is a drug target for the treatment of asthma and chronic obstructive pulmonary disease. Compounds 2, 10, 11a, 11b, and 13-15 exhibited inhibition with IC50 values less than 10 mu M, and compound 15 (IC50 = 1.4 mu M) showed comparable activity to the positive control rolipram (IC50 = 0.60 mu M). The active natural PGs (2, 10, and 13-15) represent the first examples of PDE4 inhibitors without an aromatic moiety, and a preliminary structure-activity relationship is also proposed.

(±)-Torreyunlignans A-D (1a/1b-4a/4b), four pairs of new 8-9' linked neolignan enantiomers featuring a rare (E)-2-styryl-1,3-dioxane moiety, were isolated from the trunk of Torreya yunnanensis. The structures were determined by combined spectroscopic and chemical methods, and the absolute configurations were elucidated by ECD calculations. The compounds were screened by using tritium-labeled adenosine 3',5'-cyclic monophosphate ([(3)H]-cGMP) as a substrate for inhibitory affinities against phosphodiesterase-9A (PDE9A), which is a potential target for the treatment of diabetes and Alzheimer's disease. All of the enantiomers exhibited inhibition against PDE9A with IC50 values ranging from 5.6 to 15.0 μM. This is the first report of PDE9A inhibitors from nature.

Chemical investigation of the South China Sea ascidian Aplidium constellatum has led to the isolation of four sterols (1–4), two carboline alkaloids (5 and 6), a ceramide (7), two furanone derivatives (8 and 9), and six nucleosides (10–15). Compounds 1–3 and 5–9 were isolated from the family Polyclinidae for the first time and compounds 1–3 and 7 were considered as the chemotaxonomic markers for the species A. constellatum.

Lygodipenoids A (1) and B (2), two novel C33 tetracyclic triterpenoids with a new 9,19:24,32-dicyclopropane skeleton, were isolated from the whole grass of Lygodium japonicum. Their structures were elucidated by spectroscopic and chemical means. Compounds 1 and 2 were tested in transfected cultured human embryonic kidney 293 HEK293 cells for an agonist assay, and compound 1 was identified as a partial agonist for liver X receptor alpha.

► The chemistry of Syzygium tetragonum Wall has been reported for the first time. ► Three isolated compounds were present in the family Myrtaceae for the first time. ► The spectroscopic data of taraxeryl acetate were revised.