15-deoxy-isoxeniolide-A,new diterpenoid from a bornean soft coral,Xenia sp.

A new xenicane diterpenoid, 15-deoxy-isoxeniolide-A (1) along with four known compounds 9-deoxy-isoxeniolide-A (2), isoxeniolide-A (3), xeniolide-A (4) and coraxeniolide-B (5) were isolated from the Bornean soft coral Xenia sp. The structures of these metabolites were elucidated on the basis of spectral analysis, NMR and HRESIMS. Compound 5 showed cytotoxic activity against ATL cell line, S1T.     

Isolation of a new cytotoxic polyhydroxysterol from the South China Sea soft coral Sinularia sp.

A new polyhydroxysterol, (22E)-24-methylenecholestane-22-ene-3β,5α,6β-triol (1), together with four known analogues (2–5) were isolated from the South China Sea soft coral Sinularia sp. Their structures were elucidated by spectroscopic analyses and comparison with previously reported data. All these compounds exhibited cytotoxic effect against both HepG2 and HeLa cell lines with IC₅₀ values ranging from 8.36 to 37.30 μM. Preliminary structure–activity relationship study identified that the presence of double bonds in the side chains of these polyhydroxysterols significantly reduced the biological effect obtained.     

Novel cytotoxic nine-membered macrocyclic polysulfur cembranoid lactones from the soft coral Sinularia sp.

One novel nine-membered macrocyclic polysulfur cembranoid lactone, sinulariaoid A (1); three new multioxygenated cembranoids, sinulariaoid B (2), sinulariaoid C (3), sinulariaoid D (4); and four known cembranoids, capilloloid (5), dihydrosinularin (6), sinularin (7), and dihydrosinuflexolide (8) were isolated from the soft coral Sinularia sp. collected off of Sanya Bay in the South China Sea. Their stereochemical structures were determined on the basis of extensive spectroscopic methods, including single crystal X-ray diffraction analysis. Sinulariaoid A (1) is the first reported nine-membered macrocyclic polysulfur cembranoid from soft coral. The cytotoxic activities of compounds 1–8 were determined in four human cancer cell lines (HepG2, HepG2/ADM, MCF-7, and MCF-7/ADM). Of these, sinulariaoid A (1) exhibited the most potent anticancer activity in vitro, and its cytotoxicity in HepG2/ADM was more potent than in the other three cell lines. Furthermore, it was found that sinulariaoid A (1) induced apoptosis, and its selective toxicity toward HepG2/ADM cells was not related to P-glycoproteins.     

Clavirolide G,a new rare dolabellane-type diterpenoid from the Xisha soft coral Clavularia viridis

One new dolabellane-type diterpenoid,named clavirolide G(1),and one known related analogue(3), have been isolated from the soft coral Clavularia viridis collected off the Xisha Islands in the South China Sea.Its structure and absolute configuration were determined on the basis of spectroscopic analysis, electronic circular dichroism,and compared with literature model compounds.The cytotoxic activity of these two compounds was evaluated against a panel of human tumor cell lines.Compound 1 showed moderate cytotoxic activity against KB and HL-60 cells.     

A new 5α,8α-epidioxysterol with immunosuppressive activity from the South China Sea soft coral Sinularia sp.

Abstract

A new 5α,8α-epidioxysterol, namely yalongsterol A (1), along with two known related steroids 5α,8α-epidioxy-24-methyl-cholesta-6,24(28)-dien-3β-ol (2) and (22E,24S)-5α,8α-epidioxy-24-methyl-cholesta-6,22-dien-3β-ol (3), were isolated from the South China Sea soft coral Sinularia sp. Their structures were established by extensive spectroscopic analyses and comparisons of the spectral data with those reported in the literature. In bioassay, compounds 1–3 showed moderate immunosuppressive activities against T and/or B lymphocyte cells with IC₅₀ values ranging from 19.30 to 59.49 μM, and low cytotoxicity on murine splenocytes with CC₅₀ values ranging from 40.88 to 62.29 μM.

     

A new sesquiterpene from the gorgonian coral Menella sp.

A new sesquiterpene named menecubebane B (1) and a known analogue (2) were isolated from the gorgonian coral Menella sp. Their structures were elucidated by the extensive analyses of spectroscopic data and by the comparison with related literature. Cytotoxic effect against both Eca9706 and HeLa cell lines was evaluated, revealing 1 exhibited moderate cytotoxicity against the two cell lines involved with IC₅₀ values being 20.8 and 30.6 μM, respectively.     

Sinularianins A and B, novel sesquiterpenoids from the Formosan soft coral Sinularia sp.

Two novel sesquiterpenoids, sinularianins A and B (1 and 2), have been isolated from the Formosan coral Sinularia sp. The skeleton of sinularianins A (1), namely sinulariolane, was found to be unprecedented. Sinularianin B (2), with a novel spiro-butenolide moiety, possesses a valerenane skeleton, which had been reported mostly from the plant. The structures of both metabolites were established by extensive analysis of spectroscopic data.     

New cytotoxic constituents from the Red Sea soft coral Nephthea sp.

Nephthea are soft coral species rich in sesquiterpenoids and steroids. An organic extract of Nephthea sp. resulted in the isolation of a new steroid (1), as well as several previously reported metabolites (2–9). Structures were elucidated by employing NMR and HR-EI-MS analyses. The total extract, fractions and purified compounds exhibited differential cytotoxicity against the breast cancer MCF-7 cell line.     

Umbellactal, a novel diterpenoid from the Formosan soft coral Xenia umbellata

Umbellactal, isolated from the soft coral Xenia umbellata, is an unprecedented diterpenoid. The structure of umbellactal was established by extensive analysis of spectroscopic data.     

南海短足软珊瑚Cladiella sp.中两个新孕甾醇苷的分离

从短足软珊瑚Cladiella sp．中,分离得到3个甾类化合物：孕甾-5,20-二烯-3β-醇-3-O-α-L-吡喃岩藻糖苷(1)、孕甾-5,20-二烯-3β-醇-3-O-β-D-吡喃木糖苷(2)和(22E,24R)-麦角甾-7,22-二烯-3β,5α,6β-三醇(3),其中1和2为新化合物．孕甾醇苷具有抗早孕和抑制肿瘤细胞生长活性．     

Chemical Constituents of a Formosan Soft Coral Sinularia sp.

A new marine sterol 7β-hydroperoxy-24-methylenecholesterol ( 1 ) along with five known compounds sarcophytol A ( 2 ), (Z)-N-[2-(4-hydroxyphenyl)ethyl]-3-methyldodec-2-enamide ( 3 ), 5α,7αH-eduesm-11(13)en-4α-ol ( 4 ), 24-methylenecholesterol ( 5 ) and 1β-hydroxy-α-cyperone ( 6 ) have been isolated from a Formosan soft coral Sinularia sp. The structures of the above compounds were determined by spectral analyses. Cytotoxicity of compounds 1–6 toward various cancer cell lines also is reported.     

中国南海软珊瑚Scleronephthya sp.化学成分的研究

对中国南海的软珊瑚Scleronephthya sp.的化学成分进行研究,从有免疫调节活性的乙醚可溶物中分离鉴定了13个化合物,经1H NMR,13C NMR,HMQC,HMBC,1H-1H COSY和MS等光谱分析并结合文献数据,确证其结构分别为:3β-羟基-20-烯孕甾烷乙酸酯(1),3β-羟基-5,20-二烯孕甾烷乙酸酯(2),3-酮-20-烯孕甾烷(3),1,2-环氧-3-酮-20-烯孕甾烷(4),1,20-二烯-3-酮孕甾烷(5),1-烯-3-酮-20S-甲基-21-羟基孕甾烷乙酸酯(6),1-烯-3-酮-20β-羟基孕甾烷乙酸酯(7),1-烯-3,22-二酮胆甾烷(8),1,24-二烯-3-酮-22,23-二羟基胆甾烷(9),O-methylisogrifolin(10),(1R,3S,4S,7E,11E)-3α,4α-环氧-7,11,15-三烯西松烷(11),玉米黄素12和6-溴-3-羧酸吲哚(13),其中化合物4,6和10是首次从自然界分离得到.首次对化合物6,7和10的波谱数据进行了报道,而且利用2D NMR对其进行了全归属.对化合物1～7可能的生源关系也进行了探讨.化合物6和7对人宫颈癌细胞(HELA)有抑制活性,IC50分别为3.3和6.3 mol/L;化合物7对肝癌细胞(BE7402)和人白血病细胞(HL-60)也显示抑制活性,IC50分别为3.1和0.26mol/L;化合物11对COX-2显示强烈的抑制活性,IC50为0.455 mol/L.     

Lobozoanthamine, a new zoanthamine-type alkaloid from the Indonesian soft coral Lobophytum sp.

A new member of the family of zoanthamine-type alkaloids, lobozoanthamine (1), has been isolated from the Indonesian soft coral Lobophytum sp. This represents the first report of a zoanthamine-type alkaloid from a marine invertebrate different from zoanthids. The densely functionalized heptacyclic stereostructure of lobozoanthamine (1) has been established through the interpretation of 2D NMR data and application of the modified Mosher method.     

Stolonidiol,a new marine diterpenoid with a strong cytotoxic activity from the Japanese soft coral

Structures of stolonidiol (1) and stolonidiol monoacetate (2), new marine diterpenoids with a strong cytotoxic activity from the Japanese soft coralClavularia sp., were established by means of spectroscopic analyses, chemical reactions, and X-ray crystallographic analysis.     

Novaxenicins A-D and xeniolides I-K, seven new diterpenes from the soft coral Xenia novaebrittanniae

Seven new diterpenes, novaxenicins A-D (1-4) and xeniolides I-K (5-7), have been isolated from the Kenyan soft coral Xenia novaebrittanniae. The structures and relative stereochemistry of the compounds were elucidated by interpretation of MS, COSY, HSQC, HMBC, and NOESY experiments. The structure of novaxenicin A (1) was secured by X-ray diffraction analysis. Compound 5 possesses anti-bacterial activity at a concentration of 1.25 μg/ml and compound 2 induces apoptosis in transformed mammalian cells at a concentration of 1.25 μg/ml.     

Novel cyclic sesquiterpene peroxides from the Formosan soft coral Sinularia sp.

Four novel cyclic peroxide-containing sesquiterpenes (1-4), with a γ-alkylidene-α-methyl-α,β-unsaturated γ-lactone moiety, have been isolated from a Formosan soft coral of the genus Sinularia. Their structures were elucidated mainly by extensive 1D and 2D NMR experiments.     

Sinuhirtins A and B,two uncommon norhumulene-type terpenoids from the South China Sea soft coral Sinularia hirta

Two new uncommon norhumulene-type norsesquiterpenoids, namely sinuhirtins A (1) and B (2), along with two known norcaryophyllene-type norsesquiterpenoids (3 and 4), were isolated from the South China Sea soft coral Sinularia hirta. The structures and absolute configurations of the new compounds were determined by extensive spectroscopic data analyses, and computer-assisted methods including GIAO ¹³C NMR and TDDFT-ECD calculations. A plausible biogenetic relationship of 1–4 was proposed.     

豆荚软珊瑚Lobophytum sp. 的次生代谢产物研究

从海南岛三亚海域采集的软珊瑚Labophytumsp.中分离得五个甾醇苷(1)～(5)。通过波谱分析，确定它们的化学结构依次为3'-O-乙酰基-4-O-[β-D-吡喃木糖苷]-孕甾-20-烯-3β,4α-二醇(1)，4-O-[β-D-吡喃木糖苷]-孕甾-20-烯-3β,4α-二醇(2),4'-O-乙酰基-4-O-[β-D-吡喃木糖苷]-孕甾-20-烯-3β,4α-二醇(3),4'-O-乙酰基-4-O-[β-D-吡喃阿拉伯糖苷]-孕甾-20-烯-3β,4α-二醇(4)和4-O-[β-D-吡喃阿拉伯糖苷]-孕甾-20-烯-3β,4α-二醇(5),其中1为新化合物。体外细胞毒性实验表明：化合物(1),(2)和(5)对SKMG-4,Hep-G2和CNE2三种人体癌细胞具有抑制作用。     

Three novel bis(indole) alkaloids from a stony coral, Tubastraea sp.

Three novel bis(indole) alkaloids with an unprecedented skeleton have been isolated from a stony coral, Tubastraea sp. These indoles could biogenetically be derived from two molecules of aplysinopsin via a Diels-Alder reaction.