Cipatrijugin G,a new trijugin-type limonoid bearing an uncommonγ-hydroxybutenolide unit from the aerial parts of Cipadessa cinerascens

A new trijugin-type limonoid,cipatrijugin G(1),together with the related known cipatrijugin A(2),were isolated from the aerial parts of Cipadessa cinerascens.The structure of the new compound was determined by extensive analysis of its spectroscopic data and by comparison of its NMR data with those reported in the literature.Compound 1 showed cytotoxicity against tumor cell line A549 with an IC_(50) value of 9.78μM.This is the first report of a trijugin-type limonoid bearing aγ-hydroxybutenolide unit,in comparison to the common furan unit as ring E.

Lagerindicine, a New Pyrrole Alkaloid Isolated from the Flowers of Lagerstroemia indica Linnaeus

A phytochemical investigation of the EtOH extract of the flowers of Lagerstroemia indica L.led to the isolation and char-acterization of a new pyrrole alkaloid,named lagerindicine(1),along with four known compounds(2-5).Their structures were elucidated by the detailed spectroscopic analysis and comparison with literature data,whereas the structure,in par-ticularly,the absolute configuration(AC)of 1,was firmly determined by total synthesis.All the isolates were evaluated for their cytotoxic effects against human colon cancer cell(HCT-116),and compound 3 exhibited weak cytotoxicity with IC50 value of 28.4μM.

Further New Highly Oxidative Cembranoids from the Hainan Soft Coral Sarcophyton trocheliophorum

Three new highly oxidative cembranoids,sarcophytrols D-F(1-3),were obtained from the South China Sea soft coral Sarcophyton trocheliophorum,along with two known related ones(4 and 5).Their structures were elucidated by extensive spectroscopic analyses and by comparison with literature data.The discovery of these new secondary metabolites enriched the family of cembranoids deduced from the title animal.

Ocellatuspyrones A‒G,new antibacterial polypropionates from the Chinese mollusk Placobranchus ocellatus

Marine invertebrates serve as rich sources of secondary metabolites with intriguing chemical diversities and a wide spectrum of biological activities.Particularly,marine shell-less sacoglossan mollusks have attracted much attentions due to the fact that mollusks apply complex metabolites as chemical defense agents against to their predators.With the purpose of discovering bioactive secondary metabolites to develop marine-derived medicines from the South China Sea,we have conducted a chemical study on the photosynthetic mollusk Placobranchus ocellatus.As a result,seven newγ-pyrone polypropionates,namely(±)-ocellatuspyrone A(1),(±)-ocellatuspyrone B(2),and ocellatuspyrones C−G(5,9−12),along with fve known polypropionates,have been isolated and characterized from the South China Sea photosynthetic mollusk Placobranchus ocellatus.Extensive spectroscopic analysis,single crystal X-ray difraction analysis,modifed Mosher’s method,ECD comparison,CD exciton chirality method,TDDFT-ECD calculation,and chemical conversion were used to determine the structures and absolute confgurations of the new compounds and the stereochemistry of undefned known compounds 4,6 and 7.All these isolated polypropionates were evaluated in bioassays for their biological activities,including antibacterial,neuroprotective efect,anti-infammatory,PTP1B inhibitory,and antiviral activities.Compounds 7,8 and 11 were found for the frst time to show antibacterial activity against fsh pathogenic bacteria Streptococcus parauberis(the main pathogen causing fsh streptococcal infections and acute death)with MIC values of 35.8,34.2,and 37.4μg/mL,respectively,which might be potential novel antibacterial agents for the treatment of fsh infectious diseases.

Terpenoids of Sinularia soft corals:chemistry and bioactivity

Soft corals of the genus Sinularia are one of the most widespread soft corals.They are a rich source of bioactive su bstances with intriguing and unique structural features.The present paper reviews the latest progress in the chemistry and pharmacological activities of terpenoids from Sinularia soft corals and provides a perspective on future areas of research interest.

Sinucrassins A-K, Casbane-type Diterpenoids from the South China Sea Soft Coral Sinularia crassa

A detailed chemical study on the Hainan soft coral Sinularia crass has resulted in the isolation and characterization of eleven cas-bane-type diterpenoids,named sinucrassins A-K(1-11),along with six known related ones(12-17).Their structures were elucidated by extensive spectroscopic analyses and comparison with the reported data.The absolute configurations of new compounds were determi ned by the X-ray diffracti on analysis and computer-assisted structural elucidati on in eluding 13C NMR data calculati on and time-dependent density functional theory/electronic circular dichroism calculation.

Nitrogenous Sesquiterpenoids from the South China Sea Nudibranch Hexabranchus sanguineus and Its Possible Sponge-Prey Acanthella cavernosa: Chiral Separation, Stereochemistry and Chemical Ecology

A detailed chemical investigation of the South China Sea nudibranch Hexabranchus sanguineus,as well as its possible sponge-prey Acanthella cavernosa,led to the isolation of fifteen new nitrogenous sesquiterpenoids,namely ximaocavernosins A-0,including seven cadinanes(1-7),seven spiroaxanes(12-18)and one aromadendrane(19),together with thirteen known related compounds(8-11 and 20-28).

Uncommon Polycyclic Merosesquiterpenoids and Asteriscanoids from the Hainan Soft Coral Sinularia hurnesi

A rare highly fused racemic merosesquiterpenoid,9-epi-verrubenzospirolactone(1),six new asteriscane-type sesquiterpenoids,sinuhumesins A-F(4-9),and two related known ones(10 and 11)were isolated from Hainan soft coral Sinularia humesi.Compound 1 was further separated by chiral HPLC resolution to one pair of enantiomers[(+)-1 and(-)-1],respectively.The full structures of the new compounds were unambiguously determined by extensive spectroscopic analysis,chemical computation approaches,modified Mosher's method and/or X-ray diffract!on analysis,as well as comparison with previously reported data of related model compounds.

Chemical Constituents from Mycelia and Spores of Fungus Cordyceps cicadae

Objective To isolate and identify the chemical constituents from mycelia and spores of the fungus Cordyceps cicadae,respectively.Methods The chemical constituents were isolated and purified by repeated silica gel,Sephadex LH-20,and reversed phase HPLC.The structures of these compounds were elucidated on the basis of extensive spectroscopic analysis,including 1 D and 2D NMR.Results Nine known sterols such as ergosterol（1）,ergosterol peroxide（2）,9,11-dehydroergosterol peroxide（3）,3β,5α,9α-trihydroxy-（22E,24R）-ergosta-7,22-dien-6-one（4）,3β,5α,9α,14α-tetrahydroxy-（22E,24R）-ergosta-7,22-dien-6-one（5）,5 α,6α-e poxy-（22 E,,24 R）-e rgosta-8（14）,22-diene-3α,7α-diol （6）, 3β,5α,6β-（22E,24R）-ergosta-7,22-dien-3,5,6-triol （7）, 3β,5α,6α-6- methoxyergosta-（22E,24R）-7,22-diene-3,5-diol （8）, 4-hydroxy-17R-methylincisterol （9）, together with a resorcinol derivative, 5-n-nonadecylresorcinol （10）, a cydo- desipeptide, beauvericin （11）, and a nucleoside, N^6-（2-hydroxyethyl）adenosine （12） were successively isolated from the cultivated C. cicadaemycelia and spores. Conclusion Compounds 3-10 are reported for the first time from the title sample, beauvericin exhibits significant cytotoxicity against human leukemia cell line and human lung cancer cell line.

Xishaglaucumins A—J,New Cembranoids with Anti-Inflammatory Activities from the South China Sea Soft Coral Sarcophyton glaucum

Ten new cembrane-type diterpenoids,namely xishaglaucumins A—J(1—10),along with ten known related ones(11—20),have been isolated from the soft coral Sarcophyton glaucum collected off the Xisha Island in the South China Sea.Their structures were elucidated by extensive spectroscopic analysis,quantum mechanical nuclear magnetic resonance(QM-NMR)methods,X-ray diffraction analysis,chemical methods and comparison with the reported data in the literature.The absolute configuration of new compounds 1,5 and known compounds 11,12,16 and 20 were determined either by chemical methods or by X-ray diffraction analysis using Cu Kα(λ=1.5417A).In in vitro bioassay,compound 4 exhibited inhibitory effects on lipopolysaccharide(LPS)-induced inflammatory responses in BV-2 microglial cells.

Polyoxygenated Cembranoids from Soft Coral Lobophytum Crassum and Their Anti-tumoral Activities

Main observation and conclusion Four new cembranoids,6-oxo-cembrene-A(1),lobocrassins G-H(2-3),and 14-epi-lobophytolide B(4),along with eight known re-lated compounds(5-12),were isolated from the South China Sea soft coral Lobophytum crassum.Their structures were established by extensive spectroscopic analysis and by comparison of the spectral data with those reported in the literatures.The absolute stere-ochemistry of 14-epi-lobophytolide B(4)was established by time-dependent density functional theory electronic circular dichroism(TDDFT-ECD)calculations,whereas that of three known metabolites(6,11 and 12)was also determined,for the first time,by using modified Mosher's method and/or X-ray diffraction analyses.In bioassay,the cembranoids 6,7 and 12 showed significant an-ti-tumoral activity against A549,HT-29,SNU-398 and Capan-1 tumor cell lines with IC_(50) values ranging from 1.5 to 7.4μmol/L.A pre-liminary structure-activity relationship was also discussed.

Uncommon Bis-quinolizidine Alkaloids from the Hainan Sponge Neopetrosia chaliniformis

Main observation and conclusion Two new bis-quinolizidine alkaloids,neopetrosiasins A(1)and B(2),possessing cis-and trans-quinolizidine nuclei,one known related analogue petrosin(3)and three known xestospongins(4-6),were isolated from the South China Sea sponge Neopetrosia chaliniformis.

5-Alkylpyrrole-2-carboxaldehyde derivatives from the Chinese sponge Mycale lissochela and their PTP1B inhibitory activities

Two new 5-alkylpyrrole-2-carboxaldehyde derivatives,mycalenitrile-15（1） and mycalenitrile-16（2）,along with five known related ones（3-7）,were isolated from the South China Sea sponge Mycale lissochela.The structures of the new compounds were elucidated on the basis of extensive spectroscopic analysis and by comparison of their NMR data with those reported in the literature.In bioassay,compounds 1 and 7 exhibited significant PTPIB（Protein-tyrosine phosphatase 1B,a recognized target for diabetes and obesity） inhibitory activities with IC（50） values of 8.6 and 3.1 μmoI/L,respectively.A preliminary SAR analysis of the isolated compounds with their PTP1 B inhibitory effects was described.

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

One new dolabellane-type diterpenoid.named clavirolide C（1）,and one known related analogue（3）.have been isolated from the soft coral Cavularia 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.

New Cembrane-Type Diterpenoids from the South China Sea Soft Coral Sinularia nanolobata

In the present study,nine new cembrane-type diterpenoids,namely ximaonanolobatins A—I(1—9),together with six related known analogs(10—15)and four known tetraprenylated alkaloids malonganenones D,E,H,and K(16—19)were isolated from the soft coral Sinularia nanolobata collected off the Ximao Island in the South China Sea.The structures of 1—9 were robustly established by a combination of detailed spectroscopic analyses,chemical reactions,quantum mechanical(QM)-NMR methods,biogenetic consideration,and the comparison with those literature data.The absolute configuration of 1 was confirmed by X-ray diffraction analysis,and the absolute configuration of 2 was determined by QM-NMR calculations and chemical transformation.In addition,the absolute configuration of 3 was determined using the modified Mosher's method.All these isolates were evaluated for their anti-inflammatory and anti-tumor activities.The results showed that only compound 15 exhibited potential anti-inflammatory effect against LPS-induced TNF-αrelease in RAW264.7 macrophages with an IC50 value of 12.6μmol/L.

Marine alkaloids as the chemical marker for the prey–predator relationship of the sponge Xestospongia sp.and the nudibranch Jorunna funebris

The dietary relationship study between marine sponge Xestospongia sp.and its nudibranch predators Jorunna funebris based on the discovery of isoquinolinequinones has long been studied.In this study,chemical investigation of the sponge Xestospongia sp.and nudibranch J.funebris from the South China Sea yielded a new marine alkaloid neopetroside C(1),together with nine known alkaloids(2-10).The chemical structures of all the compounds were elucidated by extensive spectroscopic analysis.Neopetroside C(1)featured a riboside of nicotinic acid with a rareα-N glycosildic linkage and an acyl residue of(Z)-2-methylbut-2-enoic acid attached to C-5′.The plausible chemical ecology relationship between sponge Xestospongia sp.and its nudibranch predator J.funebris was proposed based on the biogenetic relationship of the common marine alkaloids.The observation of two structural fragments,(Z)-2-methylbut-2-enoyloxy and trigonelline groups in both sponge and nudibranch,indicated that nudibranch might uptake chemicals from sponge and then modify and transform them into chemical weapons to defend against predators.