A new dolabellane diterpene and a new polyacetylene from the soft coral Clavularia viridis

A new dolabellane diterpene (1) and a new polyacetylene (2) were isolated from the soft coral Clavularia viridis. The structures of 1 and 2 were elucidated by spectroscopic analyses including 1D and 2DNMR experiments and HRESIMS data. The absolute configuration of 1 was determined by the modified Mosher’s method and 2 by ECD calculations. Compound 1 exhibited moderate cytotoxicities against MCF-7 and A549 cell lines with IC₅₀ values of 10.5 and 12.6 µM, respectively.     

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.     

Nepethalates A and B: Two New Phthalate Derivatives from Nepeta clarkei

The structure elucidation of two new phthalate derivatives named nepethalates A ( 1 ) and B ( 2 ) is reported. Both of these secondary metabolites were isolated from the MeOH extract of Nepeta clarkei. HR‐EI‐MS, IR and UV absorption spectrometry, and NMR experiments including COSY, HMQC, and HMBC were used for the determination of the structures and complete ¹H‐ and ¹³C‐NMR assignments.     

中心对称吡嗪衍生物电子光谱和三阶非线性光学性质的理论计算研究

采用量子化学abinitio HF和半经验ZINDO-SOS方法计算了吡嗪及其衍生物的电子光谱和三阶非线性光学系数.结果表明,中心对称的吡嗪衍生物随着体系共轭链的增长,最大吸收谱线波长增大,前线轨道能级差减小,体系的三阶非线性光学系数增大;引入取代基后可改变其三阶非线性光学性质.在相同骨架中引入吸电子基团-NO₂形成A-π-A共轭结构,其三阶非线性光学系数比引入供电子基-NH₂的体系大.     

Two New Iridoid Alkaloids,Daphmacropodosidines A and B,from Daphniphyllum macropodum

Two new iridoid alkaloids, daphmacropodosidines A ( 1 ) and B ( 2 ), together with two known ones, daphcalycinosidine B and caldaphnidine F, were isolated from the fruits of Daphniphyllum maropodum. Their structures were established by spectral methods, especially 2D NMR spectra (¹H,¹H‐COSY, HMQC, HMBC, and NOESY), as well as chemical means.     

Habaenines A and B,Two New Norditerpenoid Alkaloids from Aconitum habaense

Two new norditerpenoid alkaloids, habaenine A and B ( 1 and 2 ), together with two known compounds, were isolated from Aconitum habaense. The structures of the new compounds were elucidated on the basis of spectral analyses as (1α,6α,16β)‐8‐(acetyloxy)‐20‐ethyl‐13‐hydroxy‐1,6,16‐trimethoxy‐4‐(methoxymethyl)‐19‐oxoaconitan‐14‐yl 4‐methoxybenzoate ( 1 ) and (1α,6α,16β)‐8‐(acetyloxy)‐13‐hydroxy‐1,6,16‐trimethoxy‐4‐(methoxymethyl)‐aconitan‐14‐yl 4‐methoxybenzoate ( 2 ).     

Two New O-terpenoidal Coumarins, Excavacoumarin A and B from Clausena excavata

Cla!tsenaexcavataBurm.f(Rutaceae)isabushwidelydistributedinYunnan,China.Leavesandbarksofthisplanthavebeenusedasfolkrnedicineforthetreatmentofdysentery,enteritis,andurethrainfection1.ClalISenaspeciesareknowntobetherichsourcesofcarbazolealkaloidsandcoumarins=-j.TheconstituentsofCexcavalacollectedinXishuangbannahavebeenstudied'andthispaperdescribestheisolationandstructureelucidationoftwonewO-terpenoidalcoumarins,excavacoumarinA(2)andexcavacoumarinB(3),andthel3CNMRspectraldataassignmentsfora…     

Two New Metabolites,Epoxydine A and B,from Phoma sp.

The new compounds, epoxydines A and B ( 1 and 2 , resp.), along with the known and related metabolites, 3 – 6 , were isolated from the fungal endophyte Phoma sp. The structures of the new compounds were elucidated by detailed spectroscopic analysis, and the relative configuration of 1 was confirmed by ROESY experiments. Preliminary studies indicated that compounds 2 – 5 possess good antibacterial, antifungal, and algicidal properties. Similarly, compound 1 showed antifungal and algicidal, and compound 6 antibacterial and algicidal properties.     

Two New Octahydronaphthalene Derivatives from Trichoderma spirale,an Endophytic Fungus Derived from Aquilaria sinensis

Two new octahydronaphthalene derivatives, trichodermic acid A ( 1 ) and trichodermic acid B ( 2 ), along with a known analog, trichodermic acid ( 3 ), and a known modified dipeptide, trichodermamide A ( 4 ), were isolated from the extract of Trichoderma spirale, an endophytic fungus present in the medicinal plant Aquilaria sinensis. The structures of these compounds were established by extensive analysis of their spectroscopic data including 1D‐ and 2D‐NMR and MS data.     

Philinopsides A and B,Two New Sulfated Triterpene Glycosides from the Sea Cucumber Pentacta quadrangularis

Two new sulfated triterpene glycosides, philinopsides A ( 1 ) and B ( 2 ), were isolated from the sea cucumber Pentacta quadrangularis. Their structures were established by extensive spectral analysis (2D‐NMR and MS) and chemical evidence. Philinopside A ( 1 ) and B ( 2 ) showed significant cytotoxicity (ED₅₀ 0.75–3.50 μg/ml) against ten tumor cell lines. Compound 1 also significantly inhibited the proliferation, migration, and tube formation of human microvascular endothelial cells.     

Two New Phenylpropanoid Derivatives from Codonopsis tangshen Oliv.

Two new 3‐hydroxy‐3‐methylglutaric acid derived phenylpropanoid glucosides, tangshenoside V ( 1 ) and tangshenoside VI ( 2 ), were isolated from the roots of Codonopsis tangshen Oliv ., along with the two known compounds tangshenoside I ( 3 ) and tangshenoside III ( 4 ). Their structures were elucidated by spectroscopic methods (IR and 1D‐ and 2D‐NMR) and by mass spectrometry (HR‐ESI‐MS).     

Coagulansins A and B,New Withanolides from Withania coagulans Dunal

Coagulansins A ( 1 ) and B ( 2 ), two new withanolides, were isolated from the CHCl₃‐soluble fraction of Withania coagulans Dunal , along with two known withanolides, coagulin R and withanolide P. Their structures were assigned by means of ¹H‐ and ¹³C‐NMR spectra, DEPT, and ¹H,¹H‐COSY, NOESY, HMQC, and HMBC experiments.     

Scyphiphorins A and B,Two New Iridoid Glycosides from the Stem Bark of a Chinese Mangrove Scyphiphora hydrophyllacea

Two new iridoid glycosides, named scyphiphorins A ( 1 ) and B ( 2 ), together with four known compounds, geniposidic acid (=(1S,4aS,7aS)‐1‐(β‐D ‐glucopyranosyloxy)‐1,4a,5,7a‐tetrahydro‐7‐(hydroxymethyl)cyclopenta[c]pyran‐4‐carboxylic acid; 3 ), 4‐(4‐hydroxy‐3‐methoxybenzyl)butan‐2‐one, oleanolic acid (=(3β)‐3‐hydroxyolean‐12‐en‐28‐oic acid), and stigmasterol β‐D ‐glucoside (=(3β,22E)‐stigmasta‐5,22‐dien‐3‐yl β‐D ‐glucopyranoside), were isolated for the first time from the stem bark of a Chinese mangrove, Scyphiphora hydrophyllacea Gaertn . f. The structures of compounds 1 and 2 were determined as 10‐O‐benzoylgeniposidic acid and 10‐O‐[(2E,6R)‐8‐hydroxy‐2,6‐dimethyl‐1‐oxooct‐2‐en‐1‐yl]geniposidic acid, respectively, on the basis of spectroscopic data and chemical methods, including 2D NMR techniques.     

Leiocyclocin A and B, Two Cyclopeptides from Goniothalamus leiocarpus

Ongoing phytochemical studies on Goniothalamus species have led to the isolation of a number of annonaceous acetogenins and unusual new styryllactones which were found to possess significant cytotoxic activities against several hunan tumour cell lines1,2. Firstly, cyclopeptides were reported to be isolated from genus Goniothalamus in this paper.Goniothalamus leiocarpus is an evergreen tree which grows in the south of Yunnan, China. Four new anticancer styryllactones3,4 from the stem bark and…     

Ypsilactosides A and B,Two New C22‐Steroidal Lactone Glycosides from Ypsilandra thibetica

Two new C₂₂‐steroidal lactone glycosides, ypsilactosides A ( 1 ) and B ( 2 ), were isolated from the EtOH extract of the whole plant of Ypsilandra thibetica. Their structures were established as (3β,5α,16β,20S)‐3,16‐dihydroxy‐6‐oxopregnane‐20‐carboxylic acid γ‐lactone 3‐(β‐D ‐glucopyranoside) ( 1 ) and (3β,16β)‐3,16‐dihydroxypregna‐5,20‐diene‐20‐carboxylic acid γ‐lactone 3‐{O‐α‐L ‐rhamnopyranosyl‐(1→4)‐O‐α‐L ‐rhamnopyranosyl‐(1→4)‐O‐[α‐L ‐rhamnopyranosyl‐(1→2)]‐β‐D ‐glucopyranoside} ( 2 ) on the basis of extensive spectroscopic analyses and chemical degradations.     

Two Pyrone Derivatives from Fungus Phellinus Igniarius

Two new pyrone derivatives phelligridins A 1 and B 2 were isolated from the fruit body of Phellinus igniarius. Their structrues were elucidated as 8, 9-dihydroxy-3-methyl- 1H,6H-pyrano[4,3-c][2]benzopyran-l,6-dione and 4-hydroxy-6-(3‘,4‘-dihvdroxystyryl)-3-methoxycarbon-yl-2-pyrone, respectively, by means of spectral methods,including IR, MS, 1D and 2DNMR spectra.     

Macrorhynines A and B,Two Novel Norditerpenoid Alkaloids from Aconitum macrorhynchum

Two novel norditerpenoid alkaloids, macrorhynines A and B ( 1 and 2 ), together with seven known compounds, were isolated from Aconitum macrorhynchum. The structures of the new compounds were elucidated as (1α,6α,14α)‐8‐acetoxy‐1,6,16‐trimethoxy‐4‐(methoxymethyl)aconitan‐14‐yl 4‐methoxybenzoate ( 1 ) and (1α,6α,14α)‐8‐acetoxy‐13‐hydroxy‐1,6,16‐trimethoxy‐4‐(methoxymethyl)aconitan‐14‐yl 4‐methoxybenzoate ( 2 ) on the basis of spectral analyses. The novel compounds were found to contain the rare C(19)?N, azomethine, group.