Sesquiterpenes from the marine algicolous fungus Drechslera sp.

A marine fungal isolate, identified as Drechslera sp., was mass cultivated and found to produce a new naturally occurring seco-sativene type sesquiterpene helminthosporic acid (1) and three known sesquiterpenes, helminthosporol (2), drechslerine A (3) and (+) secolongifolene-diol (4). The structures of all compounds were determined by interpretation of their spectroscopic data 1D (¹H and ¹³C), 2D (COSY, DQF, NOE, HSQC and HMBC) NMR, MS, UV and IR analyses. All compounds have been tested toward antioxidants, antimicrobial and antifouling effects.     

Two New Sesquiterpenes from the Fungus Stereum sp.

Two new sesquiterpenes, stereumin F ( 1 ) and stereumin G ( 2 ), together with two known compounds (3β,5α,22E,24R)‐5,8‐epidioxyergosta‐6,22‐dien‐3‐ol ( 3 ) and 4‐(2‐hydroxyethyl)phenol ( 4 ), were isolated from the AcOEt extract of the culture broth and the MeOH extract of the mycelium of the fungal strain Stereum sp. CCTCC AF 207024. Their structures were established on the basis of spectral analyses.     

Two New Sesquiterpenes from Myrrh

Two new sesquiterpenes, named 9‐methoxymyrrhone ( 1 ) and rel‐(1S,2S,3R,4S)‐1,2‐epoxy‐3‐methoxyfuranogermacr‐10(15)‐en‐6‐one ( 2 ), together with nine known compounds ( 3 – 11 ), were isolated from the resin of Commiphora opobalsamum. The structures were established by HR‐ESI‐MS, 1D‐, and 2D‐NMR spectroscopic analyses.     

New Sesquiterpenes from Edible Fungus Clavicorona pyxidata

Three new sesquiterpenes, pyxidatol A–C ( 1 – 3 , resp.), were obtained from the fermentation culture of Clavaria pyxidata, together with two known ones, tsugicoline E ( 4 ) and omphadiol ( 5 ). Their structures were elucidated through spectroscopic analyses, including 1D‐ and 2D‐NMR experiments, HR‐ESI‐Q‐TOF mass spectrometry, chemical correlation, and X‐ray single‐crystal diffraction.     

Two New Sesquiterpenes from Ligularia lankongensis

In continuation of a systematic investigation into the chemotaxonomic and bioactive components of pyrrolizidine alkaloids and sesquiterpenoids of Ligularia plants, two new, highly oxygenated, rare bisabolene sesquiterpenes, compounds 1 and 2 , were isolated from the roots of Ligularia lankongensis. Their structures and relative configurations were elucidated by means of 1D‐ and 2D‐NMR as well as MS analyses.     

Two New Sesquiterpenes from Euonymus alatus

Two new sesquiterpenes, 1 and 2 , as well as the five known compounds 3 – 7 , were isolated from the stems of Euonymus alatus. Compounds 2 – 7 have a β‐dihydroagarofuran skeleton. The structures of these compounds were elucidated mainly by spectroscopic methods (1D‐, 2D‐NMR, ESI‐MS, and HR‐ESI‐MS). We also report the X‐ray crystal structure of evonine ( 3 ) for the first time.     

Two New Guaiane Sesquiterpenes from the Fruits of Daucus carota

Two new sesquiterpenes, 11‐(acetyloxy)torilolone ( 1 ) and 1β‐hydroxytorilolone ( 2 ) were obtained from the fruits of Daucus carota. Their structures were elucidated on the basis of various spectroscopic analyses and chemical evidence.     

New Sesquiterpenes from a Taiwanese Marine Sponge of the Genus Parahigginsia

An undescribed Taiwanese marine sponge of the genus Parahigginsia yielded two new sesquiterpene hydrocarbons-parahigginine ( 1 ) and parahigginone ( 2 ). The structures of the new compounds were established on the basis of NMR spectroscopic and mass spectrometric data. Compounds 1 and 2 exhibited moderate cytotoxicity against murine P-388 and human KB-16, A-549, and HT-29 tumor cells.     

Sesquiterpenes from the Marine Red Alga Laurencia saitoi

Together with five known sesquiterpenes, EtOH extraction of Laurencia saitoi yielded four new compounds, including three sesquiterpenes and one norsesquiterpene derivative. Their structures and relative configurations were elucidated by spectroscopic methods, including 1D‐ and 2D‐NMR (¹H,¹H‐COSY, HMQC, HMBC, and NOESY), as well as low‐ and high‐resolution mass‐spectrometric analyses.     

New N‐Containing Sesquiterpenes from Hainan Marine Sponge Axinyssa sp.

Three new N‐containing sesquiterpenes, isofarnesyl formamide ( 2 ), 7‐formamido‐7,8‐dihydro‐α‐bisabolane ( 3 ), 4,5‐epi‐10‐isothiocyanatoisodauc‐6‐ene ( 4 ), and a known sesquiterpene, farnesyl formamide ( 1 ), were isolated from the Hainan marine sponge Axinyssa sp. The structures of the new compounds were elucidated by detailed analyses of their spectroscopic data and by comparison of their NMR data with those of structurally related compounds.     

Two New Sesquiterpenes from Ligularia Duciformis

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Two New Highly Oxidized Humulane Sesquiterpenes from the Basidiomycete Lactarius mitissimus

Two new highly oxidized humulane sesquiterpenes, mitissimols F ( 1 ) and G ( 2 ), were isolated from the fruiting bodies of Lactarius mitissimus. Their structures were elucidated by using extensive spectroscopic techniques including 1D‐ and 2D‐NMR experiments. The absolute configuration of mitissimol F ( 1 ) was determined by ¹H‐NMR resolution of its diastereoisomeric α‐methoxy‐α‐(trifluoromethyl)benzeneacetates (MTPA). It was shown to be (1S,3E,6S,8R,9R,10S,11R)‐8,9 : 10,11‐diepoxy‐1,6‐dihydroxyhumul‐3‐en‐5‐one (=(1S,2R,4R,6S,8E,11S,12R)‐6,11‐dihydroxy‐1,6,10,10‐tetramethyl‐3,13‐dioxatricyclo[10.1.0.0^2,4]tridec‐8‐en‐7‐one).     

Two New Sesquiterpenes from the Roots of Valeriana fauriei Briq.

A phytochemical investigation of the MeOH extract of Valeriana fauriei Briq . roots resulted in the isolation of two new sesquiterpenes, isovalerianin A (=(1β,4Z,6β,8α)‐8‐(acetyloxy)‐1,10‐dihydroxy‐6,11‐cyclogermacr‐4‐en‐15‐al=rel‐(1R,2Z,6S,7R,9R,10S)‐9‐(acetyloxy)‐6,7‐dihydroxy‐7,11,11‐trimethylbicyclo[8.1.0]undec‐2‐ene‐3‐carboxaldehyde; 1 ) and valerianin C (=(2α,3α,6α,8α)‐3‐(acetyloxy)‐2,4,8‐trihydroxyguai‐1(10)‐ene‐12,6‐lactone=rel‐(3R,3aS,4R,7S,8S,9R,9aR,9bR)‐8‐(acetyloxy)‐3a,4,5,7,8,9,9a,9b‐ octahydro‐4,7,9‐trihydroxy‐3,6,9‐trimethylazuleno[4,5‐b]furan‐2(3H)‐one; 2 ), together with six known compounds, i.e., camphor, methyl 4‐hydroxybenzoate, 2‐methoxybenzoic acid, benzoic acid, quercetin, and kaempferol. The structures of the compounds were established by detailed spectral analysis and comparison with previously reported data.     

南海海洋真菌#2526中蒽醌类代谢产物的研究

从分离自香港红树林的南海海洋真菌sterigmatocystin,通过完整的波谱数据分别解析它们为averufin(A),nidurufin(B),versicolorin C(C)和大黄素甲醚(D);初步生理活性试验表明,化合物A不显示有意义的抑菌活性,并且和化合物D一样,不显示有意义的hTOPI酶抑制活性.     

Two New Sesquiterpenes from Inula salsoloides and Their Inhibitory Activities against NO Production

Two new sesquiterpenes, inulasalene ( 1 ) and inulasalsolide B ( 2 ), as well as 22 known compounds were isolated from the aerial parts of Inula salsoloides. The structures of the new sesquiterpenes were determined on the basis of their spectroscopic data and chemical properties. Compounds 1 – 4 exhibited potent inhibitory activities against NO production with IC₅₀ values range of 0.010–1.290 μg/ml in lipopolysaccharide (LPS)‐stimulated RAW264.7 cells.     

Halogenated Sesquiterpenes from the Marine Red Alga Laurencia saitoi (Rhodomelaceae)

Four new halogenated sesquiterpenes, 10‐bromo‐3‐chloro‐2,7‐epoxychamigr‐9‐en‐8α‐ol ( 1 ), 2,10β‐dibromochamigra‐2,7‐dien‐9α‐ol ( 2 ), (9S)‐2‐bromo‐3‐chloro‐6,9‐epoxybisabola‐7(14),10‐diene ( 3 ), and (9R)‐2‐bromo‐3‐chloro‐6,9‐epoxybisabola‐7(14),10‐diene ( 4 ), were characterized from the marine red alga Laurencia saitoi. In addition, two known halosesquiterpenes, 2,10‐dibromo‐3‐chlorochamigr‐7‐en‐9α‐ol ( 5 ) and isolaurenisol ( 6 ), were also isolated and identified. Their structures were established on the basis of extensive analysis of spectroscopic data.     

New Lactone and Xanthone Derivatives Produced by a Mangrove Endophytic Fungus Phoma sp. SK3RW1M from the South China Sea

A new lactone, 1,8‐dihydroxy‐10‐methoxy‐3‐methyldibenzo[b,e]oxepine‐6,11‐dione ( 1 ), and two new xanthones, 1‐hydroxy‐8‐(hydroxymethyl)‐6‐methoxy‐3‐methyl‐9H‐xanthen‐9‐one ( 2 ) and 1‐hydroxy‐8‐(hydroxymethyl)‐3‐methoxy‐6‐methyl‐9H‐xanthen‐9‐one ( 3 ), were isolated from a mangrove endophytic fungus Phoma sp. SK3RW1M collected from the South China Sea. This is the first report on xanthone derivatives isolated as secondary metabolites from Phoma species. Their structures were elucidated by spectroscopic methods, mainly 1D‐ and 2D‐NMR techniques, and the structure of compound 2 was confirmed by X‐ray crystallography. Cytotoxicity assays showed that compounds 1 – 3 were inactive against KB and KBv200 cells.     

A New Triterpene and New Sesquiterpenes from the Roots of Ligularia sagitta

One new triterpene and seven new eremophilane‐type sesquiterpenes were isolated from the roots of Ligularia sagitta, among them 1a , an O‐acetylated oleanane type triterpene, 2a and 3a , two 11‐nor eremophilane‐type sesquiterpenes, 4a, 5 , and 6 , three standard eremophilane‐type sesquiterpenes, and 7 and 8 , two tri‐nor eremophilane‐type sesquiterpenes. Their structures were established by extensive spectral analyses (1D, 2D‐NMR, IR, and MS). Compound 1a showed moderate cytotoxicity against two tumor cell lines.