Tocopherols and Triterpenoids from Sida acuta

A new tocopherol derivative, 7_a‐methoxy‐α‐tocopherol ( 1 ), and a new taraxastane triterpene, taraxast‐1,20(30)‐dien‐3‐one ( 5 ), together with four known compounds, β‐tocopherol ( 2 ), α‐tocopherol ( 3 ), α‐tocospiro B ( 4 ) and taraxasterone ( 6 ) were isolated from the whole plant of Sida acuta. Their structures were elucidated by spectral analysis including MS, 1D and 2D‐NMR spectroscopy. Among those compounds, compounds 1 , 2 , and 3 showed significant antioxidant effect (EC₅₀ = 86.9, 68.2, and 70.9 μM, respectively) in the DPPH radicals scavenging activity assay.     

A New Megastigmane Palmitate and a New Oleanane Triterpenoid from Aster yomena Makino

A new megastigmane palmitate, 9‐oxomegastigm‐5(13)‐ene‐2β‐palmitate ( 1 ), and a new oleanane triterpenoid, (3β)‐3,23,28‐trihydroxyolean‐12‐en‐11‐one ( 2 ), together with three known oleanane‐type triterpenoids, β‐amyrin ( 3 ), erythrodiol ( 4 ), and (3β)‐olean‐12‐ene‐3,23,28‐triol ( 5 ), were isolated from the aerial parts of Aster yomena (Asteraceae). Their structures were identified based on 1D‐ and 2D‐NMR analysis, including ¹H,¹H‐COSY, HSQC, HMBC, and NOESY techniques.     

Sesterterpenes and 2H‐Pyran‐2‐ones (=α‐Pyrones) from the Mangrove‐Derived Endophytic Fungus Fusarium proliferatum MA‐84

Two new tricyclic sesterterpenes, fusaprolifins A and B ( 1 and 2 ), and three new 2H‐pyran‐2‐one derivatives, prolipyrones A – C ( 3 – 5 ), were isolated and characterized from Fusarium proliferatum MA‐84, an endophytic fungus obtained from the fresh tissue of the marine mangrove plant Bruguiera sexangula. In addition, two known sesterterpenes, terpestacin ( 6 ) and fusaproliferin ( 7 ), and one known 2H‐pyran‐2‐one derivative, gibepyrone D ( 8 ), were also identified. The structures of these compounds were elucidated by detailed spectroscopic analyses. Fusaprolifin A ( 1 ) showed moderate activity against brine shrimp (Artemia salina), with a lethality rate of 49.5% at 100 μg/ml, while fusaprolifin B ( 2 ) showed weak activity.     

Biflavonoids,Lignans, and Related Compounds from the Roots of Diplomorpha canescens

Two new biflavonoids, 14″‐O‐methyldihydrodaphnodorin B ( 1 ) and 14″‐O‐methyldaphnodorin J ( 2 ), along with 16 known compounds, i.e., dihydrodaphnodorin B ( 3 ), daphnodorin J ( 4 ), 3″‐epidihydrodaphnodorin B ( 5 ), daphnodorin B ( 6 ), neochamaejasmin B ( 7 ), sikokianin B ( 8 ), (?)‐syringaresinol ( 9 ), (?)‐syringaresinol 4‐O‐β‐D ‐glucopyranoside ( 10 ), (+)‐nortrachelogenin ( 11 ), (?)‐lariciresinol ( 12 ), (?)‐pinoresinol ( 13 ), syringin ( 14 ), syringinoside ( 15 ), daphnoretin ( 16 ), phorbol 13‐acetate ( 17 ), and methyl paraben ( 18 ) were isolated from the roots of Diplomorpha canescens (Meisn.) C.A. Meyer . The structures were determined on the basis of spectroscopic data.     

Cytotoxic Naphtho‐γ‐pyrones from the Mangrove Endophytic Fungus Aspergillus tubingensis (GX1‐5E)

Four new dimeric naphtho‐γ‐pyrones, named rubasperone D ( 1 ), rubasperone E ( 2 ), rubasperone F ( 3 ), and its atropisomer rubasperone G ( 4 ), together with four known monomeric naphtho‐γ‐pyrones, TMC 256 A1 ( 5 ), rubrofusarin B ( 6 ), fonsecin ( 7 ), and flavasperone ( 8 ), were isolated from the mangrove endophytic fungus Aspergillus tubingensis (GX1‐5E) cultivated in solid rice medium. Their structures were elucidated by spectroscopic methods, including IR, 1D‐ and 2D‐NMR, and MS. In the in vitro cytotoxicity assays, 5 displayed inhibitory activities against tumor cell lines of MCF‐7, MDA‐MB‐435, Hep3B, Huh7, SNB19, and U87 MG with IC₅₀ values between 19.92 and 47.98 μM . Compounds 1, 6 , and 8 also showed mild cytotoxic activity.     

Structure Elucidation of Two New Diterpenoids from Isodon phyllostachys: Phyllostacins A and B

Two new ent‐kaurane‐derived diterpene derivatives, phyllostacins A ( 1 ) and B ( 2 ), were isolated from the aerial parts of Isodon phyllostachys, together with two known compounds, irroratin A ( 3 ) and serrin B ( 4 ). Both 1 and 2 were found to be present as diastereoisomers. In the case of 1 , the corresponding diastereoisomeric diacetates 5 and 6 were prepared and separated. The structures of the new compounds were elucidated by extensive 1D‐ and 2D‐NMR spectroscopic methods, in combination with MS experiments. In (D₅)pyridine solution, the two epimers of 1 are present in equal amounts, but in CDCl₃ or CD₃OD, the (S)‐epimer predominates in the mixture of hemiacetals.     

Lycodine‐Type Alkaloids from Lycopodium casuarinoides

Two new lycodine‐type alkaloids, huperzinine N‐oxide ( 1 ) and 8,15‐dihydrohuperzinine ( 2 ) as well as five known compounds, huperzinine ( 3 ), huperzine B ( 4 ), huperzine D ( 5 ), N‐demethylhuperzinine ( 6 ), and β‐obscurine ( 7 ), were isolated from the club moss Lycopodium casuarinoides. The structures of 1 and 2 were elucidated by spectroscopic methods and chemical transformation. The absolute configuration of 1 was established by chemical correlation with 3 , and that of 2 was determined by its CD spectrum.     

Sesquiterpenoids from the Fruits of Alpinia oxyphylla and Their Anti‐Acetylcholinesterase Activity

Fourteen sesquiterpenoids were isolated from the fruits of Alpinia oxyphylla Miq . Their structures were elucidated based on NMR analyses (¹H, ¹³C, DEPT, ¹H,¹H‐COSY, HMQC, HMBC, and NOESY) and identified as 12‐nornootkaton‐6‐en‐11‐one ( 3 ), (+)‐(3S,4aS,5R)‐2,3,4,4a,5,6‐hexahydro‐3‐isopropenyl‐4a,5‐dimethyl‐1,7‐naphthoquinone ( 5 ), nootkatene ( 6 ), 9β‐hydroxynootkatone ( 7 ), 2β‐hydroxy‐δ‐cadinol ( 8 ), 4‐isopropyl‐6‐methyl‐1‐tetralone ( 11 ), oxyphyllone E ( 12 ), oxyphyllone D ( 13 ), oxyphyllanene B ( 15 ), oxyphyllone A ( 16 ), oxyphyllol E ( 17 ), (9E)‐humulene‐2,3;6,7‐diepoxide ( 18 ), mustakone ( 20 ), and pubescone ( 21 ). Among them, 3 was a new norsesquiterpenoid, 8 was a new natural product, and 5, 6, 11, 20, 21 were isolated from A. oxyphylla for the first time. Twenty sesquiterpenoids, 1 – 5 and 7 – 21 , were investigated for their in vitro acetylcholinesterase (AChE) inhibitory activities, including previously isolated seven sesquiterpenoids from A. oxyphylla, (11S)‐12‐chloronootkaton‐11‐ol ( 1 ), (11R)‐12‐chloronootkaton‐11‐ol ( 2 ), nootkatone ( 4 ), oxyphyllenodiol A ( 9 ), oxyphyllenodiol B ( 10 ), 7‐epiteucrenone B ( 14 ), and alpinenone ( 19 ). TLC‐Bioautographic assay indicated that 1 – 4, 7, 14, 16, 18, 19 , and 21 displayed anti‐AChE activities at 10 nmol. Microplate assay confirmed that 19, 18, 16 , and 21 displayed moderate‐to‐weak anti‐AChE activities at the concentration of 100 μM , and 19 was the most potent inhibitor with an IC₅₀ value of 81.6±3.5 μM . The presence of anti‐AChE sesquiterpenoids in A. oxyphylla may partially support the traditional use of this fruit for the treatment of dementia.     

Three Unusual New Sesquiterpenes from Alpinia oxyphylla

Two new norcadinene sesquiterpenes oxyphyllones C and D ( 1 and 2 , resp.), and one new 1,10‐secoguaiane sesquiterpene, (+)‐mandassidion ( 3 ), together with two known compounds, oxyphyllenodiol B ( 4 ) and (1R,2R)‐p‐menth‐3‐ene‐1,2‐diol ( 5 ), were isolated from the fruits of Alpinia oxyphylla. Their structures were determined on the basis of spectroscopic analysis, including 2D‐NMR spectroscopic techniques. Compounds 1, 2 , and 3 exhibited no cytotoxicity against three cancer cell lines.     

Three New Chromanones from Calea clausseniana

Three new chromanones, uniflorol A acetate ( 1 ), uniflorol B acetate ( 2 ), and 2,2‐dimethyl‐6‐{1‐[(4′‐acetoxy)angeloyloxy]ethyl}chroman‐4‐one ( 3 ), together with the known chromanone 4 , and two known p‐hydroxyacetophenone derivatives, 5 and 6 , were isolated from the CH₂Cl₂ crude extract of the underground parts of Calea clausseniana Baker . The structures of the new compounds were elucidated by spectroscopic analyses, including 2D‐NMR techniques.     

Benzoannulation of Quinones by a Cycloaddition‐Fragmentation Approach. A Simple Synthesis of Methoxycarbonyl‐Substituted Polyacenoquinones

The cycloadducts 2A‐5A obtained from the Diels‐Alder cycloadditions of 1,2,3,4‐tetrachloro‐4,5‐dimethoxycyclopentadiene ( 1 ) with p‐benzoquinone ( 2 ), 1,4‐naphthoquinone ( 3 ), 1,4‐anthraquinone ( 4 ), and 2,3‐dicyano‐1,4‐benzoquinone ( 5 ) were subjected to the reaction with triethylamine in dichloromethane at room temperature. Cycloadducts 2A and 5A enolized to give the corresponding hydroquinones 2B and 5B , which were oxidized with DDQ to afford naphthoquinone ester 2D and anthraquinone ester 5D , respectively. In the cases of cycloadducts 3A and 4A , the enolization occurred concurrently with oxidation and fragmentation to produce directly the polyacenoquinone esters 3D and 4D , respectively. Under the same reaction condition, the unsymmetrical cycloadduct 6A derived from naphthoquinone ester 2D and 1 yielded isomeric polyacenoquinone esters 6Da and 6Db in a ratio of about 8:1.     

Prenylated Indole Alkaloid Derivatives from Marine Sediment‐Derived Fungus Penicillium paneum SD‐44

Three new prenylated indole alkaloids, including two β‐carbolines, penipalines A and B ( 1 and 2 , resp.), and one indole carbaldehyde derivative, penipaline C ( 3 ), as well as two known indole derived analogs, 4 and 5 , were isolated from the deep‐sea‐sediment derived fungus Penicillium paneum SD‐44 cultured in a 500‐l bioreactor. The structures of the new compounds were determined on the basis of 1D‐ and 2D‐NMR spectroscopy, as well as by high‐resolution mass spectrometry. The new compounds 2 and 3 showed potent cytotoxic activities against A‐549 and HCT‐116 cell lines.     

Bioactive Trichothecenes Produced by the Myrothecium sp. QB‐1

Three new simple trichothecenes, 15‐acetyltrichoverrol B ( 3 ), 13′‐acetyltrichoverrin B ( 5 ), and 6′‐dehydroxytrichoverrin B ( 6 ), along with five known trichothecenes trichodermadienediol B ( 1 ), trichoverrol B ( 2 ), trichoverrin B ( 4 ), and roridins A ( 7 ) and D ( 8 ), have been isolated from the liquid culture of Myrothecium roridum (strain no. QB‐1). The structures of the new compounds were established by comprehensive analysis of 1D‐ and 2D‐NMR data. All the compounds were evaluated for antifungal activity, only compounds 7 and 8 showed significant antifungal activity against the tested fungi (MIC ranged from 10 to 5 μg/ml).     

Novel Alkaloids from Stemona sessilifolia

Two new alkaloids, sessilifolines A ( 1 ) and B ( 2a ), were isolated from the stems of Stemona sessilifolia, together with three known alkaloids, tuberstemonine ( 3 ), sessilifoliamide A ( 4 ), and stemoninoamide ( 5 ). Their structures were established by mass‐spectrometric and spectroscopic methods, especially 2D‐NMR techniques.     

New and Bioactive Sesquiterpenes from Schisandra sphenanthera

Three new sesquiterpenes, schisansphenins A ( 1 ) and B ( 2 ) and (?)‐γ‐cuparenol ( 3 ), were isolated from an acetone extract of the fruits of Schisandra sphenanthera. The known compound 4 was isolated for the frist time from a natural source. The structures of the isolated compounds were elucidated through extensive spectroscopic analyses, particularly 2D‐NMR experiments (¹H,¹H‐COSY, HMQC, HMBC, and NOESY). A plausible biogenetic pathway for schisansphenin B ( 2 ) is proposed. Compounds 2 and 3 significantly reduced activation of NF‐AT and NF‐κB in the luciferase‐reporter assay.     

A New p‐Terphenyl Derivative from the Mushroom Thelephora vialis

One novel p‐terphenyl compound, named vialisyl A ( 1 ), was isolated from the fruiting bodies of Thelephora vialis, together with six known compounds, ganbajunin B ( 2 ), phenylacetic acid ( 3 ), a mixture of ganbajunins D ( 4 ) and E ( 5 ), and vialinins A ( 6 ) and B ( 7 ). Their structures were established by extensive analysis of spectroscopic data (including ¹H‐ and ¹³C‐NMR, HSQC, HMBC, 2D‐INADEQUATE) as well as by comparison with literature reports.     

New Tryptophan Metabolites from Cultures of the Lipophilic Yeast Malassezia furfur

Eleven new indole alkaloids were isolated from cultures of the human pathogenic yeast Malassezia furfur after addition of L ‐tryptophan as the sole N‐source: pityriacitrin B ( 2 ), the malassezindoles A ( 3 ) and B ( 4 ), malassezialactic acid ( 6 ), the malasseziazoles A ( 7 ), B ( 8 ), and C ( 9 ), pityriazole ( 10 ), malasseziacitrin ( 11 ), and malassezione ( 12 ), along with the known d‐ indole‐3‐lactic acid (=(αR)‐α‐hydroxy‐1H‐indole‐3‐propanoic acid 5 ), and 2‐hydroxy‐1‐(1H‐indol‐3‐yl)ethanone ( 13 ). The structural elucidation of these compounds was performed by spectroscopic methods (MS as well as 1D‐ and 2D‐NMR). The biogenetic relationships (Scheme) and biological activities of the new metabolites are discussed.     

Biflavones and Furanone Glucosides from Zabelia tyaihyonii

Two new biflavones, (aR)‐3′‐methoxycupressuflavone ( 1 ) and (aR)‐3′,3′′′‐dimethoxycupressuflavone ( 2 ), and two new furanone glucosides, zabeliosides A and B ( 3 and 4 , resp.), along with two known biflavones, cupressuflavone ( 5 ) and amentoflavone ( 6 ), were isolated from the leaves of Zabelia tyaihyonii. The structures of the new compounds were elucidated by 1D‐ and 2D‐NMR, HR‐ESI‐MS, and circular dichroism.     

A New Glycine Derivative and a New Indole Alkaloid from the Fermentation Broth of the Plant Endophytic Fungus Pestalotiopsis podocarpi Isolated from the Chinese Podocarpaceae Plant Podocarpus macrophyllus

A new glycine derivative, podocarpiamide ( 1 ), a new indole alkaloid, 1‐methoxy‐1H‐indol‐3‐ethanol ( 2 ), together with two known compounds, 1‐methoxy‐1H‐indole‐3‐acetic acid ( 3 ) and methyl 1‐methoxy‐1H‐indole‐3‐acetate ( 4 ), were isolated from the fermentation broth of the plant endophytic fungus Pestalotiopsis podocarpi. Their structures were elucidated by extensive spectroscopic analysis including 1D‐ and 2D‐NMR (HSQC, HMBC, and COSY) and MS experiments. Compound 1 has an interesting unusual carbamic acid structure.     

New C19－Diterpenoid Alkaloids from the Roots of Delphinium Giraldii

Three new C19-diterpenoid alkaloids, giraldines A (1), B (3) and C (4), were isolated from the roots of Delphinium giraldii Diels, together with three known C19-diterpenoid alkaloids, dihydrogadesine (5), tatsiensine (6) and siwanine A (7), as well as their structures were elucidated by chemical evidence and spectral analyses, including IR, MS, 1D NMR and 2D NMR.