Chemical Constituents from the Roots of Neolitsea hiiranensis

One triterpenoid, taraxerone ( 1 ); four germacrane-type sesquiterpene lactones, linderane ( 2 ), linderalactone ( 6 ), pseudoneolinderane ( 7 ), (+)-linderadine ( 8 ); one sesquiterpene dilactone, pseudoneoliacine ( 10 ); three elemane-type sesquiterpenes, isolinderalactone ( 3 ), compound 4 and sericealactone ( 9 ); one eudesmane type sesquiterpene, cryptomeridol ( 11 ); one glucoside, β-sitosterol-β-D-glucoside ( 12 ) along with β-sitosterol (5) were isolated from the roots of Neolitsea hiiranensis. The structures of these compounds were identified on the basis of spectral properties.     

Terpenoids—LXXII: Chemical studies of marine invertebrates—XXVI Δ9(12)-capnellene-3β,8β,10α,14-tetrol,a novel polyoxygenated sesquiterpene from the alcyonarian capnella imbricata

The structure determination of the new sesquiterpene, Δ9(12)-capnellene- 3β,8β,10α,14-tetrol 1, is described.     

Biotransformation of aristolane- and 2,3-secoaromadendrane-type sesquiterpenoids having a 1,1-dimethylcyclopropane ring by Chlorella fusca var. vacuolata, mucor species, and Aspergillus niger

Biotransformation of the aristolane-type sesquiterpene hydrocarbon (+)-1(10)-aristolene (1) from the crude drug Nardostachys chinensis and of the 2,3-secoaromadendrane-type sesquiterpene lactone plagiochilide (2) from the liverwort Plagiochila fruticosa by three microorganisms, Chlorella fusca var. vacuolata, Mucor species, and Aspergillus niger was investigated. C. fusca var. vacuolata and Mucor sp. introduced oxygen function into the cyclohexane ring of aristolene while A. niger oxidized stereoselectively one methyl of the 1,1-dimethyl group on the cyclopropane ring of aristolanes and 2,3-secoaromadendrane to give C-12 primary alcohol and C-12 carboxylic acid. The possible metabolic pathway of the formation of new metabolites is discussed. The stereostructures of new metabolites were established by a combination of NMR spectroscopy including HMBC and NOESY, X-ray crystallographic analysis, and chemical reaction.     

A New Phytotoxic Sesquiterpene from Inula japonica

Chemistry of Natural Compounds - A new eudesmane sesquiterpene, 12-acetoxy-1β,2α-dihydroxyeudesma-4(15),11(13)-diene (1), was isolated from Inula japonica. The chemical structure of...     

Stereocontrolled total synthesis of (±)-Δ9(12)-capnellene

The first total synthesis of the marine triquinane sesquiterpene Δ⁹⁽¹²⁾-capnellene ($\text{1}$) is described.     

Trichodiene Synthase: Synthesis and Inhibition Kinetics of 12‐Fluoro‐farnesylphosphonophosphate for Sesquiterpene Cyclases

trans, trans‐Farnesyl diphosphate (FPP) serves as a universal substrate for a large family of sesquiterpene cyclases that are responsible for biosynthesis of more than 300 structurally diverse sesquiterpenes in nature. A new FPP substrate analogue, 12‐fluoro‐farnesylphosphonophosphate (12‐F‐F‐CH₂PP), was synthesized in this paper for applications on kinetic and mechanistic studies of the enzyme family. Trichodiene synthase (TS), a sesquiterpene cyclase, catalyzes the conversion of trans, trans‐farnesyl diphosphate (FPP) to trichodiene. 12‐F‐F‐CH₂PP was tested as a potential inhibitor of TS. Inactivation and inhibition kinetic experiments showed that 12‐F‐F‐CH₂PP was not a mechanism‐based inactivator for TS; instead, a mixed‐type reversible inhibition was observed with inhibition constants K_i1 = 2.33 ± 0.50 μM and K_i2 = 25.80 ± 7.70 μM, values close to those previously determined for farnesylphosphonophosphate, K_i1 = 3.25 μM and K_i2 = 9.10 μM. Although 12‐F‐F‐CH₂PP did not irreversibly inactivate TS, this new analogue serves as a potential active‐site directed inactivator and mechanistic probe of other sesquiterpene cyclases and FPP‐utilizing enzymes, which utilize FPP as a common acyclic substrate.     

A diastereoselective total synthesis of the sesquiterpene (±)-mutisianthol

The total synthesis of the phenolic sesquiterpene mutisianthol has been accomplished in 12 steps from the readily available 2-methylanisole. The required trans-1,3-disubstituted indan intermediate was obtained through a diastereoselective thallium(III) mediated ring contraction of a 1-methyl-1,2-dihydronaphthalene derivative.     

A New Sesquiterpene from the Roots of Chloranthus multistachys

Chemistry of Natural Compounds - A new sesquiterpene, 1β-hydroxy-4(5),7(8),11(12)-triene-6,9-dione-7,8-furanoeudesmane (1), was isolated from the root extract of Chloranthus multistachys C....     

Structure elucidation and complete NMR spectral assignments of a novel sesquiterpene glycoside from Ixeris sonchifolia

A novel sesquiterpene glycoside was isolated from the whole plant of Ixeris sonchifolia. The structure was established as 1(10)E-4Z-3alpha-hydroxy-germacra-1(10),4,11(13)-trien-6, 12-olide-14-O-beta-D-glucopyranoside (1) on the basis of spectroscopic techniques and chemical analysis.     

无患子皂苷成分的串联质谱分析

我们采用电喷雾串联质谱直接对无患子总皂苷中各皂苷成分进行鉴定. 该方法方便快捷, 适合于无患子或其它皂苷混合物的快速分析.     

STRUCTURE OF VERSICOLACTONE A,A NOVEL SESQUITERPENE LACTONE FROM ARISTOLOCHIA VERSICOLAR S.M.HWANG

A novel sesquiterpene tactone,versicolactone A,with 12-carbonring skeleton,has been isolated from the roots of Aristolochia versicolarS.M.Hwang,and the structure was elucidated on the basis of 2D NMR and MSspectral data.     

A New Acyclic Sesquiterpene Oligoglycoside from Pericarps of Sapindus mukurossi

A new acyclic sesquiterpene oligoglycoside, named mukurozioside A, was isolated from pericarps of Sapindun mukurossi. On the basis of chemical and spectral evidence, the structure of mukurozioside A has been established as:11(S)-2,6(E,E)-dodecadiene-3,7,11-trimethyl-1,12-diol-1,12-bis-O-α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→3)]-6-O-acetyl-β-D-Glucopyranoside(1).     

Sesquiterpene Lactone Glycosides from Carpesium macrocephalum

Two new sesquiterpene lactone glycosides were isolated from the seeds of Carpesium meacrocephalum. Their structures were elucidated as 2α-O-β-D-glucopyranosy-5α,11αH-eudesma-4(15)-en-12,8β-olide and 2α-O-β-D-glucopyranosy-5αH-eudesma-4(15),11(13)-dien-12,8β-olide by spectral methods (HRMS,1D and 2D NMR).     

Struktur und stereochemie eines sesquiterpen-esters und dreier sesquiterpen-alkaloide von Celastrus paniculatus Willd

A new sesquiterpene ester (Malkangunin) and three sesquiterpene alkaloids (Celapanin, Celapanigin, Celapagin) were isolated from Celastrus paniculatus Willd. The complete structure and stereochemistry of Malkangunin, a sesquiterpene tetra-ol of the β-dihydroagarofurane type two of whose hydroxyls being esterified with acetic and benzoic acids, is discussed. The alkaloids described here are derived from a new sesquiterpene tetra-ol (Celapanol) which is alternately esterified with acetic, benzoic, nicotinic and β-furoic acids.     

Anti-inflammatory sesquiterpenes from Curcuma zedoaria

From the methanolic extract of the rhizome of Curcuma zedoaria, we isolated anti-inflammatory sesquiterpene furanodiene (1) and furanodienone (2) along with new sesquiterpene compound 3 and known eight sesquiterpenes, zederone (4), curzerenone (5), curzeone (6), germacrone (7), 13-hydroxygermacrone (8), dehydrocurdione (9), curcumenone (10), and zedoaronediol (11). Their structures were elucidated on the basis of spectroscopic data. The anti-inflammatory effect of isolated components on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation of mouse ears were examined. Compounds 1 and 2 suppressed the TPA-induced inflammation of mouse ears by 75% and 53%, respectively, at a dose of 1.0 micromol. Their activities are comparable to that of indomethacin, the normally used anti-inflammatory agent.     

Application of the intramolecular magnesium-ene reaction to the stereocontrolled total syntheses of (±)-12-acetoxysinularene and (±)-5-epi-12-acetoxysinularene

The sesquiterpene (±)-12-acetoxysinularene (1) and its C(5)-epimer (13) were each synthesized stereoselectively from the norbornyl-iodoacetal 7 in 5% and 7% overall yields. The critical step (10) → (11) involves the regio- and stereoselective “magnesium-ene” reaction (6) → (5).     

Chemical Constituents from Notoseris Species

The genus Notoseris (Asteraceae) comprising of 14 species is endemic in China^[1]. Two new sesquiterpene lactones,notoserolides A and B,along with 12 known compounds were isolated from the aerial parts of N. Porphyrolepis^[2], but nothing is known about secondary metabolites of other N species.     

First total synthesis of heterocurvistone

The sesquiterpene ketone (±)-heterocurvistone was synthesized in eight steps and 12% overall yield from known methyl R-(+)-3-(4-methyl-3-cyclohexen-1-yl)-3-butenoate, readily available from R-(+)-limonene. The key synthetic step is an oxymercuration-induced cyclization.     

Iodo–sesquiterpene hydroquinone and brominated indole alkaloids from the Thai sponge Smenospongia sp.

6′-Iodoaureol, an iodo–sesquiterpene hydroquinone, 6′-aureoxyaureol, a bissesquiterpene hydroquinone, and four brominated indole alkaloids 3–6 were isolated from the Thai sponge Smenospongia sp. Additionally, four known sesquiterpene hydroquinones 12–15, ten known brominated indole alkaloids 7–11, 17–18, and 20–22, ergosterol, and furospinosulin-1 were also isolated. Compound 1 is the first reported iodo–sesquiterpene hydroquinone and compounds 7–11 were isolated for the first time from natural sources. The structures were characterized by spectroscopic analyses as well as comparison with literature data. Several of these metabolites were evaluated for cytotoxic activity against seven tumor cell lines.