Eremophilane Sesquiterpenoids from Coleus xanthanthus

A new eremophilane sesquiterpenoid, along with two known ones, was isolated from the ethyl acetate soluble fraction of the aerial part of Coleus xanthanthus C. Y. Wu et Y. C. Huang. Their structures were elucidated as 4,5,11_trimethyl_8,9_seco_1(10),7(11)_eremophiladien_8,12_olid_9_oic acid (1), 2,9_dioxoeuryopsin (2) and 9_oxoeuryopsin (3) by spectral methods. The 1H_NMR and 13 C NMR data of compounds 1, 2 and 3 were unambiguously assigned on the basis of two_dimensional NMR spectroscopy.

Two novel fomannosane-type sesquiterpenoids from the culture of the basidiomycete Agrocybe salicacola

Two novel fomannosane-type sesquiterpenoids,agrocybins H(1)and I(2),together with a known compound illudosin(3),were isolated from the culture broth of the mushroom Agrocybe salicacola.Their structures were elucidated by extensive spectroscopic analysis.The relative stereochemistry of 1 was determined by the use of single crystal X-ray crystallographic diffraction.

Drimane Sesquiterpenoids and Isochromone Derivative from the Endophytic Fungus Pestalotiopsis sp. M-23

Three new drimane sesquiterpenoids(1–3)together with the known 2a-hydroxyisodrimeninol(4),and a new isochromone derivative(5),were obtained from the solid cultures of fungal strain Pestalotiopsis sp.M-23,an endophytic fungus isolated from the leaves of Leucosceptrum canum(Labiatae).Their structures were determined by comprehensive 1D and 2D NMR,and MS analyses.The metabolites were evaluated for their antibacterial activities,and compound 3 showed weak inhibitory activity against Bacillus subtilis.

Drimane sesquiterpenoids from a wetland soil-derived fungus Aspergillus calidoustus TJ403-EL05

Soil-derived fungi represent an insufficiently tapped reservoir for discovering new and bioactive natural products(NPs),and despite an ever-increasing number of unknown NPs have been discovered over the past few decades,much of the hidden biosynthetic potential is still in an urgent need to be disclosed.In this research,a chemical inves-tigation was performed on a wetland soil-derived fungus Aspergillus calidoustus TJ403-EL05,leading to the isolation of a total of fourteen drimane sesquiterpenoids(1-14),incorporating three new ones,namely ustusols F-H(1-3).Their structures,comprising absolute configurations,were completely authenticated by widespread spectroscopic data,quantum chemical 13C NMR and ECD calculations,and X-ray crystallography experiments.Compound 14 exhibited moderate anti-inflammatory activity by inhibiting the LPS-induced NO release(IC_(50)=25.6μM).

Sesquiterpenoids from the Rhizomes of Homalomena occulta

Naturally occurring oplopanane sesquiterpenoids are rarely reported.A phytochemical investigation on the rhizomes of Homalomena occulta(Lours)has resulted in the discovery of six oplopanane sesquiterpenoids(1–6),including four new(1–4)and one 3,5-seco-oplopanane(6),together with three previously reported sesquiterpenoids(7-9).In addition three new oplopananes(2a–4a)were also obtained by chemical transformation.All structures of these sesquiterpenoids were established based on the comprehensive spectroscopic analyses,including NMR,MS,and IR,and comparing with the literatures.

Sesquiterpenoids and 2-(2-Phenylethyl)chromone Derivatives from the Resinous Heartwood of Aquilaria sinensis

One novel spirolactone,aquilarisinolide(1),three new sesquiterpenoids,(2R,4S,5R,7R)-2-hydroxyeremophila-9,11-dien-8-one(2),(1R,4S,5S,7R,11R)-13-hydroxyepidaphnauran-9-en-8-one(3),and(4R,5S,7R,8S,10S,13R)-8,13-dihydroxyrotunda-1,11-dien-3-one(4),together with 13 known compounds(5-17)were isolated from the resinous heartwood of Aquilaria sinensis(Thymelaeaceae).The structures of the new compounds were elucidated based on the analysis of NMR and MS data and theoretical calculations their ECD spectra.The isolated compounds were evaluated for their protective activities against PC12 cell injury induced by corticosterone(CORT)and 1-methyl-4-phenylpyridine ion(MPP+),as well as inhibitory activities against BACE1.Compound 4,5,6-dihydroxy-2-(2-phenylethyl)chromone(5),daphnauranol B(7),6-methoxy-2-[2-(3-methyoxyphenyl)ethyl]chromone(10),isoagarotetrol(14),and 1-hydroxy-1,5-diphenylpentan-3-one(16)showed significant protective effects on CORT-induced injury in PC12 cells at a concentration of 20μM(P<0.001).Isoagarotetrol(14)showed a significant protective effect on MPP+-induced injury in PC12 cells at a concentration of 20μM(P<0.001),while compound 4 showed a moderate activity(P<0.01).The BACE1-inhibitory activities of all tested compounds were very weak with less than 30%inhibition at a concentration of 20μM.

New Azulene-Type Sesquiterpenoids from the Fruiting Bodies of Lactarius deliciosus

In the^(1)H NMR-guided fractionation of extracts from the edible mushroom Lactarius deliciosus,two new azulene-type sesquiterpenoids,7-isopropenyl-4-methyl-azulene-1-carboxylic acid(1)and 15-hydroxy-3,6-dihydrolactarazulene(2),together with seven known compounds were characterized.Their structures were determined on basis of spectroscopic evidence,as well as by comparing with literature data.Amongst the known metabolites,the^(13)C NMR assignment of 15-hydroxy-6,7-dihydrolactarazulene(3)is reported here for the first time.Moreover,7-acetyl-4-methylazulene-1-carbaldehyde(5)displayed a moderate antibacterial activity against Staphylococcus aureus.

Two New Eudesmane Sesquiterpenoids from the Flowers of Chrysanthemum indicum

The fowers of Chrysanthemum indicum,i.e.Ye-ju-hua recorded in the Chinese Pharmacopoeia,has been widely used in China as an important heat-clearing and detoxifying herb for the treatment of infammation,headache,and vertigo.A phytochemical investigation of this herb has led to the isolation of two new eudesmane sesquiterpenoids,7-epi-eudesm4(15),11(13)-diene-1β,3β-diol(1)and 7-epi-1β-hydroxy-β-eudesmol(2).The molecular structures of these new sesquiterpenoids were established based on the comprehensive spectroscopic analyses,including NMR,MS,and IR,and comparing with the literatures.

Two new drimane sesquiterpenoids from cultures of the basidiomycete Trichaptum biforme

Two new drimane sesquiterpenoids(1 and 2),as well as five known compounds(3-7),were isolated from the basidiomycete Trichaptum biforme.The structures of new compounds were elucidated by extensive spectroscopic methods,and the known compounds were identified by comparing their spectroscopic data with those reported in the literature.The cytotoxicities results against five human cancer cell lines of compounds 1 and 2 were negligible.

Two Eremophilane-type Sesquiterpenoids from the Rhizomes of Ligularia veitchiana(Hemsl.) Greenm

Two eremophilane-type sesquiterpenoids from the rhizomes of Ligularia veitchiana（Hemsl.） Greenm were isolated and determined as 10α,11-endoperoxide-1（2）-en-7α-hydroeremophilane（1） and 1（10）-en-2-oxo-7α-isopropanol-eremophilane（2）.Compound 1 was a new compound and compound 2 was a new natural product.The structures of the two compounds were established by means of spectral methods including 1^H NMR,13^C NMR,2D NMR and MS.

The new synthesis of sesquiterpenoids 10-bromo-α-chamigrene

The new synthesis of 10-bromo-α-chamigrene was achieved as follows; 6-methyl-5-heptene-2-one was transformed into corresponding thioacetals, and then successively treated with Cp2Ti（P（OEt）3）2. The intermediate reacted with mono-ketal of cyclohexane-1,4-dione, and gave the carbonyl coupling product. It was then transformed into the key intermediate γ-bisabolene via deketalization, Grignard reaction, dehydration and then furnished the target molecule by polyene cyclization, with total yield 2%. All structures were confirmed by ^1H NMR and ^13C NMR. The final compound was confirmed by ^1H NMR, ^13C NMR and MS.

Five new 2-(2-phenylethyl)chromone derivatives and three new sesquiterpenoids from the heartwood of Aquilaria sinensis, an aromatic medicine in China

Five new 2-(2-phenylethyl)chromone derivatives,(5S,6R,7R,8S,7ʹR)-7ʹ-hydroxyagarotetrol(1),(5S,6R,7R,8S,7ʹS)-7ʹ-hydroxyagarotetrol(2),(6S,7S,8R)-2-[2-(4-methoxyphenyl)ethyl]-6,7,8-trihydroxy-5,6,7,8-tetrahydrochromone(3),(6S,7S,8R)-2-(2-phenylethyl)-6,7,8-trihydroxy-5,6,7,8-tetrahydrochromone(4),(5S,6R,7S,8R)-2-(2-phenylethyl)-5,6,7-trihydroxy-5,6,7,8-tetrahydro-8-[2-(2-phenylethyl)-7-methoxychromonyl-6-oxy]chromone(5),three new sesquiterpenoids,(4S,5S,7S,8S,10S,13R)-7,8,13-trihydroxyrotunda-1,11-dien-3-one(6),(4S,5S,7S,8S,10S,13S)-7,8,13-trihydroxyrotunda-1,11-dien-3-one(7),and(4R,5S,7S,8S,10S,13S)-7,8,13-trihydroxyrotunda-1,11-dien-3-one(8),along with 14 known compounds were isolated from the resinous heartwood of Aquilaria sinensis(Thymelaeaceae).The chemical structures of these new compounds were elucidated by 1D and 2D NMR and MS data,single-crystal X-ray diffraction analysis,and electronic circular dichroism(ECD)calculations.The neuroprotective activities of these isolates were evaluated using an in vitro model of rat adrenal pheochromocytoma(PC12)cell injury induced by corticosterone.At concentrations from 5 to 40μM,compounds 4 and 6,agarotetrol(9),and 6-hydroxy-2-(2-phenylethyl)chromone(17)showed significant protective activities against corticosterone-induced PC12 cell injury(P<0.001).

Lignans and sesquiterpenoids from the stems of Schisandra bicolor var. tuberculata

A pair of new tetrahydrofuran lignan enantiomers,(±)-schibiculatin A[(±)-1],a new enedione lignan,schibiculatin B(2),two new cadinane-type sesquiterpenoids,schibiculatins C(3)and D(4),along with two known seco-cadinane-type sesquiterpenoids(5 and 6)and seven known miscellaneous lignans(7-13)were isolated from the stems of Schisandra bicolor var.tuberculata.The structures of 1-4 were elucidated by comprehensive analysis of their spectro-scopic data,quantum chemical calculations,as well as single-crystal X-ray diffraction.A few isolated compounds were tested for their protective activities against corticosterone-induced apoptosis in PC12 cells.Among them,compounds 5 and 6 showed moderate activities.

Five new 5,6-seco-tremulane sesquiterpenoids from the basidiomycete Conocybe siliginea

Five new 5,6-seco-tremulane sesquiterpenoids(1-5),as well as three known analogues(6-8),were isolated from the basidiomycete Conocybe siliginea.The structures of new compounds were elucidated by extensive spectroscopic methods.The known compounds were identified by comparing their spectroscopic data with those reported in the literature.

New Sesquiterpenoids from Hedychium yunnanense gagnep

Two new sesquiterpenoid trialcohol isomers named 1 beta, 4 alpha 11 alpha -trihydroxyeudesmane (1) and Yunnanensehedychetriol (2), were isolated from the fresh rhizomes of Hedychium Yunnanense gagnep. Their structures were elucidated by spectroscopic methods.

Non-isoprenoid botryane sesquiterpenoids from basidiomycete Boletus edulis and their cytotoxic activity

Three non-isoprenoid botryane sesquiterpenoids,named boledulins A-C(1-3),have been isolated from the cultures of basidiomycete Boletus edulis Bull.The structures were established by means of spectroscopic methods.Boledulin A(1)exhibited moderate inhibitory activity against five human cancer cell lines.

Seco-sativene and Seco-longifolene Sesquiterpenoids from Cultures of Endophytic Fungus Bipolaris eleusines

Two new seco-sativene sesquiterpenoids,bipolenins D(1)and E(2),a new seco-longifolene sesquiterpenoid,bipolenin F(3),together with three known analogues(4–6),were obtained from cultures of endophytic fungus Bipolaris eleusines.Their structures were established by MS and NMR data.Compounds 1–6 showed no activity to five human cancer cell lines.

Cytosporinols A-C,new caryophyllene sesquiterpenoids from Cytospora sp.

Three new caryophyllene sesquiterpenoids,cytosporinols A-C(1-3),have been isolated from solid cultures of Cytospora sp.The structures of 1-3 were elucidated primarily by NMR spectroscopy,and 3 was further confirmed by X-ray crystallography.The absolute configurations of the C-11 secondary alcohol in 1 and the 6,8-diol moiety in 3 were deduced using the modified Mosher and Snatzke’s method,respectively.Compounds 2 and 3 showed moderate cytotoxicity against HeLa cells.

Antioxidant bisabolane-type sesquiterpenoids from algalderived fungus Aspergillus sydowii EN-434

A new aromatic bisabolene-type sesquiterpenoid(7 S,8 S)-8-hydroxysydowic acid(1),together with a pair of new bisabolene derivative(±)-(7 R*,10 R*)-10-hydroxysydowic acid(2),as well as two known analogues hydroxysydonic acid(3)and sydowic acid(4)were isolated and identifi ed from the endophytic fungal strain Aspergillus sydowii EN-434 that was obtained from the marine red alga Symphyocladia latiuscula.Their structures were elucidated by nuclear magnetic resonance(NMR),high resolution electrospray ionization mass spectroscopy(HRESIMS),and quantum chemical electronic circular dichroism(ECD)calculations as well as comparison of the data with literature reports.Compound 1 exhibited potent DPPH free radical scavenging activity with IC 50 value of 113.5μmol/L.

Unusual illudin-type sesquiterpenoids from cultures of Agrocybe salicacola

Seven new illudin-type sesquiterpenoids,agrocybins A-G(1-7),along with three known analogues(8-10),have been isolated from the culture broth of the fungus Agrocybe salicacola.Their structures were elucidated on the basis of extensive spectroscopic data analysis and comparison with data reported in the literature.The relative stereoconfigurations of 1 and 6 were elucidated by the X-ray crystallographic diffraction analysis.Compound 1 was highly cyclized containing seven chiral carbons which arranged compactly in six rings.