Two New C‐seco Limonoids from the Fruit of Melia azedarach

A phytochemical investigation of the fruits of Melia azedarach led to the isolation of two new C‐seco‐nimbolinin‐type limonoids, 3α‐acetoxy‐1α,7α‐dihydroxy‐12α‐methoxynimbolinin ( 1 ) and 3α‐acetoxy‐1α,12α‐dihydroxy‐7α‐(2‐methylprop‐2‐enoyl)nimbolinin ( 2 ), together with eleven known compounds, 3 – 13 . Their structures were elucidated on the basis of extensive spectroscopic analysis, including ¹H‐ and ¹³C‐NMR, HMQC, HMBC, NOESY, and HR‐FAB‐MS.     

New limonoids from the fruits of Melia toosendan

<正>Two new limonoids,1α-tigloyloxy-3α-acetoxyl-7α-hydroxyl-12α-ethoxyl nimbolinin(1) and lα-benzoyloxy-3α-acetoxyl-7α- hydroxyl-12α-ethoxyl nimbolinin(2),were isolated from the fruits of Melia toosendan.Their structures were established on the basis of various NMR spectroscopic analyses,including 2D-NMR techniques(HSQC,HMBC,NOESY) and HR-ESI-MS.     

Triterpenoids from Melia toosendan

Eleven new triterpenoids, named mesendanins K–U ( 1 – 11 , resp.), together with seven known analogs, were isolated from the leaves and twigs of Melia toosendan. Their structures were elucidated on the basis of extensive spectroscopic analysis.     

New lactoyl glycoside quercetin from <Emphasis Type="Italic">Melia azedarach</Emphasis> leaves

In the course of phytochemical investigations of Melia azedarach leaves, a novel cinnamoyl glycoside, cinnamoyl-1-α-L-rhamnoside (1), and a novel acylated quercetin triglycoside, quercetin-3-O-[rhamnosyl 1→6(4″-lactoyl glucoside)]-4′-O-glucoside (2), have been isolated and characterized on the basis of spectroscopic methods, together with the six known flavonoid compounds kaempferol-3-O-rutinoside, 3-O-rhamnoside, quercetin-3-O-rutinoside, 3-O-rhamnoside, and the aglycones quercetin and kaempferol. All isolated compounds have been evaluated for their structures by chromatographic methods, chemical degradation, and UV and NMR spectroscopy. The antioxidant activity of the extract was studied as well. Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 12–14, January–February, 2008.     

Limonoids from the aerial parts of Munronia pinnata

Six new limonoids, munropins A?F (1–6), were isolated from the aerial parts of a Chinese medicinal plant, Munronia pinnata (Meliaceae). The structures of 1–6 were assigned by detailed analyses of their spectroscopic data. Munropins A (1) and B (2) are limonoids possessing a prieurianin skeleton with α,β-unsaturated γ-lactam moieties at C-17. Munropins C (3), D (4), and E (5) are also prieurianin type limonoids with an α,β-unsaturated γ-lactone moiety, an acetyl group, and an acetoxyacetyl group at C-17, respectively. Munropin F (6) was assigned as a nimbolinin type limonoid with a γ-hydroxy-α,β-unsaturated γ-lactone moiety.     

Meliarachins A–K: Eleven Limonoids from the Twigs and Leaves of Melia azedarach

Eleven new limonoids, meliarachins A–K ( 1 – 11 , resp.), together with five known ones, were isolated from the twigs and leaves of Melia azedarach. The structures of the new compounds were elucidated on the basis of spectroscopic analysis. Compounds 4 and 8 exhibited moderate antibacterial activities against Gram‐positive bacteria.     

Two New Trijugin‐Type Limonoids from Cipadessa cinerascens

Two new trijugin‐type limonoids, cipatrijugins G and H ( 1 and 2 , resp.) along with four known limonoids, were isolated from the leaves of Cipadessa cinerascens. All structures were elucidated on the basis of spectroscopic analyses, including IR, 1D‐ and 2D‐NMR, and ESI‐MS and HR‐ESI‐MS techniques.     

A New Isoflavanol from the Fruits of Kotschya strigosa (Fabaceae)

The phytochemical investigation of the MeOH extract from fruits of Kotschya strigosa using repeated normal and reversed‐phase column chromatography and Sephadex LH‐20 chromatography led to the isolation and characterization of a new isoflavanol, named kotstrigoisoflavanol ( 1 ), together with three known compounds, diosmetin ( 2 ), β‐sitosterol ( 3 ), and the 3‐O‐β‐d‐glucopyranoside of β‐sitosterol ( 4 ). The antioxidant activity of crude extract, 1, and 2 was determined using the 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH˙) method. The crude extract (IC₅₀ 61.7 ± 0.2 μg/ml) and 2 (IC₅₀ 70.2 ± 0.1 μg/ml) showed moderate antioxidant activities, while 1 was weakly active (IC₅₀ 153.1 ± 0.1 μg/ml), as compared with the standard reference l ‐ascorbic acid (IC₅₀ 21.9 ± 0.0 μg/ml).     

Seco‐Tremulanes from Cultures of the Basidiomycete Flavodon flavus BCC 17421

A new seco‐tremulane, 11,12‐epoxy‐5,6‐secotremula‐1,6(13)‐dien‐5,12‐olide ( 1 ), was isolated together with the known compounds, conocenolides A ( 2 ) and B ( 3 ), tremulenediol A ( 4 ), tremulenolide A ( 5 ), and two lanostane triterpenoids, trametenolic acid B ( 6 ), and pinicolic acid A ( 7 ), from cultures of the basidiomycete Flavodon flavus BCC 17421. Interconversion of conocenolides A/B was demonstrated. Compound 1 exhibited weak cytotoxic activities, whereas tremulenediol A showed antiplasmodial activity (IC₅₀ 8.6 μg/ml). Pinicolic acid A exhibited activity against herpes simplex virus type‐1 (IC₅₀ 15 μg/ml) as well as cytotoxic activities.     

Two New Flavonoids from Derris eriocarpa How

Two new flavonoids, 1 and 2 , together with two known flavonoids, tephrosin ( 3 ) and 12a‐hydroxy‐α‐toxicarol ( 4 ), were isolated from the whole herb of Derris eriocarpa How . The structures and absolute configurations of the new compounds were elucidated on the basis of their MS, NMR, and ECD data. The structures of the known compounds were established by extensive spectroscopic (MS, 1D‐ and 2D‐NMR) analyses and comparison with the literature data. All compounds were isolated from D. eriocarpa for the first time. Compound 3 showed modest inhibitory activities against the growth of human cancer cells HEL and A549 with the IC₅₀ values of 15.03 ± 0.62 and 13.27 ± 0.39 μm , respectively.     

Three New Pregnane Alkaloids from Pachysandra terminalis

Three new pregnane alkaloids, pachystermine C ( 1 ), pachysanamine A ( 2 ), and pachysanamine B ( 3 ), together with four known ones, pachystermine B ( 4 ), pachysamine A ( 5 ), (20S)‐20‐(dimethylamino)‐16α‐hydroxy‐3β‐(3′α‐isopropyl)lactam‐5α‐pregnan‐4‐one ( 6 ), and E‐salignone ( 7 ), were isolated from Pachysandra terminalis. The chemical structures of the new alkaloids were elucidated by spectroscopic methods. All the compounds were evaluated for their inhibitory activities against HL‐60, SMMC‐7721, A‐549, MCF‐7, and SW480 cell lines, some of the compounds showed stronger cytotoxicity for the test cell lines, especially compounds 2 , 3 , and 7 .     

Aphagranols D – H: Five New Limonoids from the Fruits of Aphanamixis grandifolia

Five new limonoids, aphagranols D–H ( 1 – 5 , resp.), were isolated from the EtOH extract of the fruits of Aphanamixis grandifolia by chromatographic methods. Their structures were established on the basis of extensive spectroscopic analyses. The absolute configuration of 1 was determined by comparison the experimental and calculated electronic circular dichroism (ECD) spectra. All of the isolates were evaluated for insecticidal activities.     

New ent‐Pimarane Diterpenes from the Roots of Aralia dumetorum

Four new ent‐pimarane diterpenes were isolated from the EtOH extract of Aralia dumetorum, together with three known compounds involving ent‐pimar‐8(14),15‐dien‐19‐oic acid ( 5 ), ent‐pimar‐8(14),15‐dien‐19‐ol ( 6 ), and ent‐kaur‐16‐en‐19‐oic acid ( 7 ). By detailed analyses of the MS, IR, and NMR data, the structures of four new diterpenes were characterized as (5β,9β,10α,13α)‐pimara‐6,8(14),15‐trien‐18‐oic acid ( 1 ), (5β,7β,9β,10α,13α)‐7‐methoxypimara‐8(14),15‐dien‐18‐oic acid ( 2 ), (5β,9β,10α,13α,14β)‐14‐methoxypimara‐7,15‐dien‐18‐oic acid ( 3 ), and (5β,10α,13α,14α)‐14‐hydroxypimara‐7,9(11),15‐trien‐18‐oic acid ( 4 ). The cytotoxic activities of compounds 1  –  7 were assayed in vitro through MTT method.     

Two New Cyclic Tetrapeptides of Streptomyces rutgersensis T009 Isolated from Elaphodus davidianus Excrement

Two new cyclic tetrapeptides, cyclo(l ‐Val‐l ‐Leu‐l ‐Val‐l ‐Ile) ( 1 ) and cyclo(l ‐Leu‐l ‐Leu‐l ‐Ala‐l ‐Ala) ( 2 ), and 15 known compounds, cyclo(Gly‐l ‐Leu‐Gly‐l ‐Leu) ( 3 ), cyclo(l ‐Ser‐l ‐Phe) ( 4 ), cyclo(l ‐Leu‐l ‐Ile) ( 5 ), cyclo(l ‐Tyr‐l ‐Phe) ( 6 ), cyclo(Gly‐l ‐Trp) ( 7 ), cyclo(l ‐Leu‐l ‐Tyr) ( 8 ), cyclo(Gly‐l ‐Phe) ( 9 ), cyclo(l ‐Phe‐trans‐4‐hydroxy‐l ‐Pro) ( 10 ), cyclo(l ‐Leu‐l ‐Leu) ( 11 ), cyclo(l ‐Val‐l ‐Phe) ( 12 ), cyclo(l ‐Val‐l ‐Leu) ( 13 ), cyclo(l ‐Ile‐l ‐Ile) ( 14 ), cyclo(l ‐Tyr‐l ‐Tyr) ( 15 ), turnagainolide A ( 16 ), and bacimethrin ( 17 ) were isolated from the fermentation broth of Streptomyces rutgersensis T009 obtained from Elaphodus davidianus excrement. Their structures were identified on the basis of spectroscopic analysis. Meanwhile, the absolute configurations of the amino acid residues of compounds 1 and 2 were determined by advanced Marfey method. Compound 3 was obtained from a natural source for the first time. The X‐ray single crystal diffraction data of bacimethrin ( 17 ) were also reported for the first time. Compounds 1  –  17 exhibited no antimicrobial activities with the MICs > 100 μg/ml.     

Anti‐Inflammatory Activity of a Novel Acetylene Isolated from the Roots of Angelica tenuissima Nakai

Three polyacetylenes, one novel and two known, were isolated from the root of Angelica tenuissima. Using ¹H‐ and ¹³C‐NMR, COSY, HMBC, and HMQC, their structures were found to be (3R,8S)‐heptadeca‐1‐en‐4,6‐diyne‐3,8‐diol ( 1 ), falcarindiol ( 2 ), and oplopandiol ( 3 ). Absolute configurations of compound 1 were established using Mosher's esterification. In addition, the polyacetylenes ( 1 – 3 ) were evaluated for their anti‐inflammatory activity. Compounds 1 and 3 showed potent inhibitory activity against lipopolysaccharide‐induced nitric oxide (NO) production in RAW267.7 macrophage cells with IC₅₀ values of 4.31 and 5.06 μm, respectively. Compound 1 strongly inhibited inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)‐2 in a concentration‐dependent manner.     

Three New Abietane‐type Diterpenes from the Bark of Cryptomeria japonica

Three new abietane‐type diterpenoids, 7β‐acetoxy‐12‐methoxyabieta‐8,11,13‐triene‐6α,11‐diol ( 1 ), 7α‐acetoxy‐12‐methoxyabieta‐8,11,13‐triene‐6α,11‐diol ( 2 ), and 6α‐acetoxy‐12‐methoxyabieta‐8,11,13‐triene‐7α,11‐diol ( 3 ), as well as two known abietane‐type diterpenoids, 12‐methoxyabieta‐8,11,13‐triene‐6α,7β,11‐triol ( 4 ) and 6α‐acetoxy‐12‐methoxyabieta‐8,11,13‐triene‐7β,11‐diol ( 5 ), were isolated from the MeOH extract of the bark of Cryptomeria japonica. Their structures were determined by analysis of spectroscopic data and comparison of NMR data with those of related metabolites.     

Identification of Two New Phosphorylated Polyketides from a Brazilian Streptomyces sp. Through the Use of LC–SPE/NMR

Two new polyketide phosphate monoesters, phosdiecin A ( 1 ) and phosdiecin B ( 2 ), were isolated from a culture of the marine Streptomyces sp. SS99BA‐2 using the hyphenated technology LC–SPE/NMR. The compounds showed to be new representatives of an important class of antitumor antibiotic metabolites known as fostriecins. Their structures, including relative configuration attribution, were fully elucidated through extensive analyses of NMR and MALDI‐TOF/TOF HR‐MS data. Herein, the application of this system to isolate and identify the new compounds is described.     

Aurovertin‐Type Polyketides from Calcarisporium arbuscula with Potent Cytotoxic Activities against Triple‐Negative Breast Cancer

Two new polyene polyketides, namely aurovertins T and U ( 1 and 2 ), were isolated from Calcarisporium arbuscula, together with aurovertins B ( 3 ), D and E ( 4 and 5 ), and M ( 6 ). The structures were elucidated by extensive spectroscopic methods (especially 2D‐NMR techniques). The cytotoxic activities of all isolates against human triple‐negative breast cancer cell line (MDA‐MB‐231) were evaluated. As a result, compounds 3 , 4 , and 6 exhibited more potent cytotoxic activities against MDA‐MB‐231 cell line than the positive control taxol. Also, discussion about the relationships between structure and activity of these aurovertins was presented.     

New Highly Oxidized Formamidobisabolene‐Derived Sesquiterpenes from a Hainan Sponge Axinyssa variabilis

Two new highly oxidized formamidobisabolene sesquiterpenes ( 1 and 2 ), together with seven known related analogues ( 3 – 9 ), were isolated from a Hainan sponge Axinyssa variabilis. Their structures were determined by extensive 1D‐ and 2D‐NMR and MS spectra analyses, and by comparison of their spectroscopic data with those of the related model compounds. The plausible biosynthetic relationship between compounds 1 – 9 has also been described.