Structure and absolute configuration of the sesquiterpenoid emmotins

The trunk wood of Emmotum nitens (Icacinaceae) contains the aromatic sesquiterpenes (2R,3S)-2-hydroxy-3-(2′-hydroxyisopropyl)-5,8-dimethyl-1-oxo-1,2,3,4-tetrahydronaphthalene (emotin-F), 2-hydroxy-3-(2′-hydroxyisopropyl)-5,8-dimethylnaphthalene (emmotin-G) and 3-(2′-hydroxyisopropyl)-5,8-dimethyl-1,2-naphtho-quinone (emmotin-H). The identity of the carbon skeletons of these emmotins was proved by conversion of all three into an identical quinoxaline derivative. The nature of this skeleton and the absolute configuration of emmotin-F, as well as of the previously described emmotins A and B, was established by conversion of emmotin-F into (+)-occidol.     

(−)-Ent-12β-acetoxylongipin-2(10)-en-3-one,an Ent-longipinane derivative from the liverwort Marsupella aquatica

The structure of a new ent-longipinane type of sesquiterpenoid, (?)-ent-12β-acetoxylongipin- 2(10)-en-3-one from the liverwort Marsupella aquatica, has been elucidated by spectroscopic and chemical methods.     

New acyclic sesquiterpenoid derivatives and a monoterpene disaccharide from Dichondra repens Forst.

A new highly oxygenated acyclic sesquiterpenoid (2E, 6E)-8,10,11-trihydroxyl-7,11-dimethyl-3-hydroxymethyl-2,6-dodecadienoic acid (1) and its glucoside (2), together with a new pinane monoterpene disaccharide glucoside 6,6-dimethyl-2-methlenebicyclo [3.1.1]hept-3-O-(6-O-apiofuranosyl)-β-d-glucopyranoside (3) were isolated from hydrophilic extract of Dichondra repens. Their structures were elucidated on the basis of spectroscopic analyses and chemical methods. The three compounds did not show any cytotoxic activity (IC50 > 20 μM) against two human lung cancer cell lines (NCI-H661 and A549).     

New eudesmane sesquiterpenes from Alpinia oxyphylla and determination of their inhibitory effects on microglia

The fruits of Alpinia oxyphylla are used as healthcare products for the protection on neurons and prevention of dementia. Two new noreudesmane sesquiterpenoids, (5R,7S,10S)-5-hydroxy-13-noreudesma-3-en-2,11-dione (1) and (10R)-13-noreudesma-4,6-dien-3,11-dione (2), and a new eudesmane sesquiterpenoid, (5S,8R,10R)-2-oxoeudesma-3,7(11)-dien-12,8-olide (3), as well as 12 known sesquiterpenoids, were isolated from the fruits of A. oxyphylla. The structures of the new compounds (1–3) were elucidated on the basis of spectroscopic data and circular dichroism experiments. All isolates were evaluated their neuroprotective potential by inhibitory assay on nitric oxide (NO) and tumor necrosis factor-α (TNF-α) production in lipopolysaccharide (LPS)-induced mouse microglia BV-2 cells.     

Chemical constituents from Teucrium viscidum

A new guaiane sesquiterpenoid (1), two known guaiane sesquiterpenoids (2 and 3), and eleven known compounds (4–14), were isolated from Teucrium viscidum. Their structures were identified by spectroscopic analyses and by comparison of their spectral data with those reported in the literature. The absolute configuration of lipidiol (2) was determined by single-crystal X-ray diffraction analysis with Cu Kα radiation. Compounds 12 and 13 were isolated as natural products for the first time. All compounds were isolated from T. viscidum for the first time.     

Cadinane-type sesquiterpenoids from Schisandra bicolor

The phytochemical investigation on the stems of Schisandra bicolor led to the isolation of seven cadinane-type sesquiterpenoids, 2-hydroxy-11,12-dehydrocalamenene (1), ent-T-muurolol (2), (+)-ent-epicubenol (3), (1S,4S)-7,8-dihydroxy-11,12-dehydrocalamenene (4), cadinane-T-cadinol (5), (−)-cadin-4,10(15)-dien-11-oic acid (6), and cadina-4,10(15)-dien-3-one (7). Their structures were determined by extensive analysis of their spectroscopic data. All the isolates were isolated from this species for the first time. The chemotaxonomic significance of these compounds was also summarized.     

Anti-influenza patchoulol-type sesquiterpenoids from Pogostemon cablin

Four new patchoulol-type sesquiterpenoids, including 6α,9β-dihydroxypatchoulol 6-O-β-d-glucopyranoside (1), 6α-hydroxypatchoulol 6-O-β-d-glucopyranoside (2), 3α,9β-dihydroxypathoulol (3), and 4β-hydroxynorpatchoulol 4-O-β-d-glucopyranoside (10), were isolated from the roots of Pogostemon cablin (Blanco) Benth, together with eleven known sesquiterpenoids. Their structures were elucidated on the basis of extensive NMR spectral and high resolution mass spectrometry analysis. This is the second report of patchoulol glucopyranoside from P. cablin and compound 10 represented as the first example of nor-patchoulol glucopyranoside. The anti-influenza virus activities of 1–10 against A/WSN/33/2009 and A/Puerto Rico/8/1934 strains (tamiflu resistant viruses) were evaluated. Compounds 2β,12-dihydroxypathoulol (5) and (5R)-5-hydroxypatchoulol (8) exhibited moderate anti-influenza activity against A/WSN/33/2009 strain with EC₅₀ value of 52.7 μM and 49.6 μM (positive control oseltamivir, EC₅₀ = 6.75 μM). Compounds 8 and pogostol (12) showed potent anti-influenza activity against A/Puerto Rico/8/1934 strain with EC₅₀ values of 3.06 μM and 0.07 μM, respectively, versus the postive control (amantadine, EC₅₀ = 67.9 μM).     

Stereostructure of curlone,a sesquiterpenoid of Curcuma longa rhizomes

From the crude drug ‘ukon’ (turmeric) (obtained from the rhizomes of Curcuma longa) a new sesquiterpenoid, curlone, has been isolated and shown as (6S)-2-methyl-6-[(1S)-4-methylene-2-cyclohexen-1-yl]-2-hepten-4-one on the basis of its spectral properties and its chemical conversion to the known (+)-ar-turmerone.     

Chemical constituents of Pteris wallichiana J.Agardh (Pteridaceae)

Chemical investigation on the whole plants of Pteris wallichiana J. Agardh led to the isolation and identification of a new pterosin glycoside, ptemuloside A (1), along with other seventeen known compounds (2–18) (Fig. 1). The structure of compound 1 was elucidated by means of spectroscopic techniques, including HRESIMS, and 1D and 2D NMR experiments. Compounds 2, 3, and 5–17 are first time reported from the title plant. The pterosins in P. wallichiana could serve as its chemotaxonomic markers.     

Nitric oxide inhibitory constituents from Siegesbeckia pubescens

Two new sesquiterpenoids (1 and 2) and a new ent-pimarane type diterpenoid (3), together with eighteen known compounds (4–21), were isolated from the whole plants of Siegesbeckia pubescens. The structures of the new compounds were determined on the basis of 1D-, 2D NMR and HRESIMS data. All compounds were evaluated for their inhibitory effects on LPS-induced nitric oxide production in RAW 264.7 macrophages. Of these, highly oxygenated germacrane type sesquiterpenoids (1–2 and 13–14) showed significant inhibitory effects with IC₅₀ values ranging from 3.9 to 16.8 μM.     

Two New Sesquiterpenoid Glucosides from the Aerial Parts of Saussurea involucrate

Two new sesqulterpenoid glucosides, namely α-hydroxycostic acid 6-β-D-glucopyranoside （compound 1） and 11 βH-11,13-dlhydrodehydrocostuslactone 8α-O-（6＇-acetyl）-β-D-glucopyranoside （compound 2）, along with 11 known sesqulterpenoids （compounds 3-13） were isolated from the aerial parts of Saussurea involucrate （Kar. et Kir.） Sch.- BIp. The structures of the new sesquiterpenoid glucosides were established by one- and two-dimensional nuclear magnetic resonance and mass spectrometry analysis.     

Raimondal,a new sesquiterpenoid from pigment glands of Gossypium raimondii

A new sesquiterpenoid isolated from pigment glands of leaves and immature bolls of Gossypium raimondii has been named raimondal and identified as 5-iso-propyl-2-methoxy-3-methyl-1,6,7-trihydroxy-8-naphthaldehyde. Raimondal was oxidized by ferric chloride to o-hemigossypolone (8-formyl-5-iso-propyl-3-methyl-6,7-dihydroxy-1,2-naphthoquinone) which was readily reduced to its hydroquinone, 2-hydroxyhemigossypol. Neither of the two oxidation products were detected in extracts from G. raimondii.     

Sesquiterpenoid lactones from the liverwort Frullania tamarisci

Four isomeric sesquiterpenoid lactones have been isolated from the liverwort Frullania tamarisci They have been identified as the simple eudesmanolides (I–III) and costunolide (IV).     

Artemisianins A-D,new stereoisomers of seco-guaianolide involved heterodimeric [4+2] adducts from Artemisia argyi induce apoptosis via enhancement of endoplasmic reticulum stress

Artemisianins A-D (1–4), four stereoisomers of sesquiterpenoid dimers, forming via [4+2] cycloaddition from a 1, 10-seco-guaianolide dienophile and a guaianolide diene, along with two biosynthetically related precurors 5 and 6, were isolated from the famous traditional Chinese medicine Artemisia argyi. The structures of 1–4, including their absolute configurations, were elucidated by extensive spectroscopic data and ECD/TDDFT calculation analysis. Compounds 1–4 exhibited cytotoxicity with IC₅₀ values ranging from 7.2 to 23.3 μM. The accumulation of Ca²⁺ in cytoplasm and enlarged endoplasmic reticulum (ER) indicated that 1 mediated HT-29 cancer cell apoptosis through improvement of ER-stress, which was further proved by unfolded protein response (UPR) pathway on basis of the upregulation of IRE1α, p-PERK, ATF6, and CHOP.     

A New Sesquiterpenoid from Russula lepida

A new aristolane sesquiterpenoid named rulepidol was isolated from the fruiting body ofRussula lepida Fr. Its structure was elucidated as (1aa,5a,7a,7aa,7b)-1,1a,4,5,6,7,7a,7b-octahydro-5-hydroxy-1,1,7,7a-tetramethyl-5H-cyclopropa［α］naphthalen-2-one mainly by 1D and 2D-NMR techniques.     

Characterization of the transacylase activity of rat liver 60-kDa lysophospholipase-transacylase. Acyl transfer from the sn-2 to the sn-1 position

Rat liver 60-kDa lysophospholipase-transacylase catalyzes not only the hydrolysis of 1-acyl-sn-glycero-3-phosphocholine, but also the transfer of its acyl chain to a second molecule of 1-acyl-sn-glycero-3-phosphocholine to form phosphatidylcholine (H. Sugimoto, S. Yamashita, J. Biol. Chem. 269 (1994) 6252–6258). Here we report the detailed characterization of the transacylase activity of the enzyme. The enzyme mediated three types of acyl transfer between donor and acceptor lipids, transferring acyl residues from: (1) the sn-1 to -1(3); (2) sn-1 to -2; and (3) sn-2 to -1 positions. In the sn-1 to -1(3) transfer, the sn-1 acyl residue of 1-acyl-sn-glycero-3-phosphocholine was transferred to the sn-1(3) positions of glycerol and 2-acyl-sn-glycerol, producing 1(3)-acyl-sn-glycerol and 1,2-diacyl-sn-glycerol, respectively. In the sn-1 to -2 transfer, the sn-1 acyl residue of 1-acyl-sn-glycero-3-phosphocholine was transferred to not only the sn-2 positions of 1-acyl-sn-glycero-3-phosphocholine, but also 1-acyl-sn-glycero-3-phosphoethanolamine, producing phosphatidylcholine and phosphatidylethanolamine, respectively. 1-Acyl-sn-glycero-3-phospho-myo-inositol and 1-acyl-sn-glycero-3-phosphoserine were much less effectively transacylated by the enzyme. In the sn-2 to -1 transfer, the sn-2 acyl residue of 2-acyl-sn-glycero-3-phosphocholine was transferred to the sn-1 position of 2-acyl-sn-glycero-3-phosphocholine and 2-acyl-sn-glycero-3-phosphoethanolamine, producing phosphatidylcholine and phosphatidylethanolamine, respectively. Consistently, the enzyme hydrolyzed the sn-2 acyl residue from 2-acyl-sn-glycero-3-phosphocholine. By the sn-2 to -1 transfer activity, arachidonic acid was transferred from the sn-2 position of donor lipids to the sn-1 position of acceptor lipids, thus producing 1-arachidonoyl phosphatidylcholine. When 2-arachidonoyl-sn-glycero-3-phosphocholine was used as the sole substrate, diarachidonoyl phosphatidylcholine was synthesized at a rate of 0.23 μmol/min/mg protein. Thus, 60-kDa lysophospholipase-transacylase may play a role in the synthesis of 1-arachidonoyl phosphatidylcholine needed for important cell functions, such as anandamide synthesis.     

β2-Chimaerin binds to EphA receptors and regulates cell migration

Ephrins and Eph receptors have key roles in regulation of cell migration during development. We found that the RacGAP β2-chimaerin (chimerin) bound to EphA2 and EphA4 and inactivated Rac1 in response to ephrinA1 stimulation. EphA4 bound to β2-chimaerin through its kinase domain and promoted binding of Rac1 to β2-chimaerin. In addition, knockdown of endogenous β2-chimaerin blocked ephrinA1-induced suppression of cell migration. These results suggest that β2-chimaerin is activated by EphA receptors and mediates the EphA receptor-dependent regulation of cell migration.

Structured summary

MINT-7013428: EphA1 (uniprotkb:Q60750) physically interacts (MI:0218) with Chimaerin beta 2 (uniprotkb:Q80XD1-2) and EphA4 (uniprotkb:O08542) by anti tag coimmunoprecipitation (MI:0007)MINT-7013515: Chimaerin beta 2 (uniprotkb:Q80XD1-2) physically interacts (MI:0218) with Rac1 (uniprotkb:P63001) by anti tag coimmunoprecipitation (MI:0007)MINT-7013410: EphA1 (uniprotkb:Q60750) physically interacts (MI:0218) with Chimaerin beta 1 (uniprotkb:Q80XD1-1) and EphA4 (uniprotkb:O08542) by anti tag coimmunoprecipitation (MI:0007)MINT-7013503: Chimaerin beta 1 (uniprotkb:Q80XD1-1) physically interacts (MI:0218) with EphA4 (uniprotkb:O08542) by anti tag coimmunoprecipitation (MI:0007)MINT-7013472: Chimaerin beta 2 (uniprotkb:Q80XD1-2) physically interacts (MI:0218) with EphA2 (uniprotkb:O43921) by anti tag coimmunoprecipitation (MI:0007)MINT-7013450: EphA1 (uniprotkb:Q60750) physically interacts (MI:0218) with EphA2 (uniprotkb:O43921) and Chimaerin beta 2 (uniprotkb:P52757-1) by anti tag coimmunoprecipitation (MI:0007)MINT-7013491: Chimaerin beta 2 (uniprotkb:Q80XD1-2) physically interacts (MI:0218) with EphA4 (uniprotkb:O08542) by anti tag coimmunoprecipitation (MI:0007)     

Eusiderins and 1,3-diarylpropanes from Virola species

Trunk wood of Virola divergens Ducke and V. guggenheimii W. Rodrigues (Myristicaceae) contains the 1,3-diarylpropanes virolane and (2S)-virolanol. The latter species contains in addition the benzodioxane-type neolignan eusiderin. Bark of V. pavonis (A. DC.) A.C. Smith contains two novel representatives of this group, rel-(2S, 3R)-7-allyl-5-methoxy-2-(3′, 4′, 5′-trimethoxyphenyl- and rel-(2S, 3R)-7- allyl-5-methoxy-2-(3′,4′-dimethoxyphenyl)-3-methyl-benzodioxane, designated eusiderin-C and eusiderin-D, respectively.     

Functional analysis and tissue-differential expression of four FAD2 genes in amphidiploid Brassica napus derived from Brassica rapa and Brassica oleracea

Fatty acid desaturase 2 (FAD2), which resides in the endoplasmic reticulum (ER), plays a crucial role in producing linoleic acid (18:2) through catalyzing the desaturation of oleic acid (18:1) by double bond formation at the delta 12 position. FAD2 catalyzes the first step needed for the production of polyunsaturated fatty acids found in the glycerolipids of cell membranes and the triacylglycerols in seeds. In this study, four FAD2 genes from amphidiploid Brassica napus genome were isolated by PCR amplification, with their enzymatic functions predicted by sequence analysis of the cDNAs. Fatty acid analysis of budding yeast transformed with each of the FAD2 genes showed that whereas BnFAD2-1, BnFAD2-2, and BnFAD2-4 are functional enzymes, and BnFAD2-3 is nonfunctional. The four FAD2 genes of B. napus originated from synthetic hybridization of its diploid progenitors Brassica rapa and Brassica oleracea, each of which has two FAD2 genes identical to those of B. napus. The BnFAD2-3 gene of B. napus, a nonfunctional pseudogene mutated by multiple nucleotide deletions and insertions, was inherited from B. rapa. All BnFAD2 isozymes except BnFAD2-3 localized to the ER. Nonfunctional BnFAD2-3 localized to the nucleus and chloroplasts. Four BnFAD2 genes can be classified on the basis of their expression patterns.     

肋果茶中的萜类化学成分研究

从肋果茶(Sladenia celastrifolia)95％乙醇提取物的乙酸乙酯部位中分离得到15个萜类化合物,经波谱学方法分别鉴定为sladeniafolin A(1),grasshopper ketone (2),(3S,5R,6S,7E,9R) -7-megastigmene-3,6,9-triol (3),hedytriol (4),(3S,5R,6R,7E,9R) -3,5,6,9-tetrahydroxy-7-megastigmene(5),1′S*,4′R*-8-(4′-hydroxy-2′,6′,6′-trimethylcyclohex-2-enyl)-6-methyloct-3E,5E,7E-trien -2-one (6),2α,3α,19α,23-tetrahydroxyurs-12-en-28-oic acid (7),2α,3β,19α,23-tetrahydroxyurs-12-en-28-oic acid(8),pomolic acid(9),3-O-acetyl pomolic acid(10),ursaldehyde (11),camarolide (12),3β-hydroxyurs-11-en-13β(28) -olide (13),3β-hydroxy -11α,12α-epoxy-urs-13β,28-olide (14)和28-0-β-D-glucopyranosyl euscaphic acid (15).以上化合物均首次从该植物中分离得到,其中1为新的C9裂环烯醚萜.