Four New Neoclerodane Diterpenoids from Ajuga decumbens

Four new neoclerodane diterpenoids, 15‐epilupulin A ( 1 ), 6‐O‐deacetylajugamarin ( 2 ), and ajugadecumbenins A ( 3 ) and B ( 4 ), were isolated from the whole plants of Ajuga decumbens. Their structures were elucidated on the basis of spectroscopic data and chemical correlations.     

Novel abietane diterpenoids and aromatic compounds from Cladonia rangiferina and their antimicrobial activity against antibiotics resistant bacteria

From Cladonia rangiferina were isolated two novel abietane diterpenoids, hanagokenols A (1) and B (2). Also in this investigation, four known abitetane diterpenoids (3-6), four known labdane diterpenoids (7-10), one known isopimarane diterpenoid (11), and six known aromatic compounds were isolated. These structures were elucidated primarily through extensive NMR experiments. Hanagokenol A (1) was a unique abietane diterpene having an ether linkage between C-6 and C-18 of sugiol. Hanagokenol B (2) is also a unique secoabietane diterpene, having gamma-lactone which occurred by cleavage and subsequently oxidation between C-6/C-7 of 12-hydroxydehydroabietinol. Furthermore, all the isolated compounds (1-17) were tested for the antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE).     

Structures of two new diterpenoids from Teucrium polium

Two new acids of the neoclerodane series have been isolated fromTeucrium polium L. (Lamiaceae); they have been called tepolin A and tepolin B and their structures have been established on the basis of spectral characteristics as 7,12,19-trihydroxy-6,18:15,16-diepoxycleroda-3,13(16),14-triene-9-carboxylic acid and 12,19-dihydroxy-6,18:15,16-diepoxycleroda-3,13(16)-14-triene-9-carboxylic acid, respectively. Institute of Fine Organic Chemistry, Armenian Academy of Sciences, Erevan. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 503–508, September–October, 1992.     

Structures of two new diterpenoids from Teucrium polium

Two new acids of the neoclerodane series have been isolated fromTeucrium polium L. (Lamiaceae); they have been called tepolin A and tepolin B and their structures have been established on the basis of spectral characteristics as 7,12,19-trihydroxy-6,18:15,16-diepoxycleroda-3,13(16),14-triene-9-carboxylic acid and 12,19-dihydroxy-6,18:15,16-diepoxycleroda-3,13(16)-14-triene-9-carboxylic acid, respectively.Institute of Fine Organic Chemistry, Armenian Academy of Sciences, Erevan. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 503–508, September–October, 1992.     

Tri-nordammarane triterpenoids and neoclerodane diterpenoids from Salvia aspera (Labiatae)

From the aerial parts of Salvia aspera one new tri-nordammarane named amblyol (1) was isolated besides amblyone (2). An X-ray analysis was performed on compound 1. In addition, three known neoclerodane diterpenoids were also isolated. The structures of these compounds were established by spectral and chemical methods. The presence of dammarane triterpenoids in a Mexican Salvia is described for the first time.     

Novel Diterpenoids from Salvia dugesii

Two novel rearranged clerodane diterpenoids, dugesin A ( 1 ) and dugesin B ( 2 ), were isolated from the aerial parts of Salvia dugesii, together with five known clerodane diterpenoids: isosalvipuberulin ( 3 ), salvipuberulin ( 4 ), tilifodiolide ( 5 ), salvifolin ( 6 ), and salvifaricin ( 7 ). Their structures were elucidated on the basis of different spectroscopic techniques. The isolation and identification of these compounds are significant from both biosynthetisis and chemotaxonomy points of view.     

Two new diterpenoids from the buds of Wikstroemia chamaedaphne

Two new diterpenoids, wikstroelide Q (1) and prostratin Q (5), together with three known diterpenoids, pimelea factors P? (2), P? (3), and prostratin (4), and five known lignans, (+)-epipioresinol (6), (+)-isolariciresinol (7), (?)-lariciresinol (8), (+)-epi-sesaminone (9), and prestegane B (10), were isolated from the buds of Wikstroemia chamaedaphne Meissn. Their structures were elucidated by a combination of spectroscopic analyses. Compounds 1–10 were evaluated for their cytotoxicities against HL-60, SMMC-7721, A549, MCF-7, SW480, and BEAS-2B cell lines in vitro.     

Salvileucalin B, a novel diterpenoid with an unprecedented rearranged neoclerodane skeleton from Salvia leucantha Cav

Salvileucalin B (2), having an unprecedented rearranged neoclerodane skeleton, was isolated from the aerial parts of Salvia leucantha Cav. (Labiatae) along with salvileucalin A (1). The absolute structures were elucidated by spectroscopic analysis, X-ray crystallographic analysis, and vibrational circular dichroism. Compound 2 represents a novel neoclerodane, characterized by a tricyclo[3.2.1.0 (2,7)]octane substructure incorporating the exocyclic C-20 methylene of 1. This molecule exerted cytotoxic activity against A549 and HT-29 cells with IC50 values of 5.23 and 1.88 microg/mL, respectively.     

Two New Furanoid Diterpenoids from Tinospora sagittata

Two new clerodane‐based furanoid diterpenoids, tinosagittones A and B ( 1 and 2 , resp.), were isolated from the roots of Tinospora sagittata, together with five known diterpenoids, i.e., columbin ( 3 ), its glucoside palmatoside C ( 4 ), isocolumbin ( 5 ), 6‐hydroxycolumbin ( 6 ), and tinophylloloside ( 7 ). Their structures were established by mass spectrometry and spectroscopic methods, especially 2D‐NMR techniques.     

Diterpenoids from Rabdosia nervosa

Six ent-kaurene type diterpenoids have been isolated from the leaves of Rabdosia nervosa. Among them, ganervosin A and B were new compounds, the structures of which were elucidated as 1 and 2 respectively by spectral and chemical methods. The other four were identified as odonicin (3), novelrabdosin (4), nodosin (5) and shikokianal acetate (6), Compounds 5 and 6 were for the first time isolated from this herb.     

Ent-kaurane diterpenoids from Isodon rubescens var. rubescens

Five new ent-kaurane diterpenoids xindongnins H-L (1-5), together with five known ones, xindongnins A and B (6, 7), melissoidesins G (8), dawoensin A (9), and glabcensin V (10) were isolated from Isodon rubescens var. rubescens. Their structures were elucidated by spectroscopic methods including extensive 2D NMR techniques.     

Cytotoxicity of labdane-type diterpenoids from Hedychium forrestii

Two new labdane-type diterpenoids, hedyforrestin D (1) and 15-ethoxy-hedyforrestin D (2), and three known compounds, yunnancoronarin A (4), B (3) and C (5) were isolated from the rhizomes of Hedychium forrestii. The structure of the new diterpenoids was established as 6beta,15xi-dihydroxylabda-8(17),11,13-trien-15,16-olide (1), and 6beta-hydroxy-15xi-ethoxylabda-8(17),11,13-trien-15,16-olide (2) on the basis of spectroscopic analyses. In addition, the isolated compounds were evaluated for their cytotoxicity against the lung adenocarcinoma cells A549 and leukemia cells K562 through 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assays. Of these, compounds 3 and 4 exhibited the most activity with IC(50) values of 0.92 and 2.20 microM, respectively, whereas 5 was inactive against A549 cells and 1 was inactive against both cell lines up to a concentration of 300.81 microM. This shows that both the hydroxy substitution and orientation of unsaturated lactone group in the five-membered ring of C-13 to C-16 seem to play an important role in the anti-tumor activities of human lung adenocarcinoma and leukemia.     

Salvinicins A and B, new neoclerodane diterpenes from Salvia divinorum

[reaction: see text] Two new neoclerodane diterpenes, salvinicins A (4) and B (5), were isolated from the dried leaves of Salvia divinorum. The structures of these compounds were elucidated by spectroscopic techniques, including (1)H and (13)C NMR, NOESY, HMQC, and HMBC. The absolute stereochemistry of these compounds was assigned on the basis of single-crystal X-ray crystallographic analysis of salvinicin A (4) and a 3,4-dichlorobenzoate derivative of salvinorin B.     

Diterpenoids from Blumea balsamifera and Their Anti-Inflammatory Activities

Six new diterpenoids, blusamiferoids A–F (1–6), including four pimarane-type diterpenoids, one rosane-type diterpenoid (3), and one rearranged abietane-type diterpenoid (6), were isolated from the dry aerial parts of Blumea balsamifera. Their structures were characterized by spectroscopic and computational methods. In particular, the structures of 1 and 4 were confirmed by X-ray crystallography. Compounds 5 and 6 were found to dose-dependently inhibit the production of TNF-α, IL-6, and nitrite oxide, and compound 5 also downregulated NF-κB phosphorylation in lipopolysaccharide (LPS)-induced RAW 264.7 cells.     

Two new diterpenoids from Plectranthus nummularius Briq

Two new antioxidative diterpenoids, plectranthol A (3)[19-O-(3,4-dihydroxybenzoyl)-11,12-dihydroxy-20(10-->5)-abeo-abieta-1(10),6,8,11,13-tetraene] and plectranthol B (4)[12-O-(3-methyl-2-butenoyl)-19-O-(3,4-dihydroxybenzoyl)-11-hydroxyabieta-8,11,13-trienel along with two known diterpenoids, parvifloron E (1) and F (2) were isolated from the leaves of Plectranthus nummularius Briq. Antioxidative activities of the compounds were measured by the alpha,alpha-diphenyl-beta-picrylhydrazyl (DPPH) method.     

Two New Diterpenoids from Isodon rubescens

In order to further study on minor diterpenoid constituents of lsodon rubescens, wereinvestigated this species, which was collected in Taibai mountain, Shaanxi Province.TWo new diterpenoids, taibairubescensins A (l) and B (2), were isolated. In this paper,we present the structure elucidation of these two new diterpenoids.Taibairubescensin A (l ), C,.H,#O, (FABMS m/z 435[M 11 ), an amorphous powder,showed UV and iR absorption bands for the existence of hydroxyl, acetoxyl and a fivemembe…     

Regulated expressions of MMP-2, -9 by diterpenoids from Euphorbia formosana Hayata

Two new abietane type diterpenoids, namely seco-helioscopinolide (1) and 3b,7b-dihydroxy-ent-abieta-8,13-diene-12,16-olide (2) were isolated from the aerial parts of Euphorbia formosana Hayata together with helioscopinolide A (3), helioscopinolide B (4), helioscopinolide C (5) and ent-(5b,8a,9b,10a,12a)-12-hydroxyatis-16-ene-3,14-dione (6). The structures of compounds 1-6 were elucidated by analyzing their spectroscopic data and comparison with the literature. Further biological tests by gelatin zymographic analysis revealed that 3-5 significantly up-regulated the expressions and activation of MMP-2 and -9 in human fibrosarcoma cell line HT1080.     

Neoclerodane diterpenoids from Ajuga taiwanensis

Phytochemical investigation of Ajuga taiwanensis resulted in the isolation of seven neoclerodane diterpenes, four of which ajugalide-A (1), -B (2), -C (3), and -D (4), are new and the remaining three are known diterpenes, ajugamacrin B (5), ajugapantin A (6), and ajugamarin C1 (7). Their structures were elucidated in spectral and chemical transformation studies.     

New taxane diterpenoids from Taiwanese Taxus sumatrana

Two new taxane diterpenoids, tasumatrols A (1) and B (2), have been isolated from extracts of the leaves and twigs of Taiwanese Taxus sumatrana. Tasumatrol A is a rare 5/6/6 taxene system, having a novel gamma-lactone at C-10 and C-19. The structures of compounds 1 and 2 were determined on the basis of two dimensional (2D)-NMR techniques, including correlation spectroscopy (COSY), 1H-detected heteronuclear multiple quantum coherence (HMQC) and heteronuclear multiple bond connectivity (HMBC) experiments.     

Neoclerodane diterpenoids from Scutellaria barbata with cytotoxic activities

Abstract

Two new neoclerodane diterpenoids, barbatin F (1), barbatin G (2) together with four known compounds, scutebata A (3), scutebata B (4), scutebata C (5) and scutebata P (6) were isolated from the whole plant of Scutellaria barbata D.Don. Their structures were elucidated on the basis of spectroscopic studies. In vitro cytotoxicity of selected compounds against cancer cell lines LoVo, SMMC-7721, HCT-116, and MCF-7 were evaluated, compound 1 and 2 showed weak cytotoxic activities against HCT-116 colon cancer cell lines with IC₅₀ value of 44.3, 32.3?μM, respectively, while compound 3 and 4 exhibited moderate cytotoxic activities against four tested human cancer cell lines with IC₅₀ values of 5.31～28.5?μM.