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.     

ent‐Clerodanoids from Isodon scoparius

Three new ent‐clerodane diterpenoids, isoscoparin A, B, and C ( 1 – 3 ), were isolated from Isodon scoparius. Their structures were determined by NMR‐spectra analysis. The biogenetic implication of the diterpenes from Isodon genus is discussed.     

Splendidins A – C,Three New Clerodane Diterpenoids from Salvia splendens

Three new clerodane diterpenoids, splendidins A–C ( 1 – 3 , resp.), were isolated from Salvia splendens, together with six known ones. Their structures were elucidated by extensive spectroscopic analysis. Splendidin C ( 3 ) was the first diterpenoid glucoside reported from this plant. These compounds were evaluated for their cytotoxic activity; however, none of them were cytotoxic.     

Four New Diterpenoids from Ballota limbata

Six diterpenoids ( 1 – 6 ) belonging to the clerodane and tetracyclic diterpene types were isolated from the CHCl₃ extract of Ballota limbata. The structures of the new compounds 1 and 4 – 6 (named ballatenolide A and limbatenolides A–C, resp.) were established by their spectral data, and their relative configuration was determined by 2D NMR. Compounds 2 and 3 were identified as known clerodanes. Compound 1 had a unique feature, i.e., an α,β‐unsaturated γ‐lactone moiety at C(4)/C(6), whereas limbatenolides A–C ( 4 – 6 ) belonged to the rare class of tetracyclic diterpenoids, which are known to occur only in the genus Ballota. All of the isolated compounds showed inhibitory potential in a cholinesterase‐inhibition assay.     

neo‐Clerodane Diterpenoids from the Aerial Part of Scutellaria barbata

Three new neo‐clerodane diterpenoids, barbatellarines C–E ( 1 – 3 ), were isolated from the CHCl₃‐soluble fraction of the aerial part of Scutellaria barbata. Their chemical structures were elucidated by detailed analysis of NMR and MS data. Compounds 1 and 2 were C(13) epimers, which was confirmed by an NOE difference experiment and the NOESY spectrum. The relative configuration was determined on the basis of the ¹H‐NMR J‐value and NOE data, while the absolute configuration of the previously isolated analogue, barbatellarine B ( 4 ), as a representative member of the group, was assigned by CD analysis.     

Three new diterpenoids from Leonurus japonicus

Phytochemical investigation of the aerial parts of Leonurus japonicus led to the isolation of one unusual clerodane diterpenoid,leojaponin A(1),characterized by a C4–C7oxa-bridge,and two new labdane diterpenoids,leojaponins B(2) and C(3).The structures of these new compounds were determined based on extensive 1D and 2D NMR spectroscopic data.To the best of our knowledge,compound 1 is the first clerodane diterpenoid obtained from Leonurus.japonicus.All of them were evaluated for their cytotoxicity.     

Diterpene lactones with labdane, halimane and clerodane frameworks

The labdane, halimane and clerodane type diterpenoids are compounds that have been isolated in plants of several families. These molecules and their derivatives with a lactone group on the side chain or on the decaline system, have a great interest because of their biological properties as insect antifeedant, antiviral, cytotoxic and trypanocidal. The scope of this review is lactones diterpenoids with labdane, halimane and clerodane frameworks.     

Structure-antibacterial activity relationship of secondary metabolites from Ajuga pseudoiva Rob. leaves

A selection of steroids, glycerides, clerodane diterpenoids, and a beta-hydroxy fatty acid methyl ester, all previously isolated from Ajuga pseudoiva leaves, were tested for their antibacterial activity toward three Gram- rods and one Gram+ coccus using the dilution method; MIC values were determined. The results suggested some importance for a free beta-hydroxy group in the fatty acid ester and also in the glycerides and clerodane derivatives; the absolute configurations of the latter, notably at C2, had little influence on activity.     

Diterpenoids ofPulicaria salviifolia. I. Structures of salvin and salvinin

Two new diterpenoids of the clerodane series — salvin and salvinin — have been isolated from the epigeal part ofPulicaria salviifolia Bgl. in Mem. A structure and a most probable stereochemistry are proposed.Presented at the VIIth Indo-Soviet Symposium on the Chemistry of Natural Compounds [16].Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 201–205, March–April, 1985.     

Eight new clerodane diterpenoids from the bark of Ptychopetalum olacoides

Eight new clerodane type diterpenoids, named 7-oxo-kolavelool (1), 7alpha-hydroxykolavelool (2), 6alpha,7alpha-dihydroxykolavenol (3), 12-oxo-hardwickiic acid (4), ptycholide I (5), ptycholide II (6), ptycholide III (7), and ptycholide IV (8) were isolated from the MeOH extract of the bark of a Brazilian medicinal plant, Ptychopetalum olacoides. The structures of 1-8 were elucidated by analyzing spectroscopic data and by comparing their NMR data with those of the previously reported compounds kolavelool (la), kolavenol (3a), hardwickiic acid (4a), and ptychonolide (5a). Compounds 5 and 6 existed as a 1:1 mixture of inseparable epimers at C-15.     

Diterpenoids of the clerodane series

The review considers advances in the field of the study of natural clerodane diterpenoids, with coverage of the literature up to February, 1985.Deceased.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 169–185, March–April, 1987.     

Thrombin Inhibitory Constituents from Duranta repens

The C‐alkylated flavonoids 3,7,4′‐trihydroxy‐3′‐(4‐hydroxy‐3‐methylbutyl)‐5,6‐dimethoxyflavone ( 1 ), 3,7‐dihydroxy‐3′‐(4‐hydroxy‐3‐methylbutyl)‐5,6,4′‐trimethoxyflavone ( 2 ) and the trans‐clerodane diterpenoids 6β‐hydroxy‐15,16‐epoxy‐5β,8β,9β,10α‐cleroda‐3,13(16),14‐trien‐18‐oic acid ( 3 ) and 2β‐hydroxy‐15,16‐epoxy‐5β,8β,9β,10α‐cleroda‐3,13(16),14‐trien‐18‐oic acid ( 4 ) were isolated from Duranta repens. Their structures and the relative configuration of 3 and 4 were determined by spectroscopic methods (¹H‐ and ¹³C‐NMR, IR, and MS) and 2D‐NMR experiments. The known flavonoid 5 is also reported for the first time from this species. The compounds 1 , 3 , and 5 showed significant enzyme‐inhibitory activity against thrombin.     

A tandem mass spectrometric investigation of the low‐energy collision‐activated fragmentation of neo‐clerodane diterpenes

Mass spectrometric fragmentation data of neo‐clerodane diterpenes are almost inexistent but they can prove helpful for the qualitative and quantitative analysis of these compounds as well as for the identification of unknown compounds belonging to this class of plant secondary metabolites. [M–H]^– ions of nine neo‐clerodane diterpenes (1–9), recently isolated from Teucrium chamaedrys, were generated by electrospray ionization and were fragmented in the collision cell of a Triple Quadrupole (TQ) and of a Quadrupole Ion Trap (QIT) mass spectrometer. The deprotonated neo‐clerodane glucosides, chamaedryoside A and B (1, 2), readily lost the sugar residue to give, as their main fragmentation channel, the neo‐clerodane ions, I and II, which were structurally characterized by TQ and QIT MS. The collision‐activated dissociation (CAD) mass spectra of I and II and of deprotonated neo‐clerodanes 3–9 allowed us to reach some general conclusions on the fragmentation pathways of this class of compounds. For example, teuflin and its OH derivatives, teucrin A, teuflidin and 6‐β‐hydroxyteucridin, showed a characteristic fragmentation pattern involving the loss of 94 Da and 124 Da from the lactone moiety, whereas a loss of 44 Da was observed for teucrin E, and of 58 Da for teucrin F and G. In addition, several compound‐specific fragmentations were observed and can be proposed for the identification of individual compounds. The systematic approach allowed us to hypothesize the mechanisms of the most important collision‐activated dissociation/isomerization channels. Copyright © 2010 John Wiley & Sons, Ltd.     

Chemistry and biological activities of terpenoids from copaiba (Copaifera spp.) oleoresins

Copaiba oleoresins are exuded from the trunks of trees of the Copaifera species (Leguminosae-Caesalpinoideae). This oleoresin is a solution of diterpenoids, especially, mono- and di-acids, solubilized by sesquiterpene hydrocarbons. The sesquiterpenes and diterpenes (labdane, clerodane and kaurane skeletons) are different for each Copaifera species and have been linked to several reported biological activities, ranging from anti-tumoral to embriotoxic effects. This review presents all the substances already described in this oleoresin, together with structures and activities of its main terpenoids.     

A new sesquiterpenoid from Polyalthia petelotii

A new sesquiterpenoid (?)-ethyl dihydrophaseate (1) was isolated from the stems and leaves of Polyalthia petelotii, together with two clerodane diterpenoids, 16α-hydroxycleroda-3,13(14)Z-dien-15,16-olide (2), 15-hydroxy-cis-ent-cleroda-3,13(E)-diene (3), a eudesmane sesquiterpenoid, eudesm-4(15)-ene-7α,11-diol (4), an aromatic aldehyde, vanillin (5), a bisisoquinolines alkaloid, spinosine (6) and an aporphine alkaloid, (?)-oliveroline-β-N-oxide (7). Their structures were established by extensive spectroscopic analysis, including 2D-NMR techniques. Compounds 3, 4 and 6 were isolated from the genus Polyalthia for the first time and the others obtained originally from P. petelotii. The isolates were assessed for their cytotoxicity against five human tumour lines (HL-60, SMMC-7721, A-549, MCF-7 and SW-480), and the result showed that only 2 displayed weak inhibitory activity.     

Three New Clerodane Diterpene Derivatives from Casearia Membranacea

Three new clerodane diterpene derivatives were isolated from the leaves of Casearia membranacea Hance collected in Taiwan. The isolated metabolites were identified as caseamembrins P (1), Q (2), and R (3). Identification of the structures was based on detailed analysis of the spectral data, especially 2D NMR.     

Two New Diterpenes from Solidago canadensis

Two new clerodane‐type diterpenes, solidagocanins A and B ( 1 and 2 , resp.), as well as two known compounds, mellein ( 3 ) and physcion ( 4 ), were isolated from the aerial parts of Solidago canadensis. The structures of the new compounds were elucidated by spectroscopic analyses, including 2D‐NMR techniques.     

Salvifarinin A,a neo-clerodane diterpenoid with a 6/5/7 tricyclic skeleton from Salvia farinacea

Salvifarinin A (1), a rearrangement product of Languidulane-type clerodane diterpenoids with a 6/5/7 tricyclic ring skeleton fused with γ-lactone ring and furan ring, and two new biogenetically related diterpernoids, salvifarinins B (2) and C (3), were isolated from the aerial parts of Salvia farinacea. The absolute configuration of 1 was elucidated by extensive spectroscopic methods, and confirmed by single crystal X-ray diffraction and bio-inspired semisynthesis. The plausible biogenetic pathway was also proposed. Compound 2 displayed a potent effect on reducing hepatic steatosis.     

ent‐Kaurane Diterpenoids from Isodon japonicus

Two new 6,7‐seco‐ent‐kaurane diterpenoids, isojaponins A ( 1 ) and B ( 2 ), together with 18 known ent‐kaurane diterpenoids were isolated from the aerial parts of Isodon japonicus. The structures of the two new compounds were elucidated by extensive 1D‐ and 2D‐NMR spectroscopic methods in combination with MS experiments.     

Two New Abietane Diterpenoids from the Roots of Tripterygium wilfordii Hook. f.

Two new abietane‐type diterpenoids, named triptobenzene R ( 1 ) and triptobenzene S ( 2 ), together with three known abietane‐type diterpenoids, triptophenolide ( 3 ), triptonodiol ( 4 ), and triptonoterpene methyl ether ( 5 ), were isolated from the roots of Tripterygium wilfordii Hook . f. Their structures and relative configurations were established by detailed spectral studies, including 1D‐ and 2D‐NMR (HSQC, HMBC, and NOESY), and HR‐ESI‐TOF‐MS, and by comparison with published data. Their absolute configurations were assigned by the CD technique, applied for the first time to abietane diterpenes from Tripterygium wilfordii. Compound 2 is the first abietane‐type norditerpenoid isolated from the genus Tripterygium.