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.     

Phytochemical characters of Teucrium marum from Sardinia: an endemic plant

In this work the iridoidic fraction of Teucrium marum from Sardinia, was examined. A new clerodane, teumarin B, was isolated and identified by 1H- and 13C-NMR spectra analysis. The endemic character of this plant was further confirmed. Teumarin B showed cytotoxic properties.     

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.     

Two new cytotoxic clerodane diterpenoids from Casearia membranacea

In addition to casearlucin A (3), two new clerodane diterpenes, caseamembrols A (1) and B (2) have been isolated from the leaves and twigs of Casearia membranacea by bioassay-guided fractionation. The structures of the new compounds were established on the basis of extensive 1D- and 2D-NMR spectroscopic analysis. Compounds 1-3 exhibited significant cytotoxicity against human prostate (PC-3) cancer cells.     

Cordifolide A, a sulfur-containing clerodane diterpene glycoside from Tinospora cordifolia

Cordifolide A (1), a novel unprecedented sulfur-containing clerodane diterpene glycoside, together with other two new diterpene glycosides, cordifolides B (2) and C (3), and four known analogues, was isolated from a methanol-soluble extract of the stems of Tinospora cordifolia. The structures of the new compounds were determined on the basis of spectroscopic data interpretation, with that of cordifolide A (1) confirmed by a single-crystal X-ray crystallographic analysis. All isolates were evaluated for their in vitro immunomodulatory activity using mouse bone marrow-derived dentritic cells (BMDCs).     

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.     

Chemical Constituents from Croton insularis

Three new clerodane‐type terpenoids, furocrotinsulolide A ( 1 ), furocrotinsulolide B ( 2 ), and crotinsulactone ( 3 ), as well as a new phenolic disaccharide ( 4 ) have been isolated from the aerial parts of Croton insularis, together with eight known compounds. Their structures were established by in‐depth 1D‐ and 2D‐NMR spectroscopy, mass spectroscopy, and quantum‐mechanical calculations.     

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.     

New clerodane diterpenoid from the bulbils of Dioscorea bulbifera

A new clerodane diterpenoid has been isolated from the acetone extract of bulbils of Dioscorea bulbifera. The structure of compound 1 was established as 15,16-epoxy-6alpha-O-acety1-8beta-hydroxy- 9-nor-clero-13(16),14-diene-17,12;18,2-diolide on the basis of comprehensive spectroscopic techniques.     

Clerodane diterpenoids and flavonoids with NGF-potentiating activity from the aerial parts of Baccharis gaudichaudiana

A new clerodane diterpene, 15-hydroxy-16-acetoxy-ent-clerod-3-en-18-oic acid (1), together with three known clerodane diterpenes (2-4) and three known flavones (5-7), were isolated from the aerial parts of Baccharis gaudichaudiana. Their structures were elucidated on the basis of spectroscopic analysis. Compounds 2, 3, and 5 showed enhancing activity of nerve growth factor (NGF)-induced neurite outgrowth in PC 12D cells.     

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.     

Cipadonoid A, a novel limonoid with an unprecedented skeleton, from Cipadessa cinerasecns

Cipadonoid A ( 1), a novel limonoid with an unprecedented skeleton, was isolated from the leaves of Cipadessa cinerasecns. Its structure and relative configuration were determined by spectroscopic analysis and computer modeling. 1 represents a new type of limonoid, characterized by a rearranged tetrahydropyranyl ring B incorporating usually exocyclic C-30. A possible biosynthetic pathway of 1 was also proposed.     

Kopsihainanines A and B, two unusual alkaloids from Kopsia hainanensis

Kopsihainanine A (1), an unprecedented skeleton with a 6/5/6/6/6 pentacyclic rearranged ring system, together with a new biogenetically related compound, kopsihainanine B (2), were isolated from Kopsia hainanensis. Their structures were elucidated by means of spectroscopic methods. The absolute configuration of 1 was determined by ECD calculation.     

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.     

Chukrasones A and B: Potential Kv1.2 Potassium Channel Blockers with New Skeletons from Chukrasia tabularis

Two new limonoids, chukrasone A (1) incorporating a highly rearranged A/B ring system and chukrasone B (2) possessing the first 16,19-dinor limonoid backbone with an extended C3 unit at C-15, were isolated from Chukrasia tabularis. Their structures were characterized on the basis of detailed spectroscopic analysis. Compounds 1 and 2 exhibited potential inhibition of the delayed rectifier (I(K)) K(+) current.     

Crotomacrine, a new clerodane diterpene from the fruits of Croton macrostachyus

A new clerodane diterpene, crotomacrine 1, together with the known crotepoxide were isolated from the fruits of Croton macrostachyus. Their structures were elucidated on the basis of spectral evidence.     

Bioactive clerodane diterpenes from roots of Carex distachya

Two new clerodane diterpenes were isolated from roots of Carex distachya Desf., a perennial plant widely distributed in the coastal area of the Mediterranean basin. Chemical characterization of the metabolites was carried out mainly by 1D and 2D NMR spectroscopy. The isolated compounds influenced either positively or negatively the plant growth (root and shoot elongation) of three coexisting herbaceous species.     

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.     

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.     

The cumbiasins, structurally novel diterpenes possessing intricate carbocyclic skeletons from the West Indian sea whip Pseudopterogorgia elisabethae (Bayer)

From the hexane extract of the West Indian gorgonian Pseudopterogorgia elisabethae, two diterpenes, cumbiasins A (1) and B (2), having a novel tetracyclic carbon skeleton named cumbiane, have been isolated. In addition, we have isolated cumbiasin C (3), a ring cleavage product of cumbiasin B that possesses an unusual carbocyclic framework named seco-cumbiane. The structures and relative configurations of metabolites 1-3 were elucidated by interpretation of overall spectral data, which included 2D NMR correlation methods, IR, UV, and accurate mass measurements (HREI-MS and HRFAB-MS). The carbocyclic skeletons of the cumbiasins are unprecedented and represent new classes of C20 rearranged diterpenes. Cumbiasins A and B display mild in vitro anti-tuberculosis activity.