A new abietane and two dimeric abietane diterpenes from the black heartwood of Cryptomeria japonica

Three new diterpenes, sugikurojins A-C (1-3) were isolated from the black heartwood of Cryptomeria japonica. The structure of sugikurojin A was deduced to be 19-hydroxy-6,7-dehydroferruginol on the basis of extensive NMR experiments. Sugikurojin B was a dimer of 6,7-dihydroxyferruginol and 6,7-dehydroferruginol with a 6-O-11' linkage. Sugikurojin C was a dimeric ferruginol with 6-O-7' and 7-O-6' linkages. Also obtained in this investigation were the known compounds formosaninol (4), 15 sesquiterpenes (5-19), 16 diterpenes (20-35), three phenylpropanoids (36-38), and a phenolic compound (39).     

Three new sesquiterpenes from the black heartwood of Cryptomeria japonica

Three new sesquiterpenes, (4S)-2,6,10-bisaboratrien-4-ol-1-one (1), 1,8-epoxy-1(6),2,4,7,10-bisaborapenta-en-4-ol (2), and 1-methoxy-4-cadinene (3) have been isolated from the black heartwood of Cryptomeria japonica. Compounds 1 and 2 were designated sugikurojinols A and B, respectively, and the structures of compounds 1-3 were established by extensive NMR experiments. Compounds 1 and 2 were also examined for antibacterial activity against Staphylococcus aureus and Escherichia coli, and for termiticidal activity against Coptotermes formosanus SHIRAKI.     

Isolation of antibacterial diterpenoids from Cryptomeria japonica bark

The aims of the present study were to determine the antibacterial activity of bark extract of Cryptomeria japonica D. Don and to isolate potential antibacterial constituents. The results showed that the ethanolic extract of C. japonica bark possessed a good antibacterial activity. Nine compounds including seven diterpenoids (ferruginol (I), isopimaric acid (II), iguestol (III), isopimarol (IV), phyllocladan-16alpha-ol (V), sandaracopimarinol (VI) and sugiol (VII)) and two steroids (beta-sitosterol (VIII) and beta-sitostenone (IX)) were isolated from active subfractions; beta-sitostenone was isolated for the first time from this plant. Among these compounds, ferruginol possessed the strongest antibacterial activity and had MIC values ranging from 6.3 to 12.5 microg mL(-1) against all bacteria tested. Isopimaric acid was also an antibacterial natural product. Cryptomeria japonica bark extract and its diterpenoids, ferruginol and isopimaric acid, have the ability to inhibit the bacterial growth and can be used as the source for natural bactericides.     

New abietane and seco-abietane diterpenes from the roots of Taiwania cryptomerioides

Four new diterpenes, 3-oxosaprorthoquinone (1), 3-oxomicrostegiol (2), 3-oxoisotaxodione (3), and taiwaninal (4), together with two known compounds, 3-oxosapriparaquinone (5) and 6-dehydrohinokiol (6), were isolated from the roots of Taiwania cryptomerioides. The structures of 1-4 were principle elucidated based on spectral evidence.     

Two new abietane diterpenes from Cordia latifolia

Two new abietane diterpenes cordioic acid and cordifolic acid were isolated from the methanolic extract of Cordia latifolia stem bark. The structures of these diterpenes were elucidated using spectroscopic techniques. To the best of our knowledge, this is the first instance of isolation of diterpenoids from this source. Furthermore, cordifolic acid is a rare 2,3-seco-abietane suggestive of its biogenesis from 3-keto-analogue.     

Two new abietane diterpenes huperphlegmarins A and B from Huperzia phlegmaria

Two new abietane diterpenes, huperphlegmarin A–B (1–2), were isolated from the aerial parts of Huperzia phlegmaria (L.) Rothm. (Lycopodiaceae), in addition to five known compounds including lycoxanthol (3), 21β-hydroxyserrat-14-en-3β-yl acetate (4), 21α-hydroxyserrat-14-en-3β-yl acetate (5), 21α-hydroxyserrat-14-en-3β-ol (6), and fawcettidine (7). Their structures were determined by the combination analyses of spectroscopy, including 1D-, 2D-NMR, HRESIMS, CD and comparison with the reported data in the literature. Huperphlegmarin B (2) presented the rare 1,11-epoxy group in the molecule. Compounds 3, 4, 5 and 6 were performed for AChE inhibitory activity and compound 3 showed the inhibitory activity against AChE with IC₅₀ of 465.6 μg/mL.     

Abietane diterpenoids from the barks of Cryptomeria japonica

From the bark of Cryptomeria japonica were isolated sugikurojins I (1) and J (2), and an abietane derivative (3) was obtained for the first time as a natural product. These structures were elucidated primarily through extensive NMR experiments. Sugikurojin I (1) has a unique skeleton incorporating an abietane diterpene and a 1,10-secocadinane sesquiterpene. Sugikurojin J (2) is a peroxyester of hydroxyabietane diterpene and isopimarane acid diterpene. Compound 3 was p-quinone acid, which occurred by cleavage between C-7 and C-8 of sugiol; it was deduced to [4'-isopropyl-1(S),3,3-trimethyl-3',6'-dioxo-bicyclohexyl-1',4'-dien-2(R)-yl]-acetic acid. Also obtained in this investigation were three known diterpenes (4-6).     

1H and 13C NMR assignments of abietane diterpenes from Aegiphila lhotzkyana

An NMR study of one new and several known abietane diterpenes isolated from the roots of Aegiphila lhotzkyana is described. In addition to 1D NMR, several 2D shift‐correlated NMR pulse sequences (¹H–¹H‐COSY, NOESY, HMQC and HMBC) were used to establish all the structures, and unambiguously perform the ¹H and ¹³C chemical shift assignments of the new natural diterpene and three derivatives, the NMR data for which have not been reported previously. Revision of current data assignment for teuvincenone H is also suggested. Copyright © 2003 John Wiley & Sons, Ltd.     

Synthesis of C-7 oxidized abietane diterpenes from racemic ferruginyl methyl ether

A series of naturally occurring C-7 oxidized abietane diterpenes have been synthesized from racemic ferruginyl methyl ether in high yields. 6-Hydroxyl-5,6-dehydrosugiol (7) can be converted into stable xanthoperol (12) using high temperature. Among the products, the structures of sugiyl methyl ether (2) and 6(-hydroxysugiyl methyl ether (8) were determined by X-ray analysis.     

A New Seco-Abietanoid from the Bark of Cryptomeria japonica

Chemistry of Natural Compounds - A new seco-abietanoid, 12-hydroxy-6,7-seco-abieta-8,11,13-triene-6,7-dioic acid (1), was isolated from the methanol extract of the bark of Cryptomeria japonica. The...     

New labdane diterpenes from the stem bark of Larix laricina

Two new labdane diterpenes, cis-19-hydroxyabienol (1) and 8alpha-hydroxy-12Z,14-labdadien-19-al (2), along with another labdane described for the first time in the genus Larix, 19-acetoxy-13S-hydroxy-8(17),14-labdadiene (3) and a stilbene, 3-methoxy-3,3',5'-trihydroxystilbene (4), were isolated from the stem bark of Larch (Larix laricina). Their structures were established by standard chemical and spectroscopic methods. Compounds 2 and 3 were shown to be moderately cytotoxic against A-549, DLD-1 and normal skin fibroblast cell lines, WS1. Compound 1 was found to be selectively active against colon carcinoma cell lines, DLD-1.     

Three novel 5(6-->7)abeoabietane-type diterpenes from the bark of Taiwania cryptomerioides

Three new 5(6-->7)abeoabietane diterpenes with the uncommon skeleton of fused 6-5-6 rings were isolated from the bark of Taiwania cryptomerioides designated as taiwaniaquinone F (8), taiwaniaquinol C (9) and taiwaniaquinol D (10). Meanwhile, two known compounds, taiwaniaquinones A (1) and D (4), were also obtained. Their structures were determined principally from spectral evidence.     

Three new sesquiterpenes from Ainsliaea glabra

Three new sesquiterpenes: 4-acrylic-6-methyl-α-tetralone (1), ainsliaea acid A (2) and ainsliaea acid B (3), together with 8 known compounds (4-11) were isolated from the whole herb of Ainsliaea glabra and their structures were established by means of 1D and 2D NMR spectroscopy and HR-ESIMS. Compounds 1–6 were tested for the inhibition of nuclear factor kappa B (NF-κB) in the 293-NF-κB-luciferase reporter cell line induced by lipopolysaccharide (LPS), and compound 2 was further tested for the production of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6 and IL-10 in RAW264.7 macrophages induced by LPS. The isolated compound 2 exhibited significant anti-inflammatory activity.     

Three new diterpenes from Jatropha curcas

Jatrophalactone (1) and jatrophalone (2), together with jatrophadiketone (3), a 6/6/6 tricyclic diterpene transformed from rhamnofolane skeleton, have been isolated from the methanolic extract of Jatropha curcas. The structures were established on the basis of extensive spectroscopic methods and further confirmed by X-ray crystallographic analysis. The cytotoxicity against selected cell lines was evaluated. Among them, compound 1 displayed cytotoxicity against HL-60, SMMC-7721, A-549, MCF-7, and SW480 cell lines with IC₅₀ values of 8.5, 20.6, 19.7, 20.1, and 19.2 μM, respectively. The possible biosynthetic pathways for 1 and 3 are proposed.     

Three new eudesmane sesquiterpenes from Artemisia vestita

Three eudesmane sesquiterpene lactones,namely artemivestinolides A–C(1–3),along with three known 11-epimeric lactones(4–6),were isolated from the aerial parts of Artemisia vestita.Their structures were elucidated on the basis of extensive spectroscopic analyses(IR,HR-ESIMS,1D NMR and 2D NMR),and the absolute confgurations were determined by single-crystal X-ray diffraction(with copper radiation).Furthermore,in an in vitro assay,the three new compounds exhibited a moderate inhibition of the lipopolysaccharide(LPS)-induced nitric oxide(NO)production in BV-2 microglial cells.     

Three new sesquiterpenes from Euonymus schensianus Maxim

Three new sesquiterpenes,namely schensianol A(1),schensianolside A(2) and schensianolside B(3) were isolated from the stems and leaves of Euonymus schensianus Maxim.Their structures were established by chemical methods and spectroscopic techniques including 2D NMR.     

Seco-Abietanoids from Cryptomeria japonica and Their Inhibitory Activity Toward Xanthine Oxidase

Chemistry of Natural Compounds - A new seco-abietanoid, 12-methoxy-7-oxo-6,7-secoabieta-8,11,13-trien-6-oic acid (1), and a known seco-abietanoid,12-hydroxy-6,7-secoabieta-8,11,13-triene-6,7-dial...     

Three new dimeric diterpenes from Rhododendron molle

Birhodomolleins A-C (1-3), three novel diterpenoids dimerized from two grayanane diterpenes through an oxygen bridge, were isolated from the flowers of Rhododendron molle. Their structures were elucidated by interpretation of their 1D and 2D NMR and other spectroscopic data. Birhodomollein A (1) contains a rare chloro-substitution on one of the grayanane moieties. These are the first examples of dimeric diterpenes from the Ericaceae family.