Ent-kaurane diterpenoids from Isodon rubescens var. lushanensis

Four new ent-kaurane diterpenoids lushanrubescensins F-I (1-4), together with 11 known ones, lasiodonin (5), oridonin (6), ponicidin (7), isodonoiol (8), isodonal (9), rabdosin B (10), rabdoternins A and B (11 and 12), enmenol (13), epinodosin (14), and inflexusin (15), were isolated from Isodon rubescens var. lushanensis, and the structures were elucidated by spectroscopic analysis. The inhibitory effect against the K562, Bcap37, BGC823, BIU87, CA, CNE, and Hela cell lines of compounds 3 and 5-10 were evaluated.     

Ent-kaurane and ent-abietane diterpenoids from Isodon phyllostachys

Four new diterpenoids, phyllostachysins I–L(1–4), along with a known one, hebeiabinin B(5), were isolated from the aerial parts of Isodon phyllostachys(I. phyllostachys). Compounds 1 and 2 feature an ent-kaurane backbone, and 3, 4 and 5 bear an ent-abietane skeleton. Their structures were elucidated by means of spectroscopic analysis. Compounds 3 and 4 exhibited significant cytotoxic activity against human tumor cell lines(HL-60, SMMC-7721, A-549, MCF-7 and SW-480), and strongly inhibited NO production in LPS-stimulated RAW264.7 cells.     

Rubesanolides A and B: diterpenoids from Isodon rubescens

From the medicinal plant Isodon rubescens, we isolated two novel diterpenes, rubesanolides A (1) and B (2). The compounds contain a unique β-lactone subgroup. This is the first discovery for a natural diterpene having rings A, B, and C in chair, boat, and twist-chair conformations, respectively. The structures were elucidated by analysis of spectroscopic data, and the absolute configuration of 1 was determined by X-ray diffraction.     

A Novel Asymmetric ent‐Kaurane Dimer from Isodon rubescens var. rubescens

A novel asymmetric ent‐kaurane dimer, xindongnin P ( 1 ), was isolated from Isodon rubescens var. rubescens. Its structure was elucidated by detailed spectroscopic analysis. Compound 1 contains a tetrahydrofuran moiety whose formation leads to inversion of configuration at C(16). This differentiates 1 from known related dimers, which were isolated before from the Isodon genus. A likely biogenetic pathway from the alleged monomer precursor 3 is proposed.     

Biogenetically related caged ent-kaurane diterpenoids from Isodon eriocalyx var. laxiflora

Two novel caged ent-kauranoids, neolaxiflorins D (1) and E (2), along with three other new ent-kauranoids, neolaxiflorins F–H (3–5), and a known one, eriocalyxin B (6), were obtained from Isodon eriocalyx var. laxiflora. Neolaxiflorin D (1) is the first 15,16-seco-16,17-dinor-ent-kaurane diterpenoid, and neolaxiflorin E (2) is the first 15,16-seco-17-homo-ent-kauranoid. The absolute configurations of ent-kauranoids 1 and 2 were determined by single-crystal X-ray diffraction analyses. Structural analysis of intermediate compounds 3–5 indicated that eriocalyxin B (6) is a biogenetic precursor of caged ent-kauranoids 1 and 2 as illustrated. The cytotoxic activity of the new compounds was evaluated by an MTT assay.     

Anti-hepatitis B virus and cytotoxic diterpenoids from Isodon lophanthoides var. gerardianus

Four new diterpenoides, isolophanthins A-D (1-4) together with seven known abietane diterpenoides (5-11), have been isolated from Isodon lophanthoides var. gerardianus. The new diterpenoides were elucidated by spectroscopic analysis. Some of them showed significant activities against HBsAg and HBeAg of hepatitis B virus in Hep G 2.2.15 cells, as well as the human tumor cell lines, HL-60, A-549, MOLT-4, and BEL-7402.     

Rubesanolides C-E: abietane diterpenoids isolated from Isodon rubescens and evaluation of their anti-biofilm activity

Phytochemical study of the leaves of the medicinal plant Isodon rubescens led to the isolation of three novel abietane diterpenoids, rubesanolides C-E (1-3). These diterpenes contain a unique γ-lactone subgroup formed between C-8 and C-20. Their structures were determined from analysis of spectroscopic data, and were further confirmed by X-ray crystallographic data. The compounds were evaluated for their antibacterial activity, and rubesanolide D (2) demonstrated inhibition activity against biofilm formation of the dental bacterium Streptococcus mutans.     

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…     

ent-Kaurene diterpenoids from Isodon phyllostachys

Four new ent-kaurene diterpenoids, phyllostachysins M–P (1–4) have been isolated from the aerial parts of Isodon phyllostachys. Compound 1 features a novel dihydro-2H-pyran ring motif, which was formed by an unusual cleavage in ring-A. 2 and 3 bear a rare 20-nor-ent-kaurene structure, but 4 has a rare 7,20-cyclo-ent-kaurene skeleton. Their structures were elucidated on the basis of extensive spectroscopic analyses. Compounds 1, 3, and 4 were evaluated for their cytotoxic activity against five human tumor cell lines.     

New diterpenoids from Isodon excisoides

<正>Two new ent-kaurane diterpenoids,taihangexcisoidesin C(1) and its acetonide,taihangexcisoidesin D(2) were isolated from the leaves of Isodon excisoides.Their structures were determined by 1D and 2D spectroscopic analysis.     

冬凌草中的新对映-贝壳杉烷二萜化合物

对河南省济源地区产冬凌草[Isodon rubescens(Hemsl.)Hara]再次进行了深入 的研究，从其叶的乙酸乙酯提取物中分离得到了16个化合物，其中1和2为两个新的 7，20-环氧-对映-贝壳杉烷类二萜化合物，其结构通过波谱分析确定为16（S）-羟 甲基-1α，6β，7β，11β-甲羟基-7α，20-环氧-对映-贝壳杉烷-15-酮（1）和 16（R）-羟甲基-1α，6β，7β，14β-四羟基-7α，20-环氧-对映-贝壳杉烷-15- 酮（2），分别命名为冬凌草已素（1）和庚素（2）；其余的已知化合物分别鉴定 为lasiodonin（3），冬凌草甲素（oridonin，4），乙素（ponicidin），丙素（ rubescensin C），丁素（rubescensin D），牛尾草丙素（rabdoternin C），荛 花香茶菜乙素（wikstroemioidin B），enmenol-1α-O-β-D-glucoside， enmenol，胡麻素（pedalitin），水杨酸，乌索酸，β-谷甾醇和胡萝卜甙。     

Four new diterpenoids from Isodon melissoides

Three new 11beta,16beta-epoxy-ent-kauranoids melissoidesins I-K (1-3) and one new ent-abietanoid melissoidesin L (4) were obtained from the aerial parts of Isodon melissoides (BENTHAM) H. HARA, their structures were established on the basis of the spectral methods, especially two dimensional (2D) NMR spectroscopy.     

Two new diterpenoids from Isodon eriocalyx

Isodoneriocalyx(Dunn)Hara(Labiatae).Ithasbeenusedasfolkmedicinetotreatsorethroat,inflammationaswellasreducingbloodpressure'.Previousstudiesonthisgenushaverevealed,anumberofditerpenoidspossessvariousbioactivitiessuchasanti-tUmorandanti-bacterial='3act...     

Cytotoxic ent-kaurane diterpenoids from Isodon henryi

Five new ent-kaurane diterpenoids, isodonhenrins A-E (1-5), together with thirteen known ones were isolated from the aerial parts of Isodon henryi. Their structures were identified by means of extensive spectroscopic analysis, and the absolute configurations of 1 were determined by single-crystal X-ray diffraction. Most of the diterpenoids were evaluated for their cytotoxicity against HL-60, SMMC-7721, A-549, MCF-7, and SW480 cell lines. Compound 17 showed significant inhibitory effects on five cell lines, and compounds 6, 9, 10, 11, 12 and 16 exhibited selective activity.     

Two new diterpenoids from Isodon serra

From the aerial part of Isodon serra,two new ent-6,7-seco-kaurane-type diterpenoids,15α,20β-dihydroxy-6β-methoxy-6,7- seco-6,20-epoxy-1,7-olide-ent-kaur-16-ene (1) and 6α,15α-dilaydroxy-20-aldehyde-6,7-seco-6,11α-epoxy-1,7-olide-ent-kaur-16- ene (2) were isolated.Their structures were elucidated by spectroscopic means.     

New ent-kaurane-type diterpenoids from Isodon nervosus

Two new ent-kaurane-type diterpenoids,6β,7β,13α-trihydroxy-1α-acetoxy-7α,20-epoxy-ent-kaur-16-en-15-one（1）and 15β- hydroxy-6,7-seco-6,11β：6,20-diepoxy-1α,7-olide-ent-kaur-16-ene（2）were isolated from the Isodon nervosus,and the structures were elucidated by spectroscopic analysis.     

Three New diterpenoids from Isodon Gesneroides

InthePreviouspaPed'],werePOrtedthebioactivditerPeedds,namedasgeSnerofdinAC,wereisolatedfromtlhaPlan.theinveedgationOfthisPlanlettoisolationofthreenewditerPenuldswiasgeSnerofdinsD-F(l-3).AspapewhdealwiththednddridationFigUrel.The1H-13Clong-rangeCOSYoflGesneroidinD(l),~lizedfromaeeone,mPl29.5-l3o.5"C,HRMS(5l8.2477,calc.5l8.25l6)SUggestedtheformulaCasH38O9.EIMS(7oeV)wt(rel.int.%)f5l8mp+(lO),458(3O),4l6(35),356(85),296(1oo).DuetotheabsencesofthecharaCteristicallsorptioninUVandIR…     

New ent‐Abietanoids from Isodon rubescens

Six new ent‐abietane diterpenoids, rubescensins I–M ( 1 – 5 ) and P ( 6 ), along with two related acetonide derivatives ( 7 and 8 ), were isolated from Isodon rubescens. Their structures were elucidated by detailed spectroscopic analysis. Compound 5 is the first N‐containing diterpenoid from the genus Isodon, exhibiting notable cytotoxicity against human tumor K562 cells.     

Rubescensins S and T: Seco‐ent‐Kaurane Diterpenoids from Isodon rubescens var. taihangensis

Two new diterpenoids, rubescensin S (=(1α,6β,14β)‐7α,20‐epoxy‐1,7,14‐trihydroxy‐16‐oxo‐15,16‐seco‐ent‐kauran‐6,15‐olide; 1 ) and rubescensin T (=(1α,6β,11β,20S)‐7α,20‐epoxy‐1,6,7‐trihydroxy‐20‐methoxy‐8,15‐seco‐ent‐kaur‐16‐en‐11,15‐olide; 2 ) were isolated from the Chinese medicinal herb Isodon rubescens var. taihangensis. Compound 1 possesses a unique, unprecedented 15,16‐seco‐ent‐kaurane skeleton. Both compounds exhibited cytotoxic activities against K562 human leukemia cells.     

Ent-abietane and ent-labdane diterpenoids from Isodon parvifolius

A phytochemical investigation on the leaves of Isodon parvifolius yielded three new ent-abietanoids parvifolines L-N (1-3), together with five known ent-abietanoids (4-8) and one known ent-labdane diterpenoid (9). Their structures were determined on the basis of extensive spectroscopic analysis.