Two New Diterpenoids and Other Constituents from Isodon japonicus

Two new ent‐kaurene diterpenoids, 15α,20‐dihydroxy‐6,7‐seco‐entkaur‐16‐ene‐7,1α(6,11α)‐diolide ( 1 ), 6β‐butyroxy‐3β‐hydroxy‐6,7‐seco‐6,20‐epoxy‐7,1α‐olide‐entkaur‐16‐en‐15‐one ( 2 ), together with 25 known compounds, 3 – 27 , were isolated from the leaves of Isodon japonicus. Their structures were established by spectroscopic methods, including 2D‐NMR techniques.     

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.     

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.     

Diterpenoids from Isodon sculponeatus

Further investigation on the leaves of Isodon sculponeatus afforded two new ent-kaurane diterpenoids,sculponeatins J and K .Their sturctures were elucidated on the basis of their spectral properties,as well as X-ray crystallographic analysis ,The cytotoxicities of these two new compounds against human tumor cells K562 and T24 were also tested ,and sculponeation J showed significant inhibitory effects with IC50 values less than 1.0 μg/mL。     

Two New ent-Kaurane Diterpenoids from Isodon xerophilus

In continuation of our research on diterpenoids in the Isodon species, several newcompounds"' were obtained from the leaves oflsodon xerophilus (C. Y. Wu et H. W. Li)H. Hara (Labiatae), a perennial shrub native to Yunnan province. Further fractionation ofthe EtOAc extract led to the isolation of tWo new enl-kauranoids, xerophilusin E (l) andxerophilusin F (2). This paper deals with the structUral elucidation of the newcompounds.Xerophilusin E (l), a minor constitUent, was obtained as p…     

Two new ent-kaurane diterpenoids from Isodon henryi

Two new ent-kaurane diterpenoids, minheryins H （1） and I （2）, were isolated from the leaves of Isodon henryi. Their structures were elucidated by means of spectroscopic analysis, including 2D NMR spectra.     

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.     

Two New ent-Kaurane Diterpenoids from Isodon adenantha

As a medicinal herb locally used for the treatment of enteritis and dysentery in Yunnan province2, Isodon adenantha (Diels) Hara has been previously studied, which led to the isolation of several ent-kaurane diterpenoids including a new one3-5. In continuation of our research on the bio-active constituents from Isodon species6, two new ent-kaurane diterpenoids, adenanthins B (1) and C (2), were isolated from I. adenantha collected in Dali, Yunnan. In this paper, we report the structural el…     

Two new 19-oxygenated ent-kaurane diterpenoids from Isodon pharicus

<正>Two new 19-oxygenated ent-kaurane diterpenoids,pharicinins D and E(1 and 2),together with an artifact,pharicinin D acetal (3) were isolated from the leaves of Isodon pharicus.Their structures were determined by 1D and 2D NMR spectroscopic analysis. All of them were evaluated for their cytotoxicity.     

Three New Diterpenoids from Isodon Eriocalyx

Isodoneriocalyxisknowntoberichinent-kaurenoids.Inspiteofthatmanyent-kaurenoidswereisolated,newent-kaurenoidswerestillisolatedfromcollectionindifferentregions'-,o.FromthedriedleavesofthisspeciescollectedinHeqingcounty,Yunnan,threenewcompounds,eriocalyxinsC-El-3,wereisolated.Inthispaper,wereportthestructureelucidationofthesenewcompoundsbyspectralanalysis.EriocaIyxinClC22H2sO7(HRMS4O4.l825calc4O4.1835),ElMS(7OeV)In/z(reI.Int%)t4O4[M1 (lO),386[M-H2O] 'lO),368IM-2H,O] (2O),344(l00),32…     

Novel ent ‐Kaurane Diterpenoids from Isodon xerophilus

Further investigation on the leaves of Isodon xerophilus afforded three novel ent‐kaurane diterpenoids, xerophilusins D‐F (1–3), together with seven known compounds, phyllostachysin A (4), oleanolic acid, caffeic acid, rosmarinic acid, rutin, quercetin‐3‐O‐β‐D‐glucopyranoside, and quercetin. Structures of 1–3 were elucidated on the basis of their spectral properties and X‐ray crystallographic analysis. Compound 1 showed broad spectra inhibiting human tumor cells and significant cytotoxicity.     

Structure Elucidation of Two New Diterpenoids from Isodon phyllostachys: Phyllostacins A and B

Two new ent‐kaurane‐derived diterpene derivatives, phyllostacins A ( 1 ) and B ( 2 ), were isolated from the aerial parts of Isodon phyllostachys, together with two known compounds, irroratin A ( 3 ) and serrin B ( 4 ). Both 1 and 2 were found to be present as diastereoisomers. In the case of 1 , the corresponding diastereoisomeric diacetates 5 and 6 were prepared and separated. The structures of the new compounds were elucidated by extensive 1D‐ and 2D‐NMR spectroscopic methods, in combination with MS experiments. In (D₅)pyridine solution, the two epimers of 1 are present in equal amounts, but in CDCl₃ or CD₃OD, the (S)‐epimer predominates in the mixture of hemiacetals.     

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‐Kaurane Diterpenoids from Isodon phyllostachys

Phytochemical investigation of the medicinal plant Isodon phyllostachys led to the isolation of four new ent‐kaurane diterpenoids, phyllostacins F–I ( 1 – 4 , resp.), together with 11 known compounds, rosthorin A ( 5 ), rabdoternin C ( 6 ), enmenol ( 7 ), oridonin ( 8 ), lasiocarpanin ( 9 ), xerophilusin B ( 10 ), ponicidin ( 11 ), macrocalin B ( 12 ), phyllostachysin A ( 13 ), sculponeatin C ( 14 ), and macrocalyxoformin E ( 15 ). The structures of the new compounds were established by spectroscopic methods, including extensive 1D‐ and 2D‐NMR analyses. Compounds 1, 2, 7, 10 , and 13 were evaluated for their inhibitory activity against K562 and HepG2 cell lines.     

Three New Diterpenoids from Isodon nervosus

Three new ent‐kaurane diterpenoids, rabdonervosins D–F ( 1 – 3 ), were isolated from the leaves and stems of Isodon nervosus. Their structures were elucidated on the basis of spectroscopic methods including 1D‐ and 2D‐NMR analyses. Compounds 1 – 3 were evaluated for their cytotoxicity against HepG2, CNE2, PC‐9/ZD, HeLa, MCF‐7, and HCT116 cell lines. No compounds exhibited potent cytotoxicity.     

A New ent-Kaurane Diterpenoid from Isodon enanderianus

Isodon enanderianus (Hand. -Mazz.) H. W. Li, has been used in folk medicine as anti-inflammatory and detoxified agent1. The Isodon genus is known to be rich in ent-kaurane diterpenoids, a series of new ent-kaurane diterpenoids have been isolated from the dried leaves of I. enanderianus2-4. In order to find more biologically active substances, we have carefully investigated the chemical constituents of I. enanderianus collected in Shiping county of Yunnan province, and as a result, enanderi…     

Two New ent—Kaurane Diterpenoids from Isodon japonica

Two new ent-kauranoids,named maoyecrystals A (1) and B(2),were isolated from the EtOAc extract of the dried leaves of Isodon japonica (Burman f.) Hara collected in Tongbai mountains ,Henan Province,Their structures were determined on the basis of spectral data,especially by 2D NMR.     

Two Novel Sub-skeleton Types of ent-Kauranoids from Isodon gesneroides

Two novel ent-kauranoids with new sub-skeleton types, gesneroidins G and H were isolated as white powder from the ether extract of the leaves of Isodon gesneroides through normal phase column chromatography. Their structures were elucidated as 3β,6α,7β-triacetoxyl-15-hydroxyl-14-oxo-ent- 15,16-seco-kaur-11,17-olide and Iα-hydroxyl-3β,6α,7β,11 β-tetraacetoxyl-ent-nor-15,17-kaur-8,16-olide on the basis of the spectral evidences including ID and 2D NMR spectra.     

Antibacterial Constituents from Isodon Excisoides

Two new ent‐kaurane diterpenoids, taihangexcisoidesin C (1) and its acetonide, taihangexcisoidesin D (2), along with 9 known compounds were isolated from the leaves of Isodon excisoides. The structures of the new compounds were elucidated using 1D and 2D NMR spectroscopy analysis. Compounds 3‐6 and 8‐9 were tested for their antibacterial activity against Escherichia coli, Staphylococcus aureus, S. epidermidis and S. saprophyticus. Compound 6 showed inhibitory effects on Staphylococcus aureus, S. epidermidis and S. saprophyticus MIC values 32, 16 and 16 μg/mL, respectively. All of the compounds didn't show effects on Escherichia coli (MIC > 10 mg/mL).     

Two New ent—Kauranoids from Isodon sculponeata

Two new ent-kauranc dierpenoids,sculponcatins L(1) and M (2) ,were isolated from the EtOAc extract of Isodon sculponeata.Their structures,were clucidated by spectroscopic cvidences.The cytotoxicities of 1 and 2 against human tumor cells k562 and T24 were tested.