Four ent-kaurane-type diterpenoids from Croton tonkinensis Gagnep

From the leaves of the endemic Vietnamese medicinal plant Croton tonkinensis GAGNEP. (Euphorbiaceae) the four new ent-kaurane-type diterpenoids ent-1alpha,14alpha-diacetoxy-7beta-hydroxykaur-16-en-15-one (1), ent-1alpha,7beta-diacetoxy-14alpha-hydroxykaur-16-en-15-one (2), ent-18-acetoxy-14alpha-hydroxykaur-16-en-15-one (3), and ent-(16S)-18-acetoxy-7beta-hydroxykauran-15-one (4) were isolated. Their structures were elucidated by spectroscopic analyses.     

Three diterpenoids (excoecarins V1-V3) and a flavanone glycoside from the fresh stem of Excoecaria agallocha

Three new diterpenoids, excoecarins V1-V3 (1-3) and a new flavanone glycoside (7) were isolated from the fresh stem of Excoecaria agallocha L. Their structures were elucidated as: 2alpha,3alpha,18-trihydroxy-3beta,20-epoxybeyer-15-ene (1), ent-2,3-secokaur-16-en-2,3-dioic acid (2), ent-3,4-seco-16alpha-hydroxyatis-4(19)-en-3-oic acid (3), and 3,5,7,3',5'-pentahydroxy-2R,3R-flavanonol 3-O-alpha-L-rhamnopyranoside (7) on the basis of spectroscopic data, chemical evidence, and/or X-ray analysis.     

Terpenoids from Chloranthus multistachys

Two new diterpenoids, ent-17-hydroxyl-16beta-methoxyl-kauran-3-one (1) and ent-17-acetoxyl-16beta-methoxyl-kauran-3-one (2), along with nine known compounds (3-12), ent-17-hydroxyl-kaur-15-en-3-one (3), ent-3beta-acetoxyl-kaur-15-en-16beta, 17-diol (4), ent-kauran-3beta, 16beta, 17-triol (5), ent-3beta-acetoxyl-kauran-16beta, 17-diol (6), ent-kauran-16beta, 17-diol (7), abbeokutone (8), ent-17alpha-acetyl-16beta-hydroxyl- kauran-3-one (9), shizukaol F (10), cycloshizukaol A (11) and curcolonol (12), were isolated from Chloranthus multistachys (Chloranthaceae). Their structures were elucidated by spectroscopic spectra.     

Two new ent-kaurane diterpenoids from the aerial parts of Isodon excisoides简

Two new ent-kaurane diterpenoids, ent-7a,14b-dihydroxykaur-16-en-15-one-20-oic acid(1) and 1,7a,12b,14b-tetrahydroxy-1,10-seco-ent-kaur-10,16-dien-15-one(2), together with six known ones(3–8), were isolated from the EtOAc extract of the aerial parts of Isodon excisoides. Their structures were elucidated on the basis of 1D NMR and 2D NMR analyses as well as HR-ESI-MS experiments.     

A novel ent-kaurane diterpenoid from the Croton tonkinensis GAGNEP

A novel ent-kaurane diterpenoid, ent-1alpha-acetoxy-7beta,14alpha-dihydroxy-kaur-16-en-15-on has been isolated from leaves of Croton tonkinensis GAGNEP. Its structure was determined by a combination of spectroscopy, X-ray crystallographic analysis and the chemical reaction acetylation.     

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.     

Terpenoids and phenolics from Plectranthus strigosus, bioactivity screening

Further studies on Plectranthus sp. (Lamiaceae) led to the isolation of terpenes and phenol esters from Plectranthus strigosus Benth. ent-16-Kauren-19-ol (1), ent-16-kauren-19-oic acid (2), xylopic acid (3), xylopinic acid (4), hinokiol (5), 4 beta,6 beta-dihydroxy-1 alpha,5 beta(H)-guai-9-ene (6) 4 beta,6 beta-dihydroxy-1 alpha,5 beta(H)-guai-10(14)-ene (7), mixtures of hexacosan-1,26-diol and octacosan-1,28-diol ferulate diesters (8), of esters from ferulic acid and fatty alcohols (9) and of esters from fatty acids and 2-(4-hydroxyphenyl)-ethanol (10) were for the first time isolated from this genus. Supplementary spectral data for 3,8 and parvifloron D (11) metabolites are also presented. A bioactivity study revealed herpetic inhibitory properties for (1) and (2), and antioxidant ability for (5) and (8) phenolic constituents.     

Isolation and biological activity of new and known isolation and biological activity of new and known diterpenoids from Sideritis stricta Boiss. & Heldr

Nine known and one new ent-kaurene diterpenoid were isolated from the acetone extract of Sideritis stricta Boiss & Heldr. The new compound, identified as ent-1 beta-hydroxy-7 alpha-acetyl-15 beta,16 beta-epoxykaurane (1) by IR, 1D and 2D NMR techniques and mass spectra, was isolated along with sideroxol (2), 7-acetyl sideroxol (3), 7-epicandicandiol (4), linearol (5), ent-7 alpha,15 beta,18-trihydroxy-kaur-16-ene (6), ent-7 alpha-acetyl,15,18-dihydroxy-kaur-16-ene (7), foliol (8), sideridiol (9) and siderol (10). The antibacterial and antifungal activities of these compounds and the whole crude acetone extract were evaluated against E. coli, S. aureus, K. pneumeonia and C. albicans.     

Licamichauxiioic-A and -B acids--two ent-kaurene diterpenoids from Licania michauxii

Bioassay-guided fractionation allowed the isolation of two new cytotoxic ent-kaurene diterpenoids, licamichauxiioic-A and -B acids (1 and 2) from the root extract of Licania michauxii Prance (Chrysobalanaceae). They were characterized as ent-15-oxo-9(11),16-kauradien-19-oic acid (1) and ent-15-oxo-13(14),16-kauradien-19-oic acid (2) by various spectroscopic methods, in particular, 1D and 2D NMR spectra, and chemical evidence.     

Effect of some ent-kaurenes on the viability of human peripheral blood mononuclear cells

The possible cytotoxic activity of some ent-kaurenes on human mononuclear cells, obtained from peripheral blood, was studied having in mind future studies on their antitumor activity. The cells were obtained using the Ficoll-Hypaque method, adjusted to 2 x 10(6) cells/mL, and incubated with kaurenes for 48 hours at 3 x 10(-5), 30 x 10(-5), 300 x 10(-1) and 3000 x 10(-5) micromol/well. Ent-kaurenic acid showed no toxicity at all concentrations studied. The least toxic of all the kaurene derivatives studied was ent-15,16-epoxy-17-acetoxy-(-)-kauran-19-oic acid, with a cellular viability of 99% at 3 x l0(-5) micromol/well, and 94% at 30 x 10(-1) micromol/well. Another compound that showed low toxicity was the 2,3,4,6-tetra-acetyl-alpha-D-pyranosyl ester of ent-15-oxo-(-)-kaur-16-en-19-oic acid with 44% viability at 3000 x 10(-5) micromol/well. The most toxic compounds at all concentrations tested were ent-kaur-16-en-19-ol acetate and ent-16alpha-hydroxy-(-)-kauran-19-oic acid. On the other hand, ent-kaur-9(11)16-dien-19-oic acid, ent-kauran-19-oic acid, and ent-kaur-16-en-19-ol were toxic only at the highest concentration studied. According to these results, and considering the concentrations employed, ent-kaur-16-en-19-oic acid and ent-15,16-epoxy-17-acetoxy-(-)-kauran-19-oic acid could be used for in vivo experiments and possibly for therapeutic purposes on humans, without much risk.     

<Emphasis Type="Italic">seco</Emphasis>-Kaurane skeleton diterpenoids from <Emphasis Type="Italic">Croton oblongifolius</Emphasis>

A new seco-kaurane type diterpenoid, ent-3,4-seco-17-oxo-kaur-4(19),15(16)-dien-3-oic acid, and a known compound, ent-3,4-seco-kaur-4(19),16(17)-dien-3-oic acid, were isolated from the stem bark of Croton oblongifolius. The structures of these compounds were established on the basis of spectroscopic data.     

Diterpenes from Sideritis trojana

Six known ent-kaurene, a new ent-kaurane and a new pimarane diterpenes were isolated from Sideritis trojana. The structures of new compounds were determined as ent-7alpha-15beta,16beta-epoxykaurane (1), and ent-2alpha-hydroxy-8(14),15-pimaradiene (2) along with the known compounds siderol (3), sideridiol (4), 7-epicandicandiol (5), isocandol B (6), candol A acetate (7) ent-7alpha-acetoxykaur-15-ene (8) by IR, 1D and 2D NMR techniques and HRMS.     

New lanostane-type triterpenes from Fomes officinalis

Five new lanostane-type triterpenes, named fomefficinic acid A-E (1-5), were isolated from the dried sclerotium of Fomes officinalis, respectively. Their structures were established as 24-methylene-3-oxo-lanost-8-en-21-oic acid (1), 3alpha,15alpha-dihydroxy-24-methylene-lanosta-7,9(11)-dien-21-oic acid (2), 3alpha,15alpha-dihydroxy-24-methylene-lanost-8-en-21-oic acid (3), 15alpha-hydroxy-3-oxo-24-methylenelanost-8-en-21-oic acid (4), 15alpha-acetoxy-3-oxo-24-methylenelanosta-7,9(11)-dien-21-oic acid (5), by spectral analysis and chemical methods as well as comparison with known compounds.     

The Constituents from the Stems of Annona cherimola

Thirty-five compounds including twenty-one alkaloids, lysicamine ( 1 ), liriodenine ( 2 ), atherospermidine ( 3 ), oxoxylopine ( 4 ), oxoanolobine ( 5 ), oxoglaucine ( 6 ), (-)-anonaine ( 7 ), (-)-asimilobine ( 8 ), (-)-xylopine ( 9 ), (-)-anolobine ( 10 ), (-)-norisocorydine ( 11 ), (+)-laurotetanine ( 12 ), (+)-isocorydine ( 13 ), (-)-N-methylasimilobine ( 14 ), (+)-N-methyllaurotetanine ( 15 ), (-)-norushinsunine ( 16 ), (-)-ushinsunine ( 17 ), (-)-N-formylanonaine ( 18 ), (+)-stepharine ( 19 ), (+)-orentaline ( 20 ), and (-)-kikemanine ( 21 ); four kauranes, ent-kaur-16-en-19-oic acid ( 22 ), 16β-hydroxy-17-acetoxy-ent-kauran-19-al ( 23 ), 17-acetoxy-16β-ent-kauran-19-oic acid ( 24 ), and 16β-hydroxy-17-acetoxy-ent-kauran-19-oic acid ( 25 ); two amides, N-trans-femloyltyramine ( 26 ), and N-trans-caffeoyltyramine ( 27 ); one purine, adenosine ( 28 ); one lactam amide, squamolone ( 29 ); and six steroids, β-sitosterol ( 30 ), stigmasterol ( 31 ), β-sitostenone ( 32 ), stigmasta-4,22-dien-3-one ( 33 ), 6β-hydroxy-β-sitosterone ( 34 ), and 6β-hydroxystigmasterone ( 35 ) are isolated from the stems of Annona cherimola. These compounds were characterized and identified by physical and spectral evidence. Among them, (-)-norisocorydine (11) was elucidated as a new enantiomer with a levorotary configuration, which is isolated for the first time.     

Identification of Twenty-one Novel Constituents of Oriental Tobacco Flavour (Nicotiana tabacumL.) including (E)-3-methyl-non-2-en-4-one,pentadecan-15-olide, 8α, 13:9α, 13-diepoxy-15, 16-dinorlabdane, (Z)-octadec-9-en-18-olide,and (E)-2-ethylidene-6, 10, 14-trimethyl-pentadecanal

Investigation by gas liquid chromatography of a small but organoleptically typical subfraction of Oriental tobacco condensate led to the identification of 47 compounds. Of these 21 have hitherto not been reported as Oriental tobacco constituents, and 14 appear to be novel to all tobacco types. The latter are (E)-3-methyl-non-2-en-4-one ( 1 ), (E)-1-(2, 3, 6-trimethylphenyl)-but-2-en-1-one ( 3 ), pentadecan-15-olide ( 12 ), 8α, 13:9α, 13-diepoxy-15, 16-dinorlabdane ( 17 ), (Z)-octadec-9-en-18-olide ( 18 ), (E)-2-ethylidene-6, 10, 14-trimethylpentadecanal ( 21 ), the norlabdanoids 9 , 10 , 11 , 14 , 15 , 16 , tridecan-2-one, and 2-phenylethyl isovalerate. The macrolides 12 and 18 represent the first musk compounds detected in tobacco. Identification were made by direct comparison (MS. and/or ¹ H-NMR./IR.) with the authentic chemicals synthesized whenever necessary.     

New Triterpenes from the Heartwood of Melaleuca leucadendron L.

Fourteen chemical constituents were isolated from the CHCl₃ soluble portion of the heartwood of Melaleuca leucadendron L. These compounds include β-sitosterol (1) , β-sitostenone (2) , 6-hydroxy-4,6-dimethyl-3-hepten-2-one (3) , naphthalene (4) , squalene (5) , 2α3β-dihydroxyurs-12-en-28-oic acid (6) , 3β-hydroxylup-20(29)-en-27,28-dioic acid (7) , 2α,3β-dihydroxyolean-12-en-28-oic acid (8) , 3β,23-dihydroxyolean-12-en-28-oic acid (9) , 2α,3β,23-trihydroxyolean-12-en-28-oic acid (10) , 3β-trans-p-coumaroyloxy-2α,23-dihydroxyolean-12-en-28-oic acid (11) , and three novel oleanane derivatives 23-trans-p-coumaroyloxy-2α,3β-dihydroxyotean-12-en-28-oic acid (12), 3β-trans-caffeoyloxy-2α,23-dihydroxyolean-12-en-28-oic acid (13) , and its isomer 3β-cis-caffeoyloxy-2α,23-dihydroxyolean-12-en-28-oic acid (14) , The three novel compounds were characterized as the two and three O-methylated derivatives, respectively.     

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…     

New diterpenoid glucosides from Siegesbeckia pubescens

Plants of the genus Siegesbeckia are annual herbs widely distributed in tropical and temperate zones and they are used as a traditional medicine to treat rheumatic arthritis, hypertension, malaria, neurasthenia and snake-bite in China. In previous papers, we reported on five new ent-kaurane and ent-pimarane diterpenoids, siegesbeckioside, siegesbeckiol and siegesbeckic acid1, orientalin A and B, and eight know compounds2,3. The present paper describes the isolation and structural elucidation …     

Five new diterpenoids from the bark of Taiwania cryptomerioides

Five new diterpenoids, 11-hydroxyabieta-8,11,13-trien-7-one (1), 11,12,14-trihydroxyabieta-8,11,13-trien-7-one (2), 6beta,7alpha-diacetoxyroyleanone (3), 7beta-hydroxymanoyl oxide (4), and 9alpha-hydroxyisopimara-8(14),15-dien-7-one (5) were obtained from the bark of Taiwania cryptomerioides. The structures of the new compounds 1-5 were elucidated on the basis of spectral analysis and chemical evidence.     

New triterpenoid saponins from Stelmatocrypton khasianum

Four new triterpenoid saponins, designated as stelmatotriterpenosides E-H (1-4), together with three known compounds, asterbatanoside B (5), 2alpha,3beta,19alpha,23-tetrahydroxy-olean-12-en-28-oic acid-3-O-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyl ester (6) and 2alpha,3beta,19alpha,23-tetrahydroxy-urs-12-en-28-oic acid-3-O-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyl ester (7), were isolated from the stems of Stelmatocrypton khasianum. On the basis of chemical and spectral evidence, the structures of 1-4 were established as 2alpha,3beta,23-trihydroxy-olean-12-en-28-oic acid-3-O-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester (1), 2alpha,3beta,23-trihydroxy-urs-12-en-28-oic acid-3-O-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester (2), 2alpha,3beta,19alpha-trihydroxy-urs-12-en-28-oic acid-3-O-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl ester (3), and 2beta,3beta,19alpha-trihydroxy-urs-12-en-24,28-dioic acid-24-O-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyl diester (4).