Labdane diterpenes from the rhizomes of Hedychium coronarium

A new labdane diterpenoid, (E)-labda-8(17),12-dien-15,16-olide (1) together with eight known compounds, coronarin D (2), coronarin D methyl ether (3), coronarin D ethyl ether (4), isocoronarin D (5), coronarin B (6), labda-8(17),11,13-trien-15,16-olide (7), (E)-labda-8(17),12-diene-15,16-dial (8) and 16-hydroxylabda-8(17),11,13-trien-15,16-olide (9), are isolated from the rhizomes of Hedychium coronarium. Compounds 2-4, 5 and 9 are isolated as mixtures of C-15, C-14 and C-16 epimers, respectively. Their structures are determined on the basis of their spectroscopic data. The epimeric mixtures of 2 and 3 have not been reported before. Some of them were evaluated for their cytotoxicity.     

Cytotoxicity of labdane-type diterpenoids from Hedychium forrestii

Two new labdane-type diterpenoids, hedyforrestin D (1) and 15-ethoxy-hedyforrestin D (2), and three known compounds, yunnancoronarin A (4), B (3) and C (5) were isolated from the rhizomes of Hedychium forrestii. The structure of the new diterpenoids was established as 6beta,15xi-dihydroxylabda-8(17),11,13-trien-15,16-olide (1), and 6beta-hydroxy-15xi-ethoxylabda-8(17),11,13-trien-15,16-olide (2) on the basis of spectroscopic analyses. In addition, the isolated compounds were evaluated for their cytotoxicity against the lung adenocarcinoma cells A549 and leukemia cells K562 through 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assays. Of these, compounds 3 and 4 exhibited the most activity with IC(50) values of 0.92 and 2.20 microM, respectively, whereas 5 was inactive against A549 cells and 1 was inactive against both cell lines up to a concentration of 300.81 microM. This shows that both the hydroxy substitution and orientation of unsaturated lactone group in the five-membered ring of C-13 to C-16 seem to play an important role in the anti-tumor activities of human lung adenocarcinoma and leukemia.     

Terpenoids from Turraeanthus species

Chemical investigation of the root bark of Turraeanthus mannii and the stem of T. longipes resulted in the isolation of two new diterpenes, 13-methyl-labda-8(17)-en-15-oic acid (1) and 13-(hydroxymethyl)-14-hydroxy-ent-labda-8(17)-en-15-oic acid (2), along with two known diterpenes, 19-hydroxy-ent-labda-8(17),13-dien-15,16-olide (3) and 19-acetoxy-ent-labda-8(17),13-dien-15,16-olide (4), and the phytosterol, stigmasterol. The structure elucidation of the new compounds has been achieved using spectroscopic techniques.     

A new labdane diterpene from the flowers of Solidago canadensis

A new labdane diterpene, 9alpha,16xi-dihydroxy-6-oxo-7,13-labdadien-15,16-olide (solicanolide, 1) and six known compounds identified as quercetin (2), 3-O-caffeoylquinic acid (3, neochlorogenic acid), 5-O-caffeoylquinic acid (4, chlorogenic acid), 4,5-di-O-caffeoylquinic acid (5), 3,5-di-O-caffeoylquinic acid (6) and 3,4-di-O-caffeoylquinic acid (7) were isolated from the flowers of Solidago canadensis. To our knowledge, compound 7 was isolated for the first time in S. canadensis. This work describes the isolation of compounds 1-7 and the structure elucidation of a new compound identified as compound 1. Solicanolide (1) showed cytotoxic activity against A549 (IC(50): 13+/-2 microM), DLD-1 (IC(50): 26+/-2 microM) and WS1 (IC(50): 17+/-1 microM) cell lines.     

Trypanocidal labdane diterpenoids from the seeds of Aframomum aulacocarpos (Zingiberaceae)

Two novel labdane type diterpenoids, 8β(17)-epoxy-14,15,16-trihydroxylabd-12(E)-ene (aulacocarpin C) and 15,16-epoxy-14ξ,16ξ-dimethoxylabda-8(17),12-(E)-diene (aulacocarpin D) together with the known aulacocarpin A and B; 14,15-epoxy-8(17),12(E)-labdadien-16-al, coronarin E, and 15,16-epoxy-12β-hydroxy-labda-8(17)-13(16),14-triene were isolated from the seeds of Aframomum aulacocarpos. To the best of our knowledge, the last compound was isolated from a natural source for the first time. Acid hydrolysis of aulacocarpin D led to another new labdane type diterpenoid, 15,16-epoxy-12β-methoxylabda-8(17)-13(16),14-triene. The structures of all compounds were established on the basis of their spectroscopic data. These new compounds exhibit moderate trypanocidal activity.     

Two New Diterpenoids from Hedychium forrestii

Two new labdane diterpenes isolated from the rhizomes of Hedychium forrestii were determined by spectroscopic evidence to be labda-8(17), 11, 13-trien-7β-hydroxyl- 15(16)-olide (1,hedyforrestin B) and labda-8(17), 11, 13-trien-7β,16-dihydroxyl-16(15)-olide (2, hedyforrestinC).     

穿心莲内酯硫酸酯化反应体系中四个新的衍生物的分离与表征

通过色谱方法, 从复杂的穿心莲内酯硫酸酯化反应体系中分离获得4个新的穿心莲内酯衍生物, 应用谱学方法进行了表征. 主要利用1H NMR, 13C NMR, DEPT, 1H-1H COSY, HSQC, HMBC及NOSEY等1D和2D NMR技术, 并通过与母体化合物NMR数据的对比分析, 鉴定这4个化合物分别为3,19-二羟基-8,11,13-赖百当三烯-15,16-内酯(1), 3-羟基-8,11,13-赖百当三烯-15,16-内酯-19-硫酸酯(2), 8,11,13-赖百当三烯-15,16-内酯-3,19-二硫酸酯(3), 3-羟基- 8(R)-12(S)-8(12)-环氧-13-赖百当烯-15,16-内酯-19-硫酸酯(4).     

Two new sesquiterpene lactones from Ixeris chinensis

Phytochemical investigation of Ixeris chinensis NAKAI (Asteraceae) has resulted in the isolation of a new guaianolide-type sesquiterpene lactone, ixerochinolide (1) as well as the related glucoside, ixerochinoside (2). In addition, the known guaianolides, 8beta-hydroxy-3-oxo-guaia-4(15),10(14),11(13)-trien-1alpha,5alpha,6beta,7alphaH-12,6-olide (8beta-hydroxydehydrozaluzanin), 8beta,15-dihydroxy-2-oxo-guaia-1(10),3,11(13)-trien-5alpha,6beta,7alphaH-12,6-olide (lactucin), 3beta,8alpha,10alpha-trihydroxy-guaia-4(15),11(13)-dien-1alpha,5alpha,6beta,7alphaH-12,6-olide (10alpha-hydroxy-10,14-dihydro-desacylcynaropicrin) and 3beta-D-glucopyranosyloxy-8beta-(p-hydroxyphenylacetyloxy)-guaia-4(15),10(14),11(13)-trien-1alpha,5alpha,6beta,7alphaH-12,6-olide (8-epicrepioside) were identified. The structures were determined on the basis of spectral analyses, especially 1- and 2D NMR. Compound 1 exhibited significant cytotoxicity against human PC-3 tumor cells.     

Complete assignments of 1H and 13C NMR spectral data for three sesquiterpenoids from Inula helenium

The complete assignments of all the (1)H and (13)C NMR signals of three sesquiterpene lactones, 4-oxo-5(6),11-eudesmadiene-8,12-olide (1), 4-oxo-11-eudesmaene-8,12-olide (2) and (1(10)E)-5beta-Hydroxygermacra-1(10),4(15),11-trien-8, 12-olide (3), were carried out by various 2D NMR experiments. Compounds 1-3 were isolated from the roots of Inula helenium for the first time. Among them, 1 was identified as a new nor-sesquiterpene lactone, and 2 was isolated from a natural source for the first time. The (13)C-NMR data of compound 3 was also reported for the first time.     

Synthesis and inhibitory effect of novel glycyrrhetinic acid derivatives on IL-1 beta-induced prostaglandin E(2) production in normal human dermal fibroblasts

Olean-11,13(18)-dien-3beta,30-diol dihemiphthalate (3), which was derived from glycyrrhetinic acid (GA), has been reported to produce a potent of anti-inflammatory effect in in vivo assays. Using 3 as a lead compound, we attempted to synthesize some modified compounds which varied in the following; i) the position of a carboxyl group in the phthalate moiety, ii) the number of carboxyls attached to the benzoyl group, iii) conversion of benzene ring to another ring system, iv) the linkage form between the benzene ring and oleanene skeleton at position 3 and/or 30. These were screened for their inhibitory activity against interleukin-1 beta (IL-1 beta)-induced prostaglandin E(2) (PGE(2)) production in normal human dermal fibroblasts (NHDF). Although conversion of the ortho-carboxyl group of 3 into the meta-position or the para-position led to an increase in inhibitory activity, the elimination or increase of the carboxyl group resulted in loss of the inhibitory activity. Conversion of the ester bond to the amide bond at position 3 and/or 30 of 3 did not contribute to a significant increase in inhibitory activity. On the other hand, among the derivatives possessing an anthranilic acid moiety at position 30 of 3beta-O-acetyl-olean-11,13(18)-dien-30-oic acid (20), 3beta-hydroxy-30-nor-olean-11,13(18)-dien-20 beta-[N-(2-carboxyphenyl)]carboxamide (30) showed the most potent inhibitory activity (IC(50) 1.0 microM) in this series.     

A New Eremophilane Sesquiterpenoid from Ligularia przewalskii

Chemistry of Natural Compounds - A new eremophilane sesquiterpenoid, 3β-acetoxy-6α-angeloyloxy-eremophil-1(10),7(11),8(9)-trien-12,8-olide (1), was isolated from Ligularia przewalskii....     

A new diterpene from the leaves of Andrographis paniculata Nees

Phytochemical investigation of the methanolic extract of the leaves of Andrographis paniculata Nees yielded a minor, new diterpene, 21-nor-3,19-isopropylidine-14-deoxy-ent-labda-8(17),13-dien-16,15-olide (1), together with five known labdane type diterpenes, andrographolide 3, 14-deoxyandrographolide 4, 14-deoxy-12-hydroxyandrographolide 5, 14-deoxy-11,12-dihydroandrographolide 6, neoandrographolide 7, and two acids, cinnamic acid 8, and ferulic acid 9. The chemical structures were established by spectroscopic analyses, including 1D- and 2D-NMR spectroscopic experiments, and on the basis of HR-ESI MS analyses. The methanolic extract of the leaves exhibited moderate antibacterial and antifungal activities at a dose of 200 microg/mL in comparison with the reference standards.     

New norditerpenoids with trypanocidal activity from Vitex trifolia

Trypanocidal constituents of the fruits of Vitex trifolia were investigated. Activity-guided isolation of the acetone extract resulted in the isolation of two new norditerpene aldehydes, 1 and 2, together with five known diterpenes: vitexifolin E (3), vitexifolin F (4), vitexilactone (5), 6-acetoxy-9-hydroxy-13(14)-labden-16,15-olide (6), and previtexilactone (7). In vitro minimum lethal concentrations of the isolated compounds against epimastigotes of Trypanosoma cruzi were 11 microM (1), 36 microM (2), 34 microM (3), 34 microM (4), 66 microM (5), 66 microM (6), and >265 microM (7).     

Microbial transformation of deoxyandrographolide by Alternaria alternata AS 3.4578

Biotransformation of deoxyandrographolide (1) by Alternaria alternata AS 3.4578 gave five derivatives identified by spectral methods including 2D NMR as the known dehydroandrographolide (2) and 9beta-hydroxy-dehydroandrographolide (3) and the new compounds 9beta-hydroxy-deoxyandrographolide (4), 3alpha,17,19-trihydroxy-8,13-ent-labdadien-15,16-olide (5) and 3-oxo-9beta-hydroxy-deoxyandrographolide (6).     

An unusual bisnor-clerodane diterpenoid from Polyalthia simiarum

The stem bark of Polyalthia simiarum has yielded a new bisnor-type clerodane diterpenoid, 2-oxo-14,15-bisnor-3,11E-kolavadien-13-one (1), and three previously known clerodane derivatives, kolavenic acid (2), 16beta-hydroxycleroda-3,13(14)Z-dien-15,16-olide (3), and 16-oxocleroda-3,13(14)E-dien-15-oic acid (4). The structures of these compounds were unambiguously determined by extensive NMR studies as well as by comparison with related compounds. Till now this is the second report of the occurrence of any unusual C-18 clerodane diterpenoid from nature. The crude light petroleum extract and the purified compound 3 demonstrated moderate free radical scavenging activity with IC50 values of 21.5 and 23.5 microg/mL, respectively.     

Macrolides from the scent glands of the tropical butterflies Heliconius cydno and Heliconius pachinus

The four major components present in scent gland extracts of the male Costa Rica longwing butterflies Heliconius cydno and Heliconius pachinus were identified as 12- and 14-membered macrolides containing a C(18)-carbon skeleton. By use of micro-reactions and spectrometric examinations, structural proposals were made and subsequently proven by synthesis, using ring-closing-metathesis as the key steps. These macrolides, (9Z,11E,13S)-octadeca-9,11-dien-13-olide (5, S-coriolide), (9Z,11E,13S,15Z)-octadeca-9,11,15-trien-13-olide (6), (9Z,13S)-octadec-9-en-13-olide (13), and (9Z,11S)-octadec-9-en-11-olide (25), are biosynthetically obviously derived from oleic, linoleic, and linolenic acids. Their absolute configurations were determined by gas chromatographic investigations on chiral phases, showing all to possess (S)-configuration.     

Clerodane diterpenoids from Microglossa angolensis

Two new diterpenoids, 6β-(2-methylbut-2(Z)-enoyl)-3α,4α,15,16-bis-epoxy-8β,10βH-ent-cleroda-13(16),14-dien-20,12-olide and 10β-hydroxy-6-oxo-3α,4α,15,16-bis-epoxy-8βH-cleroda-13(16),14-dien-20,12-olide, together with the known β-amyrin, spinasterol, 5,7-dihydroxy-3,8,3′,4′-tetramethoxyflavone and 5,7-dihydroxy-3,8,3′,4′,5′-pentamethoxyflavone have been isolated from the aerial parts of Microglossa angolensis Oliv. et Hiern (Compositae). The structures were elucidated on the basis of spectral studies and comparison with published data.     

Epoxy lactones by photooxidative rearrangement of 6β-acetoxyvouacapane

The first study of photooxidation reaction of 6β-acetoxyvouacapane isolated from Caesalpinia platyloba is reported. The reaction yielded four new epoxy lactones, 6β-acetoxy-15,16α-epoxy-13-spirocassa-12,16-olide, 6β-acetoxy-15,16β-epoxy-13-spirocassa-12,16-olide, 6β-acetoxy-12,13β-epoxycassa-16,12-olide and 6β-acetoxy-12,13α-epoxycassa-16,12-olide. All the structures were supported by 1D and 2D NMR spectroscopy as well as mass spectrometry. The stereochemistry was established on the base of single crystal X-ray diffraction.     

Antioxidant activity of some lichen metabolites

Antioxidant activity of several classes of lichen metabolites were assessed in the in vitro superoxide radical (SOR), nitric oxide radical and 2,2-diphenyl-1-picrylhydrazil radical scavenging assays. The despsides sekikaic acid and lecanoric acid showed promising antioxidant activity in SOR assay with IC?? values of 82.0?±?0.3?μmol and 91.5?±?2.1?μmol, respectively, while the depsidone lobaric acid exhibited an IC?? value of 97.9?±?1.6?μmol, all relative to the standard, propyl gallate (IC???=?106.0?±?1.7?μmol). One of the most abundant mononuclear phenolic compounds, methyl-β-orcinol carboxylate was found to be a potent NO scavenger (IC???=?84.7?± 0.1?μmol), compared to the standard rutin (IC???=?86.8?±?1.9?μmol).