Antifeedant/insecticidal terpenes from asteraceae and labiatae species native to Argentinean semi-arid lands

To validate the potential as added-value resources of Asteraceae and Labiatae species of Argentinean semi-arid lands, we have selected 13 of their major terpenoids belonging to several chemical classes and tested their insect antifeedant and toxic activity on the herbivorous insects Spodoptera littoralis and Leptinotarsa decemlineata. The antifeedant effects of the test compounds were structure- and species-dependent. The most active antifeedant to L. decemlineata was the eudesmane sesquiterpene gamma-costic acid (13), followed by the labdane diterpene 2alpha,3alpha-dihydroxycativic acid (8), the clerodane diterpenes 6-acetylteucjaponin B (5), bacchotricuneatin A (1), bartemidiolide (7), butanolide (4), and the sesquiterpenes ilicic acid (11) and tessaric acid (10) (eudesmane and eremophilane type, respectively). S. littoralis was only affected by the clerodanes and showed the strongest response to salviarin (3) and 5, followed by hawtriwaic acid (6) and 12-epi-bacchotricuneatin A (2). Orally injected S. littoralis larvae were negatively affected by 5. Most of the diterpenes had selective cytotoxic effects to insect-derived Sf9 cells with the clerodane 1 being the most active, followed by the eudesmane costic acid (12), the only cytotoxic sesquiterpene. None of these compounds was cytotoxic to mammalian CHO cells.     

Diterpenes and tetranorditerpenes from Acritopappus species

The investigation of four Acritopappus species afforded twenty-three new diterpenes of the labdane or kolavane type and three tetranorditerpenes as well as two new benzofuran derivatives and a hydroxybicyclogermacrene. The structures were elucidated by spectroscopic methods and by some chemical transformations. Though the absolute configuration were not established in all cases, most probably all diterpenes were ent-labdanes or kolavanes (clerodanes). The chemotaxonomic importance of this investigation is discussed briefly.     

Three clerodane diterpenoids from Croton eluteria Bennett.

Three furanoid clerodanes have been isolated from the stem bark of Croton eluteria Bennett. Their structures have been established by spectroscopic methods. The compounds were named cascarillin B (7alpha-acetoxy-3,4,15,16-diepoxy-12-oxo-cleroda-13(16),14-dien-20-al), cascarillin C (7alpha-acetoxy-15,16,12,20-diepoxy-20-hydroxy-cleroda-3,4,13(16),14-triene) and cascarillin D (7alpha-acetoxy-3,4,15,16-diepoxy-cleroda-13(16),14-dien-20-al).     

Clerodane and labdane diterpenoids from Baccharis species

The investigation of eight Baccharis species afforded, in addition to known compounds, five new clerodanes, three labdane derivatives and a nor-diterpene as well as one hydroperoxide derived from 4α-hydroxygermacra-1(10), 5-diene. The structures were elucidated by spectroscopic methods. The structures of esters isolated previously from B. cassinaefolia have to be revised. Chemotaxonomic aspects are discussed briefly.     

Polystachynes A-E, five cis-neo-clerodane diterpenoids from Salvia polystachya

From the aerial parts of Salvia polystachya five new neo-clerodane diterpenoids, polystachynes A-E, have been isolated. The structures were established by spectroscopic methods, including the X-ray analysis of polystachynes C and D. The known clerodanes salvifaricin, linearolactone and dehydrokerlin were also isolated.     

A diterpene with a new carbon skeleton from Solidago altissima

An Indian sample of Solidago altissima afforded in addition to several clerodanes already isolated from other Solidago species, a diterpene with a new carbon skeleton. Furthermore a ketone and a new anethole derivative were present.     

Diterpenes from Koanophyllon species

The investigation of two Koanophyllon species afforded, in addition to known compounds, several new diterpenes, two new geranylgeraniol derivatives and four diterpenes, most probably closely related to clerodanes; their structures, however, could not be deduced with certainty. The chemotaxonomic situation of this genus is discussed briefly.     

Clerodane diterpenoids from Teucrium and Ajuga plants

A new clerodane diterpenoid, chamaepitin has been isolated from Ajuga chamaepitys. The previously known clerodanes, 19-acetylgnaphalin, auropolin, teucrin A and teuflin, have been isolated from Teucrium species (T. polium subsp. belion, T. polium subsp. capitatum and T. asiaticum) collected in Majorca. X-ray diffraction analysis on crystals of auropolin has allowed the assignment of configuration at C-20 as S for this compound.     

Diterpenes with a new carbon skeleton from Printzia Laxa

The aerial parts of the South African composite Printzia laxa contain two manoyl oxides and three clerodane derivatives together with two further acids, which belong to a new type of diterpene, biogenetically closely related to the clerodanes. The structures have been elucidated by spectroscopic methods. The constituents may indicate some relationship of Printzia to the tribe Astereae.     

Effects of six diterpenes on macrophage eicosanoid biosynthesis

Six diterpenes (three clerodanes, two abietanes and one rosane) were tested for interactions with the cyclooxygenase and 5-lipoxygenase pathways of arachidonate metabolism and for effects of nitric oxide production. Two abietane diterpenes, aethiopinone and 11,12-dihydroxy-6-oxo-8,11,13-abietatriene and the rosane lagascatriol showed a remarkable effect on COX-1 pathway of PGE2 release in calcium ionophore A23187-stimulated peritoneal macrophages. Only the two latter diterpenes showed inhibition on COX-2 pathway of PGE2 release in E. coli LPS-stimulated peritoneal macrophages. In addition, all compounds assayed were inhibitors of LTC4 release with IC50 < or = 10 microM. Clerodane diterpenes were inactive in COX assay. None of the diterpenes assayed, except 11,12-dihydroxy-6-oxo-8,11,13-abietatriene, affected NO production. The results obtained suggest that the cellular mechanisms of action of some of these substances may involve inhibition of cyclooxygenase/lipoxygenase pathways and nitric oxide production.     

Thermal conversions of trimethylsilyl peroxides of linoleic and linolenic acids

The trimethylsilyl (TMS) peroxides/esters of the fatty acid hydroperoxides (9S,10E,12Z)-9-hydroperoxy-10,12-octadecadienoic acid (9-HPOD) and (9Z,11E,13S,15Z)-13-hydroperoxy-9,11,15-octadecatrienoic acid (13-HPOT) were subjected to gas chromatography-mass spectrometry and products formed by thermal rearrangements were identified. The main products were decadienals and the TMS derivatives of 13-oxo-9,11-tridecadienoic acid, epoxyalcohols, hemiacetals, and ketodienes. Oxy radicals as well as epoxyallylic radicals served as intermediates in the formation of these compounds. The thermal TMS peroxide conversions documented provided biomimetic models for enzymatic conversions of fatty acid hydroperoxides and also offered a method to generate an array of oxylipin derivatives of value as reference compounds in GC-MS studies.     

Sequential enzymes of linoleic acid oxidation in corn germ: lipoxygenase and linoleate hydroperoxide isomerase

Linoleic acid oxidation catalyzed by lipoxygenase (lipoxidase) activity in extracts of defatted corn germ does not terminate in the product, linoleic acid hydroperoxide, unless the lipoxygenase is first partially purified. If purification is not attempted, the hydroperoxide product exists only as a barely detectable intermediate in the synthesis of three products. One of these was identified as 9-hydroxy-10-oxo-cis-12-octadecenoic acid formed from the hydroperoxide by the enzyme, linoleate hydroperoxide isomerase. Another product, 13-hydroxy-10-oxo-trans-11-octadecenoic acid, is believed to be formed by an isomerase also. The third product was the linoleate ester of one of the hydroxy-oxo-fatty acids, 9-(cis-9,cis-12-octadecadienoyl)-10-oxo-cis-12-octadecenoic acid. It is not known if the synthesis of the ester is enzyme-catalyzed. When a mixture of 13-hydroperoxy-cis-9,trans-11-octa-decadienoic acid and 9-hydroperoxy-trans-10,cis-12-octa-decadienoic acid from soybean lipoxygenase oxidation of linoleic acid was used as a substrate, 13-hydroxy-12-oxo-cis-9-octadecenoic acid and 9-hydroxy-12-oxo-trans-10-octadecenoic acid were formed as the major products of catalysis by linoleate hydroperoxide isomerase(s) from corn. Smaller quantities of 9-hydroxy-10-oxo-cis-12-octadecenoic acid and 13-hydroxy-10-oxo-trans-11-octadecenoic acid were also formed.     

Photoaffinity labeling of human retinoid X receptor beta (RXRbeta) with 9-cis-retinoic acid: identification of phytanic acid, docosahexaenoic acid, and lithocholic acid as ligands for RXRbeta

We utilized [20-methyl-(3)H]-9-cis-retinoic acid ([(3)H]9-cis-RA) as a direct photoaffinity probe for the characterization of human recombinant retinoid X receptor beta protein (RXRbeta). The photoaffinity labeling was light- and concentration-dependent, saturable, and protected by unlabeled 9-cis-RA in a concentration-dependent manner, indicating that binding occurred in the RXR retinoid binding site. all-trans-Retinoic acid (atRA) did not affect labeling with the 9-cis derivative, confirming that atRA does not compete for the 9-cis-RA binding site. Several retinoid, fatty acid, and bile acid ligands were evaluated for their ability to recognize the 9-cis-RA binding site. Retinol, atRA glucuronide, 13-cis-RA, dolichol, 5,6-epoxy-RA, and vitamin D(3) did not compete for the 9-cis-RA binding site. However, the saturated diterpenoid phytanic acid (PA) and docosahexaenoic acid, which have been recently shown to activate the nuclear receptor, RXR, competed with 9-cis-RA labeling, showing high affinity for the 9-cis-RA binding site. Oleic acid, arachidonic acid, and butyric acid did not interact. However, the bile acid lithocholic acid competed efficiently with 9-cis-RA for the binding site. These data validated the photoaffinity assay as an excellent system for the identification and evaluation of ligands for RXR.     

The two calcium-binding proteins, S100A8 and S100A9, are involved in the metabolism of arachidonic acid in human neutrophils.

Recently, we identified the two myeloid related protein-8 (MRP8) (S100A8) and MRP14 (S100A9) as fatty acid-binding proteins (Klempt, M., Melkonyan, H., Nacken, W., Wiesmann, D., Holtkemper, U., and Sorg, C. (1997) FEBS Lett. 408, 81-84). Here we present data that the S100A8/A9 protein complex represents the exclusive arachidonic acid-binding proteins in human neutrophils. Binding and competition studies revealed evidence that (i) fatty acid binding was dependent on the calcium concentration; (ii) fatty acid binding was specific for the protein complex formed by S100A8 and S100A9, whereas the individual components were unable to bind fatty acids; (iii) exclusively polyunsaturated fatty acids were bound by S100A8/A9, whereas saturated (palmitic acid, stearic acid) and monounsaturated fatty acids (oleic acid) as well as arachidonic acid-derived eicosanoids (15-hydroxyeicosatetraenoic acid, prostaglandin E(2), thromboxane B(2), leukotriene B(4)) were poor competitors. Stimulation of neutrophil-like HL-60 cells with phorbol 12-myristate 13-acetate led to the secretion of S100A8/A9 protein complex, which carried the released arachidonic acid. When elevation of intracellular calcium level was induced by A23187, release of arachidonic acid occurred without secretion of S100A8/A9. In view of the unusual abundance in neutrophilic cytosol (approximately 40% of cytosolic protein) our findings assign an important role for S100A8/A9 as mediator between calcium signaling and arachidonic acid effects. Further investigations have to explore the exact function of the S100A8/A9-arachidonic acid complex both inside and outside of neutrophils.     

灵芝液态深层发酵产物中10种不饱和脂肪酸类化合物的鉴定

通过规模化液态深层发酵获得灵芝发酵产物,采用多种硅胶色谱柱层析及重结晶的方式,从中分离得到10个化合物。通过核磁、质谱等波谱分析,鉴定出这些化合物均属于含羟基或酮基的不饱和脂肪酸类化合物,分别为(9S,10R,11E,13R)-9,10,13-trihydroxyoctadec-11-enoic acid（1）和(9S,10R,11E,13S)-9,10,13-trihydroxyoctadec-11-enoic acid（2）的混合物、12S^*,13S^*-dihydroxy-9-oxo-10(E)- octadecenoic acid（3）、9R*,10R*-dihydroxy-13-oxo-11(E)-octadecenoic acid（4）、12S*,13R*-dihydroxy- 9-oxo-10(E)-octadecenoic acid（5）、9S*,10R*-dihydroxy-13-oxo-11(E)-octadecenoic acid（6）、10(S)-hydroxy-8(Z)-octadecenoic acid（7）、12-oxooctadeca-8,10-dienoic acid（8）、9,12-dihydroxy-10-eicosenoic acid（9）和9-oxooctadeca-10,12-dienoic acid（10）。这些化合物均为首次从灵芝发酵产物中获得,且具有不同程度的体外抗肿瘤活性。其中,化合物8和化合物10对L1210细胞增殖抑制的IC₅₀值分别为13.00μmol/L和16.88μmol/L,对K562细胞增殖亦有良好的抑制效果,是具有抗肿瘤潜力的天然产物。     

Clerodane-type diterpenes from the seed pods of Hymenaea courbaril var. stilbocarpa.

Three known and two new diterpenes were isolated from the ethyl acetate extract of Hymenaea courbaril var. stilbocarpa seed pods. One of the compounds was elucidated as (5R*,8S*,9S*,10R*)-cleroda-3,13E-dien-15-oic acid and the other was elucidated, after treatment with diazomethane, as methyl (5S*,8S*,9S*,10R*)-cleroda-3,13E-dien-15-oate. The known diterpenes were identified as (-)-ozic acid, (-)-isoozic acid and (-)-kovalenic acid which were characterized as their methyl ester derivatives.     

Metabolism of prostaglandins D2 and F2 alpha in primary cultures of rat hepatocytes

3H-Labeled prostaglandins D2 and F2 alpha rapidly degraded to more-polar metabolites in primary cultured rat hepatocytes. The metabolites of prostaglandins D2 and F2 alpha accumulated in the culture medium. The metabolites extracted by ethyl acetate at pH 3 were purified by silicic acid column and thin-layer chromatography of silica gel, and were analysed by gas chromatography-mass spectrometry. The major metabolites from prostaglandin D2 were identified as dinor-prostaglandin D1 (7 alpha,13-dihydroxy-9-ketodinorprost-11-enoic acid) and tetranor-prostaglandin D1 (5 alpha,11- dihydroxy-7-ketotetranorprost-9-enoic acid). Those from prostaglandin F2 alpha were identified as dinor-prostaglandin F1 alpha (7 alpha,9 alpha,13-trihydroxydinorprost-11-enoic acid), tetranor-prostaglandin F1 alpha (5 alpha,7 alpha,11-trihydroxytetranorprost-9-enoic acid) and 9 alpha,11 alpha,15-trihydroxyprost-13-ene-1,20-dioic acid. These data indicate that prostaglandins D2 and F2 alpha mainly degraded by beta-oxidation, which is the same process as reported earlier for prostaglandins E1 and E2, and that prostaglandin F2 alpha was also subjected to omega-oxidation.     

The Induction of Lipid Peroxidation in Rat Liver by Oral Intake of 9-Oxononanoic Acid Contained in Autoxidized Linoleic Acid

A component in the autoxidation products of linoleic acid (LA) which induced the endogenous lipid peroxidation was searched for. Secondary autoxidation products (SP) of LA induced the production of thiobarbituric acid reactive substances (TBARS) in liver as well as the LA hydroperoxides stimulated. SP were separated chromatographically into some fractions which were administered orally to rats. One fraction composed mainly of 9-oxononanoic acid (9-ONA) markedly stimulated the TBARS production in liver. Authentic 9-ONA also increased the lipid peroxide level as determined by a new test, as well as the activities of glutathione peroxidase and reductase in liver. Thus, hepatic lipid peroxidation was induced by orally given 9-ONA which was present in the autoxidation products of LA.     

Fatty acid allene oxides. II. Formation of two macrolactones from 12,13(S)-epoxy-9(Z),11-octadecadienoic acid

An unstable fatty acid allene oxide, 12,13(S)-epoxy-9(Z),11-octadecadienoic acid, was recently identified as the product formed from 13(S)-hydroperoxy-9(Z), 11(E)-octadecadienoic acid in the presence of corn (Zea mays L.) hydroperoxide dehydrase (M. Hamberg (1987) Biochim. Biophys. Acta 920, 76-84). The present paper is concerned with the spontaneous decomposition of 12,13(S)-epoxy-9(Z),11-octadecadienoic acid in acetonitrile solution. Two major products were isolated and characterized, i.e. macrolactones 12-keto-9(Z)-octadecen-11-olide and 12-keto-9(Z)-octadecen-13-olide.     

Chiral resolutions of (9-anthryl)methoxyacetic acid and (9-anthryl)hydroxyacetic acid by capillary electrophoresis

The resolutions of (9-anthryl)methoxyacetic acid (9AMAA) and (9-anthryl)hydroxyacetic acid (9AHAA) were performed by capillary electrophoresis using hydroxypropyl-beta-cyclodextrin (HP-beta-CD) as a chiral selector. Various factors affecting migration time and resolutions of these compounds were investigated with a run voltage of 20 kV, column temperature 20 degrees C and 20 mM Tris-H(3)PO(4) buffer (pH 6.5) containing 5 mM HP-beta-CD for 9AMAA, or 10 mM HP-beta-CD for 9AHAA, (+/-)-9AMAA and (+/-)-9AHAA were successfully separated at Rs 3.27 and 1.92, respectively.