Benzoate esters and flavonoids from Desmos pedunculosus

The genus Desmos (Annonaceae) is comprised of about thirty-three species of trees and shrubs found in southern Asia, Indonesia, and northern Australia. The chemistry of many of these species is largely unreported. Phytochemical investigation of a methanol extract of the aerial parts of D. pedunculosus led to the isolation of two flavonoids and eight benzoate ester derivatives. Three of these benzoate esters are new compounds, while two others are known synthetic compounds reported here as natural products for the first time. The compounds were characterized by mass spectrometry and 1D and 2D NMR spectroscopy. Based on a comparison of extracts of D. chinensis and D. pedunculosus from Vietnam, several of the compounds we report may serve as marker compounds to chemically distinguish these similar species.     

Semantic and prosodic effects of Dutch linking elements

The studies presented here investigate the contribution of linking -en- and rhythm to a compound’s conceptual plurality. Participants were asked to estimate the conceptual plurality of the modifier constituents of Dutch compounds. In the first study, pseudo-compounds (compounds composed of pseudo-words, burb+en+tijpis) and novel compounds (novel combinations of existing nouns, aap+en+leraar, ‘monkey teacher’) with linking -en- were investigated. In study two, we examined written existing compounds that occur with and without -en- (bloem+bak or bloem+en+bak, ‘flower box’) and present a stress clash or not at the constituent boundaries. Finally, study three investigated the same question as study two for spoken existing compounds. The results reveal that existing compounds written or spoken with linking -en- are considered to bear more plural meaning than the ones without linking element. Furthermore, an effect of rhythm on plurality was observed in pseudo-compounds and in spoken existing compounds. When these compounds contain linking -en- to prevent a stress clash, they are considered to bear less plural meaning than those with linking -en- in a neutral context. These studies demonstrate that rhythm can affect the interpretation of linking elements. The fact that we only find a rhythmic effect in pseudo-compounds and spoken existing compounds but not in written existing compounds is explained in terms of processing.     

Leaf flavonoids of eupomatiaceae

The leaf flavonoids of Eupomatia bennettii and E. laurina were examined and five flavonoid compounds were detected. The most distinctive of these compounds were two methylated flavones: 7-O-methylapigenin and 7,3′-di-O-methylluteolin (velutin). The flavonoids of Eupomatiaceae are most similar to those of the Winteraceae and this similarity may be indicative of a phylogenetic relationship between the two families.     

Substrate-like water soluble lipase inhibitors from Filipendula kamtschatica

Filipendula kamtschatica is a plant utilized as a traditional medicine by Ainu people in Japan, but its chemical constituents are not much studied. Pancreatic lipase inhibitors are a promising tool for the treatment of obesity. We searched for natural lipase inhibitors from F. kamtschatica and two new compounds were isolated along with the known flavonoid glycoside. The structure elucidation of new compounds revealed these two to be 2-O-caffeoyl-4-O-galloyl-l-threonic acid and 3-O-caffeoyl-4-O-galloyl-l-threonic acid, which can be recognized as a pancreatic lipase’s substrate-like structure. The isolated compounds all showed an inhibitory activity against porcine pancreatic lipase and one of the isomer, 3-O-caffeoyl-4-O-galloyl-l-threonic acid, possessed the most potent activity with IC₅₀ value showing an order lower value compared to others. The substrate-like structure of the new compounds seemed to be important for their activity.     

Statistical molecular design of a focused salicylidene acylhydrazide library and multivariate QSAR of inhibition of type III secretion in the Gram-negative bacterium Yersinia

A combined application of statistical molecular design (SMD), quantitative structure–activity relationship (QSAR) modeling and prediction of new active compounds was effectively used to develop salicylidene acylhydrazides as inhibitors of type III secretion (T3S) in the Gram-negative pathogen Yersinia pseudotuberculosis. SMD and subsequent synthesis furnished 50 salicylidene acylhydrazides in high purity. Based on data from biological evaluation in T3S linked assays 18 compounds were classified as active and 25 compounds showed a dose-dependent inhibition. The 25 compounds were used to compute two multivariate QSAR models and two multivariate discriminant analysis models were computed from both active and inactive compounds. Three of the models were used to predict 4416 virtual compounds in consensus and eight new compounds were selected as an external test set. Synthesis and biological evaluation of the test set in Y. pseudotuberculosis and the intracellular pathogen Chlamydia trachomatis validated the models. Y. pseudotuberculosis and C. trachomatis cell-based infection models showed that compounds identified in this study are selective and non-toxic inhibitors of T3S dependent virulence.     

Cuauthemone derivatives from Tessaria integrifolia and Pluchea symphytifolia

The aerial parts of Tessaria integrifolia afforded in addition to known compounds nine further cuauthemone derivatives and those from Pluchea symphytifolia also a further sesquiterpene of this type. The structures of two pairs of similar compounds are revised from 11-hydroxy to 11-peroxy derivatives.     

Phenolic dimers and an indole alkaloid from Campylospermum flavum (Ochnaceae)

From the leaves and stem bark of Campylospermum flavum (Ochnaceae), three compounds, namely 4?-O-methylagathisflavone, flavumchalcone, and flavumindole have been isolated together with 10 known compounds, including three flavonoids, two biflavonoids, two alkaloids, two nitrile glucosides, and glucopyranosyl-β-sistosterol. The structures of these compounds and their relative configurations were established by 1D and 2D NMR experiments. The methanolic crude extracts of leaves and stem bark of C. flavum and compounds displayed a significant cytotoxicity towards Artemia salina larvae.     

Characterization of tyrosinase inhibitory constituents from the aerial parts of Humulus japonicus using LC-MS/MS coupled online assay

In the screening of natural products for the development as cosmetic ingredients, the EtOAc-soluble fraction of Humulus japonicus showed tyrosinase inhibitory activity. HPLC-MS/MS coupled online tyrosinase assay of EtOAc-soluble fraction of H. japonicus characterized the twenty-eight constituents including two unknown ones and their tyrosinase inhibitory activity. Fractionation of H. japonicus using various chromatographic techniques yielded thirty-eight compounds. The chemical structures of isolated compounds were identified by spectroscopic analysis. As characterized by HPLC-MS/MS analysis, we isolated twenty-four predicted compounds and further identified two unknown ones, named humulusides A (1) and B (2). Additional ten compounds were also identified by purification. Tyrosinase inhibitory activity of isolated compounds were evaluated, which was closely correlated with the results from HPLC-MS/MS coupled online tyrosinase assay. Consistent with predicted data, two major compounds, trans-N-coumaroyltyramine (14) and cis-N-coumaroyltyramine (15) showed tyrosinase inhibition with IC₅₀ values of 40.6 and 36.4?μM. Taken together, H. japonicus is suggested as whitening ingredient in cosmetic products. In addition, HPLC-MS/MS coupled tyrosinase assay is powerful tool for predicting active compounds with short time and limited amounts, although identification of new compounds and verification of predicted data are also needs to be demonstrated by further experiment.     

In silico–based combinatorial pharmacophore modelling and docking studies of GSK-3β and GK inhibitors of Hippophae

Type 2 diabetes is an inevitably progressive disease, with irreversible β cell failure. Glycogen synthase kinase and Glukokinase, two important enzymes with diverse biological actions in carbohydrate metabolism, are promising targets for developing novel antidiabetic drugs. A combinatorial structure-based molecular docking and pharmacophore modelling study was performed with the compounds of Hippophae salicifolia and H. rhamnoides as inhibitors. Docking with Discovery Studio 3.5 revealed that two compounds from H. salicifolia, viz Lutein D and an analogue of Zeaxanthin, and two compounds from H. rhamnoides, viz Isorhamnetin-3-rhamnoside and Isorhamnetin-7-glucoside, bind significantly to the GSK-3 β receptor and play a role in its inhibition; whereas in the case of Glucokinase, only one compound from both the plants, i.e. vitamin C, had good binding characteristics capable of activation. The results help to understand the type of interactions that occur between the ligands and the receptors. Toxicity predictions revealed that none of the compounds had hepatotoxic effects and had good absorption as well as solubility characteristics. The compounds did not possess plasma protein-binding, crossing blood–brain barrier ability. Further, in vivo and in vitro studies need to be performed to prove that these compounds can be used effectively as antidiabetic drugs.     

Neue sesquiterpene,triterpene, flavanone und andere aromatische verbindungen aus Flourensia heterolepis

The investigation of a further Flourensia species afforded in addition to already known compounds 12 new sesquiterpene acids isolated as their methyl esters, a new eudesmane diol, four lupane derivatives and two flavanones, two cinnamic acid derivatives, also isolated as methyl esters and a ketone. The structures are elucidated mainly by spectroscopic methods and by some chemical transformations. Several of the compounds isolated are more or less similar to those isolated from other Flourensia species; the considerable amounts of eudesmanes, however, are unusual. The overall picture of the genus is still relatively uniform. Close relationships to Helianthella are obvious, while to Helianthus, placed in the same subtribe, no clear relations are visible.     

Behavioural and endocrine responses of female mice to synthetic analogues of volatile compounds in male urine

The urine of intact, adult male mice elicits more investigatory sniffing from female mice than does the urine of castrated males. When either of two androgen-dependent urinary compounds, 2-sec-butyl dihydrothiazole or dehydro-exo-brevicomin are added to castrate urine, its relative attractiveness remains the same. When both compounds are added to castrate urine, however, its activity is enhanced and the castrate urine becomes as attractive to females as whole, intact male urine. Females exposed to the reconstituted ‘normal’ urine for 3 min per day, displayed more frequent oestrus cycles. The two synthetic compounds are synergistic in the context of castrate urine, producing an olfactory message that behaviourally and physiologically mimics the activity of the normal biological signal.     

Antifouling activities expressed by marine surface associated Pseudoalteromonas species

Members of the marine bacterial genus Pseudoalteromonas have been found in association with living surfaces and are suggested to produce bioactive compounds against settlement of algal spores, invertebrate larvae, bacteria and fungi. To determine the extent by which these antifouling activities and the production of bioactive compounds are distributed amongst the members of the genus Pseudoalteromonas, 10 different Pseudoalteromonas species mostly derived from different host organisms were tested in a broad range of biofouling bioassays. These assays included the settlement of larvae of two ubiquitous invertebrates Hydroides elegans and Balanus amphitrite as well as the settlement of spores of the common fouling algae Ulva lactuca and Polysiphonia sp. The growth of bacteria and fungi, which are the initial fouling organisms on marine surfaces, was also assayed in the presence of each of the 10 Pseudoalteromonas species. It was found that most members of this genus produced a variety of bioactive compounds. The broadest range of inhibitory activities was expressed by Pseudoalteromonas tunicata which inhibited all target fouling organisms. Only two species, Pseudoalteromonas haloplanktis and Pseudoalteromonas nigrifaciens, displayed negligible activity in the bioassays. These were also the only two non-pigmented species tested in this study which indicates a correlation between production of bioactive compounds and expression of pigment. Three members, P. tunicata, Pseudoalteromonas citrea and Pseudoalteromonas rubra, were demonstrated to express autoinhibitory activity. It is suggested that most Pseudoalteromonas species are efficient producers of antifouling agents and that the production of inhibitory compounds by surface associated Pseudoalteromonas species may aid the host against colonisation of its surface.     

Triterpenoids,lignans and a benzofuran derivative from the bark of Aglaia elaeagnoidea

One 1H-cyclopentatetrahydro[b]benzofuran, two lignans, two dammarane triterpenoids and one limonoid were isolated from the bark of Aglaia elaeagnoidea. The structures of the isolated compounds were established on the basis of spectral data. The lignan trans-2,3-bis(3,4,5-trimethoxybenzyl)-1,4-butanediol diacetate and 20S,24S-epoxy-25-hydroxymethyldammarane-3-one are new compounds. trans-3,4-Bis(3,4,5-trimethoxybenzyl)tetrahydrofuran has been synthesized, but not previously reported as a natural product.     

N-Coronafacoyl-L-isoleucine and N-coronafacoyl-L-alloisoleucine,potential biosynthetic intermediates of the phytotoxin coronatine

Two new naturally-occurring analogues of the phytotoxin coronatine have been isolated from liquid cultures of Pseudomonas syringae pv. glycinea. These have been identified as N-coronafacoyl-L-isoleucine and N-coronafacoyl-L-alloisoleucine by mass spectrometry and by studies of the products of acid hydrolysis of the two compounds. The compounds were purified as a mixture of ca 2:1 composition, but the two parent components were not preparatively separated. The possible significance of the two compounds, to the biosynthesis of coronatine, is discussed.     

New sesquiterpene lactones,geranyllinalol derivatives and other constituents from Geigeria species

The investigation of three Geigeria species and five subspecies afforded, in addition to known compounds, the following 32 new compounds: two geigeranolides with a new carbon skeleton, two xanthanolides, five guaianolides, three pseudoguaianolides, a sesquiterpene related to ivaxillarin, a nerolidol derivative, 15 geranyllinalol derivatives, two thiophene acetylenes and a dimeric coniferyl isobutyrate. The structures and the stereochemistry of the new compounds were elucidated by spectroscopic methods and a few chemical transformation. Chemotaxonomic aspect and relationship of the comnounds are discussed.     

Les constituants flavonoïdes de Cephalanthus spathelliferus

We have isolated from Cephalanthus spathelliferus (Rubiaceae) five compounds: umbelliferone, skimmin, 7,4′-dimethylkaempferol,7,4′-dimethylaromadendrin and its 5-glucoside. The latter two are new compounds.     

A new ent-kaur-16-en-19-oic acid from the aerial parts of Inula bifrons

The phytochemical study of the chloroform extract of the aerial parts of Inula bifrons (L.) L. led to the isolation of one new ent-kaurane diterpenes acid along with twelve known compounds (two ent-kaurane diterpenoids, an eudesmane acid, five sesquiterpene lactones, three triterpenoids and β-sitosterol). All known compounds are found for the first time in I. bifrons. Their structures were elucidated by using spectral methods (NMR, HRESIMS and IR). The distribution of these compounds in the genus Inula and their chemotaxonomic significance is discussed.     

Highly hydroxylated steroids of the starfish Archaster typicus from the Vietnamese waters

Five new steroidal compounds, including an unusual glucoside, along with several known steroids were isolated from the starfish Archaster typicus collected in shallow waters of Quang Ninh province (Vietnam). Three new compounds are 27-nor-cholestane derivatives and the other two are 24,26-dihydroxycholestane derivatives. A biogenesis pathway for the unusual side chain of 27-nor-cholestane derivatives is proposed. Isolated compounds presented moderate toxic effects in the sperm- and 8-blastomere tests on embryonal development of the sea urchin Strongylocentrotusintermedius.     

Enantiospecific synthesis and insect feeding activity of sulfur-containing cyclitols

The first syntheses of two deoxythiocyanocyclitols (4-deoxy-4-thiocyano-l-chiro-inositol and deoxythiocyanoconduritol F) and two deoxysulfonylcyclitol acetals are reported by a chemoenzymatic enantioselective route. The compounds were prepared by a sequence of enzymatic and ruthenium-catalyzed dihydroxylations, and the results were studied regarding reaction conditions and co-catalyst for different derivatives. The new compounds were included in a minilibrary of deoxygenated cyclitols and evaluated for their capacity to influence the feeding behavior of Epilachna paenulata (Coleoptera: Coccinellidae), a common pest of the Curcubitaceae crops.     

3,5,7,3′,5′-Pentahydroxyflavan and 3α-methoxyfriedelan from Humboldtia laurifolia

The leaf, bark and timber extractives of Humboldtia laurifolia were investigated and the following compounds have been isolated: O-acetyloleanolic aldehyde, a sitosteryl ester, lupeol, sitosterol, a fatty acid, 5,7,4′-trihydroxyflavone (apigenin), (2R,3R)-3,5,7,3′,5′-pentahydroxyflavan and 3α-methoxyfriedelan. The latter two compounds are new natural products.