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Introduction Catha edulis (qat, khat, mirra) is a woody plant species that is grown and consumed in East Africa and Yemen for its stimulant alkaloids cathinone, cathine and norephedrine. Two Celastraceae species, in addition to qat, have been noted for their stimulant properties in ethnobotanical literature. Recent phylogenetic reconstructions place four genera in a clade sister to Catha edulis, and these genera are primary candidates to search for cathine and related alkaloids. Objective Determine if cathine or related alkaloids are present in species of Celastraceae other than Catha edulis. Methods Leaf samples from 43 Celastraceae species were extracted in water followed by basification of the aqueous extract and partitioning with methyl-t-butyl ether to provide an alkaloid-enriched fraction. The extract was derivatised in a two-stage process and analysed using GC–MS for the presence of cathine. Related alkaloids and other metabolites in this alkaloid-enriched fraction were tentatively identified. Results Cathinone, cathine and norephedrine were not detected in any of the 43 Celastraceae species assayed other than Catha edulis. However, the phenylalanine- or tyrosine-derived alkaloid phenylethylamine was identified in five species. Nine species were found to be enriched for numerous sterol- and terpene-like compounds. Conclusion These results indicate that cathine is unique to Catha edulis, and not the compound responsible for the stimulant properties reported in related Celastraceae species. Copyright © 2017 John Wiley & Sons, Ltd.

Catha edulis (qat, khat, mirra) is a woody plant species that is grown and consumed in East Africa and Yemen for its stimulant alkaloids cathinone, cathine and norephedrine. Two Celastraceae species, in addition to qat, have been noted for their stimulant properties in ethnobotanical literature. Recent phylogenetic reconstructions place four genera in a clade sister to Catha edulis, and these genera are primary candidates to search for cathine and related alkaloids.Determine if cathine or related alkaloids are present in species of Celastraceae other than Catha edulis.Leaf samples from 43 Celastraceae species were extracted in water followed by basification of the aqueous extract and partitioning with methyl-t-butyl ether to provide an alkaloid-enriched fraction. The extract was derivatised in a two-stage process and analysed using GC-MS for the presence of cathine. Related alkaloids and other metabolites in this alkaloid-enriched fraction were tentatively identified.Cathinone, cathine and norephedrine were not detected in any of the 43 Celastraceae species assayed other than Catha edulis. However, the phenylalanine- or tyrosine-derived alkaloid phenylethylamine was identified in five species. Nine species were found to be enriched for numerous sterol- and terpene-like compounds.These results indicate that cathine is unique to Catha edulis, and not the compound responsible for the stimulant properties reported in related Celastraceae species. Copyright © 2017 John WileySons, Ltd.

A new biscoumarin (7-hydroxy-6,6′-dimethoxy-3,7′-dicoumarinyl ether), named hymenain (1) and the known biscoumarin ipomopsin (2) were isolated from the germinated seeds of Hymenaea courbaril var. stilbocarpa. Their structures were elucidated by spectroscopic methods. Scopoletin was also detected in the extracts by TLC and GC–MS analyses. Hymenain and ipomopsin showed direct scavenging effect on a stable free radical, 2,2-diphenyl-1-picryl-hydrazyl (DPPH) with the EC50 values of 100 and 300 μM, respectively.

The increased incidence of drug-resistant fungal infections, a process in which active efflux plays an important role, calls for the development of new treatments. Candida albicans and Candida glabrata are the most frequent human fungal pathogens. The latter, in spite of its increased azole tolerance, is rarely used in medicinal plant screening. Several extracts inhibiting the growth of this pathogenic yeast are identified here. The ethyl acetate extract of the herb Dalea formosa of the American Southwest, not previously known to possess antifungal activity, proved most active against azole-sensitive and azole-resistant isolates. The model yeast Saccharomyces cerevisiae, related to C. glabrata, was used to evaluate the influence of multidrug efflux on the antifungal activity of identified extracts and selected fractions from further purification steps, together with their ability to modulate ketoconazole resistance. The differential involvement of the major pleiotropic drug transporters of the ATP-binding cassette superfamily Pdr5p, Snq2p, and Yor1p as well as their transcriptional activators Pdr1p and Pdr3p in the detoxification of the antifungal constituents of several important medicinal plants is demonstrated. These include Artemisia annua and its widely used antimalarial component artemisinin. This approach revealed the concomitant presence of multidrug efflux pump substrates and modulators in the extract of A. annua and also allowed the identification of an extract not affected by the major pleiotropic drug-resistance genes.

An extract of roots of Centaurea diffusa (diffuse knapweed) yielded caryophyllene oxide and linoleic acid which were shown to be phytotoxic. Also isolated were germacrene B, a previously-known phytotoxin as well as the inactive polyene aplotaxene. A combination of these compounds, if transferred to the soil, could be one factor in the invasive behavior of this weed. Contrary to a literature report, 8-hydroxyquinoline was not detected in root exudates of in vitro grown C. diffusa nor could it be identified in the root extract. However, a recent report from a different group maintains that 8-hydroxyquinoline can be released from roots of C. diffusa following a diurnal rhythm.

Gene expression in response to signaling molecules has been well studied in the leaves of the model plant species Arabidopsis thaliana. However, knowledge of gene expression and metabolic regulation at the root level is limited. Here, the signaling compounds salicylic acid (SA), methyl jasmonate (MeJA) and nitric oxide (NO) were applied exogenously to induce various defense responses in roots, and their effect was studied using a combination of genomic, molecular and biochemical approaches. Genes involved in defense signaling/activation, cellular redox state, metabolism, transcription factors and membrane transport were altered in expression following treatment with SA, MeJA and NO. In addition, it was found that SA-, MeJA- and NO-elicited roots increased the root exudation of phytochemicals compared with the roots of nontreated control plants. Transport systems likely to be involved in the root exudation of phytochemicals, including the MATE, ABC, MFS, amino acid, sugar and inorganic solute transporters, showed altered expression profiles in response to treatments. Overall, significant differences were found in the signaling compound-elicited expression profiles of genes in roots vs those in leaves. These differences could be correlated to the underground nature of roots and their exposure to higher microbial inoculum rates under natural conditions.

Invasive plants are a widespread problem but the mechanisms used by these plants to become invasive are often unknown. The production of phytotoxic natural products by invasive weeds is one mechanism by which these species may become successful competitors. Here we conducted a bioactivity-driven fractionation of root extracts and exudates from the invasive plant leafy spurge (Euphorbia esula L.), and structurally characterized jatrophane diterpenes and ellagic acid derivatives. Ellagic acid derivatives and one of the jatrophane diterpenes, esulone A, have been previously reported from leafy spurge, but another of the jatrophane diterpenes, kasuinine B, has not. We show that these compounds are phytotoxic but affect plants in different ways, either inducing overall plant necrosis or reducing root branching and elongation.

Centaurea maculosa Lam. is a noxious weed in western North America that produces a phytotoxin, (±)-catechin, which is thought to contribute to its invasiveness. Areas invaded by C. maculosa often result in monocultures of the weed, however; in some areas, North American natives stand their ground against C. maculosa and show varying degrees of resistance to its phytotoxin. Two of these resistant native species, Lupinus sericeus Pursh and Gaillardia grandiflora Van Houtte, were found to secrete increased amounts of oxalate in response to catechin exposure. Mechanistically, we found that oxalate works exogenously by blocking generation of reactive oxygen species in susceptible plants and reducing oxidative damage generated in response to catechin. Furthermore, field experiments show that L. sericeus indirectly facilitates native grasses in grasslands invaded by C. maculosa, and this facilitation can be correlated with the presence of oxalate in soil. Addition of exogenous oxalate to native grasses and Arabidopsis thaliana (L.) Heynh grown in vitro alleviated the phytotoxic effects of catechin, supporting the field experiments and suggesting that root-secreted oxalate may also act as a chemical facilitator for plant species that do not secrete the compound.

Centaurea diffusa is one of the most destructive invasive weeds in the western USA and allelopathy appears to contribute to its invasiveness (Callaway & Aschehoug 2000). Here we identify a chemical from the root exudates of C. diffusa, 8-hydroxyquinoline, not previously reported as a natural product, and find that it varies biogeographically in its natural concentration and its effect as an allelochemical. 8-Hydroxyquinoline is at least three times more concentrated in C. diffusa-invaded North American soils than in this weed’s native Eurasian soils and has stronger phytotoxic effects on grass species from North America than on grass species from Eurasia. Furthermore, experimental communities built from North American plant species are far more susceptible to invasion by C. diffusa than communities built from Eurasian species, regardless of the biogeographical origin of the soil biota. Sterilization of North American soils suppressed C. diffusa more than sterilization of Eurasian soils, indicating that North American soil biota may also promote invasion by C. diffusa. Eurasian plants and soil microbes may have evolved natural resistance to 8-hydroxyquinoline while North American plants have not, suggesting a remarkable potential for evolutionary compatibility and homeostasis among plants within natural communities and a mechanism by which exotic weeds destroy these communities.

(+/-)-Catechin is a potent phytotoxin, with the phytotoxicity due entirely to the (-)-catechin enantiomer. (+)-Catechin, but not the (-)-enantiomer, has antibacterial and antifungal activities. Tetramethoxy, pentaacetoxy, and cyclic derivatives of (+/-)-catechin retained phytotoxicity. The results indicate that antioxidant properties of catechins are not a determining factor for phytotoxicity. A similar conclusion was reached for the antimicrobial properties. Centaurea maculosa (spotted knapweed) exudes (+/-)-catechin from its roots, but the flavanol is not re-absorbed and hence the weed is not affected. The much less polar tetramethoxy derivative may, however, be absorbed and hence be able to cause toxicity. Because of the combination of phytotoxicity and antimicrobial activity, (+/-)-catechin could be a useful natural herbicide and antimicrobial.

This article has been retracted at the request of the Editor-in-Chief and author. Please see Elsevier Policy on Article Withdrawal ( http://www.elsevier.com/locate/withdrawalpolicy ). Reason: A detailed study of extracts of the Russian knapweed Acroptilon [Centaurea] repens roots has failed to establish the presence of 7,8-benzoflavone, which therefore remains unknown as a plant natural product. The above authors therefore wish to retract the original publication which previously reported its existence, and deeply regret any inconvenience to the scientific readership.

Bioassay-directed fractionation for Staphylococcus aureus multidrug resistance efflux pump inhibitors resulted in isolation of novel acylated neohesperidosides from Geranium caespitosum. The more highly acylated compounds had no direct activity against S. aureus, but potentiated activity of the antibiotics berberine, rhein, ciprofloxacin and norfloxacin. Cellular concentrations of berberine were greatly increased in the presence of active esters.

Root fluorescence is a phenomenon in which roots of seedlings fluoresce when irradiated with ultraviolet (UV) light. Soybean (Glycine max) and rye grass (Elymus glaucus) are the only plant species that have been reported to exhibit this occurrence in germinating seedling roots. The trait has been useful as a marker in genetic, tissue culture and diversity studies, and has facilitated selection of plants for breeding purposes. However, the biological significance of this occurrence in plants and other organisms is unknown. Here we report that the Andean tuber crop species Oxalis tuberosa, known as oca in the highlands of South America, secretes a fluorescent compound as part of its root exudates. The main fluorescent compounds were characterized as harmine (7-methoxy-1-methyl-b-carboline) and harmaline (3, 4-dihydroharmine). We also detected endogenous root fluorescence in other plant species, including Arabidopsis thaliana and Phytolacca americana, a possible indication that this phenomenon is widespread within the plant kingdom. # 2002 Elsevier Science Ltd. All rights reserved.

Two known furanocoumarins, (+)-oxypeucedanin and (+)-saxalin, two known coumarins, umbelliferone and (+)-epoxysuberosin, and two new coumarins (+)-trachypleuranin-A and (±)-trachypleuranin-B, were isolated from the methanol extract of Harbouria trachypleura. An efficient five-step asymmetric synthesis of (+)-trachypleuranin-A was performed using a sequential [3,3] Claisen–Cope rearrangement and a Shi asymmetric epoxidation. (±)-Trachypleuranin-B, a chlorinated coumarin, was synthesized from (±)-epoxysuberosin.

Kernel number, individual kernel weight, individual kernel volume, crude fat, crude protein, reducing sugars, starch content, amylose/amylopectin ratio and fatty acid composition were determined for six popcorn hybrids, grown in Colorado or Nebraska and harvested in 1997. The popcorn hybrids were A358W, 353W, BKH, 019, 1601 and 5501. Also, popcorn hybrids were categorized based on their popped color and popped shape as hybrid types, where A358W and 353W were white butterfly-type popcorn hybrids, BKH and 019 were yellow butterfly-type hybrids and 1601 and 5501 were yellow mushroom-type hybrids. Yellow mushroom hybrids showed significantly fewer number of kernels than the white and yellow butterfly-type hybrids. The number of kernels per 250 g of popcorn hybrids at 14% moisture content ranged from 1454 to 2219. Individual kernel weight of the popcorn hybrids ranged from a low mean of 112.6 mg for hybrid 353W to a high mean of 172.0 mg for hybrid 1601. Individual kernel volume of popcorn hybrids containing 14% moisture ranged from a low mean of 0.130 cm 3 for hybrid 353W to a high mean of 0.200 cm 3 for hybrid 1601. The popcorn hybrids contained 3.8–4.6% crude fat, 8.1–10.5% crude protein, 0.07–0.23% reducing sugars and 61.0–67.9% starch, in which 27.0–28.5% of the starch was amylose. Individual kernel volume (size of the kernel) was correlated with starch content ( r =0.84). Fat content was highly correlated with starch content ( r =−0.82). Popcorn hybrids contained on an average approximately 12.6% palmitic, 2.0% stearic, 25.5% oleic, 58.4% linoleic and 1.5% linolenic acids, respectively. The major fatty acids in the popcorn hybrids were linoleic and oleic acids.

Flavonolignans represent natural compounds whose biosynthesis presumes a radical coupling of a ring B catecholic flavonoid with a molecule of coniferyl alcohol or an analogue. Many natural flavonolignans can exist as regioisomers, depending on how the coupled coniferyl alcohol moiety orients to the flavonoid. These regioisomers are often difficult to separate and have virtually identical NMR spectra. Structural assignments for some have changed with time or have been given without proof. We here report syntheses of both regioisomers of the flavonolignan hydnocarpin and one isomer of a plant isolate previously known as 5'-methoxyhydnocarpin. This isomer, here renamed 5'-methoxyhydnocarpin-D, was recently shown to be a potent inhibitor of a Staphylococcus aureus multidrug resistant efflux pump.

Piperidine alkaloids are reported for the first time from Picea omorika (Serbian spruce), Abies balsamea (balsam fir), and Abies concolor (Rocky mountain white fir). The alkaloids of P. omorika and P. sitchensis were similar, but not identical, and very different from those reported from P. breweri, a species with which they have been taxonomically linked. We were not able to detect alkaloids in A. procera, A. lowiana, or A. grandis. The total base fraction of A. bifolia yielded a nonbasic monoterpenoid known as Muller's lactone, presumed to be an artifact of the isolation procedure.

Stereoselective hydrogenation of the iridoids geniposide (9) and aucubin (19) was achieved by using the 1-methyl-1-methoxyethyl ether as a protecting group for the allylic alcohol, as it enhanced the stereoselectivity and prevented undesired hydrogenolysis. Ozonolysis of the hydrogenation product from 9, adoxoside (11), with reductive workup, afforded either a chiral lactone (25) or a chiral polyol (26), depending on the reduction conditions. Polyol 26 was subjected to protecting-group manipulation and subsequent oxidation and reductions to yield cyclopentane building blocks (29−34), which, by Mitsunobu couplings with purines, afforded carbocyclic nucleoside analogues (7, 8, and 35).

A new amide of threo - γ -hydroxyglutamic acid, justiciamide, was isolated from Justicia ghiesbreghtiana and shown to be (−)- N -(2-hydroxy-4,5-dimethoxyphenyl)-(2 S ,4 S )- γ -hydroxyglutamic acid. Justiciamide is the first amide of an uncommon amino acid found in this genus.

The iridoid glycosides scandoside, scandoside methyl ester, monotropein, and galioside were found in Cornus canadensis from several widely distributed collection sites. Cornin and hastatoside were isolated from C. nuttallii . No iridoids were found in C. stolonifera , that instead yielded cornoside and halleridone, also independent of collection location. The results were compared with previous studies and current phylogenetic work on the genus Cornus .

The role of chemical constituents in the foraging behavior of black bears ( Ursus americanas ) was investigated using two field studies. Vascular tissue samples were collected from Douglas-fir ( Pseudotsuga menziesii ) trees recently foraged by black bears. Samples were extracted and analyzed by liquid and gas chromatography to determine carbohydrates and terpenes, respectively. Chemical data were subjected to correlation analyses and multiple regression to examine if they adequately describe observed foraging preferences. Free-ranging black bears also were offered a choice of four test diets that differed in content of carbohydrates and terpenes. Results indicated that forage preferences were based in part on chemical constituents in the forage. Black bears maximized intake of carbohydrates and minimized intake of terpenes. In multiple choice tests, free-ranging bears preferred a low-terpene diet to a high-terpene diet with identical carbohydrate content. Bears also preferred a high-carbohydrate diet to a low-carbohydrate diet with identical terpene content.

L-Malic acid (2) reacts with trifluoroacetic anhydride under anhydrous conditions to give (S)-trifluoroacetoxy-succinic acid anhydride (3). The anhydride 3 undergoes regioselective ring opening with an excess of anilines or primary aliphatic amines leading to N-substituted-(S)-3-hydroxy-succinamic acids (4a–g). Structural elucidation of the reaction products 4a–g was based on analytical and spectroscopic data and on an X-ray structure analysis of 4b. Secondary aliphatic amines react with 3 by condensation and subsequent elimination to furnish N,N′-disubstituted fumaric acid amides 5a, b. Some N-substituted-2-hydroxysuccinamic acids (7a,b) were also prepared for spectral comparison with the 3-hydroxy compounds.

New needle bundles of Picea englemannii (Engelmann spruce) and Picea pungens (blue spruce) contain disubstituted piperidine alkaloids. No alkaloids were found in western spruce budworm larvae (Choristoneura occidentalis), which were feeding on the needles, but needle alkaloids were present in the budworm frass. Excretion of the alkaloids by the budworm larvae, either intact or after a metabolic change, was the common processing pathway. No sequestration could be demonstrated.

Norditerpenoid alkaloids which are present in the roots of Delphinium occidentale are assimilated into its root parasite, Castilleja sulphurea. The alkaloids are found in all plant parts of the Castilleja (roots, stems, leaves, flowers, seeds) and in the flower nectar. The major root alkaloids (browniine, delcosine, deltaline and dictyocarpine; analyzed by positive ion electrospray mass spectrometry, ESMSH+) were transmitted into the Castilleja. Little or none of the highly mammalian toxic alkaloids (such as methyllycaconitine) were found in D. occidentale. ESMSH+ also was used to identify alkaloids of D. barbeyi, where browniine, delcosine and a small amount of methyllycaconitine (roots only) were found. ESMSH+ provided a useful method for analysis of norditerpenoid alkaloids. Their presence as assimilates in a root parasite plant could provide a defense against herbivory.

The pattern of ponderosa pine (Pinus ponderosa) piperidine alkaloid accumulation from seeds to 28-day-old seedlings was assessed. Seeds were devoid of alkaloids but eight-day-old seedlings contained several alkaloids whose concentrations remained low with continued growth, while the concentration of pinidine [cis-2-methyl-6-(2-propenyl)-piperidine] steadily increased. 13C-Labelled cis-pinidinone [cis-2-methyl-6-(2-oxopropyl)-piperidine] was taken up through seedling roots and was incorporated into pinidine.

Pyrrolizidine alkaloids (PAs) are potent carcinogenic and anti-mitotic compounds produced by a large number of plant species. In this study, we investigated in vitro the DNA-protein cross-linking activity of several structurally diverse PAs. The DNA cross-linked proteins induced by PAs were also isolated and characterized in mammalian cells. At 300 and 500 microM, the pyrrolic PAs (dehydrosenecionine, dehydromonocrotaline, dehydroseneciphylline, dehydroriddelliine) induced potent DNA cross-links. Protein-associated DNA cross-links accounted for approximately 50% of the total cellular DNA cross-links at 300 microM. The simple necine pyrrole dehydroretronecine induced few DNA--protein cross-links and none were detected with indicine N-oxide. The major proteins cross-linked to DNA from either PA-exposed cells or pyrrolic PA-exposed nuclei were in the molecular weight 40-60 kDa range and were primarily acidic in nature (Ca. pI 4.2-5.0). The patterns of the proteins cross-linked to DNA were similar to that induced by standard bifunctional alkylating agents mitomycin C, cisdichlorodiammine platinum(II) and nitrogen mustard. The macrocyclic pyrrole dehydrosenecionine induced DNA cross-links in pBR322 plasmid DNA with BSA as a protein target. Our data indicated that pyrrolic PAs with a macrocyclic diester such as dehydrosenecionine, dehydroseneciphylline, dehydroriddelliine and dehydromonocrotaline were more potent cross-linkers than the simple necine pyrrolic dehydroretronecine. Cross-linking potency of the PAs examined here coincides with known potency differences in animal toxicity and led us to conclude that DNA--protein cross-linking activity is probably involved in PA-related

Previously undescribed iridoid glycosides were isolated from Penstemon species as follows: P. parryi : 8-epitecomoside or 7β-hydroxyplantarenaloside, 2′- O -coumaroyl-8-epitecomoside and 2′- O -coumaroylplantarenaloside, and P. barrettiae : 2′- O -foliamenthoylplantarenaloside. Detailed high field NMR assignments were made for durantoside-I which was isolated from P. glaber .

Five new iridoid glucosides and three new monoterpenoid glucosides were identified from Penstemon albidus, P. cyathophorus and P. virens. N

Pyrrolizidine alkaloids (PAs), which are common constituents of hundreds of plant species around the world, have been reported to have cytotoxic, carcinogenic, antineoplastic, and genotoxic activity in vivo and in vitro. The exact mechanism of these biological toxicities is not yet clear. The ability of eight PA congeners to inhibit mitosis and induce megalocyte formation in cultured bovine kidney epithelial cells was studied to examine possible structural influences on these endpoints. Representatives of the three PA structural groups, the macrocycles (seneciphylline, senecionine, riddelliine, retrorsine, monocrotaline), open diesters (heliosupine, latifoline), and a necine base (retronecine), were cocultured for 2 hr with a NADPH-generating system and rat liver S9. Macrocyclic PAs with alpha,beta-unsaturation (seneciphylline, senecionine, riddelliine, retrorsine) showed a dose-dependent inhibition of colony formation at 50, 100, and 300 microM and induction of megalocytosis at 500 microM. Colony growth resumed 3 weeks after removal of PAs at 50 and 100 microM, and normal cellular morphology returned 5 or 6 weeks after removal of PAs at 500 microM. The saturated macrocyclic (monocrotaline) and open diesters (heliosupine, latifoline), elicited only a slight inhibition of colony formation and had no effect on cellular morphology at 500 microM. The necine base (retronecine) had no effect on either colony formation or cell morphology. Pyrrolic PAs (dehydrosenecionine, dehydromonocrotaline, dehydroretronecine) were more active in inhibition of colony formation than their parent compounds and were potent inducers of abnormal cellular morphology at 500 microM. An N-oxide metabolite, indicine N-oxide, was completely inactive. The results support previous studies showing that there are structural influences on PA-induced cytopathological effects.

A series of 2,6-disubstituted piperidine alkaloids have been isolated from several Pinus (pine) and Picea (spruce) species and characterized structurally. The pines appear to contain only cis-disubstituted piperidines, while the spruces contain both cis- and trans-disubstituted piperidines. The structural relationships among the alkaloids suggest a plausible biosynthetic scheme and a reason why previous attempts to elucidate the biosynthesis of pinidine failed beyond establishing its polyketide origin. A mixture of alkaloids from needles of Pinus ponderosa proved to be highly teratogenic. The alkaloids might therefore be involved in so-called pine needle abortion which occurs in pregnant range cows which feed on Ponderosa pine needles

A small population of a polyvoltine checkerspot butterfly,Thessalia leanira fulvia (also known asChlosyne leanira ssp.fulvia), was found to useCastilleja integra as a larval food plant at a localized site (Burnt Mill) southwest of Pueblo, Colorado. Field-captured adult butterflies contained the major iridoid glycosides (catalpol and macfadienoside) of theCastilleja. The content of a third iridoid glycoside, methyl shanzhiside, was also relatively high in the collected butterflies even though most individualCastilleja plants at Burnt Mill contained little or no methyl shanzhiside. Only a few plants, restricted to a small area, did contain appreciable methyl shanzhiside. Most of the plants that lacked the ester methyl shanzhiside contained shanzhiside, the corresponding free carboxylic acid.Thessalia larvae did not normally methylate the acid to produce methyl shanzhiside. Larvae that stopped feeding at an early instar, but yet survived several weeks, did contain major amounts of methyl shanzhiside. It is suggested that only larvae that overwinter or otherwise enter diapause convert shanzhiside to methyl shanzhiside. TheCastilleja food plant also contained iridoids other than catalpol and macfadienoside, sometimes in major amounts, but these were never found in larvae, pupae, or butterflies.

In the first alkaloid investigation of the genus Cryptantha (Boraginaceae), pyrrolizidine alkaloids were identified from C. cana , C. clevelandii , C. confertiflora , C. flava , C. fendleri , C. leiocarpa , C. thyrsiflora , C. virgata and C. virginensis . Six perennial species from section (or subgenus) Oreocarya were similar in their alkaloid content, which was dominated by lycopsamine and intermedine and in some species with their acetyl derivatives. In two other species from this section, amabiline and tessellatine (heliospathine) were also major components. In contrast, in three annual species from section (or subgenus) Krynitzkia , the major pyrrolizidine alkaloids were angelylretronecine and echiumine derivatives. New pyrrolizidine alkaloids found were threo -2″,3″-dihydroxyechiumine, erythro -3″-chloro-2″-hydroxyechiumine and 2″,3″-epoxyechiumine. bl

The flowers, bracts and leaves of 16 individual Castilleja integra plants were quantitatively analysed for their iridoid glycoside content. Catalpol and macfadienoside were found in all plant parts. Shanzhiside, methyl shanzhiside, 8-epiloganic acid and gardoside were concentrated mainly in the leaves, while adoxosidic acid and adoxoside were mainly or exclusively concentrated in the bracts and flowers. A trace component was shown to be 6-β-hydroxyadoxosidic acid, a previously undescribed iridoid. There was a high degree of variability in iridoid content and patterns among individual plants as well as plant parts.

(Z)-Ligustilide [1] is a dihydrophthalide purported to be the active ingredient of Ligusticum plant species widely used as herbal medicines in the Orient and in Native American and Hispanic cultures. It readily underwent 1,6-conjugate addition with methyl thioglycolate in the presence of triethylamine. The methyl thioglycolate reaction also yielded a product from addition to the C-6-C-7 double bond and a diadduct from both 1,6-addition and addition to the C-6-C-7 bond. Reaction of 1 with benzylamine did not afford a 1,6-adduct, but yielded instead an N-benzyllactam, presumably formed by rearrangement from initial 1,2-addition to the carbonyl. An improved total synthesis of 1 was developed. (Z)-Ligustilide had weak antiviral properties and weak antimicrobial activity against Gram-positive, Gram-negative, and yeast microorganisms. The broad biological activity of 1 and its electrophilic reactivity are consistent with the use of Ligusticum species in folk medicine.

A new alkaloid, isothalisopavine, was isolated from Thalictrum minus and shown to be 2,3,8-trimethoxy-7-hydroxyisopavine from spectral evidence. The known thalisopavine, from T. dasycarpum, is 2,3,8-trimethoxy-9-hydroxyisopavine. Isothalisopavine is the first of its class to be substituted unsymmetrically in the two aromatic rings.

L-Malic acid (2) reacts with trifluoroacetic anhydride under anhydrous conditions to give (S)-trifluoroacetoxy-succinic acid anhydride (3). The anhydride 3 undergoes regioselective ring opening with an excess of anilines or primary aliphatic amines leading to N-substituted-(S)-3-hydroxy-succinamic acids (4a–g). Structural elucidation of the reaction products 4a–g was based on analytical and spectroscopic data and on an X-ray structure analysis of 4b. Secondary aliphatic amines react with 3 by condensation and subsequent elimination to furnish N,N′-disubstituted fumaric acid amides 5a, b. Some N-substituted-2-hydroxysuccinamic acids (7a,b) were also prepared for spectral comparison with the 3-hydroxy compounds.

The following new iridoid glycosides were isolated from Penstemon species: (5αH)-6-epidihydrocornin (the first iridoid glycoside with a trans -fused cyclopentanopyran ring system), 8-epihastatoside, 10-hydroxyepihastatoside, 10-griselinosidic acid, and 10-benzoylcatalpol. The new glycoside 3-methoxy-4-primeverosylacetophenone was also identified. In addition to the trans -fused iridoid glycoside, P. secundiflorus yielded two pairs of C-8 epimeric iridoids. The presence of these compounds suggests a unique anomaly in the normal cyclization mechanism from a monoterpene precursor for this species.

Twenty iridoid glycosides, including four few ones (10- O -foliamenthoylaucubin, 6″ R ,7″-dihydro-10- O - foliamenthoylaucubin, 6β-hydroxy-8-epiboschnaloside and aldoxoside), were identified from eight taxa of Cordylanthus (Scrophulariaceae). Pairs of C-8 epimeric iridoids (e.g. boschnaloside/8-epiboschnaloside and their 6β-hydroxy derivatives) were found together in the same plant for the first time in the Scrophulariaceae. Verbascoside was found in all species.

New iridoids were isolated from Orthocarpus purpurascens (6β-hydroxyboschnaloside [4]) and Orthocarpus attenuatus (8-deoxylamiol [6] and 5,8-bisdeoxylamiol [7]), while the novel phenylpropanoid glycoside 2-O-acetylrossicaside A [8] was found in Orthocarpus densiflorus var. gracilis. Known iridoid and phenylpropanoid glycosides were also isolated from these species and from O. densiflorus var. densiflorus and Orthocarpus erianthus

There are several factors thought to assist invasive weeds in colonization of ecosystems. One of these factors is allelopathy, the negative effect of chemicals produced by one plant on neighboring plants, frequently mediated through root exudates and other plant leachates. Acroptilon repens (Asteraceae) is one of the most invasive and ecologically threatening weed species in western North America. A bioassay-guided fractionation of the root extracts of this plant led to the isolation of five polyacetylenic compounds, of which one [5'-methoxy-1'-(5-prop-1-yn-1-yl-2-thienyl)-hexa-2',4'-diyin-6'-yl acetate] was hitherto unknown. The structures of these compounds were elucidated on the basis of spectroscopic analysis (IR, ESIMS, (1)H, (13)C NMR and 2D NMR). All of the compounds obtained, except 1-chloro-4-(5-penta-1,3-diyn-1-yl-2-thienyl)but-3-yn-2-ol, showed phytotoxic activity against Arabidopsis thaliana seedlings. The presence of 4'-chloro-1'-(5-penta-1,3-diyn-1-yl-2-thienyl)-but-2'-yn-3'-ol was detected in the root exudates of aeroponically grown A. repens plants. None of the polyacetylenes isolated in this study were found in Colorado soils collected between September 2006 and July 2007 in an A. repens colonized site. However, polyacetylene 5 in A. repens infested soil from Washington was found in June, 2007. Contrary to our previous report, the compound 7,8-benzoflavone (6) was not detected in root exudates, nor was it encountered in extracts of roots, aerial parts or infested soil. Since we could not repeat this work, the original report has been retracted [Stermitz, F.R., Bais, H.P., Foderaro, T.A., Vivanco, J.M., 2003. 7,8-Benzoflavone: a phytotoxin from root exudates of invasive Russian knapweed [A retraction]. Phytochemistry 64, 493-497.].

Antimicrobial photodynamic inactivation (APDI) combines a nontoxic photoactivatable dye or photosensitizer (PS) with harmless visible light to generate singlet oxygen and reactive oxygen species that kill microbial cells. Cationic phenothiazinium dyes, such as toluidine blue O (TBO), are the only PS used clinically for APDI, and we recently reported that this class of PS are substrates of multidrug efflux pumps in both gram-positive and gram-negative bacteria. We now report that APDI can be significantly potentiated by combining the PS with an efflux pump inhibitor (EPI). Killing of Staphylococcus aureus mediated by TBO and red light is greatly increased by coincubation with known inhibitors of the major facilitator pump (NorA): the diphenyl urea INF271, reserpine, 5′-methoxyhydnocarpin, and the polyacylated neohesperidoside, ADH7. The potentiation effect is greatest in the case of S. aureus mutants that overexpress NorA and least in NorA null cells. Addition of the EPI before TBO has a bigger effect than addition of the EPI after TBO. Cellular uptake of TBO is increased by EPI. EPI increased photodynamic inactivation killing mediated by other phenothiazinium dyes, such as methylene blue and dimethylmethylene blue, but not that mediated by nonphenothiazinium PS, such as Rose Bengal and benzoporphyrin derivative. Killing of Pseudomonas aeruginosa mediated by TBO and light was also potentiated by the resistance nodulation division pump (MexAB-OprM) inhibitor phenylalanine-arginine beta-naphthylamide but to a lesser extent than for S. aureus . These data suggest that EPI could be used in combination with phenothiazinium salts and light to enhance their antimicrobial effect against localized infections.

Iridoid structures published for the first time during 1980-1989 are listed with available physical and spectral data: mp, [α]D, UV, 1 H nmr, 13 C nmr. Also included are revisions of iridoid structures originally published prior to 1980. The compounds are indexed alphabetically and by molecular weight, and a plant source index is also included

A greater variety of qualitative chemical defenses has been reported in eastern forest trees than might be expected from current interpretation of the plant apparency theory. For the gypsy moth there is an association between the occurrence of alkaloids and unfavorability of certain tree species, as well as the presence of saponins. The latter association, however, is not statistically significant. Species in the genusIlex have been reported to contain both alkaloids and saponins (Barbosa and Krischick, 1987). In this study, determinations were made of the occurrence of alkaloids and saponins inI. opaca and their changes in concentration over time. No alkaloids were detected. Saponins were isolated, and the aglycone siaresinolic acid was identified. Saponin concentration changes seasonally, being highest in early May and lowest in early June leaves.

A bivoltine checkerspot butterfly,Poladryas minuta, is aPenstemon specialist, not known to utilize any other plant genus for oviposition and larval feeding. At several intermontane plains sites of central Colorado, the butterfly utilizesPenstemon virgatus as its sole host plant. Analysis of the host plant showed it to contain three cinnamyl-type catalpol esters (scutellarioside-II, globularin, globularicisin) and catalpol. The host plant contained an average of 10% dry weight iridoids, but some variation among individual plants and leaves within plants was noted. Field-collected butterflies contained 2.1-8.7% dry weight catalpol, but no other iridoids. Adults from larvae fedP. virgatus in the lab contained 4.2-9.0% dry weight catalpol and excreted large amounts of catalpol in the meconium. No catalpol was found in the larval frass. Larvae did not consume three alternate iridoid-containing host-plant species, and most eventually died rather than feed on the alternate plants. Larvae did consume small amounts of artificial diets containing the alternate species andP. virgatus, but most went into diapause and some died. Survival was good on artificial diet containing 10% dry weight of the iridoid esters fromP. virgatus. Only catalpol was found in pupae and adults, but it was absent from the larval frass. The cinnamic-type acids expected from larval hydrolysis of the esters were not found in larval frass, pupae, or adults. These results are contrasted with those found for another checkerspot,Euphydryas anicia, which consumes a different host-plant species but was present at one of the same sites withPoladryas minuta.