Antimicrobial Isoflavans and Other Metabolites of Dalea jamesii.

The phytochemical investigation of extracts of Dalea jamesii root and aerial portions led to the isolation of ten phenolic compounds. Six previously undescribed prenylated isoflavans, summarily named ormegans A - F (1 - 6: ), were characterized, along with two new arylbenzofurans (7, 8: ), a known flavone (9: ), and a known chroman (10: ). The structures of the new compounds were deduced by NMR spectroscopy, supported by HRESI mass spectrometry. The absolute configurations of 1 - 6: were determined by circular dichroism spectroscopy. Compounds 1 - 9: exhibited in vitro antimicrobial activities, causing 98% or greater growth inhibition at concentrations as low as 2.5 - 5.1 µM against methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecalis, and Cryptococcus neoformans. Interestingly, the most active compound was the dimeric arylbenzofuran 8: (> 90% growth inhibition at 2.5 µM) against both methicillin-resistant S. aureus and vancomycin-resistant E. faecalis, tenfold more active than its corresponding monomer (7: ).

Investigation of Dalea parryi (Fabaceae) metabolites for anthelmintic activity against the human pathogenic hookworm Ancylostoma ceylanicum.

The US Southwest plant Dalea parryi (Fabaceae) was investigated as part of an ongoing study of the potential of plant compounds for anthelmintic activity to the human pathogenic hookworm Ancylostoma ceylanicum. This has resulted in the isolation of three previously undescribed isoflavonoid metabolites, denoted parryans A-C, a chalcone, six pterocarpans, and three known compounds from the roots of D. parryi. Parryans A and B express a rarely-seen O-prenyl substituent. Structures of the previously undescribed compounds were established using 1D and 2D NMR spectroscopy and mass spectrometry. The relative and absolute configurations of the undescribed stereoisomers were assigned using chemical shift and coupling constant data and comparisons of specific rotations to published data. The most active of the isolated compounds only expressed a 17% reduction in survival of A. ceylanicum adult hookworm in an ex vivo assay at 50 µg/mL after 5 days exposure. Toxicity, ranging from 47 to 93% reduction in survival of mammalian splenocytes was expressed by four of the compounds.

Phenolic Metabolites of Dalea ornata Affect Both Survival and Motility of the Human Pathogenic Hookworm Ancylostoma ceylanicum.

Hookworms are ubiquitous human parasites, infecting nearly one billion people worldwide, and are the leading cause of anemia and malnutrition in resource-limited countries. Current drug treatments rely on the benzimidazole derivatives albendazole and mebendazole, but there is emerging resistance to these drugs. As part of a larger screening effort, using a hamster-based ex vivo assay, anthelmintic activity toward Ancylostoma ceylanicum was observed in the crude extract of aerial parts of Dalea ornata. These studies have led to the isolation and characterization of phenolic metabolites 1-10. The structures were determined by 1D and 2D NMR spectroscopy, and the absolute configuration of 1 was assigned using electronic circular dichroism data. The new compound, (2S)-8-(3-methylbut-2-en-1-yl)-6,7,4'-trihydroxyflavanone (1), was weakly active at 7.3 µM, with 17% reduction in survival of the hookworms after 5 days. The rotenoids deguelin (9) and tephrosin (10), predictably perhaps, were the most active, with complete worm mortality observed by day 4 (or earlier) at 6.3 and 6.0 µM, respectively. The effects of 1-10 on hookworm motility and on toxicity to hamster splenocytes were also explored as important measures of treatment potential.

Antimicrobial and antiinsectan phenolic metabolites of Dalea searlsiae.

Continued interest in the chemistry of Dalea spp. led to investigation of Dalea searlsiae, a plant native to areas of the western United States. Methanol extractions of D. searlsiae roots and subsequent chromatographic fractionation afforded the new prenylated and geranylated flavanones malheurans A-D (1-4) and known flavanones (5 and 6). Known rotenoids (7 and 8) and isoflavones (9 and 10) were isolated from aerial portions. Structure determination of pure compounds was accomplished primarily by extensive 1D- and 2D-NMR spectroscopy. The absolute configurations of compounds 1-5, 7, and 8 were assigned using electronic circular dichroism spectroscopy. Antimicrobial bioassays revealed significant activity concentrated in the plant roots. Compounds 1-6 exhibited MICs of 2-8 µg/mL against Streptococcus mutans, Bacillus cereus, and oxacillin-sensitive and -resistant Staphylococcus aureus. Aerial metabolites 7-10 were inactive against these organisms, but the presence of 7 and 8 prompted investigation of the antiinsectan activity of D. searlsiae metabolites toward the major crop pest Spodoptera frugiperda (fall armyworm). While compounds 1-10 all caused significant reductions in larval growth rates, associated mortality (33-66%) was highest with flavanone 4 and rotenoids 7 and 8. These findings suggest a differential allocation of antimicrobial and antiinsectan plant resources to root and aerial portions of the plant, respectively.

Fungal ABC transporter-associated activity of isoflavonoids from the root extract of Dalea formosa.

New potential treatments for disseminated fungal infections are needed, especially for infections caused by the commonly drug-resistant pathogens Candida albicans and C. glabrata. These pathogens cause systemic candidiasis, a significant cause of mortality in immune-compromised patients. ABC transporters of the pleiotropic drug resistance subfamily, such as Cdr1p of C. albicans, play an important role in antifungal resistance and are potential bioassay targets for antifungal therapies against drug-resistant pathogens. We observed strong antifungal growth inhibitory activity in the methanol extract of Dalea formosa roots. This extract afforded six new isoflavonoids, sedonans A-F (1-6), a new but-2-enolide, 4'-O-methylpuerol A (7), and the new pterocarpan ent-sandwicensin (8). The structures and absolute configurations of these compounds were assigned using spectroscopic and chiroptical techniques. The direct antifungal activity of 1 against C. glabrata (MIC = 20 µM) was higher than that of fluconazole. Sedonans A-F and ent-sandwicensin were also active against Saccharomyces cerevisiae strains that express differing ABC transporter-associated resistance mechanisms but differed in their susceptibility to Cdr1p-mediated detoxification. A sedonan A (1)/ent-sandwicensin (8) combination exhibited synergistic growth inhibition. The results demonstrate that multiple crude extract compounds are differentially affected by efflux-mediated resistance and are collectively responsible for the observed bioactivity.

A randomized, double-blind, placebo-controlled study to evaluate the effect of EFF1001, an Actinidia arguta (hardy kiwi) preparation, on CADESI score and pruritus in dogs with mild to moderate atopic dermatitis.

Canine atopic dermatitis (AD) is common and new therapies are beneficial. This multicentric, randomized, double-blind, placebo-controlled study tested the efficacy of Actinidia arguta (hardy kiwi) (EFF1001) in dogs with mild/moderate AD. The study was divided into two stages. Stage 1 lasted 6 weeks. In the first 2 weeks prednisolone [days 1-3: 0.2 mg/kg twice daily (BID), days 4-14: 0.2 mg/kg every other day (EOD)] was administered. Responsive dogs were placed on prednisolone 0.2 mg/kg EOD + assigned test article [either placebo or EFF1001 (30 mg/kg)] once daily for 4 weeks. Stage 1 responders were advanced to stage 2, which involved 4 weeks of just EFF1001. Clinicians scored lesions using Canine Atopic Dermatitis Extent and Severity Index (CADESI) and owners scored pruritus using a Pruritus Visual Analogue Scale. Seventy-seven dogs were enrolled, 76 were randomized on day 14, and 57 (57/76 = 75%) completed stage 1 (27 in EFF1001 and 30 in placebo). At the end of stage 1, 35 of 57 dogs (35/57 = 61%) responded (18 in EFF1001 and 17 in placebo) and advanced to stage 2. At completion of stage 1, CADESI scores did not significantly differ between groups while pruritus decreased in EFF1001 group and approached significance. At completion of stage 2, 19 dogs (19/35 = 54%) responded (15/19 = 79% had received EFF1001 and 4/19 = 21% placebo in stage 1). After completing stage 2, dogs placed on EFF1001 throughout the study were 3.5 times more likely to either maintain or improve scores than those that started it in stage 2. It is concluded that EFF1001 is beneficial adjunctive therapy after prolonged use.

Clinical study of the effects on asthma-related QOL and asthma management of a medical food in adult asthma patients.

BACKGROUND: Asthma can have a negative impact on quality of life although this is not well correlated with objective evaluations of pulmonary function. A medical food, EFF1009, containing the fatty acids gamma-linolenic acid (GLA) and eicosapentaenoic acid (EPA) decreases leukotriene B(4) synthesis in patients with asthma. Two previous clinical studies with EFF1009 provided preliminary evidence that the medical food improves asthma-related quality of life (ARQOL) and asthma management. OBJECTIVE: To evaluate the impact on ARQOL of EFF1009 in adults with asthma. RESEARCH DESIGN AND METHODS: The study was a randomized, prospective, double-blind, placebo-controlled, parallel group study in twenty-one (N = 21 evaluable) subjects with mild to moderate persistent asthma who consumed the medical food emulsion or placebo emulsion daily for 28 days. All participants continued their asthma medications throughout the study. ARQOL, including asthma signs and symptoms, and asthma control were measured using the Mini Asthma Quality of Life Questionnaire (MiniAQLQ) and the Asthma Control Questionnaire (ACQ), administered at baseline, Day 14 and Day 28. Safety and tolerability parameters, including adverse events, were monitored. RESULTS: Baseline ARQOL scores, forced expiratory volume in one second (FEV(1)) and other characteristics were balanced between both groups. Mean (standard error) total MiniAQLQ scores changed by 0.73 (0.38) and -0.22 (0.36) in the EFF1009 and placebo groups, respectively, (p < 0.05). The MiniAQLQ symptom domain score was improved in the EFF1009 group (p < 0.05). Total scores for the ACQ were not significantly improved in either group. Levels of the fatty acid EPA in plasma increased in the EFF1009 group but not the placebo group (p < 0.03). The medical food was well tolerated and no safety concerns were identified. CONCLUSIONS: The dietary addition of the medical food EFF1009 to asthma management regimens can improve patient perceived, ARQOL and can also improve asthma management as evidenced by reduced asthma symptoms. An additional study of the medical food, with larger subject population and longer treatment duration, is warranted to confirm these findings.

Activity of isoflavans of Dalea aurea (Fabaceae) against the opportunistic ameba naegleria fowleri.

One new and one known isoflavan, 3 S(+)-7-methoxymanuifolin K (1) and manuifolin K (2), respectively, were isolated from methanolic extracts of Dalea aurea (Fabaceae). Isoflavans 1 and 2 exhibited significant in vitro activity against the ameba Naegleria fowleri, an organism responsible for an infrequent but rapidly fatal form of primary amebic meningoencephalitis (PAM). At concentrations of 30 microM, both 1 and 2 caused growth inhibition of N. fowleri at a level comparable to amphotericin B (at 0.1 microM), the currently preferred treatment for this disease. Over a seven-day growth period, 1 and 2 (30 microM) exhibited superior growth inhibition of N. fowleri than amphotericin B after day 4. Isoflavan 2 was evaluated in a mouse model of PAM at a dose of 25 mg/kg/day for five days. While amphotericin B (2.5 mg/kg/day) offered 12.5 % protection of the mice, compound 2 did not protect the mice from PAM infection compared to controls.

Metabolites of the "smoke tree", Dalea spinosa, potentiate antibiotic activity against multidrug-resistant Staphylococcus aureus.

Two new 2-arylbenzofuran aldehydes (1 and 2) and three known phenolic compounds (3-5) were isolated from organic extracts of Dalea spinosa. These compounds were evaluated for their intrinsic antimicrobial activity and their ability to perform as multidrug-resistance inhibitors by potentiating the activity of known antimicrobials against a variety of pathogenic microorganisms. Compound 1 and its acetate derivative 6 exhibited no direct antimicrobial activity but enhanced the effect of the weak plant antimicrobial berberine when tested against Staphylococcus aureus. Additional potentiation assays with S. aureus overexpression and knockout isogenic efflux mutants for the NorA pump were done in order to assess whether the potentiating effects were associated with inhibition of this known pump mechanism.

Phenolic metabolites of Dalea versicolor that enhance antibiotic activity against model pathogenic bacteria.

A new flavonoid (1) was isolated from organic extracts of Dalea versicolor, along with six known phenolic compounds (2-7). The structures of the seven compounds were determined by NMR and HRMS methods. These compounds were evaluated for direct activity against a variety of organisms in vitro, including the Gram-positive bacteria Staphylococcus aureus and Bacillus cereus. In addition, the compounds were evaluated for their ability to potentiate the activity of known antimicrobials through inhibition of multidrug-resistance (MDR) pumps. Compounds 1, 2, 4, and 7 exhibited direct or synergistic activity toward the human pathogen S. aureus and the opportunistic pathogen B. cereus. Compounds 4 and 7 were also found to potentiate the activity of berberine and of prescribed antibiotics, with 4 demonstrating a mode of action consistent with inhibition of the NorA MDR efflux pump in S. aureus.

New geranyl stilbenes from Dalea purpurea with in vitro opioid receptor affinity.

Three new geranyl stilbenes, pawhuskins A, B, and C (1, 2, and 3), were isolated from organic extracts of Dalea purpurea. The structures of the three compounds were determined by NMR and HRMS methods. The activities of these compounds, along with that of the known compound petalostemumol (4), were evaluated in an opioid receptor assay in vitro. Pawhuskin A (1) exhibited the strongest activity of the four compounds with a K(i) value of 0.29 +/- 0.11 microM.