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Ongoing studies have developed strategies for identifying key bioactive compounds and chemical profiles in Echinacea with the goal of improving its human health benefits. Antiviral and antiinflammatory-antipain assays have targeted various classes of chemicals responsible for these activities. Analysis of polar fractions of E. purpurea extracts showed the presence of antiviral activity, with evidence suggesting that polyphenolic compounds other than the known HIV inhibitor, cichoric acid, may be involved. Antiinflammatory activity differed by species, with E. sanguinea having the greatest activity and E. angustifolia, E. pallida, and E. simulata having somewhat less. Fractionation and studies with pure compounds indicate that this activity is explained, at least in part, by the alkamide constituents. Ethanol extracts from Echinacea roots had potent activity as novel agonists of TRPV1, a mammalian pain receptor reported as an integrator of inflammatory pain and hyperalgesia and a prime therapeutic target for analgesic and antiinflammatory drugs. One fraction from E. purpurea ethanol extract was bioactive in this system. Interestingly, the antiinflammatory compounds identified to inhibit prostaglandin E(2) production differed from those involved in TRPV1 receptor activation.

The right Asphaltene Inhibitor (AI) selection is crucial for the control of asphaltene issues in oil production. Although many factors contribute for the asphaltene precipitation/deposition in the fields, the chemical selection process in the laboratory were often conducted only under ambient temperature and pressure. In this paper, we introduced a multifaceted approach for asphaltene inhibitor selection process to overcome the test condition discrepancy between laboratory and the fields. The importance of temperature on the performance of chemicals was evidenced by our high temperature optical scanning device results. The Coupon Deposition Test (CDT) clearly demonstrated the difference between deposition and precipitation behavior and the impact of the water phase on inhibitor performance. High pressure Asphaltene Rocking Cell (ARC) enabled to incorporate high pressure, high temperature and water conditions in the laboratory to show the difference of inhibitor performances. By incorporating field conditions such as temperature, brine composition and pressure into our tests, better recommendations can be achieved that would have not been possible with any optical, precipitation based technique. Furthermore, a suite of AI test methods which cover various field conditions brings a degree of refinement in product selection unmatched by any single method and allows for selection of the best asphaltene chemical program for a particular field through its life cycle.

Abstract:The synthesis of the alkamides 2Z, 4E-undeca-2,4-dien-8,10-diynoic acid isobutyl amide (1) and 2Z, 4E-undeca-2,4-dien-8,10-diynoic acid isobutyl amide (5) was accomplished by organometallic coupling followed by introduction of the doubly unsaturated amide moiety. The distribution of these two amides in accessions of the nine species of Echinacea was determined.

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In order to provide an authentic standard and to generate pure material for biological testing, an efficient synthetic route to 1 was developed. This represents the first total synthesis of a major bioactive diynone from E. pallida. Keywordsdiynones; selective alkyne reduction; coupling reaction; selective desilylation Echinacea extracts are used by millions of people as botanical dietary supplements. 1 While they are purchased primarily to stimulate the immune system, there are many bioactive compounds in the supplements. It is important to have a good understanding of the biological profile of key components of the supplements so that unfavorable drug interactions can be avoided. Most commercial botanical dietary supplements contain mixtures of three of the nine species of Echinacea: E. pallida, E. angustifolia and E. purpurea. The chemical fingerprint of E. angustifolia has diacetylenic isobutylamides as the diagnostic hydrophobic constituents. In contrast, the chemical fingerprint of E. purpurea has tri-and tetraenic isobutyl amides as the most abundant hydrophobic constituents, while E. pallida contains acetylenic ketones as the diagnostic hydrophobic constituents. Ketones 1 and 2 represent the most abundant acetylenic ketones of E. pallida (Figure 1). Hydroxy ketone 2 is derived from ketone 1 by reaction with molecular oxygen. 2 Extracts from E. pallida also exhibit antiviral activity. Ketones 1 and 2 have been shown to be potent antifungal agents; 3 however, the full range of biological activity of these novel compounds has not yet been determined, partly due to the difficulty in obtaining pure 1 from plant extracts containing many other compounds of similar polarity.As part of an interdisciplinary team of plant scientists, food scientists and chemists whose goal is to identify key bioactive constituents of Echinacea, 4 we describe herein the first total synthesis of ketone 1. The synthetic route is illustrated below in Scheme 1. Our synthetic route began with the known acetylenic alcohol 3. 5 Alcohol 3 was protected as the tetrahydropyranyl (THP) ether 4 in 90% yield (dihydropyran, PPTS, CH 2 Cl 2 , 0 °C). The protected alcohol was converted into 5 by hydroxymethylation using ethylmagnesium bromide and formaldehyde, 6 followed by conversion of the alcohol into the iodide using triphenylphosphine and iodine. 7 The overall yield of 5 from acetylene 4 was 61%. The reaction of iodide 5 with the anion of trimethylsilylacetylene, generated from potassium carbonate and copper iodide, provided diacetylene 6 in 45% isolated yield. 8 Iodide 5 reacted very slowly with the anion of trimethylsilylacetylene. Yields of 72% for this reaction required potassium carbonate that was dried over phosphorus pentoxide. Surprisingly, the reaction of iodide 5 with the lithium salt of trimethylsilylacetylene, generated via the reaction of the acetylene with n-butyllithium, afforded only recovered starting material.

Abstract:The first synthesis of a series of ketones naturally occurring in E. pallida is described. The natural distribution of these ketones among different Echinacea species is also reported.