Terpenes activation

Terpenic compounds are resorbed from the digestive tract and sue situated in the hepatie tissues. Thanks to their ability to dissolve fats, they prevent the formation of cholesterol gathering inside the liver and they also recover proper colloidal state to the bile. Terpenes also enhance the bile content in the hepatic cells and in the liver tracts. Terpenic hydrocarbons dilating the smooth muscles [78, 79] make the hepatic tracts more distended both inside and outside. It has been pointed out that the terpenes contained in Rowachol dissolve bile stones [87-89]. The meehanism of terpenes activity has not as yet been completely explained. It was explained that menthol and other monoterpenes inhibit the activity of the lecithin-cholesterol acyltransferase in the human serum [90]. They also lower the activity of the hepatic S-3-hydroxy-3-methylglutaryl-CoA reductase, which is responsible for the physiological inhibition of cholesterol synthesis in the liver [82, 91, 92]. 

The enzymatic mechanism of terpenes activity indicates that their enantiomeric content in medicinal drugs may have a basic significance in therapy. The data of enantiomeric content in medicinal drugs including terpenes are very few. 

The most important menthadiene, an optically active monocyclic terpene found in chenopo-dium oil. Used in the manufacture of p-cymene. 

An optically active, secondary terpene alcohol. ( —)-Piperilol is found in various eucalyptus oils and (-l-) piperitol in the oil from a species of Andropogon. A somewhat viscous oil of pleasant smell. It yields piperitone on oxidation with chromic acid. 

Terpenes, specifically monoterpenes, are naturally occurring monomers that are usually obtained as by-products of the paper and citms industries. Monoterpenes that are typically employed in hydrocarbon resins are shown in Figure 2. Optically active tf-limonene is obtained from various natural oils, particularly citms oils (81). a and P-pinenes are obtained from sulfate turpentine produced in the kraft (sulfate) pulping process. Southeastern U.S. sulfate turpentine contains approximately 60—70 wt % a-pinene and 20—25 wt % P-pinene (see Terpenoids). Dipentene, which is a complex mixture of if,/-Hmonene, a- and P-pheUandrene, a- and y-terpinene, and terpinolene, is also obtained from the processing of sulfate Hquor (82). 

Ma.nufa.cture. The preparation of sulfuryl chloride is carried out by feeding dry sulfur dioxide and chlorine into a water-cooled glass-lined steel vessel containing a catalyst, eg, activated charcoal. Alternatively, chlorine is passed into Hquefted sulfur dioxide at ca 0°C in the presence of a dissolved catalyst, eg, camphor, a terpene hydrocarbon, an ether, or an ester. The sulfuryl chloride is purified by distillation the commercial product is typically 99 wt % pure, as measured by ASTM distillation method D850. 

D-limonene (Florida Chemicals). A compound of optically active terpene (CioHie) derived as an extract from orange and lemon oils limited data shows veiy low viscosity at low temperatures—only one centipoise at —50°C natural substance having questionable stabihty, Theiminol D-12 (Mon.santo). A synthetic hydrocarbon clear liquid ... 

Sometimes, on account of the difiiculty in preparing the nitroso-chloride from a highly active o-pinene, it is necessary to examine the oxidation products before it is possible to come definitely to a conclusion as to the presence or absence of the hydrocarbon. Pinene yields numerous acids as the result of oxidising processes, so that the method of preparing the product to be examined must be rigidly adhei ed to if useful results are to be obtained. The terpene is transformed into pinonic acid, CjoHj Og, in the following manner A solution of 233... 

Camphene is the only well-recognised terpene which occurs in nature in the solid condition. It occurs, like pinene, in both optically active forms. The constitution of this terpene has been a matter of considerable difference of opinion, and the constitution assigned to it by Semmler based on its similarity to bomylene was thought by many to be finally accepted. Recent researches, however, have clearly established that the formula assigned to it by Wagner is the correct one. 

Dipentene is the racemic form of the optically active d-limonene and 1-limonene, terpenes which are found to a very large extent in essential oils. Since an equal mixture of d-iimonene and f-limonene is dipentene, it is obvious that whenever optically active limonene is found with a rotation below the maximum, it must contain dipentene. Mixtures of equal quantities of a compound of the optically active limonenes are identical with the corresponding compound prepared from dipentene. It is therefore obvious that the nomenclature is unfortunate and dipentene should be termed i-limonene. 

Limonene forms a monohydrochloride, which is a liquid, and which exists in both optically active modifications. By the action of moist hydrochloric acid on the acetic or alcoholic solution of limonene, no optically active dihydrochloride is formed, the terpene becoming inactive and dipentene dihydrochloride, C (,H,g2HCl, results. This body is prepared when limonene is mixed with half its volume of glacial acetic acid, and a current of hydrochloric acid gas is passed over (not into) the well-cooled liquid, with frequent shaking. The resulting mass is pressed on a porous plate, dissolved in alcohol, and precipitated with water. It melts sharply at 50°. 

The weight of chemical evidence is strongly in favour of dipentene, being actually i-limonene, that is, merely the racemic form of the active limonenes. Semmler has suggested, however, that a slight difference may exist between the constitutions of these terpenes. ... 

The active variety of the terpene d-sylvestrene has been prepared synthetically by preparing the methyl-cyclohexane-carboxylic acid described above, and recrystallising its brucine salt. The acid contains a small quantity of the A acid, although the A variety predominates. The A acid was resolved by the brucine crystallisations, and an acid of rotation -t- 90° obtained. The synthetic process was then proceeded with, and the resulting terpene was found to be d-sylvestrene, having a rotation of -1- 66°. 

The isolation of four terpenes from the bitter principles of Ginkgo by Furukawa in 19326 marked an important advance in the quest for the identification of the active constituents of Ginkgo extracts. A second major milestone was reached in 1967 when Nakanishi and his group reported their extensive and brilliant studies which permitted the structures of these compounds to be fully defined.4 On the basis of spectroscopic data and chemical reactivity... 

It is immediately clear that Acanthomyops need not rely on dietary sources of terpenes but can synthesize citronellal and citral from either acetate or mevalonate. The higher total activity of the citronellal as compared with the citral probably reflects the natural preponderance of citronellal (ca. 90%) in the ant secretion. As the specific activities show, these results are consistent with a common biogenetic origin of both terpenes. In the mevalonic acid pathway as described from other organisms (13), the radioactive carbon of l-C14-mevalonate is lost upon formation of isopentenyl pyrophosphate. 

After identification of A9-THC as the major active compound in Cannabis and its structural elucidation by Mechoulam and Gaoni in 1964 [66], a lot of work was invested in chemical synthesis of this substance. Analogous to the biosynthesis of cannabinoids, the central step in most of the A9-THC syntheses routes is the reaction of a terpene with a resorcin derivate (e.g., olivetol). Many different compounds were employed as terpenoid compounds, for example citral [67], verbenol [68], or chrysanthenol [69]. The employment of optically pure precursors is inevitable to get the desired (-)-trans-A9-THC. 

Juvabione is a terpene-derived ketoester that has been isolated from various plant sources. There are two stereoisomers, both of which occur naturally with R-configuration at C(4) of the cyclohexene ring and are referred to as erythro- and f/trao-juvabione. The 7(.S )-cnan(iomcr is sometimes called epijuvabione. Juvabione exhibits juvenile hormone activity in insects that is, it can modify the process of metamorphosis.18... 

In addition to the QM structure of the natural terpene QMs, the reactive oxygen species (ROS) may also play a significant role in the observed biological activities. In the synthesis of taxodione and taxodone, QMs were formed from the catechol precursors through the spontaneous oxidation in the presence of silica gel.7, 8,49-51... 

Flavoring agents proper are commonly volatile oils that have been dissolved in alcohol and sprayed onto the dried granules or have simply been adsorbed onto another excipient (e.g., talc). They are added immediately prior to compression to avoid loss through volatilization. In some cases they may even have some lubricating activity. If the oil normally contains ter-penes, a low terpene grade is better so as to avoid possible deterioration in taste due to terpene oxidation... 

In regard to the experimental evidence available, a substantial number of reports on the chemical constituents of the plant are available, but much less work has been done with the pharmacological properties. Kasture et al., however, made the important observation that a triterpene isolated from R. cordifolia induces anxiety in rodents, an effect accompanied with an increase in serotonin contents in the brain (30). An interesting development from that observation would be to explore further the molecular-pharmacological pathway and the effect of this agent on the serotoninergic system because terpenes, compared with indole alkaloids, are seldom reported for serotoninergic activities. 

In addition to terpenes (as described above), carbohydrates have also been used as substrates in domino metathesis reactions, the aim being to synthesize enan-tiopure polyhydroxylated carbocyclic rings. These structures are components of several biologically active compounds such as aminoglycoside antibiotics [254], inositol phosphates [255], and carbanucleosides [256]. An efficient entry to this skeleton was developed by Madsen s group using a domino RCM/CM of the carbohy-... 

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