Extraction herbs

There are many ways of preparing herbal medicines. Tinctures and elixirs are extractions of herbs using some solvent, usually ethanol. If a plant is extracted with acetic acid, the solution is known as a vinegar, even though the solvent is also vinegar. A tisane uses hot water to extract herbs—like tea. 

Materials for flavoring may be divided into several groups. The most common groupings are either natural or artificial flavorings. Natural materials include spices and herbs essential oils and thek extracts, concentrates, and isolates fmit, fmit juices, and fmit essence animal and vegetable materials and thek extracts and aromatic chemicals isolated by physical means from natural products, eg, citral from lemongrass and linalool from hois de rose. 

The most popular natural antioxidants on the market are rosemary extracts and tocopherols. Natural antioxidants have several drawbacks which limit use. Tocopherols are not as effective ia vegetable fats and oils as they are ia animal fats. Herb extracts often impart undesirable colors or flavors ia the products where used. In addition, natural antioxidants cost considerably more than synthetic ones. Despite this, the pubHc s uncertainty of the safety of synthetic antioxidants continues to fuel the demand for natural ones (21). 

Chinese Herbal Medicines. Many traditional Chinese medicines have been screened for radioprotective activity in experimental animals. In one study of more than a thousand Chinese herbs, a number of agents increased the survival rate of dogs exposed to a lethal dose of y-rays by 30—40%, and some symptoms of radiation injury were ameHorated. These effects are potentially related to stimulation of the hemopoietic and immune systems (130). Extracts of five Chinese dmg plants, as weU as aspirin, effectively protected mice exposed to 7.5—8.0 Gy (750—800 rad) of y-radiation, and increased survival rates by 8—50% (131). Several Chinese traditional medicines, adininistered ip before or after irradiation, protected against Hpid peroxidation in a variety of mouse tissues, including BM, Hver, and spleen, as weU as in mouse Hver microsomal suspensions irradiated in vitro (132). 

Additional commercial processes are available for extraction of tea, hops, oriental herbs, tobacco leaves, and pharmaceuticals C02-enhanced oil recovery environmental appHcations such as extraction/flocculation of aqueous wastes reactions with iategrated separations such as aminations (ethylene... 

Essential Oils. Volatile oils from plants are referred to as essential oils. The oils can be obtained through steam distillation, solvent extraction, or separation of the oils from pressed fmit. They consist of oxygenated compounds, terpenes, and sesquiterpenes. The primary flavor components of essential oils are oxygenated compounds. Terpenes contain some flavors but are often removed from the essential oil because they are easily oxidized (causiag off-flavors or odors) and are iasoluble. Essential oils are prepared from fmits, herbs, roots, and spices. 

Oleo Resins. These oily residues, obtained from the solvent extraction of herbs, contain more of the characteristic flavors than do the essential oils. The solvent extraction removes nearly all of the flavor bodies from the herb. The extract solvent is distilled, reduciag the solution to an oily residue. Oleo resias of iaterest to the carbonated beverage iadustry are ginger, celery, and black pepper. 

Nepeta (Lamiaceae) is a genus of perennial or annual herbs found in Asia, Europe and North Africa. About 250 species of Nepeta are reported of which, 67 species are present in Iran. Some species of this genus are important medicinal plants and their extracts have been used for medicinal purposes. Aerial parts of Nepeta sintenisii Bornm. was subjected to hydrodistillation and the chemical composition of isolated essential oil has been analyzed by GC/MS method for first time. Identification of components of the volatile oil was based on retention indices relative to n-alkanes and computer matching with the Wiley275.L library, as well as by comparison of the fragmentation patterns of the mass spectra with those reported in the literature. 

The express method of phenolic compounds determination was designed. It is based on heterogeneous azo-coupling reaction of phenols, which different extracts of fresh raw material contain, with aryldiazonium salts grafted on the silica surface. We can carry out phenols analysis on-site, as formation of immobilized azocompounds leads to a drastic change in the sorbent s color. Thus, we pui pose a new method, that allows to indicate herb phenols in aqueous and non-aqueous medias and to compare it with a well-known Folin-Ciocalteau method. 

Back cohosh, a herb reported to be beneficial in managing symptoms of menopause, is generally regarded as safe when used as directed. Back cohosh is a member of the buttercup flower family. The dosage of standardized extract is 2 tablets twice a day, or 40 dropsof standardized tincture twice a day or one 500- to 600-mg tablet or capsule three times daily. Back cohosh tea is not considered as effective as other forms Boiling of the root releases only a portion of the therapeutic constituents... 

Blberry fruit isa safe food herb with no known adverse reactions or toxicity. There are no known contraindications to its use as directed. The dosage of standard extract is 160 to 320 mg a day. 

There are many additives in shampoos and conditioners that appear to be there mainly for marketing purposes. Honey, various herb extracts, and other compounds might add to the fragrance, but they are unlikely to have any other effects in the small concentrations used. Amino acids can act as conditioners, but the source of the amino acid is not important. Silk amino acids are essentially no different from soy amino acids. 

The dense fluid that exists above the critical temperature and pressure of a substance is called a supercritical fluid. It may be so dense that, although it is formally a gas, it is as dense as a liquid phase and can act as a solvent for liquids and solids. Supercritical carbon dioxide, for instance, can dissolve organic compounds. It is used to remove caffeine from coffee beans, to separate drugs from biological fluids for later analysis, and to extract perfumes from flowers and phytochemicals from herbs. The use of supercritical carbon dioxide avoids contamination with potentially harmful solvents and allows rapid extraction on account of the high mobility of the molecules through the fluid. Supercritical hydrocarbons are used to dissolve coal and separate it from ash, and they have been proposed for extracting oil from oil-rich tar sands. 

Just like all herbal medicinal preparations, C. sativa should be standardized if extracts or whole plant material are to be used for medicinal purposes. Basic requirements are that all detectable constituents should be known, but also a sustainable quahty control system must be established to achieve the same quahty over all batches. For industrial use of cannabis, standardization could also be necessary to equahze the quality of the product. However, it must be stated that cultivation for this purposes is mostly performed outdoors. Outdoor growth makes standardization of the product difficult due to the environmental changes. For this reason the Dutch medicinal C. sativa is grown under strictly controllable conditions, and therefore indoors, by the company Bedrocan. At this company clones are used for breeding to maintain high standards for quantity and quality. After a strictly selective breeding procedure a plant fine has been estabhshed fulfilhng all criteria as a herb for medicinal use. 

A TLC method was developed for the estimation of nieotinie aeid and nicotinamide (Fignre 10.7) in phatmacentical preparations containing other vitamins, enzymes, herbs, and drugs, etc. [16]. The percentage recoveries for nicotinic acid and nicotinamide were 100.1 + 1.9 and 100.2 1.5, respectively, with this system. Each alcohol extract of samples or standard was pnt on sihca gel TLC plates, which were developed with distilled water. Each silica gel spot visualized under UV lamp was collected and extracted with 0.1 mol/1 HCl. The optical density of each clear extract was measured at 262 run. 

As is shown in Table 11.1, PLC is mainly used before the identification of isolated compounds with spectral methods such as NMR or IR. Figure 11.6 shows a densi-togram of PLC of Fumaria officinalis herb extract with marked fractions being isolated (Figure 11.6a) and analytical chromatogram of isolated fractions (Figure 11.6b). 

FIGURE 11.6 (a) Densitogram of PLC of Fumaria officinalis herb extract and (b) photocopy of isolated fractions (after spraying with Dragendorff s reagent). Numbers indicate isolated fractions. System silica/CHjClj + PrOH + AcOH (5 4 1). Plates double developed. 

Also, different selectivity systems of were nsed for the separation of the alkaloid fraction from Corydalis solida herb. The extract was fractionated by the nse of a sihca layer elnted with 10% propanol-2 in dichloromethane (see Fignre 11.15a). Fraction 1 elnted dynamically from the adsorbent was rechromatographed by the nse of silica layer and eluent of higher strength containing acetonitrille + propanol-2 + acetic acid + dichloromethane. It enables the separation of the six zones of alkaloids from fraction I (see densitogram in Figure 11.15b). 

FIGURE 11.20 Densitogram of alkaloid fraction from Fumaria officinalis herb extract chromatographed in system silica/PrOH -i- AcOH -i- CHjClj (4 1 5) (a) fraction introduced with applicator with evaporation of solvent (b) fraction introduced from the edge of the layer with the eluent distributor. 

FIGURE 11.23 Densitograms of Fumaria muralis herb extract chromatographed in system silica/PrOH + MeOH + AcOH + water + CHjClj (28 2 2 2 66). Plates double developed (a) plate scanned at 254 nm (b) plate scanned at 400 nm after spraying with Dragendorff s reagent. 

As the sensitivity and selectivity of the above GC/MS methods are for many analytes around 1 pg injected into the GC system, cleanup by SiOa fractionation can be omitted when larger sample sizes (25-100 g) are possible. For difficult dry (e.g. hops, pharmaceutical herbs) or oily (e.g. rape seed, fat, liver) materials which start with smaller sample sizes (5-10 g) and tend to overload the chromatographic cleanup systems, however, cleanup is still an important requirement as the GC injection system is vulnerable when the ratio of co-extracted material to analyte is too high. 

In the above two cases, active components were extracted, identified, and tested both pharmacologically and clinically. Other herb preparations, no matter how long they have been used, are still entities that are pharmacologically unknown. Herbal extracts also need better quality monitoring processes, since active components in plants may vary in different varieties and different seasons. If chemical synthesis is... 

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