Plant extracts terpenoids

Fig. (3). Chemical strucutes - glycosides / steroids / terpenoids. Table 3. Selected Plant Extracts with Hypoglycemic Activity...

The secondary metabolites of higher plants include diverse chemicals such as alkaloids, terpenoids, and phenolic compounds (phenylpropanoids and flavonoids), which are produced from primary metabolites such as amino acids or acetyl coenzyme A (acetyl-CoA). Although these compounds are widely used in the health and nutrition of humans, they are mainly obtained by plant extraction. 

Another interesting application of caryophyllene and other terpenoids found in essential oils is for enhancing aroma and safety of fresh foods, such as fresh fruit-cuts [181, 182]. Plant extracts containing germacrene and aromadendrene had a strong growth inhibition effect on food-borne microorganisms such as Bacillus cereus and Salmonella thyphimurium [183]. 

Palmeri M, Dominguez XA, Franco R, Cano G 1978 Mexican medicinal plants. XXXII. Terpenoids from ether extracts of the Celastraceae, Mortonia gregii. Rev Latinoamer Quim 9 33-35... 

In their study of neutral, terpenoid metabolites from the Compositae, Bohlmann and his co-workers have discovered a series of dihydro-pyrrolizinone derivatives in Senecio species (Table 3 U). These are all macrocyclic diesters containing 12-membered rings, although it is interesting that macrocyclic diesters with both a and p stereochemistry at C-7 of the necine have been isolated. A related series of open chain esters, the senampelines (Table 3 T), have also been discovered. This work does indicate the need to carry out careful examination of both basic and neutral fractions from plant extracts when searching for pyrrolizidine derivatives. The extent of these new derivatives should also be ascertained by reinvestigating species of other families known to contain pyrrolizidine alkaloids. 

Absolute. This is concentrated extract obtained by treatment of a concrete or other hydrocarbon-type extract of a plant or plant part with ethanol. It is usually Hquid and should be totally soluble in alcohol. By this method, waxes, hydrocarbons (including terpenoid), as well as most of the odorless material of the concrete are removed from the extract. 

Supercritical fluid extraction — During the past two decades, important progress was registered in the extraction of bioactive phytochemicals from plant or food matrices. Most of the work in this area focused on non-polar compounds (terpenoid flavors, hydrocarbons, carotenes) where a supercritical (SFE) method with CO2 offered high extraction efficiencies. Co-solvent systems combining CO2 with one or more modifiers extended the utility of the SFE-CO2 system to polar and even ionic compounds, e.g., supercritical water to extract polar compounds. This last technique claims the additional advantage of combining extraction and destruction of contaminants via the supercritical water oxidation process."... 

From the hair-pencils of butterflies in Danainae and Ithomiinae (Papilion-oidea Nymphalidae), a wider variety of pyrrolizines (la-d, and 6a-d) have been identified than from Arctiidae moths. These compounds are biosynthesized from pyrrolizidine alkaloids, which are included in host plants fed by the larvae and protect them from the attacks of other herbivores [122]. In addition to novel lactones (7, 8a, and 8b) derived from an acid part of the alkaloids, many volatiles of more than 100 compounds (aromatics, terpenoids, hydrocarbons, and others) constitute scent bouquets of the male butterflies [123]. For example, the hair-pencil of Idea leuconoe (Danainae) which is distributed in South-East Asia contained 16 compounds (6b, 8a, 8b, 9, and others), and a mixture of the major volatiles applied to a butterfly dummy elicited an abdomen-curling acceptance posture in the females as a crude extract of the male hair-pencils did [ 124]. A chiral GC analysis revealed the absolute config-... 

In 1965 Seshardri et al. described the isolation of an unknown terpenoid acid B obtained from the lichens of Lobaria retigera in the western Himalayas [8]. (Note that this annotation bears no relation to the subsequent nomenclature later defined by Corey and Shibata.) Four collections had been made in the summer of 1962 from under the Rutba plants in the Valley of Flowers (12,500 feet) and on the way to Hemkund Lokpal (13,500 feet) and from underneath rocks and from pine trees in Ganghariya (10,000 feet). The samples were subjected to a series of increasingly polar extractions (petroleum ether, diethyl ether, acetone). The unknown terpenoid acid B was present in all petroleum ether extracts, except that of the sample obtained from the Valley of Flowers, in compositions ranging from 0.47 % to... 

About 120 chemical constituents have been identified in chamomile as secondary metabolites, including 28 terpenoids, 36 flavonoids and 52 additional compounds [4]. A substantial part of drag effects are determined by the essential oil content. Oil is collected from flower heads, either by steam distillation or solvent extraction, for yields of 0.24-1.90% of fresh or dry plant tissue. Among the essential oil constituents the most active are /-/-a-bisabolol and chamazulene. /-/-a-bisabolol has demonstrated anti-inflammatory, antispasmodic, antimicrobial, antiulcer, sedative and CNS activity. Chamazulene is also anti-inflammatory. Topical applications of chamomile preparation have shown benefit in the treatment of eczema, dermatitis and ulceration [5]. 

In young plants, the concentrations of limonene and other terpenoids increased in the petiole and leaf extract as the level... 

SUMMARY In essential oils, most constituents are terpenes and terpenoid molecules. The method of extraction can influence the terpene content. In citrus oils extracted by expression (squeezing or pressing the plant material), the terpenes present are similar to those found in the living plant tissue for example, orange, lemon, mandarin and grapefruit essential oils may be made up of up to 90% of the monoterpene limonene. When extraction is by steam distillation the action of the hot water and steam on thermolabile (heat-sensitive) molecules present in the plant is responsible for the formation of the bulk of the terpene content. Solvent extraction often produces absolutes that are very low in terpenes or do not contain them at all, when compared to a distillation of the same material, for example as found in lavender and rose products. 

Terpenoids occur as essential oils in lipid extractions of plants. 

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