Plants, natural building blocks

Ethane is used by petrochemical plants to make ethylene, a primary building block for many plastic products. Butane and condensate are used by refineries producing automotive fuel. For production of NGL s (natural gas liquids), die plant s recovery rate of 98% of ediane and 100% of all odier liquid products contained in natural gas, is among die best in die world. 

These epipolythiodiketopiperazine alkaloids, together with the calycanthaceous alkaloids (Fig. 9.1b), form a superfamily of natural products termed the dimeric hexahydropyrroloindole alkaloids [6-8]. The main dichotomy within this superfamily arises from the biogenetic elaboration of tryptamine versus tryptophan building blocks. The tryptamine-based calycanthaceous alkaloids, boasting members such as chimonanthine (7), calycanthine (9), and folicanthine (8), are largely plant derived and have a long and rich history in the context of natural product synthesis [7, 9]. 

Despite PHI s seemingly mystical mathematical origins, Langdon explained, the truly mind-boggling aspect of PHI was its role as a fundamental building block in nature. Plants, animals, even human beings all possessed dimensional properties that adhered with eerie exactitude to the ratio of PHI to 1. 

Dioxin vinylogous esters derived from cyclic 1,3-diketones (e.g., 4) are valuable building blocks for the construction of natural and unnatural carbocyclic products.2 In connection with a synthesis of plant-growth regulators, Crow and... 

The table lists the full series of aliphatic carboxylic acids that are found in plants and animals. In higher plants and animals, unbranched, longchain fatty acids with either 16 or 18 carbon atoms are the most common— e.g., palmitic and stearic acid. The number of carbon atoms in the longer, natural fatty acids is always even. This is because they are biosynthesized from C2 building blocks (see p.168). 

The biosynthesis of synthetic natural rubber has been completely determined and appears in Fig. 15.1. Many plants and animals use this same biosynthetic pathway to make hundreds of terpenes and steroids from their common isoprenoid building blocks. 

Terpenes are a class of naturally occurring olefins found in many plants. They are biosynthetically derived from isoprene, CsHg, and therefore consist of Cs-building blocks and are found in both cyclic and acyclic forms. An important subgroup is the monoterpenes, which consist of two isoprene units and are of the molecular formula Ci0H16. Of the monocyclic monoterpenes, by far the most industrially relevant is limonene, which is abundantly present as a fragrance in various household products. From the bicyclic monoterpenes, a-pinene, p-pinene, camphene, and carene are of industrial relevance and are also mostly used in the fragrance industry [44]. 

Apocarotenals and their corresponding carboxylates are natural colorants which occur in citrus fruits, spinach and other plants and which have vitamin A activity. They are used as fat-soluble foodstuff colorants. For their synthesis, specifically selected building blocks can be linked with one another under the conditions of the Wittig reaction ... 

Type 1 MTs, currently exclusive for oxygen atoms (OMTs), methylate hydroxyl moieties of phenylpropanoid-based compounds (Fig. 2.3). The phenylpropanoid scaffold is used as a building block for many other types of compounds in the plant. Modification of this basic unit by multiple condensation reactions yields chalcone, flavonoid, isoflavonoid, and pterocarpan skeletons, for example. Flavonoids are ubiquitous in higher plants, where they function as UV protectants,5 defense compounds,6 and stimulators of beneficial mutualistic interactions with microorganisms, insects, and other organisms.7 Isoflavonoid natural products are limited primarily to leguminous plants, where they function as pre-... 

---