Castor plant

The seeds of the castor plant are produced ia racemes, or clusters of capsules. The capsules each contain three seeds protected by a hull that is removed prior to processiag. The seeds are mottled to varyiag extents, most often with shades of dark brown ovedayiag shades of light brown. Seeds of commercial varieties range from 250 to 1800/kg. The seeds are toxic, and the ingestion of several seeds can be fatal to humans. 

Ricin Cytotoxic glycoprotein derived from seeds ofthe castor plant... 

Castor oil is derived from the castor plant Ricinus communis). The castor plant has a long and rich history of uses in human society. The oil from the plant is non-digestible, and is commonly known to be a medicinal purgative. The castor bean contains the protein ricin, a substance that is famously toxic in humans [50]. The lack of food value from the castor plant coupled with the issues of toxicity inherent in extraction of ricin has mostly limited the use of castor oil to the industrial sector. 

The castor plant is widely considered to be a nuisance plant, because it proliferates rapidly in poor, depleted soils that cannot sustain other more important commercial crops. It spreads quickly as a weed, and in some places has been listed as an intrusive species to be eliminated [51, 52]. Nevertheless, in recent years the industrial volume of castor oil has increased dramatically, driven primarily by the global interest in renewable resources for fuel and feedstocks as an alternative to petrochemicals. The majority of the volume growth has come from the Asian continent, primarily from India, where the castor plant is harvested commercially [53]. In addition to its direct use in pol3mrethane products, the oil and its components have been the focus of innovative new derivatization strategies to improve their properties for use in plastics, while retaining high levels of renewable content in the final products. These developments will be described in Section 4.5. 

Castor oil is a triglyceride that is well suited for use in polyurethane applications. Unlike most other oil-producing plants, the castor plant produces a triglyceride containing >90% of a single fatty acid, that being ricinoleic acid. Ricinoleic acid contains secondary hydroxyl groups appended to the Cjg fatty acid backbone (Fig. 8). 

Mechanism of Action A laxative prepared from the bean of the castor plant but the exact mechanism of acfion is unknown. Acts primarily in the small intestine. Maybe hydrolyzed to ricinoleicacid which reduces net absorption of fluid and electrolytes and stimulates peristalsis. Therapeutic Effect Increases peristalsis, promotes laxative effect. 

The Dow Chemical Company, Castor Oil, Inc., and the USD A Western Regional Research Center are collaborating to develop the castor plant as a suitable oilseed for specialty oils that can be converted into lubricants, coatings, foams, adhesives, and engineering thermoplastics. Castor oil already contains ricinoleic acid, a fatty acid used in many industrial applications, but project partners hope to produce other industrially desirable fatty acids within the castor bean. 

Ricin was found by Stillmark in 1889 as the first plant lectin derived from the seeds of the castor plant, Ricinus communis L., a member of the Euphorbiaceae or spurge family. Other members of this family include the popular houseplants poinsettia E. pulcherrima), and the croton species. The term castor bean is used commonly to refer to both the plant and seed of R. communis. Ricinus communis commonly grows along streams and riverbeds in addition to subtropical locations high in nutrients. Ricinus communis is a coarse perennial, 10-13 m tall in the tropics, with a stem 7.5-15 cm... 

The involvement of desaturase-type enzymes in the biosynthesis of some important lipidic antifeedants now has been firmly established (Fig. Ic) (7). An instructive example of this phenomenon is the production of ricinoleate (a purgative) by a desaturase homolog found in the castor plant. Here, a subtle variation in mechanistic pathway is responsible for the introduction of a C-12 hydroxyl group rather than a 12,13-double bond (7). Another interesting case features the putative dehydrogenation of a cyclopropyl fatty acid to produce sterculate, a potent inhibitor of the mammalian but not the plant A desaturase (8). Finally, the biosynthesis of polyacetylenes with antifungal properties such as falcarindiol is thought to involve a sequence of unique desaturase-mediated oxidations (9). 

Ricin, derived from the beans of the castor plant (Ricinus communis) is one of the most potent and easily produced toxins known. Early recognition of these characteristics led the United States to develop ricin as a chemical weapon during World... 

War I (35). Although the entire castor plant is poisonous, the seeds contain the highest concentration of ricin (36). For hundreds of years, countries all over the world have cultivated the plant for its oil, specifically for use as a laxative and for lubrication. Castor oil has many industrial and commercial uses, having served as a lubricant for racing engines (Castrol-R racing motor oil) and as an additive in paints and varnishes. One of its derivatives, sebacic acid, is a component in the production of nylon and aUcyd resins, and contributes to the manufacture of plasticizers, lubricants, diffusion pump oils, cosmetics, and candles (35). India is currently the world leader in production, followed by China and Brazil (35). 

Protein toxin from castor plant (ricinus communis) beans... 

Ricin is a potent protein cytotoxin, easily extracted from the beans of the castor plant (Ricinus communis), which is ubiquitous. When ingested, ricin causes severe GI symptoms followed by vascular collapse and death. Ricin is made up of two hemagglutinins and two toxins. The toxins, RCL III and RCU TV, are dimers with molecular masses of approximately... 

Rlcinine, l,2-Dihydro-4-methoxy-l-methyl-2-oxo-3-pyridinecarbonitrile l,2-dihydro-4-methoxy-I -meth-yl-2-oxonicOtinonitrile ricidine. C,H,NjO,I mol wt 164.16. C 58.53%, H 4.91%, N 17.07%, O 19.49%. From seeds and leaves of the castor plant, Ricinus communis L Euphorbiaceae. Extraction procedure Bdttcher. Ber. 51, 673 (1918). Synthesis starting with polymerization of cyanoacetyl chloride Schroeter et al, Ber. 65, 432 (1932). Biosynthesis Waller, Henderson, J. Biol. Chem. 236, 1186 (1961) Essery et al. Can. J. Chem. 41, 1142 (1963). 

CASTOR OIL An age-old home remedy seldom recommended now, castor oil (purge, NEOLOID, others) is derived from the bean of the castor plant, Ricinus communis, which contains two well-known noxious ingredients an extremely toxic protein, ricin, and an oil composed chiefly of the triglyceride of ricinoleic acid. The triglyceride is hydrolyzed in the small bowel by the action of lipases into glycerol and the active agent, ricinoleic acid, which acts primarily in the small intestine to stimulate secretion of fluid and electrolytes and speed intestinal transit. When taken on an empty stomach, as little as 4 mL of castor oil may produce a laxative effect within 1-3 hours however, the usual dose for a cathartic effect is 15-60 mL for adults. 

Ricin is a naturally occurring phytotoxin occurring in the beans of the castor plant Ricinus communis. Its content in the castor... 

Toxins derived from plants are generally very easy to produce in large quantities at minimal cost in a low-technology environment. Ricin, a protein derived from the bean of the castor plant, and abrin, a very similar toxin from Abrus precatorius are typical plant toxins. 

Ricin toxin, found in the bean of the castor plant, Ricinis communis, is one of the most toxic and easily produced plant toxins. It is a lectin consisting of two polypeptide chains, the A-chain and the B-chain, linked by a disulfide bond. It is one of a group of dichain ribosome-inactivating proteins, which are specific for the depurination of a single adenosine in ribosomal ribonucleic acid (RNA).1 The active chain (ie, the A-chain) has the ability to modify catalytically the 28S subunit of... 

In the late 1800s, Stillmark4 discovered that the beans of the castor plant contained a toxic protein, which he named ricin. He discovered that ricin caused agglutination of erythrocytes and precipitation of serum proteins. (The lectin properties of ricin and abrin [a closely related toxin from the bean of Abrus precatorius] and their use as tools for research were described in 1972 by Sharon and Lis.5)... 

Ricin is a 66-kilodalton (kd) globular protein that makes up 1% to 5% by weight of the bean of the castor plant, Ricinis communis. The toxic heterodimer consists of a 32-kd A-chain that is disulfide-bonded to a 32-kd B-chain.21 The toxin is stored in the matrix of the castor bean, together with a 120,000-d ricinus lectin.22 Both chains are glycoproteins containing mannose carbohydrate groups the two 32-kd chains must be associated for toxicity. 

Ricin is a large, moderately toxic, protein dichain toxin from the bean of the castor plant, Ricinis communis. It can be produced easily in relatively large quantities. Ricin was developed as a biological weapon by the United States and its allies during World War II. Although ricin is toxic by several routes, when inhaled as a respirable aerosol, it causes severe necrosis of the airways and increased permeability of the alveolar-capillary membrane. The inhalational route... 

Ricin, a type II RIP found in the bean of the castor plant, has been extensively used for targeted tumor therapies replacing the lectin B chain, which binds to almost all mammalian cells, with peptides, antibodies, or proteins targeting cancer cells leads to selective target toxicity [105]. Several clinical trials by this approach have been conducted (see Section 7). 

The castor plant Ricinus communis) is a coarse herb of the spurge family Euphorbiaceae. When processed, the seed syn. castor bean yields half its weight in a triglyceride oil that is, uniquely, up to 85% ricinoleic acid. The oil is used as an ingredient or precursor in the manufacture of paints, varnishes, resins, synthetic fibres, lubricants, polishes, cosmetics, and many other materials. 

Ricinoleic acid (Fig. 1) is the major component of castor oil, derived from the seed of Ricinus communis L., the castor plant. The oil is 90% ricinoleate and the presence of the hydroxy group imparts unique chemical and physical properties (1,2). Products derived from castor oil are listed in Table 1. In addition to these applications, there are many others that are promising but have not been implemented due to the limited supply of castor oil produced annually (1). 

Castor oil is obtained from the seed of the castor plant, Ricinus communis. The seeds of castor plants are the size of kidney beans and have beautiful and intricate designs (Figure 9.1.31). Harvesting castor beans is not without risk. Allergenic compounds found on the plant surface can cause permanent nerve damage. Castor beans also contain two toxins that are poisonous to people, animals and insects. One is ridn, a water-soluble protein. Ridn is a potent cytotoxin. The other toxic protein in the castor bean, RCA (Ricinus communis... 

The castor plant is also known as Palma Christi for its palm-shaped leaves and the magic healing power castor oil has been credited with in folk medicine. 

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