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Marihuana
Obrazovanje
Marijuana Botany by Robert Connel Clark
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<blockquote data-quote="cannebosanac" data-source="post: 20051" data-attributes="member: 1357"><p>poglavlje 4 nastavak</p><p></p><p>The first step in the pentyl cannabinoid biosynthetic </p><p>pathway is the combination of olivetolic acid with geranyl </p><p>pyrophosphate. Both of these molecules are derived from </p><p>terpenes, and it is readily apparent that the biosynthetic </p><p>route of the aromatic terpenoids may be a clue to forma- </p><p>tion of the cannabinoids. The union of these two molecules </p><p>forms CBG acid (cannabigerolic acid) which is the basic </p><p>cannabinoid precursor molecule. CBG acid may be con- </p><p>verted to CBGM (CBG acid monomethyl ether), or a </p><p>hydroxyl group (OH) attaches to the geraniol portion of the </p><p>molecule forming hydroxy-CBG acid. Through the forma- </p><p>tion of a transition-state molecule, either CBC acid (canna- </p><p>bichromenic acid) or CBD acid (cannabidiolic acid) is </p><p>formed. CBD acid is the precursor to the THC acids, and, </p><p>although CBD is only mildly psychoactive by itself, it may </p><p>act with THC to modify the psychoactive effect of the </p><p>THC in a sedative way. CBC is also mildly psychoactive </p><p>and may interact synergistically with THC to alter the </p><p>psychoactive effect (Turner et al. 1975). Indeed, CBD may </p><p>suppress the effect of THC and CBC may potentiate the </p><p>effect of THC, although this has not yet been proven. All </p><p>of the reactions along the cannabinoid biosynthetic path- </p><p>way are enzyme-controlled but are affected by environ- </p><p>mental conditions. Conversion of CBD acid to THC acid is the single </p><p>most important reaction with respect to psychoactivity in </p><p>the entire pathway and the one about which we know the </p><p>most. Personal communication with Raphael Mechoulam </p><p>has centered around the role of ultraviolet light in the bio- </p><p>synthesis of THC acids and minor cannabinoids. In the </p><p>laboratory, Mechoulam has converted CBD acid to THC </p><p>acids by exposing a solution of CBD acid in n-hexane to </p><p>ultraviolet light of 235-285 nm. for up to 48 hours. This </p><p>reaction uses atmospheric oxygen molecules (02) and is </p><p>irreversible; however, the yield of the conversion is only </p><p>about 15% THC acid, and some of the products formed in </p><p>the laboratory experiment do not occur in living specimens. </p><p>Four types of isomers or slight variations of THC acids </p><p>(THCA) exist. Both Delta1-THCA and Delta6-THCA are naturally </p><p>occurring isomers of THCA resulting from the positions of </p><p>the double bond on carbon 1 or carbon 6 of the geraniol </p><p>portion of the molecule They have approximately the </p><p>same psychoactive effect; however, Delta1-THC acid is about </p><p>four times more prevalent than Delta6-THC acid in most </p><p>strains. Also Alpha and Beta forms of Delta1-THC acid and Delta6-THC </p><p>acid exist as a result of the juxtaposition of the hydrogen </p><p>(H) and the carboxyl (COOH) groups on the olivetolic acid </p><p>portion of the molecule It is suspected that the psycho- </p><p>activity of the a and ~ forms of the THC acid molecules </p><p>probably does not vary, but this has not been proven. </p><p>Subtle differences in psychoactivity not detected in animals </p><p>by laboratory instruments, but often discussed by mari- </p><p>juana aficionados, could be attributed to additional syner- </p><p>gistic effects of the four isomers of THC acid. Total psycho- </p><p>activity is attributed to the ratios of the primary canna- </p><p>binoids of CBC, CBD, THC and CBN; the ratios of methyl, </p><p>propyl, and pentyl homologs of these cannabinoids; and </p><p>the isomeric variations of each of these cannabinoids. </p><p>Myriad subtle combinations are sure to exist. Also, ter- </p><p>penoid and other aromatic compounds might suppress or </p><p>potentiate the effects of THCs. </p><p>Environmental conditions influence cannabinoid bio- </p><p>synthesis by modifying enzymatic systems and the resul- </p><p>tant potency of Cannabis. High altitude environments are </p><p>often more arid and exposed to more intense sunlight than </p><p>lower environments. Recent studies by Mobarak et al. </p><p>(1978) of Cannabis grown in Afghanistan at 1,300 meters </p><p>(4,350 feet) elevation show that significantly more propyl </p><p>cannabinoids are formed than the respective pentyl homo- </p><p>logs. Other strains from this area of Asia have also exhibited </p><p>the presence of propyl cannabinoids, but it cannot be dis- </p><p>counted that altitude might influence which path of canna- </p><p>binoid biosynthesis is favored. Aridity favors resin produc- </p><p>tion and total cannabinoid production; however, it is un- </p><p>known whether arid conditions promote THC production </p><p>specifically. It is suspected that increased ultraviolet radi- </p><p>ation might affect cannabinoid production directly. Ultra- </p><p>violet light participates in the biosynthesis of THC acids </p><p>from CBD acids, the conversion of CBC acids to CCY acids, </p><p>and the conversion of CBD acids to CBS acids. However, it </p><p>is unknown whether increased ultraviolet light might shift </p><p>cannabinoid synthesis from pentyl to propyl pathways or </p><p>influence the production of THC acid or CBC acid instead </p><p>of CBD acid. </p><p>The ratio of THC to CBD has been used in chemotype </p><p>determination by Small and others. The genetically deter- </p><p>mined inability of certain strains to convert CBD acid to </p><p>THC acid makes them a member of a fiber chemotype, but </p><p>if a strain has the genetically determined ability to convert </p><p>CBD acid to THC acid then it is considered a drug strain. </p><p>It is also interesting to note that Turner and Hadley (1973) </p><p>discovered an African strain with a very high THC level and </p><p>no CBD although there are fair amounts of CBC acid </p><p>present in the strain. Turner* states that he has seen several </p><p>strains totally devoid of CBD, but he has never seen a </p><p>strain totally devoid of THC. Also, many early authors </p><p>confused CBC with CBD in analyzed samples because of </p><p>the proximity of their peaks on gas liquid chromatograph </p><p>(GLC) results. If the biosynthetic pathway needs alteration </p><p>to include an enzymatically controlled system involving </p><p>the direct conversion of hydroxy-CBG acid to THC acid </p><p>through allylic rearrangement of hydroxy-CBG acid and </p><p>cyclization of the rearranged intermediate to THC acid, as </p><p>Turner and Hadley (1973) suggest, then CBD acid would </p><p>be bypassed in the cycle and its absence explained. Another </p><p>possibility is that, since CBC acid is formed from the same </p><p>symmetric intermediate that is allylically rearranged before </p><p>forming CBD acid, CBC acid may be the accumulated inter- </p><p>mediate, the reaction may be reversed, and through the </p><p>symmetric intermediate and the usual allylic rearrangement </p><p>CBD acid would be formed but directly converted to THC </p><p>acid by a similar enzyme system to that which reversed the </p><p>formation of CBC acid. If this happened fast enough no </p><p>CBD acid would be detected. It is more likely, however, </p><p>that CBDA in drug strains is converted directly to THCA as </p><p>soon as it is formed and no CBD builds up. Also Turner, </p><p>Hemphill, and Mahlberg (1978) found that CBC acid was </p><p>contained in the tissues of Cannabis but not in the resin </p><p>secreted by the glandular trichomes. In any event, these </p><p>possible deviations from the accepted biosynthetic path- </p><p>way provide food for thought when trying to decipher the </p><p>mysteries of Cannabis strains and varieties of psychoactive </p><p>effect. </p><p>Returning to the more orthodox version of the canna- </p><p>binoid biosynthesis, the role of ultraviolet light should be </p><p>reemphasized. It seems apparent that ultraviolet light, nor- </p><p>mally supplied in abundance by sunlight, takes part in the </p><p>conversion of CBD acid to THC acids. Therefore, the lack </p><p>*Carlton Thrner 1979: personal communication. </p><p>of ultraviolet light in indoor growing situations could </p><p>account for the limited psychoactivity of Cannabis grown </p><p>under artificial lights. Light energy has been collected and </p><p>utilized by the plant in a long series of reactions resulting </p><p>in the formation of THC acids. Farther along the pathway </p><p>begins the formation of degradation products not metabol- </p><p>ically produced by the living plant. These cannabinoid </p><p>acids are formed through the progressive degradation of </p><p>THC acids to CBN acid (cannabinolic acid) and other can- </p><p>nabinoid acids. The degradation is accomplished primarily </p><p>by heat and light and is not enzymatically controlled by </p><p>the plant. CBN is also suspected of synergistic modification </p><p>of the psychoactivity of the primary cannabinoids, THCs. </p><p>The cannabinoid balance between CBC, CBD, THC, and </p><p>CBN is determined by genetics and maturation. THC pro- </p><p>duction is an ongoing process as long as the glandular tri- </p><p>chome remains active. Variations in the level of THC in the </p><p>same trichome as it matures are the result of THC acid </p><p>being broken down to CBN acid while CBD acid is being </p><p>converted to THC acid. If the rate of THC biosynthesis </p><p>exceeds the rate of THC breakdown, the THC level in the </p><p>trichome rises; if the breakdown rate is faster than the rate </p><p>of biosynthesis, the THC level drops. Clear or slightly am- </p><p>ber transparent resin is a sign that the glandular trichome </p><p>is still active. As soon as resin secretion begins to slow, the </p><p>resins will usually polymerize and harden. During the late </p><p>floral stages the resin tends to darken to a transparent </p><p>amber color. If it begins to deteriorate, it first turns trans- </p><p>lucent and then opaque brown or white. Near-freezing </p><p>temperatures during maturation will often result in opaque </p><p>white resins. During active secretion, THC acids are con- </p><p>stantly being formed from CBD acid and breaking down </p><p>into CBN acid.</p></blockquote><p></p>
[QUOTE="cannebosanac, post: 20051, member: 1357"] poglavlje 4 nastavak The first step in the pentyl cannabinoid biosynthetic pathway is the combination of olivetolic acid with geranyl pyrophosphate. Both of these molecules are derived from terpenes, and it is readily apparent that the biosynthetic route of the aromatic terpenoids may be a clue to forma- tion of the cannabinoids. The union of these two molecules forms CBG acid (cannabigerolic acid) which is the basic cannabinoid precursor molecule. CBG acid may be con- verted to CBGM (CBG acid monomethyl ether), or a hydroxyl group (OH) attaches to the geraniol portion of the molecule forming hydroxy-CBG acid. Through the forma- tion of a transition-state molecule, either CBC acid (canna- bichromenic acid) or CBD acid (cannabidiolic acid) is formed. CBD acid is the precursor to the THC acids, and, although CBD is only mildly psychoactive by itself, it may act with THC to modify the psychoactive effect of the THC in a sedative way. CBC is also mildly psychoactive and may interact synergistically with THC to alter the psychoactive effect (Turner et al. 1975). Indeed, CBD may suppress the effect of THC and CBC may potentiate the effect of THC, although this has not yet been proven. All of the reactions along the cannabinoid biosynthetic path- way are enzyme-controlled but are affected by environ- mental conditions. Conversion of CBD acid to THC acid is the single most important reaction with respect to psychoactivity in the entire pathway and the one about which we know the most. Personal communication with Raphael Mechoulam has centered around the role of ultraviolet light in the bio- synthesis of THC acids and minor cannabinoids. In the laboratory, Mechoulam has converted CBD acid to THC acids by exposing a solution of CBD acid in n-hexane to ultraviolet light of 235-285 nm. for up to 48 hours. This reaction uses atmospheric oxygen molecules (02) and is irreversible; however, the yield of the conversion is only about 15% THC acid, and some of the products formed in the laboratory experiment do not occur in living specimens. Four types of isomers or slight variations of THC acids (THCA) exist. Both Delta1-THCA and Delta6-THCA are naturally occurring isomers of THCA resulting from the positions of the double bond on carbon 1 or carbon 6 of the geraniol portion of the molecule They have approximately the same psychoactive effect; however, Delta1-THC acid is about four times more prevalent than Delta6-THC acid in most strains. Also Alpha and Beta forms of Delta1-THC acid and Delta6-THC acid exist as a result of the juxtaposition of the hydrogen (H) and the carboxyl (COOH) groups on the olivetolic acid portion of the molecule It is suspected that the psycho- activity of the a and ~ forms of the THC acid molecules probably does not vary, but this has not been proven. Subtle differences in psychoactivity not detected in animals by laboratory instruments, but often discussed by mari- juana aficionados, could be attributed to additional syner- gistic effects of the four isomers of THC acid. Total psycho- activity is attributed to the ratios of the primary canna- binoids of CBC, CBD, THC and CBN; the ratios of methyl, propyl, and pentyl homologs of these cannabinoids; and the isomeric variations of each of these cannabinoids. Myriad subtle combinations are sure to exist. Also, ter- penoid and other aromatic compounds might suppress or potentiate the effects of THCs. Environmental conditions influence cannabinoid bio- synthesis by modifying enzymatic systems and the resul- tant potency of Cannabis. High altitude environments are often more arid and exposed to more intense sunlight than lower environments. Recent studies by Mobarak et al. (1978) of Cannabis grown in Afghanistan at 1,300 meters (4,350 feet) elevation show that significantly more propyl cannabinoids are formed than the respective pentyl homo- logs. Other strains from this area of Asia have also exhibited the presence of propyl cannabinoids, but it cannot be dis- counted that altitude might influence which path of canna- binoid biosynthesis is favored. Aridity favors resin produc- tion and total cannabinoid production; however, it is un- known whether arid conditions promote THC production specifically. It is suspected that increased ultraviolet radi- ation might affect cannabinoid production directly. Ultra- violet light participates in the biosynthesis of THC acids from CBD acids, the conversion of CBC acids to CCY acids, and the conversion of CBD acids to CBS acids. However, it is unknown whether increased ultraviolet light might shift cannabinoid synthesis from pentyl to propyl pathways or influence the production of THC acid or CBC acid instead of CBD acid. The ratio of THC to CBD has been used in chemotype determination by Small and others. The genetically deter- mined inability of certain strains to convert CBD acid to THC acid makes them a member of a fiber chemotype, but if a strain has the genetically determined ability to convert CBD acid to THC acid then it is considered a drug strain. It is also interesting to note that Turner and Hadley (1973) discovered an African strain with a very high THC level and no CBD although there are fair amounts of CBC acid present in the strain. Turner* states that he has seen several strains totally devoid of CBD, but he has never seen a strain totally devoid of THC. Also, many early authors confused CBC with CBD in analyzed samples because of the proximity of their peaks on gas liquid chromatograph (GLC) results. If the biosynthetic pathway needs alteration to include an enzymatically controlled system involving the direct conversion of hydroxy-CBG acid to THC acid through allylic rearrangement of hydroxy-CBG acid and cyclization of the rearranged intermediate to THC acid, as Turner and Hadley (1973) suggest, then CBD acid would be bypassed in the cycle and its absence explained. Another possibility is that, since CBC acid is formed from the same symmetric intermediate that is allylically rearranged before forming CBD acid, CBC acid may be the accumulated inter- mediate, the reaction may be reversed, and through the symmetric intermediate and the usual allylic rearrangement CBD acid would be formed but directly converted to THC acid by a similar enzyme system to that which reversed the formation of CBC acid. If this happened fast enough no CBD acid would be detected. It is more likely, however, that CBDA in drug strains is converted directly to THCA as soon as it is formed and no CBD builds up. Also Turner, Hemphill, and Mahlberg (1978) found that CBC acid was contained in the tissues of Cannabis but not in the resin secreted by the glandular trichomes. In any event, these possible deviations from the accepted biosynthetic path- way provide food for thought when trying to decipher the mysteries of Cannabis strains and varieties of psychoactive effect. Returning to the more orthodox version of the canna- binoid biosynthesis, the role of ultraviolet light should be reemphasized. It seems apparent that ultraviolet light, nor- mally supplied in abundance by sunlight, takes part in the conversion of CBD acid to THC acids. Therefore, the lack *Carlton Thrner 1979: personal communication. of ultraviolet light in indoor growing situations could account for the limited psychoactivity of Cannabis grown under artificial lights. Light energy has been collected and utilized by the plant in a long series of reactions resulting in the formation of THC acids. Farther along the pathway begins the formation of degradation products not metabol- ically produced by the living plant. These cannabinoid acids are formed through the progressive degradation of THC acids to CBN acid (cannabinolic acid) and other can- nabinoid acids. The degradation is accomplished primarily by heat and light and is not enzymatically controlled by the plant. CBN is also suspected of synergistic modification of the psychoactivity of the primary cannabinoids, THCs. The cannabinoid balance between CBC, CBD, THC, and CBN is determined by genetics and maturation. THC pro- duction is an ongoing process as long as the glandular tri- chome remains active. Variations in the level of THC in the same trichome as it matures are the result of THC acid being broken down to CBN acid while CBD acid is being converted to THC acid. If the rate of THC biosynthesis exceeds the rate of THC breakdown, the THC level in the trichome rises; if the breakdown rate is faster than the rate of biosynthesis, the THC level drops. Clear or slightly am- ber transparent resin is a sign that the glandular trichome is still active. As soon as resin secretion begins to slow, the resins will usually polymerize and harden. During the late floral stages the resin tends to darken to a transparent amber color. If it begins to deteriorate, it first turns trans- lucent and then opaque brown or white. Near-freezing temperatures during maturation will often result in opaque white resins. During active secretion, THC acids are con- stantly being formed from CBD acid and breaking down into CBN acid. [/QUOTE]
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