(b)(a)Aruby-throatedhummingbirdobtainsnectar froma trumpet vineflower.The pollen grains on the bird's feathers will becarried tothe nextplant.(b)A lesserlong-nosed batobtains nectar froma cardonFigure 5-0cactus flowerand transfers pollen as it moves from flowertoflower.Bats pollinateseveral hundred species of plants.(a,Dan Dempster/DembinskyPhotoAssociates;b,MerlinTuttle/BatConservationInternational/PhotoResearchers,Inc.)
Figure 5-0
多糖戊糖核酸核苷酸半纤维家（淀粉、纤维素）A1戊糖磷酸循环丁糖葡萄糖脂肪1单糖丙糖磷酸甘油脂肪酸+糖JT磷酸甘油酸磷酸烯醇酚类化合物（酪氨酸酵卡尔文循环苯丙氨酸、色磷酸、木式丙酮酸质素、荠草酸、香豆素丝氨酸族等）鲜氨基酸CO2丙酮酸酒精乳酸丙酮酸族氨基酸类酷化合物（类胡萝卜素丙二酰辅酶A乙酰辅酶A赤霉素、橡胶、择发油、花色素、脱落酸）Fig.5-1烟碱其他氨基酸+↑蛋白质二谷氨酸族氨基酸，酮皮草酰乙酸天冬氨酸族氨基酸三酸循环JI叶味嘌呤核苷酸（叶绿家、光敏色素细胞色素）晓珀酰辅酶A
Fig.5-1
CO2PhotosynthesisPRIMARYCARBONMETABOLISMErythrose-4-phosphate3-Phosphoglycerate(3-PGA)PhosphoenolpyruvatePyruvateTricarboxylicAcetyl CoAacid cycleAliphaticamino acidsShikimicacidMalonicMevalonicMEPpathwaypathwayacidpathwayacidpathwayAromaticaminoacidsNitrogen-containingsecondaryproductsPhenolicTerpenescompoundsSECONDARYCARBONMETABOLISMFigure 5-2FIGURE13.4A simplifiedviewof themajorpathwaysofsecondary-metabolitebiosynthesis and their interrelationships withprimarymetabolism
Figure 5-2
XOCOACH:CHOHOH3xAcetyt-CoA (C2)CH,OPPyruvate (Cg)Glyceraldehyde3-phosphate (Cs)HOOHH:CH,CHOHCH>MevalonateMethylerythritolphosphatepathwayCH2pathwayatCOOHMethylerythritolMevalonicacidphosphate(MEP)PPCH2-0PPCH2+isoprene(Cs)Isopentenyldiphosphate(iPp,Cs)Dimethyallyldiphosphate(DMAPPC)PPCH2c+Monoterpenes (Cto)Geranyldiphosphate(GPp, Cro)-+Sesquiterpenes(Cis)PPH3-2XTriterpenes (Cao)Farnesyldiphosphate(FppCrs)Diterpenes (Czo)PPH2Tetraterpenes(Cao)Geranylgeranyldiphosphate (GGPP,Cao)→PolyterpenoidsFIGURE13.5Outlineofterpenebiosynthesis.Thebasice5-carbonunitsofterpenesaresynthesizedbytwo differentpathways,Thephosphorylated intermediates,IppFigure 5-5andDMAPParecombinedtomake1O-carbon,15-carbonandlargerterpenes
Figure 5-5
PhosphoenolpyruvicErythrose-4FIGURE13.9Plant phenolics areacid (fromglycolysis)phosphatebiosynthesized in several differ-(frompentoseent ways.In higherplants,mostphosphate pathway)phenolics arederived at least inShikimic acidAcetyl-CoApart fromphenylalanine,aprodpathwayuct of theshikimic acid pathway.Formulas in brackets indicate theMalonicacidbasic arrangement ofcarbon Pheylanine [-c]pathwayskeletons:Cinamic aid [-c]CGallicacidindicatesabenzeneringandC3 is a three-carbon chain.Miscellaneous[G-][G-][G-c]HydrolyzableMore detail on the pathwayphenolicstanninsfrom phenylalanineonward isFlavonoidsSimple phenolicsgiven in Figure 13.10.[-][G-c],Condensed tanninsFigure 5-6Lignin
Figure 5-6
COOHCOOHCOOH-NH,CHHH--CNH,HCH,CH,PAI.羊内纸酸截皮酸酪氨酸OHFig.5-10 Biosynthesis of ligninC4HTALCOOHCOOHCOOHCOOHCOOHCHCHCHHenHLIC11HOCOMHF5HCOMTC3HOCH,H.COHOOCH,OHOC1OH01OHolfOH芥子酸阿纯酸5-经基阿魂酸咖啡酸4-香豆酸14CLtcL14CL4CL14CLCO-SCOACO-SCOACO-SCOACO-SCoACO-SCOAt......CCOAOMTCCOA·3HCCOAOMTCCOAOMT2齐子酰COA阿续酰一CoA4一香豆酰一COA咖啡酰一CoA5一经基阿续酰一COAICCRocRfCCRICCRCHOCHOCHOCHOEMt中养子酸4一香豆醛松柏醛S轻基阿瑰能ICADCADCADICADCH,OHCH,OHCH,OHCH,OHCHCHCHCHHu1HeHCHHCHOOCH,OCH,H,COOCH,OHOnOHOH4一香豆醇松柏醇养子醇5经基阿统醇床质
Fig.5-10 Biosynthesis of lignin
Fromshikimicacid(A)pathwayvia phenylalanine[G-c]HOFrommalonicacidpathwayOH[G]OHAnthocyanidin(B)The three-carbon bridgeBasicflavonoid skeletonOHFIGURE13.12 Basicflavonoid carbon skeleton.FlavonoidsHOarebiosynthesized fromproducts oftheshikimicacid andmalonicacid pathways.Positions on theflavonoid ring system arenumbered as shown.Sugar9OHAnthocyaninFigure 5-11 5-12ThereAreFourMajorGroupsof FlavonoidsFIGURE13.13The structuresofanthocyanidins (A)andThe flavonoids are one ofthe largest classes of plantpheanthocyanin (B).Thecolorsofanthocyanidins depend innolics.Thebasiccarbon skeletonofaflavonoid contains15part on the substituents attached to ring B (see Table 13.1)An increase in thenumberof hydroxyl groups shiftscarbons arranged in two aromatic rings connected by aabsorptiontoalongerwavelengthandgivesabluer color.three-carbon bridge:Replacement ofa hydroxyl groupwitha methoxylgroup(OCH,)shiftsabsorption toa slightlyshorterwavelengthresulting in a redder color
Figure 5-11 5-12
(B)(A)木distribution offlavonols in theravs and the sensitivity ofFIGURE13.14 Black-eyedSusan (Rudbeckia sp.)as seenbyinsects topartoftheUV spectrum contributetothehumans (A)and asitmightappeartohoneybees (B).(A)"bull's-eye"pattern seen by honeybees,which presumablyTo humans,the golden-eyehas yellow rays and a brownhelps themlocatepollen and nectar.Special lighting wascentral disc.(B)Tobees,the tips of therays appear"lightused to simulate the spectral sensitivity ofthe honeybeeyellow"the innerportion of therays"dark yellow,"andvisual system.(CourtesyofThomas Eisner.)the central disc"black."Ultraviolet-absorbing flavonols arefound in theinner parts of therays but not in thetips.TheFigure 5-12-1
Figure 5-12-1
TABLE13.2Majortypes ofalkaloids,theiramino acid precursors,and well-knownexamples ofeachtypeBiosyntheticAlkaloidclassStructureExamplesHuman usesprecursorPyrrolidineOrnithine(aspartate)NicotineStimulant,depressant,tranquilizerTropaneOrnithineAtropinePreventionofintestinal spasms,antidotetootherpoisons,dilationofpupilsforexaminationCocaineStimulantofthecentralnervoussystem,localanestheticPiperidineLysine(oracetate)ConinePoison(paralyzesmotorneurons)PyrrolizidineOrnithineRetrorsineNoneTable 5-4QuinolizidineLysineLupinineRestorationofheartrhythmIsoquinolineTyrosineCodeineAnalgesic(painrelief),treatmentofcoughsMorphineAnalgesicIndolePsilocybinTryptophanHalucinogenReserpineTreatmentofhypertension,treatmentofpsychosesStrychnineRatpoison,treatmentofeyedisorders
Table 5-4
NH2COOHNH2Figure 5-13OrnithineCOOHN-MethylpyrroliniumHOOHNicotinicacidmononucleotide (NADpt)OOHNicotimic.acidCHNicotineNicotine biosynthesis begins with the biosyn-FIGURE13.18thesis of the nicotinic acid (niacin) from aspartate and glyc-eraldehyde-3-phosphate.Nicotinic acid is also acomponentofNAD+andNADp+,importantparticipantsinbiologicaloxidation-reduction reactions.The five-membered ring ofnicotine is derived from ornithine,an intermediate in argi-nine biosynthesis
Figure 5-13