(a) A ruby-throated hummingbird obtains nectar from a trumpet vine flower. The pollen grains on the birds feathers will be carried to the next plant. (b) A lesser long-nosed bat obtains nectar from a cardon Figure 5-0 cactus flower and transfers pollen as it moves from flower to flower. Bats pollinate several hundred species of plants. (a, Dan Dempster/Dembinsky Photo Associates b, Merlin Tuttle/Bat Conservation International/Photo Researchers, Inc
Figure 5-0
多糖 戊糖 核苷酸 核酸 (淀粉、纤维素) 半纤维素 葡萄糖 戊糖磷酸循环!丁糖 脂肛 单糖 丙糖磷酸 脂肪酸 糖 磷酸甘油酸 酵 砷酸烯醇 酚类化合物(酪氨酸、 卡尔文循 式丙酮酸 苯丙氨 酸、色磷酸、木 质素、莽草酸、香豆素 丝氨酸族 氨基酸 COz 丙酮酸族氨基酸二二丙酮酸—酒精、乳酸 类萜化合物 赤毒「类胡萝卜素 素、橡胶、挥发油 乙酰辅酶A 丙二酰辅酶A 花色亲、脱落酸) Fig 5-1 烟碱 其他氨基酸 天冬氨酸族氨基酸一草酰乙酸 酮戊二酸一谷氨酸族氨基酸二自 三羧酸祈环 嚎呤核苷酸 (叶绿素、光敏色素、 细胞色素 琥珀酰辅酶A
Fig.5-1
cO Photosynthesis PRIMARY CARBON METABOLISM Erythrose-4-phosphate 3-Phosphoglycerate Phosphoenolpyruvate Pyruvate (3-PGA) Tricarboxylic acid cycle Acetyl COA Aliphatic amino acids Shikimic acid Malonic Mevalonic pathway acid pathway Lacid pathway MEP pathway Aromatic amino acids Nitrogen-containing secondary products Phenolic compounds Terpenes SECONDARY CARBON METABOLISM FIGURE 13. 4 A simplified view of the major pathways of secondary-metabolite Figure 5-2 biosynthesis and their interrelationships with primary metabolism
Figure 5-2
3x Acetyl- CoA(C2) Pyruvate (c3) Glyceraldehyde C3) Mevalonate CHa-C-CH2-CH2-OH Methylerythritol CH phosphate Mevalonic acid Methylerythritol phosphate (MEP) cH2-o-① 人c2-更→ soprano(C) Isopentenyl diphosphate (IPP Co (DMAPP Cs cH2-0- Monoterpenes (Cto) Goranyl diphosphate (GPP CIo) Triterpenes(cap) Farnesyl diphosphate (FPP Cu) cH2-- Diter penes(Czo) Tetraterpenes (Cao) Geranylgeranyl diphosphate (GGPP, Czo FIGURE 13.5 Outline of terpene biosynthesis, The basie 5-carbon units of terpenes are synthesized by two different pathways, The phosphorylated intermediates, IPl and DMAPP are combined to make 10-carbon, 15-carbon and larger terpenes. Figure 5-5
Figure 5-5
FIGURE 13. 9 Plant phenolics are Erythrose- 4 Phosphoenolpyruvic biosynthesized in several differ- phosphate acid(from glycolysis) ent ways In higher plants, most(from pentose phenolics are derived at least in phosphate pathway) part from phenylalanine, a prod Shikimic acid Acetyl-CoA pathway Formulas in brackets indicate the basic arrangement of carbon skeletons: Phenylalanine (C-g Malonic acid pathway Cinnamic acid Gl‖i aci indicates a benzene ring, and C is a three-carbon chain More detail on the pathway Hydrolyzable Miscellaneous from phenylalanine onward is tannins phenolics Simple phenolics Flavonoids given in Figure 13. 10 n Figure 5-6 Condensed tannin
Figure 5-6
COOH COoH -NHY Fig 5-10 Biosynthesis of lignin OoH COOH COOH CSH COMT COMH SOCIA oCHa H2cO OCH 4狂配 阿酸 5-羟抓阿魏酸 并千酸 ACL tCL 4CL 4CL CO-SCoA CO- SCoA CO- SCOA CD-SCoA CCoA-3H CCOAOMT CCOAOMT CCoAOMT 香豆酰CoA 咖啡-CoA 阿妺酰一CA 5一黔基阿魏酰一COA 并子酰-CaA CCK R CcK CHO CHO 香豆叠 松柏 一羟基回魏覆 并子再 CAD CAI CAD CH,OH CH,OH CHOH CH,OH CH oCHa OCH 1 香豆醇 松柏 5—羟基阿魏醇
Fig.5-10 Biosynthesis of lignin
From shikimic acid pathway via phenylalanine B From malonic 4 acid pathway A‖C OH Anthocyanidin The three-carbon bridge Basic flavonoid skeleton OH FIGURE 13 12 Basic flavonoid carbon skeleton. Flavonoids are biosynthesized from products of the shikimic acid and malonic acid pathways. Positions on the flavonoid ring sys C tem are numbered as shown 0- Sugar Figure 5-11 5-12 Anthocyanin There Are Four Major Groups of Flavonoids FIGURE 13 13 The structures of anthocyanidins(A)and The flavonoids are one of the largest classes of plant phe. anthocyanin(B). The colors of anthocyanidins depend in nolics. The basic carbon skeleton of a flavonoid contains 15 part on the substituents attached to ring B(see Table 13. 1) An increase in the number of hydroxyl groups shifts carbons arranged in two aromatic rings connected by a absorption to a longer wavelength and gives a bluer color. three-carbon bridge eplacement of a hydroxyl group with a methoxyl group (OCH,) shifts absorption to a slightly shorter wavelength, c6 resulting in a redder color
Figure 5-11 5-12
FIGURE 13.14 Black-eyed Susan(Rudbeckia sp )as seen by distribution of flavonols in the rays and the sensitivity of humans(A)and as it might appear to honeybees(B).(A) insects to part of the UV spectrum contribute to the To humans, the golden-eye has yellow rays and a brown "bull s-eye"pattern seen by honeybees, which presumably central disc. (B) To bees, the tips of the rays appear"light helps them locate pollen and nectar. Special lighting was ellow, "the inner portion of the rays"dark yellow, and used to simulate the spectral sensitivity of the honeybee the central disc"black "Ultraviolet-absorbing flavonols are visual system. Courtesy of Thomas Eisner. found in the inner parts of the rays but not in the tips. The Figure 5-12-1
Figure 5-12-1
TABLE 13.2 Major types of alkaloids, their amino acid precursors, and well-known examples of each type Biosynthetic Alkaloid class Structure precursor Examples Human uses Pyrrolidine Ornithine (aspartate) Nicotine Stimulant, depressant, tranquilizer Tropane Ornithine Atropine Prevention of intestinal spasms, antidote to other poisons, dilation of pupils for examination cocaine Stimulant of the central nervous system, local anesthetic Pip perrine Lysine (or acetate) Coniine Poison (paralyzes motor neurons Pyrrolizidine Ornithine Retrorsine None Table 5-4 Quinolizidine Lupinine Restoration of heart rhythm Isoquinoline Tyrosine Codeine Analgesic (pain relief), treatment of coughs Morphi nalgesIc Indole Tryptophan Psilocybin Hallucinogen Reserpine Treatment of hypertension, treatment of psychoses Strychnine Rat poison, treatment of eye disorders
Table 5-4
NH2 CH COOH Figure 5-13 NH Ornithine COOH (P-OH,S CH3 HO H N-Methyl pyrrolinium Nicotinic acid mononucleotide (NADP+) COOH Nicotinic acid CHa Nicotine FIGURE 13.18 Nicotine biosynthesis begins with the biosyn thesis of the nicotinic acid (niacin) from aspartate and glyc- eraldehyde-3-phosphate. Nicotinic acid is also a component of NAD+ and NADP+, important participants in biological oxidation-reduction reactions. The five-membered ring of nicotine is derived from ornithine, an intermediate in argi nine biosvnthesis
Figure 5-13