ORGANIC CHEMISTRY. Chapter Steroids. Department of Chemistry, Xiamen University

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1 23.4 Steroids

2 23.4A Structures and Systematic Nomenclature of Steroids Steroids are derivatives of the following perhydrocyclopentanophenanthrene ring system. The four rings are designated A, B, C, and D, beginning at the lower left, and the carbon atoms are numbered beginning in the A ring. Angular methyl groups C A B 6 12 C 3 C R D A steroid 17 16

3 In most steroids the B,C and C,D ring junctions are trans. The A,B ring junction, however, may be either cis or trans. 2 1 A B A B C 12 C D D R R α Series of steroids (all ring junctions are trans) β Series of steroids (A,B ring junction is cis)

4 α and β Substituents Groups that lie on the same general side of the molecule as the angular methyl groups(i.e., on the top side) are designated β substituents. Groups that lie generally on the bottom (i.e., are trans to the angular methyl groups) are designated α substituents. When a and b designations are applied to the hydrogen atom at position 5, the ring system in which the A,B ring junction is trans becomes the 5α series; the ring system in which the A,B ring junction is cis becomes the 5β series.

5 23.4B Cholesterol Cholesterol, one of the most widely occurring steroids, can be isolated by extraction of nearly all animal tissues. uman gallstones are s particularly rich source. Cholesterol 5-Cholesten-3β-ol 5- -3β-

6 23.4C Sex ormones The sex hormones can be classified into three groups: The female sex hormones, or estrogens. The male sex hormones, or androgens. The pregnancy hormones, or progestins.

7 Female Sex ormones Estradiol Estrone 1,3,5(10)-Estratriene-3,17β-diol 3-ydroxy-1,3,5(10)-estratrien-17-one The first sex hormone to be isolated 4 tones of sow ovaries 12 mg estradiol

8 Male Sex ormones C 3 C 3 Testosterone 17β-ydroxy-4-androstan-3-one Androsterone 3α-ydroxy-5α-androstan-17-one

9 Pregnancy ormone C Progesterone 4-Pregnene-3,20-dione

10 Synthetic Sex ormones C 3 C C C C Norethindrone Ethynylestradiol

11 Synthetic Sex ormones C C C 2 C C 18-

12 23.4D Adrenocortical ormones ( ) Aldrenocortical hormones are secreted by the adrenal glands, small organs located near the upper end of each kidney. There are two types of adrenocortical hormones, called mineralocorticoids and glucocorticoids Mineralocorticoids such as aldosterone control tissue swelling by regulating cellular salt balance between Na + and K +. Glucocorticoids such as hydrocortisone are involved in the regulation of glucose metabolism and in the control of inflammation.

13 Mineralocorticoids C 2 C C C 2 C Aldosterone

14 Glucocorticoids C 2 C 2 C C 3 C C 3 Cortisone Cortisol

15 23.4E D Vitamines Ergosterol was isolated from yeast in 1930, which converted to vitamine D 2 under the irradiation of UV light at room temperature. hv room temperature Ergosterol Vitamine D 2

16 23.4F ther Steroids Anabolic steroids such as stanozolol, detected in several athletes during the 1988 lympics, are synthetic androgens that mimic the tissue-building effects of natural testosterone. N N Stanozolol

17 23.4G Reactions of Steroids

18 23.5 Prostaglandins

19 C Prostaglandin E 2 (PGE 2 ) C 2 Prostaglandin F 1α (PGF 1α )

20 23.6 Phosphatides

21 Most phospholipids are structurally derived from a glycerol derivative known as a phosphatidic acid. C 2 C C 2 CR CR' P From fatty acid From phosphoric acid A phosphatidic acid (a diacylglyceryl phosphate)

22 Phosphatides In phosphatides, the phosphate group of a phosphatidic acid is bonded through another phosphate ester linkage to one of the following nitrogen-containing compounds. C 2 C 2 N( ) 3 C 2 C 2 N 2 3 N C 2 Choline 2-Aminoethanol C 2 L-Serine

23 23.7 Waxes

24 Waxes are mixtures of esters between long-chain carboxylic acids and long-chain alcohols. The carboxylic acid usually has an even number of carbons from 16 through 36, while the alcohol has an even number of carbons from 24 through 36. ne of the major components of beeswax, for instance, is triacontyl hexadecanoate, the ester from the C 30 alcohol triacontanol and the C 16 acid hexadecanoic acid. (C 2 ) 14 C(C 2 ) 29 Beeswax