Cua, Pilar, Renon

HC

Plants and animals

Friedrich Kekulé – HC of turpentine◦ C10H16

Camphor -> Terpenoids◦ C10H16O

Otto Wallach◦ 5n carbon atoms

◦ Isoprene units = 2-methylbuta-1,3-diene

Robert Robinson◦ Head to tail

Leopold Ruzicka◦ Rule of Ruzicka –

classification by number of C

Number of carbon atoms Value of n Class

10 2 Monoterpenes(C10H16)

15 3 Sesquiterpenes(C15H24)

20 4 Diterpenes(C20H32)

25 5 Sesterpenes(C25H40)

30 6 Triterpenes(C30H48)

40 8 Tetraterpenes(C40H64)

>40 >8 Polyterpenes(C5H8)n

Acyclic

Monocyclic

Bicylcic

Tricyclic

Tetracyclic

Extracts /steam distillates of terpenes

Natural flavor additive

Fragrance

Pharmacological

Agent of pollination

Plant adaptation and protection

Growth hormone and pheromones

Citral Limonene Menthol Terpineol α-pineneCamphor

Santonin ArtemisininAbscisic acid

Hormones

Tetracyclic triterpenes

Cyclopentaperhydrophanthrene backbone

Me at C10 and C13- angular methyl groups◦ Above plane

Subs at same side = β and solid wedge

Non-polar◦ Cross cell membrane

Source◦ Phtyosterol

◦ Zoosterol

◦ Ergosterol

◦ Ecdysteroid

Most common and abundant

Precursor of other steroids

Cell membrane component

Squalene

8 asym C and 256 stereoisomer

Cholic and chenodeoxycholic acid

Vitamin D

Glucocorticoids

Mineralcorticoids

O at C11

Cortisone Aldosterone

Male sex hormone

Testes

Male secondary sex characteristics

Testosterone 5α-dihydrotestosterone

Female sex hormones

Ovaries

Female secondary characteristics

Regulate menstrual cycle

Estradiol Estrone

Prepare lining of uterus for implantation of an ovum

Maintenance of pregnancy

Prevent ovulation during pregnancy

Progesterone

Synthetic steroid

Deliberate damage of plant to collect the resin.

Use of incision into the tree where the resin runs through.

Used in collecting latex for rubber and gum turpentine.

Oil extraction where physical pressure is applied

The sample is pressed until the oil comes out of it.

Used for citrus oil due to abundance of raw materials.

Three forms of distillation:◦ Dry or empyrumatic

◦ Steam distillation

◦ Hydrodiffusion

Involves high temperature

The vessel containing the plant sample is directly heated

Used for oils derived from wood to vaporize chemical components

Water is added to the plant sample

Limits the temperature to 100°C

Lessens degradation of hydrocarbons

Essentially is steam distillation.

Difference is the introduction of steam at the top of the vessel while water and oils are collected at the bottom.

Plan materials carried down by the condensate.

Saves energy because it is not necessary to vaporize the oil.

Use of suitable solvent to dissolve desired sample

Comes in different type of solvents

Inlcudes:◦ Ethanolic Extraction

◦ Enfleurage

◦ Simple Solvent Extraction

Use of ethanol to extract desired sample

Not useful for extraction from plant sample because of high proportion of water to oil

More useful with products like ambergris.◦ Ambergris comes from sperm whales; used in

perfumes.

Ancient method of extraction

Plant material is covered in purified fat

Purified fat absorbs oil

Oil can be extracted from fat using ethanolicextraction

Similar to maceration; difference is the presence of heat in maceration

Use of petroleum ether, acetone, hexane and ethyl acetate and combinations to extract desired oil.

Previously benzene was used but due to health concerns was stopped.

Use of liquid carbon dioxide as solvent very effective but expensive.

Products are called concrete or resinoids

Same as simple solvent extraction

Polarity of sample is taken into consideration

May include more purification steps to separate steroids from lipoproteins to increase yield.

Glasswares must be properly silanise using dimethyldichlorosilane to prevent steroids from binding

Based on two systems:◦ One using diatomaceous inactivated earth

◦ The other one using microparticulate silica.

Analyte is eluted by passing through the solid matrix with organic solvent.

Water is absorbed by the matrix.

Uses an antibody bound to a matrix

Analyte is percolated through the antibody

Eluted by changing the concentration of salt

May use highly selective antibodies or low specific antibodies.

Molecularly Imprinted Polymers◦ May be regarded as synthetic antibodies

◦ Highly selective to specific sample

Restricted Access Material◦ Restricts molecules which are compatible with the

RAM

◦ Binds with specific molecules and elutes other

Large number of sample in one run

If steroid is UV absorbing the use of UV light and fluorescent adsorptive material could be used.

Usually uses silica gel plates

Solvent: combination of chloroform, benzene, ethyl acetate, hexane, etc.

Partition system where the steroid solute is in the vapor phase.

Due relatively high molecular weight of steroids and their derivatives, GLC has to be carried out at high temperatures, usually in excess of 200°C.

The sample is carried through the system by a gas, usually helium, because it is less dense than nitrogen.

Originally carried out using packed columns but today capillary columns of glass or fused silica are more popular.

High temperatures are not required. Material can be recovered from the column

eluates for further analytical procedures. The resolution achieved by HPLC is superior

to TLC and paper chromatography, Methods of linking HPLC to mass

spectrometers have greatly improved, allowing the routine use of LC-MS and LC-MS-MS

Typically, columns are 100–300 mm in length and around 4–5 mm internal diameter.

Bromine adds to unsaturated double and triple bonds to form dibromoalkanes and tetrabromoalkanes

Gets decolorized until reaction is complete

Uses acetic anhydride and sulfuric acid

Color changes from pink to green

Happens because of the hydroxyl group of cholesterol increases conjugation in the ring

Sample + FeCl3∙6H20 + glacial acetic acid + concentrated sulfuric acid = bluish green color

Alternatively :Sample + perbenzoic acid + glacial acetic acid →

Heat + sulfuric acid = bluish green color

Is also known as dodeca molybdophosphoricacid or PMA

It is a yellow-green compound, freely soluble in water and polar organic solvents such as ethanol.

Conjugated, unsaturated compounds reduce PMA to molybdenum blue.

Increase in intensity means increase in double bonds stained

Oxidize the carbon-carbon double bond to give alkanediols or the carbon-carbon triple bond to give carboxylic acids.

A brown precipitate of MnO2 is produced.

Disappearance of the characteristic color of permanganate ion is a positive test for unsaturation.

Compounds containing certain other types of functional groups may also decolorize permanganate ion.

A chloroform solution of sterol with 90% tricholoracetic acid which gives a blue or pink color.

Cholesterol + excess phosphoric acid + ferric ions (FeCl3) = reddish purple color

Alternative: sulfuric acid + cholesterol in chloroform = two-phase system red upper layer and green lower layer

Cholesterol + glacial acetic acid + ferric chloride + concentrated sulfuric acid = purple color

Elucidation is done by spectral comparison

Chromophores and structural environment detected for unknown samples

OH single bonds vibrate with 3600 cm-1,

carbonyl double bonds with 1700 cm-1,

and carbon-oxygen single bonds with 1200 cm-1

NMR spectra of steroids measured in CDCl3.

1D proton NMR spectra have overlapping signals of CH2 and CH groups that appear as a characteristic hump in the region 0.5–2.5 ppm.

13C NMR eliminates this problem

Detects the molecular mass of a compound with a precision of 10-4 mass units.

Due to the isotope mass defect of elements the molecular formula of a terpene can be determined by high-resolution mass spectrometry of the molecular ion.

For example, the molecular formula C17H22O4 of acanthifolin from Senecio acanthifolius(Asteraceae) is calculated from the molecular mass of 290.1525 determined by high-resolution mass spectrometry of the molecular ion.

This determines the arrangement of atoms within a crystal and provides information about:◦ 1) 3D picture of the density of electrons within a

crystal,

◦ 2) mean positions and sizes of the atoms in the crystal,

◦ 3) lengths, angles, and types of chemical bonds and

◦ 4) chemical functions, interactions, and processes.

Menthol and Cholesterol

Chemical Synthesis

Chemical Synthesis

Biosynthesis

Step 2: Decarboxylation

Step 4: Cleavage

Biosynthesis

Malaria and dengue fever

Blood-feeding arthropods

Bunyavirus

DEET

Picardin

PMD

Beautyberry = Callicarpa

Beautyberry insect repellent property◦ Callicarpenal

◦ Intermedeol

◦ Spathulenol

Low isolated amount

Stereoselective synthesis of (-)-callicarpenal

a.ethylene glycol PTSO in benzene

b. Ketal in THF+ Li/NH3

Allyl bromide

d.O3, THFPPh3NaBH4

e.CH2Cl2 TIPSOTf2,6-lutidine

f.TPAPNMOCH2Cl2

c.OsO4NMOacetone/H2O

g.CH3PPh3BrNaHMDSTHF

i.TBAFTHF

k.H2, Crabtree’s catalyst ([Ir(COD)(PCy3)(Py)]PF6CH2Cl2

l.CH3PPh3BrNaHMDSTHF

j.HClTHF

m.RuCl3.H2OEtOH

n.TPAPNMOCH2Cl2

Drug development – vary subs and alter stereochem relationships◦ Change in the biological activity

C11 – change -> change in biological effect

11-amino-12-hydroxy/keto steroids –potential HIV-1 protease (Salunke et.al.)

Short carbon bridges span characteristic portion of steroid backbone

New ring

New function at C11

Cholic acid -> stereoselective synthesis of pentacyclic steroids w/ NH2 at C11

a.MethanolPTSA

b. Ac2OpyridineDMAP

c. mesylchloridepyridine

d. ChenAcOKHMPT

cholate

methyl-3,7-diacetoxycholate

methyl 3,7-diacetyl-12-mesyl cholatemethyl 3,7-diacetylchol-11-enate

e. m-CPBA in CH2Cl2

11α,12 α-epoxide

different amines in ethanol/toluene (1:1) solution