📝 Acetate - Mevalonate Pathway (Short Notes)

🔷 SLIDE 19 — Overview (पहले ये याद करो)

Mevalonate Pathway
= Isoprenoid Pathway = HMG-CoA Reductase Pathway

📍 कहाँ होता है?
   → Eukaryotes + Archaea + Some Bacteria

🧱 क्या बनाता है?
   → 2 five-carbon units:
      ├── IPP (Isopentenyl Pyrophosphate)
      └── DMAPP (Dimethylallyl Pyrophosphate)

🎯 इनसे क्या बनता है?
   → Isoprenoids (30,000+ biomolecules)
      ├── Cholesterol
      ├── Vitamin K
      ├── Coenzyme Q10
      └── Steroidal Hormones

▶ Start: Acetyl CoA (active acetate)
▶ End: IPP + DMAPP

🔀 IPP + DMAPP → via Squalene →
      ├── Steroids
      └── Triterpenoids

➕ Also produces:
   Monoterpenoids, Sesquiterpenoids, Diterpenoids,
   Carotenoids, Polyphenols, Glycosides, Alkaloids
   (with other pathways)

🔷 SLIDE 20 — Step-by-Step Pathway (Flowchart)

Pyruvic Acid (Glycolysis का end product)
        ↓
   Acetyl CoA (C2)
        ↓ [Claisen condensation — 2 molecules]
   Acetoacetyl CoA (C4)
        ↓ [+ 3rd Acetyl CoA → Aldol addition]
   β-Hydroxy β-Methylglutaryl CoA (HMG-CoA)
        ↓ [Reduction]
   Mevalonic Acid ⭐ (Main precursor for Terpenoids)
        ↓ [ATP mediated phosphorylation]
   Mevalonic Acid Diphosphate
        ↓ [Decarboxylation]
   IPP — Isopentenyl Pyrophosphate (C5) — Unit 1
        ↓ [Isomerase enzyme]
   DMAPP — Dimethylallyl Pyrophosphate (C5) — Unit 2
        ↓ [IPP + DMAPP → Prenyl Transferase (Electrophilic addition)]
   GPP — Geranyl Pyrophosphate (C10)
   → Precursor of MONOTERPENES
        ↓ [+ 1 IPP]
   FPP — Farnesyl Pyrophosphate (C15)
   → Precursor of SESQUITERPENES
        ↓ [+ 1 IPP]
   GGPP — Geranyl Geranyl Pyrophosphate (C20)
   → Produces DITERPENES
        ↓ [+ 1 IPP]
   Geranyl Farnesyl PP (C25)
   → SESTERTERPENES
        ↓
   ┌─────────────────────────────┐
   │ 2 FPP (tail-to-tail)        │
   │ → C30 = TRITERPENE          │
   │ 2 GGPP (tail-to-tail)       │
   │ → C40 = TETRATERPENE        │
   └─────────────────────────────┘

⚡ Quick Trick — Carbon count याद रखो

🧠 Exam ke liye 3 lines recap:

Acetyl CoA → HMG-CoA → Mevalonic Acid → IPP/DMAPP → GPP(C10) → FPP(C15) → GGPP(C20) → Triterpenes/Tetraterpenes

Key enzyme = HMG-CoA Reductase (rate-limiting step)

IPP = active isoprene unit (building block of all terpenoids)

📝 Acetate - Mevalonate Pathway (Short Notes)

🔷 SLIDE 19 — Overview (Start here)

Mevalonate Pathway
= Isoprenoid Pathway = HMG-CoA Reductase Pathway

📍 WHERE does it occur?
   → Eukaryotes + Archaea + Some Bacteria

🧱 WHAT does it produce?
   → 2 five-carbon (C5) units:
      ├── IPP (Isopentenyl Pyrophosphate)
      └── DMAPP (Dimethylallyl Pyrophosphate)

🎯 WHAT is made from these?
   → Isoprenoids (30,000+ biomolecules)
      ├── Cholesterol
      ├── Vitamin K
      ├── Coenzyme Q10
      └── Steroidal Hormones

▶ START: Acetyl CoA (active acetate)
▶ END:   IPP + DMAPP

🔀 IPP + DMAPP → via Squalene →
      ├── Steroids
      └── Triterpenoids

➕ Also produces (with other pathways):
   Monoterpenoids, Sesquiterpenoids, Diterpenoids,
   Carotenoids, Polyphenols, Glycosides, Alkaloids

🔷 SLIDE 20 — Step-by-Step Flowchart

Pyruvic Acid  ← (end product of Glycolysis)
        ↓
   Acetyl CoA  (C2)
        ↓  [Claisen Condensation — 2 molecules combine]
   Acetoacetyl CoA  (C4)
        ↓  [+ 3rd Acetyl CoA → Aldol Addition]
   HMG-CoA  (β-Hydroxy β-Methylglutaryl CoA)
        ↓  [Reduction]
   Mevalonic Acid ⭐  ← MAIN PRECURSOR for Terpenoids
        ↓  [ATP-mediated Phosphorylation]
   Mevalonic Acid Diphosphate
        ↓  [Decarboxylation]
   IPP — Isopentenyl Pyrophosphate  (C5)  [Unit 1]
        ↓  [Isomerase enzyme]
   DMAPP — Dimethylallyl Pyrophosphate  (C5)  [Unit 2]
        ↓
   [IPP + DMAPP → Prenyl Transferase — Electrophilic Addition]
        ↓
   GPP — Geranyl Pyrophosphate  (C10)
        → Precursor of MONOTERPENES
        ↓  [+ 1 IPP]
   FPP — Farnesyl Pyrophosphate  (C15)
        → Precursor of SESQUITERPENES
        ↓  [+ 1 IPP]
   GGPP — Geranyl Geranyl Pyrophosphate  (C20)
        → Produces DITERPENES
        ↓  [+ 1 IPP]
   Geranyl Farnesyl PP  (C25)
        → SESTERTERPENES

   ┌──────────────────────────────────┐
   │  2 × FPP  (tail-to-tail fusion)  │
   │  → C30 unit = TRITERPENE         │
   │                                  │
   │  2 × GGPP (tail-to-tail fusion)  │
   │  → C40 unit = TETRATERPENE       │
   └──────────────────────────────────┘

⚡ Carbon Count Table — Must Remember

🧠 3-Line Exam Recap

Acetyl CoA → HMG-CoA → Mevalonic Acid → IPP/DMAPP → GPP(C10) → FPP(C15) → GGPP(C20) → C25 → Triterpene/Tetraterpene

Key enzyme = HMG-CoA Reductase (rate-limiting step of the pathway)

IPP = active isoprene unit = basic building block of ALL terpenoids

📝 Acetate-Malonate Pathway (Short Notes)

🔷 SLIDE 27 — Overview

ACETATE-MALONATE PATHWAY
        |
        ▼
Works with → ACP (Acyl Carrier Protein)
        |
        ▼
Produces → Fatty Acyl Thioesters of ACP
        |
        ▼
These are important intermediates in Fatty Acid Synthesis
        |
        ▼
C2 Acetyl CoA units added at later stage
        |
        ▼
Produces EVEN number of Fatty Acids:
   ├── Smallest → n-Tetranoic acid (Butyric acid) C4
   └── Largest  → n-Ecosanoic acid (Arachidic acid) C20

        |
        ▼
Unsaturated Fatty Acids
→ made by direct DEHYDROGENATION of Saturated FA

        |
        ▼
ENZYMES control position of double bonds in fatty acids

🔷 SLIDE 28 — Key Enzyme & Steps

COMMITMENT STEP ⭐
        |
        ▼
Formation of MALONYL-CoA
(No other metabolic role — only precursor to fatty acids)
        |
        ▼
FATTY ACID SYNTHASE (FAS)
→ carries out CHAIN ELONGATION steps

        |
    ┌───┴────────────────────────┐
    ▼                            ▼
IN MAMMALS                  IN BACTERIA & PLANTS
FAS = Large                 Individual proteins
Multienzyme Complex         associate into large complex
2 subunits                  Each protein catalyzes
Each subunit has            one individual step
multiple enzyme activities

⚡ Key Points Box (write these in notes)

🧠 3-Line Exam Recap

Acetate + ACP → Fatty Acyl Thioesters → Even-chain Fatty Acids (C4 to C20)

Malonyl-CoA formation = Commitment step (only job = fatty acid precursor)

FAS = Chain elongation enzyme - multienzyme complex in mammals, individual proteins in bacteria/plants

📝 Amino Acid Pathway (Short Notes)

🔷 WHAT IS AN AMINO ACID?

AMINO ACID
     |
     ├── Amine group    → -NH2
     ├── Carboxyl group → -COOH
     └── Side chain     → R group (unique to each AA)

🔷 CLASSIFICATION OF AMINO ACIDS

20 Protein Amino Acids
         |
    ┌────┴──────────────────┐
    ▼                        ▼
NONPOLAR / HYDROPHOBIC    POLAR / HYDROPHILIC
(9 AAs)                   (9 AAs)
Glycine                   Serine
Alanine                   Cysteine
Valine                    Tyrosine
Leucine                   Glutamic acid
Methionine                Aspartic acid
Phenylalanine             Lysine
Proline                   Arginine
Isoleucine                Threonine
Tryptophan                Histidine

         |
         ▼
    SULPHUR-CONTAINING (special group)
         ├── Cystine
         └── Methionine

🔷 WHERE DO AMINO ACIDS COME FROM?

All 20 Protein AAs are derived from intermediates of:

   ┌─────────────────────────────────┐
   │  Glycolysis                     │
   │       OR                        │
   │  Citric Acid Cycle (Krebs)      │
   │       OR                        │
   │  Pentose Phosphate Pathway      │
   └─────────────────────────────────┘
              |
              ▼
   Nitrogen enters via:
   → Glutamate  +  Glutamine

🔷 WHO CAN SYNTHESIZE AMINO ACIDS?

Bacteria & Plants → Can synthesize ALL 20 AAs ✅

Mammals → Can synthesize only ~10 AAs
          (those with SIMPLE pathways) ⚠️

Remaining ~10 = ESSENTIAL AAs
               (must be taken from diet)

⚡ Quick Summary Table

🧠 3-Line Exam Recap

AA = -NH2 + -COOH + R group. Total 20 protein AAs.

All 20 AAs derived from Glycolysis / Citric Acid Cycle / Pentose Phosphate Pathway. Nitrogen enters via Glutamate & Glutamine.

Bacteria & Plants = synthesize all 20. Mammals = only ~10 (simple pathway ones).

📝 TRACER TECHNIQUE — 5 Mark Notes

🔷 INTRODUCTION (Slide 34)

5 Techniques to investigate biosynthetic pathways:
1. Tracer Technique      ⭐ (uses radioactive isotopes)
2. Isolated organ/tissue
3. Grafting method
4. Mutant strains
5. Enzymatic studies

🔷 WHAT IS TRACER TECHNIQUE? (Slide 35)

Radioactive isotope-labelled compound
        ↓
Given to plant → enters Metabolic Pool
        ↓
Traces different intermediates & steps
in biosynthetic pathway at given rate & time

ISOTOPES:
├── Stable isotopes → don't emit radiation
│   e.g. 2H, 13C, 15N, 18O
└── Radioactive isotopes → unstable, emit radiation ⚡
    e.g. 14C, 3H, 32P, 131I
    → Radioactivity = phenomenon of emitting radiation

🔷 SIGNIFICANCE (Slide 36)

✅ Works in living systems
✅ Wide range of isotopes available
✅ High sensitivity
✅ More effective
✅ Simple administration & isolation
✅ Accurate results (with enough metabolic time)

🔷 TRACER ELEMENTS USED (Slides 37 & 38)

Study               → Tracer used
─────────────────────────────────
Protein/Alkaloid/AA → N atom (more specific than C)
Glycosidic linkage  → O, N, S, C atom
Terpenoids          → O atom
Glucose             → 14C marked glucose

🔷 STEPS IN TRACER TECHNIQUE (Slide 38)

STEP 1 → Preparation of labelled compound
        ↓
STEP 2 → Incorporation of labelled compound
        ↓
STEP 3 → Separation & Isolation of labelled compound
        ↓
STEP 4 → Determination of nature of metabolites
         in various biochemical fractions

🔷 STEP 1 — Preparation (Slide 39)

Use radioactive isotopes (14C, 3H, 32P, 131I)
        OR
Stable isotopes (2H, 15N, 13C, 18O)
→ Radioactive C & H mostly used
→ Long half-life isotopes preferred

🔷 STEP 2 — Incorporation Methods (Slides 41 & 42)

i)   Root feeding    → roots = biosynthetic site
                       e.g. Tobacco (hydroponic culture)
ii)  Stem feeding    → cut end of stem dipped in solution
                       (not for latex plants)
iii) Direct injection → hollow stem plants
                        e.g. Umbelliferae, Opium poppy
                        (micro syringe used)
iv)  Infiltration    → thread through stem → dipped in solution
v)   Floating method → leaf disc floated on compound solution
                       (when small amount of material available)
vi)  Spraying        → sprayed on leaves
                       e.g. Steroids

🔷 STEP 3 — Separation Methods (Slide 43)

Tissue Type            → Method
──────────────────────────────────
Soft tissue (fresh)    → Infusion, Maceration
Hard tissue            → Decoction, Hot percolation
Unorganized drug       → Maceration with solvent
Fat & oil              → Non-polar solvent
Alkaloids/Glycosides   → Slightly polar solvent
Plant phenol           → Polar solvent

🔷 CRITERIA for selecting tracer (Slide 40)

✔ Sufficient starting concentration
✔ Physical & chemical nature must be known
✔ Long half-life
✔ Should NOT damage tissue
✔ Low radiation energy

DETECTION instruments:
→ Scintillation chamber, GM counter,
  Autoradiography, NMR, MS-ionization technique

🧠 Exam One-liner

Tracer Technique = radioactive/stable isotope labelled compound → given to plant → traces biosynthetic pathway through 4 steps: Preparation → Incorporation → Separation → Determination

📝 TRACER TECHNIQUE — STEP 4 + Detection Instruments + Methods (Part 2)

🔷 STEP 4 — Detection Instruments (Slides 44-48)

DETECTION OF RADIOACTIVITY
         |
    ┌────┴──────────────────────────────┐
    ▼                                    ▼
RADIOACTIVE isotopes              STABLE isotopes
(3H, 14C)                         (2H, 13C, 15N)
         |                               |
Liquid Scintillation Counter      ┌──────┼──────┐
(soft & easily absorbed           ▼      ▼      ▼
 radiation)                       MS    NMR   Autoradiography
         |
    GM Counter
(measures alpha, beta,
 gamma by ionization in gas)
         |
    Ionization Chamber
(simplest gas-filled detector
 for x-rays, gamma, beta)

🔷 INSTRUMENTS — ONE LINE EACH (must write in notes)

🔷 METHODS OF TRACER TECHNIQUE (Slides 49-51)

METHOD 1 — Precursor Product Sequence
         |
Labelled precursor → fed to plant
         ↓
After time → isolate, purify → measure radioactivity
         ↓
Single compound radioactivity = NOT enough evidence
         ↓
Use Double/Triple labelling for confirmation
(different isotopes OR same isotope at 2+ positions)

Example:
Lysine (14C, 15N) → in Nicotiana glauca
→ determined which N forms piperidine ring of Anabasine
(Leete's experiment)

METHOD 2 — Competitive Feeding
         |
A → B → C  (normal pathway)
A → B'→ C  (subsidiary pathway)
         ↓
Feed INACTIVE B and B' separately to 2 plant groups
+ Feed LABELLED A as control
         ↓
If C is inhibited in group with B
but NOT inhibited in group with B'
         ↓
Conclusion: Pathway goes A → B → C ✅

🔷 APPLICATION — Morphine Example (Slide 52)

Tyrosine
   ├→ 3,4-dihydroxyphenyl ethylamine (via DOPA)
   └→ 3,4-dihydroxyphenyl pyruvic acid (DIRECT — no intermediate)
         ↓
Both → Norlaudanosoline → Reticuline → MORPHINE

Key finding: Tyrosine directly gives pyruvic acid
             (DOPA route NOT needed — proved by competitive feeding)

🔷 APPLICATION — Alkaloid Biosynthesis (Slide 53)

14C labelled Tyrosine → Conium maculatum
→ Used to elucidate biosynthesis of Tropane alkaloids
   & Conium alkaloids

🧠 Exam Recap (write this at end of notes)

Step 4 = Detection using GM Counter / Liquid Scintillation / MS / NMR / Autoradiography

2 Methods: (1) Precursor-Product sequence — feed labelled compound, isolate, measure (2) Competitive feeding — feed inactive intermediates to confirm correct pathway

Application: Leete's experiment (Anabasine), Morphine biosynthesis (Tyrosine → DOPA route), Conium alkaloids

📝 METHOD 3 — Sequential Analysis (Short Notes)

🔷 FLOWCHART

METHOD 3 — SEQUENTIAL ANALYSIS
            |
            ▼
Grow plant in atmosphere of 14CO2
            |
            ▼
Analyze plant at different TIME INTERVALS
            |
            ▼
Observe SEQUENCE in which compounds
become radioactively labelled
            |
            ▼
Degrade isolated radioactive compounds
(some units of molecule label faster than others)
            |
            ▼
Determine correct biosynthetic sequence

🔷 KEY POINTS (write these)

✔ Uses 14CO2 atmosphere (not fed directly)
✔ Plant analyzed at given time intervals
✔ Some molecule units label MORE rapidly → noted
✔ Degradation of compound is important step
✔ Used to find PATH OF CARBON in Photosynthesis ⭐

🔷 APPLICATION (Slide 55)

Mentha piperita (Peppermint plant)
        |
        ▼
Exposed to 14CO2 for as short as 5 min
        |
        ▼
Biosynthetic sequence confirmed:

GPP → Piperitone → (-)-Menthone → (-)-Menthol

⚡ All 3 Methods — Quick Recap Table

🧠 One-liner for Exam

Sequential analysis = plant grown in 14CO2 atmosphere → analyzed at time intervals → sequence of labelling reveals biosynthetic pathway → used in elucidation of carbon path in photosynthesis

📝 ALKALOIDS — Short Notes (5 Marks)

🔷 DEFINITION (Slide 2)

ALKALOIDS
= Complex organic compounds
= Natural OR synthetic origin
= BASIC in nature
= Contain 1 or more N atoms in RING system
= Heterocyclic in nature
= Specific physiological action on human/animal body
  (in small quantities)

Word origin: "Alkali-like" → describes bases of botanical group
Importance: Chemical, Physiological, Taxonomic, Biogenetic studies

🔷 PROPERTIES (Slide 3)

Physical:
✔ Colorless, crystalline solids
✔ Slightly soluble in water
✔ Soluble in organic solvents
✔ Exceptions: Coniine & Nicotine = LIQUIDS
✔ Berberine = Yellow | Sanguinarine = Red

With Acids:
→ Form SALTS
→ Salts = soluble in water, sparingly soluble in organic solvents

In plant:
→ Occur in cell sap as water-soluble salts of:
   Malic, Citric, Oxalic, Succinic, Tartaric, Tannic acid

Biosynthesis: from AMINO ACIDS

🔷 CLASSIFICATION (Slides 4-11)

ALKALOIDS
    |
    ├── 1. PHARMACOLOGICAL
    ├── 2. TAXONOMIC
    ├── 3. BIOSYNTHETIC
    └── 4. CHEMICAL

1. Pharmacological (Slide 4)

Based on pharmacological action:
CNS stimulants/depressants, Sympathomimetics,
Analgesics, Purgatives, etc.

Same drug → different alkaloids → different actions:
Opium  → Morphine (narcotic analgesic) ≠ Codeine (antitussive)
Cinchona → Quinine (antimalarial) ≠ Quinidine (cardiac depressant)

2. Taxonomic (Slide 5)

Based on distribution in plant families
→ Named after genus e.g. Ephedra, Cinchona
→ Solanaceous alkaloids, Papillionceous alkaloids

3. Biosynthetic (Slides 5-6)

Based on PRECURSOR amino acid:

Ornithine/Lysine → Tropane, Pyrrolidine, Pyrrolizidine
Tyrosine         → Benzylisoquinoline
Tryptophan       → Indole, Quinoline
Pyridine         → Pyridine, Quinolizidine, Piperidine

4. Chemical (Slides 7-11)

Based on RING STRUCTURE:

A) TRUE ALKALOIDS (heterocyclic ring)

Ring Type         | Examples
──────────────────────────────────────────
Pyrrole/Pyrrolidine  | Hygrine, Coca
Pyridine/Piperidine  | Arecoline, Nicotine, Lobeline
Tropane (bicyclic)   | Atropine, Cocaine, Hyoscine
Indole/Benzopyrrole  | Ergotamine, Strychnine, Reserpine, Vincristine
Quinoline            | Quinine, Quinidine (Cinchona)
Isoquinoline         | Morphine, Codeine, Berberine, Papaverine
Aporphine            | Boldine
Imidazole            | Pilocarpine (Pilocarpus)
Quinazoline          | Vasicine, Vasicinone
Quinolizidine        | Sparteine, Cytisine, Lupanine
Indolizidine         | Swainsonine
Pyrrolizidine        | Senecionine, Seneciphylline

B) PSEUDO ALKALOIDS (false alkaloids)

Type              | Examples
─────────────────────────────────────────
Terpenoid         | Aconine, Aconitine (C20H32 isoprene units)
Purine derivatives| Caffeine, Theophylline, Theobromine (Tea, Coffee)
Steroidal         | Conessine, Solanidine (Kurchi bark)

🧠 Exam Recap (3 lines)

Alkaloid = basic organic compound, N in heterocyclic ring, physiological action in small dose. Biosynthesized from amino acids.

4 classifications: Pharmacological / Taxonomic / Biosynthetic / Chemical

True alkaloids = heterocyclic ring (Morphine, Quinine, Atropine). Pseudo alkaloids = false alkaloids (Caffeine, Aconitine, Conessine)

📝 PART 1 — Protoalkaloids + Isolation/Extraction + Purification

🔷 3. PROTOALKALOIDS (Slide 12)

= Non-heterocyclic / Biological Amines
= N present OUTSIDE the cyclic structure

Type              | Examples
──────────────────────────────────
Alkaloidal Amines | Ephedrine (Ephedra)
                  | Colchicine (Colchicum)

🔷 ISOLATION & EXTRACTION OF ALKALOIDS (Slide 18)

METHOD 1 (Simple)               METHOD 2 (Soxhlet)
─────────────────               ──────────────────
Powdered drug + water           Powdered drug → Soxhlet
        ↓                       → Extract with light petroleum ether
+ Lime + Ammonia solution       → Filtration (remove fats)
(Lime removes acids/tannins)            ↓
Alkaloids freed as BASES        Fat-free extract + Ethanol
        ↓                               ↓
Extract with CHCl3              Concentrate to syrup
(organic solvent)                       ↓
        ↓                       + 2N H2SO4 (mineral acid)
Concentrate organic extract     → Alkaloids become water-soluble salts
        ↓                               ↓
Pure alkaloids ✅               CHCl3 layer discarded
                                        ↓
                                Basify with 10% Ammonia
                                        ↓
                                Extract with CHCl3
                                        ↓
                                Column chromatography
                                        ↓
                                PURE ALKALOIDS ✅

🔷 PURIFICATION OF CRUDE EXTRACT (Slide 19-20)

4 Methods of Purification:

1. Direct Crystallization → from solvent

2. Steam Distillation → for volatile/liquid alkaloids
                         (low molecular weight)

3. Chromatographic Techniques → TLC, Column, GC, HPLC, HPTLC
                                  separates individual alkaloids
                                  from complex mixtures

4. Gradient pH Technique →
   Crude mixture dissolved in 2% tartaric acid
           ↓
   Extract with benzene
           ↓
   pH gradually increased by 0.5 → up to pH 9
           ↓
   Extraction with organic solvent at each pH level
           ↓
   Alkaloids with different basicity extracted separately
   Strongly basic alkaloids extracted LAST

📝 PART 2 — VINCA (Indole Alkaloid) (Slides 23, 25, 26, 27, 28)

VINCA
─────────────────────────────────────────
Synonym        | Catharanthus, Periwinkle
Biological     | Dried whole plant of
Source         | Catharanthus roseus
               | Family: Apocynaceae
               | Also known as Vinca rosea
Geographical   | Indigenous to Madagascar
Source         | Cultivated in India, USA,
               | S. Africa, Europe, Australia
─────────────────────────────────────────
Macroscopic Characters:
• Leaves: green, simple, ovate/oblong, glossy
• Flowers: violet pink/white/carmine-red
• Roots: pale grey, branched tap-root
• Odour: characteristic | Taste: Bitter

CHEMICAL CONSTITUENTS:
20 dimeric indoledihydroindole alkaloids

Most important:
Vincristine ⭐  &  Vinblastine ⭐

Vinblastine = Catharanthine (indole part)
            + Vindoline (dihydroindole part)

Others: Ajmalicine, Lochnerine, Serpentine

Note: 500 kg crude drug → only 1g Vincristine (0.0002%)

USES / PHARMACOLOGICAL ACTION:
Vincristine sulphate:
→ Antineoplastic (arrests mitosis at metaphase)
→ Acute leukemia in CHILDREN (IV)
→ Dose: 10-30 mcg/kg IV (max 2 mg)

Vinblastine sulphate:
→ Antineoplastic (arrests mitosis / interferes AA metabolism)
→ Hodgkin's disease, Non-Hodgkin's lymphoma
→ Breast, uterine, cervical, bronchial cancer
→ Hypotensive + Antidiabetic action
→ Dose: 100 mcg/kg IV

📝 PART 3 — RAUWOLFIA (Indole Alkaloid) (Slide 29)

RAUWOLFIA
─────────────────────────────────────────
Synonym        | Rauwolfia root, Serpentina root,
               | Chhota Chand, Sarpgandha
Biological     | Dried roots of
Source         | Rauwolfia serpentina Benth.
               | Family: Apocynaceae
               | Contains ≥ 0.15% Reserpine + Ajmalcine
Geographical   | Tropical Asia, America, Africa
Source         | India: UP, Bihar, Orissa, Tamil Nadu,
               | WB, Karnataka, Maharashtra, Gujarat
─────────────────────────────────────────
Macroscopic:
• Colour: Root bark = greyish yellow to brown
          Wood = pale yellow
• Odour: Odourless | Taste: Bitter

🧠 Exam Recap

Protoalkaloids = N outside ring (Ephedrine, Colchicine)

Isolation: Method 1 = Lime + CHCl3 | Method 2 = Soxhlet + acid-base extraction + column chromatography

Vinca = Catharanthus roseus, Apocynaceae. Key alkaloids = Vincristine (childhood leukemia) + Vinblastine (Hodgkin's, cancer)

Rauwolfia = R. serpentina, Apocynaceae. Key alkaloids = Reserpine + Ajmalcine

📝 RAUWOLFIA — Complete Short Notes (5 Marks)

🔷 T.S. OF RAUWOLFIA ROOT (Slide 32) — just list these layers!

Outer → Inner:
Stratified Cork → Phelloderm → Starch grains
→ Calcium Oxalate Prisms → Secondary Phloem
→ Vessels → Wood Fibres → Wood Parenchyma → Medullary Ray

🔷 CHEMICAL CONSTITUENTS (Slide 33)

Total alkaloids: 0.7 - 3% (present in bark of roots)
Total: 30 Indole alkaloids

Types: Indole / Indoline / Indolenine / Oxindole / Pseudo-indoxyl

IMPORTANT ALKALOIDS:
⭐ Reserpine (most important)
• Ajmaline          • Ajmalicine
• Rauwolfinine      • Rescinnamine
• Yohimbine         • Serpentine
• Serpentinine

Other constituents: Oleo-resin, Phytosterol,
                    Fatty acids, Alcohol, Sugars

Test: Reserpine = calorimetrically determined
      by reaction with acidic solution + Sodium Nitrite

🔷 CHEMICAL TEST (Slide 35)

Test 1: Freshly fractured surface + Conc. HNO3
        → RED coloration along medullary rays

Test 2: Reserpine + Vanillin in acetic acid
        → VIOLET RED colour

Test 3 (Indole alkaloid test):
        Powdered Rauwolfia + H2SO4
        + p-di-methyl amino benzaldehyde
        → VIOLET to RED colour

🔷 PHARMACOLOGICAL ACTION & USES (Slides 35-36)

ALKALOID          ACTION / USE
──────────────────────────────────────────────────
Reserpine ⭐      • ANTIHYPERTENSIVE ← main use
                  • Lowers BP by depleting catecholamines
                    at nerve endings
                  • Prevents re-uptake of norepinephrine
                  • Used in mild anxiety & neuropsychiatric
                    disorders (tranquilizing effect)

Rescinnamine      • Antihypertensive
                  • Causes mental depression in high doses

Deserpidine       • Antihypertensive + Tranquillizer
                  • Very less side effects

Ajmalicine        • Circulatory diseases
                  • Relieves obstruction of cerebral blood flow

Syrosingopine     • Mild/moderate hypertension
                  • Less sedative than Reserpine

🔷 DOSE (Slide 37)

Rauwolfia:    100-150 mg (oral, twice daily)
Reserpine:    Initial = 250 mcg once/day (oral)
              Maintenance = 100-250 mcg once/day
Rescinnamine: Initial = 500 mcg twice/day (oral)
              Maintenance = 250 mcg daily

🔷 ALLIED DRUGS / SUBSTITUTES (Slides 37-38)

86 different species total.

R. vomitoria  → African Rauwolfia ⭐
               Commercial source of Reserpine
               Root has 5 discontinued bands of sclerenchyma
               + very large vessels

Others with Reserpine: R. caffra, R. cumminsfi,
R. mombasiana, R. oreogiton, R. obscura,
R. rosea, R. volkensii, R. tetraphylla, R. nitida

R. densiflora  → contains sclerenchyma
R. tetraphylla → uniform cork + sclerides + fibres
                 (devoid of Rescinnamine)

🧠 Exam Recap (3 lines)

Rauwolfia = R. serpentina, Apocynaceae. Dried roots. 0.7-3% alkaloids. Key = Reserpine (antihypertensive)

Reserpine lowers BP by depleting catecholamines at nerve endings. Also used as tranquillizer.

Test: Fractured surface + HNO3 = red colour. Reserpine + Vanillin = violet red.