ANTIHYPERTENSIVES
RAUWOLFIA
Regional names -: Sarpagandah, Chootchand,
Source -: Rauwolfia consist of the dried
roots and rhizomes of Rauwolfia serpentia
Family-: Apocynaceae
Geographical occurrence-: The plant is a small shrub which
grows in India, Pakistan, Burma, Thailand and Jawa.
Collection -: The plants are correctly
identified before collection. The roots and rhizomes are dug from plants which
are 2 to 4 years old. Some of the root is left in each plant for future growth.
The roots are washed and dried in air.
Characters-:
Macroscopic
i)
The
external characters of roots and rhizomes are almost similar. But rhizomes
contain small central pith and small pieces of aerial stem.
ii)
Rauwolfia
occurs in small pieces (2 to I5 cm long and 0.3 to 2 cm thick). The pieces are
cylindrical, tortuous, tapering and rarely branched.
iii)
The
outer surface is greyish yellow to light brown and may contain scars of
rootlets. The fracture is short. The fractured surface has a yellowish
iv)
Brown
dark and a pale yellow wood. The wood occupies three fourths of the area.
v)
Rauwolfia
has no odour but the taste is bitter.
Microscopic--:
A transverse section of rauwolfia root shows
the following structures.
i)
Cork -:
The cork is stratified and contains 2 to 8 zones. Each zone contains layers of
smaller, radially narrow lignified cells. They altemate with radially broad non
lignified cells.
ii)
Phalloderm -: It is made of parenchymatous
cells.
iii)
Phloem --: It is narrow and consists mainly
parenchyma. It also contains
1.
Sieve
tubes
2.
Companion
cells
3.
Starch
grains
4.
Prisms
of calcium oxalate
5.
Sclerenchyma
is absent
Xylem --: It is wide and lignified. It
contains-:
1. Fibres
2. Xylem parenchyma
3. Many small vessels
4. Medullary rays.
Medullary rays --: They radiate from the center to
cortex. They are lignified in the xylem region and non-lignified in the phloem
region Starch and oxalate prisms are also present in the medullary ray cells.
Constituents--:
Mainly alkaloids. The rauwolfia alkaloids
can be classified as-:
i) Indole
alkaloids (strongly
basic)-: Reserpine, Rescinnamine and Deserpedine.
ii) Indoline
alkaloids
(intermediately basic)-: Ajamaline, Ajamalicine.
iii) Anhydronium
alkaloids (strongly
basic)-: Serpentia, Serpentinine and Alstonine.
Uses-:
i.
Reserpine
is used as an antihypertensive and tranquilising agent.
ii.
Ajamaline
is used in angina pectoris and cardiac arrhythmias.
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