2. phenylpropanoids and flavonoids

Ms. Snehal S. Chakorkar
(M. Pharm.)
For Third Year B. Pharm. Program as per PCI syllabus,
New Delhi
Unit II
Introduction to secondary metabolite
Phenylpropanoids and Flavonoids:
Lignans, Tea, Ruta

Introduction to Lignans:
Definition: “Lignans are dimeric compounds formed
essentially by the union of two molecules of a
phenylpropene derivative.”
Some 300 lignans have been isolated and categorized in to
a number of groups according to structural features.
Amoungs that Podophl'llum spp. (q.v.) which appear to be
formed from two molecules of coniferyl alcohol or the
corresponding acid with subsequent modification.
Neolignans are also derived from the same units as lignans
but the C6-C3 moieties are linked head to tail or head to
head and not through the B-B' carbons.

Lignin is an important polymeric substance(,C o-C:), laid
down in a matrix of cellulose microfibrils to strengthen
certain cell walls.
It is an essential component of most woody tissue involves
vessels, tracheids fibres and scleroids.
Variations in lignin constitution also arise as a result of
random condensations of the appropriate alcohols with
mesomeric free radicals formed from them by the action of
a laccase type (oxidase) enzyme.

Synonyms: Podophyllum, Podophyllum
Rhizome, May-apple Root, Wild
Mandrake
Biological Source:
It consists of the dried rhizome and roots
of Podopbllunt peltatum ,
Podophyllum herandrum, syn. P. emodi
( Indian Phodophyllumn)
belonging to family Berberidaceae,
PODOPHYTTUAMN/ PODOPHYTTUM
Geographical Source:
Canada and the USA. The drug is collected in Virginia,
Kentucky, North Carolina.

Cultivation and Collection:
It is a perennial herb common in
moist shady situations in the eastern
parts of Tennesseae and Indian.
The rhizome which is about a metre
in length, is dug up. cut into pieces
about 10 cm in length, and dried.
Characteristics:
Podophyllum occurs in subcylindrical reddish-brown
pieces about 5-20 cm long and -5-6 mm thick. The
outer surfacei s smooth (autumn rhizome)or wrinkled
(sumrner rhizome).

Chemical Constituents:
The chief constituents of the root belong to the group of
lignans.
Rhizomes and root contain resinous mixture called
podophyllum resin or podophyllin.
The primary constituents are lignin glycosides,
podophyllotoxin, podophyllic acid and picropodophyllin, α-
peltalin and β-peltalin.

Uses:
Podophyllum resin has used as a purgative but has largely
been replaced by less drastic drugs.
It has a cytotoxic action and is used as a paint in the
treatment of soft venereal and other warts.
Etoposide is a lignan derivative obtained semi-
synthetically from podophyllotoxin and used in the
Treatment of lung cancer and testicular cancer as well as
lymphomas and leukaemias
Also used in paediatric neuro-blastoma.

Marketed Products:
It is one of the ingredients of the preparation known as podowart.

Synonyms: Camellia thea,
Biological Source:
It consists of prepared leaves and leaf buds
of Thea sinensis Linne,
Theae viridis Folium (Green tea leaves),
Theae Nigrae folium (black tea leaves)
belonging to family Theaceae ( Ternstroemiaceae).
TEA
China, India, Sri Lanka, Kenya, Indonesia and elsewhere.
Green tea is produced in China and Japan; it is not processed
and thus differs from black tea, which is fermented and
produced in India, Sri Lanka and Kenya. Oolong tea is
partially fermented.

Tea has been grown from seed at Kew, as
well as being brought in as young plants.
The tea bushes growing outside in the
Woodland Glade were planted and have
proved to be hardy, surviving snow and
winter temperatures of -8˚C.
Mulch is applied around the bushes to
encourage healthy growth, and in the
spring they are fed with a controlled-
release fertiliser. The soil they are grown in
has a low pH, which suits tea as it requires
acid soil. The bushes are watered during
long dry spells.

Characteristics:
An evergreen shrub, which can grow
up to 17 m high. In cultivation, it is
usually kept below 2 m high by
pruning.
Leaves: Bright green, shiny, often
with a hairy underside.
Flowers: Scented, occurring singly or
in clusters of two to four.
Fruits: Brownish-green, containing
one to four spherical or flattened
seeds.

Chemical Constituents
Tea contains caffeine (1-3%) , and much smaller amounts of
other xanthines such as theophylline and theobromine.
The polyphenols are the antioxidant constituents [in green
tea – epigallocatechin] together with theogallin, trigalloyl
glucose.
In black tea, they have been oxidized to form the ‘tea
pigments’, the theaflavins, thearubigens and theaflavic acids.

Uses :
Green tea is used medicinally more frequently than black tea.
The stimulant and diuretic properties (caffeine ) and the
astringency and antioxidant effects (polyphenols) .
Tea is useful in diarrhoea.
The polyphenols in green tea have cancer chemo-preventive
properties due to their antioxidant capacity.
Habitual consumption of green tea is generally associated
with a lower incidence of cancer and from ischaemic
heart disease.
Anti-inflammatory and antitumour effects due to inhibition
of the transcription factor NF-kB, and the risk of breast and
stomach cancers appears to be lower for green tea drinkers.

Tea is also antimicrobial and is even reputed to help weight
loss, refreshing, mildly stimulating and analgesic effects.
Tea as a beverage is non-toxic in the usual amounts
ingested, although it can cause gastrointestinal upsets and
nervous irritability, due to the caffeine content.
However there is now some concern about the safety of
concentrated preparations or excessive consumption of
green tea. Cases of hepatotoxicity have been
associated with consumption of high doses of green tea
(10–29 mg/kg/ d p.o.). In most cases, patients presented
with elevated serum alanine aminotransferase (ALT) and
bilirubin levels and in some cases liver biopsies were
performed, and periportal and portal inflammation
were observed.

Marketed Products:
It is one of the ingredients of the preparation known as green tea.

Ruta
Synonyms: Rue,
Biological Source:
It consist of Dried herb
of Ruta graveolens L;
belonging to family Rutaceae.
Mostly found in regions of mediterranean region,
Macaronesia and southwest Asia.

Rue is easy to grow. The tiny seeds, if
strewn onto a garden plot or a container
of potting soil and covered with a light
sprinkling of soil and moistened, will
sprout in a week or so.
The leaves were shade dried at room
temperature (32- 35oc) to constant
weight over a period of 60 days. 100 gm
of plant part were coarsely powdered
using a mixy and put through a sieve in
order to separate the fine from the
coarse particles.

Characteristics:
strongly scented ever green subshrubs.
20–60 cm tall,
Perennial (Existing for long time),
scented (having a pleasant scent ) and
glabrous (free from hair) herb or a sub-
shrub. Stem is slender, smooth, pale
glaucous green and reaches up to a
meter in height.
Leaves are alternate, gland-dotted,
glaucous, compound, 2-3 pinnate.
The flowers are yellow, with 4–5 petals
about 1 cm diameter, and borne in
cymes. The fruit is a 4–5-lobed capsule,
containing numerous seeds.

Chemical Constituents:
Ruta contains many secondary metabolites such as
furocoumarins, furoquinolines and acridone alkaloids,
mainly present in the leaves.
The major constituents were Rutine, 2-undecanone (33.9
%), 2-Heptanol acetate (17.5 %).
Also we can water-distilled essential oil from aerial parts.

Uses :
Extracts from rue have been used to treat eyestrain , sore
eyes, and as insect repellent.
Rue has been used internally as an antispasmodic, as a
treatment for menstrual problems, as an aborticient, and as a
sedative.
Ruta used for different medicinal purposes and possesses
antibacterial activity.
It is used to treat strains and sprains, injuries of the cartilage
and tendons around the joints, injuries to tissues lying over
the bone, injuries of the periosteum, and sciatica . Ruta is
often used for pain and stiffness in the hands, wrists, feet,
and legs.

Marketed Products:
It is one of the ingredients of the preparation known as
homeopathic eye drops and topical creams.

References Used:
1. W.C.Evans, Trease and Evans Pharmacognosy, 16th edition,
W.B. Sounders & Co., London, 2009.
2. Mohammad Ali. Pharmacognosy and Phytochemistry, CBS
Publishers & Distribution, New Delhi.
3. Text book of Pharmacognosy by C.K. Kokate, Purohit, Gokhlae
(2007), 37th Edition, Nirali Prakashan, New Delhi.
4. Herbal drug industry by R.D. Choudhary (1996), Ist Edn,
Eastern Publisher, New Delhi.
5. Essentials of Pharmacognosy, Dr.SH.Ansari, IInd edition, Birla
publications, New
Delhi, 2007

2. phenylpropanoids and flavonoids

2. phenylpropanoids and flavonoids

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