© Benaki Phytopathological Institute
Endophytic fungi & secondary metabolites in medicinal plants
57
Capsicum annuum L. (Solanaceae)
Capsaicin, the pungent alkaloid of red
pepper (
Capsicum annuum
), is present in
large quantities in the placental tissue, the
internal membranes and, to a lesser extent,
the other fleshy parts of the fruits of
Cap-
sicum
. The pharmacological properties of
capsaicin include cardio protective influ-
ence, anti-lithogenic effect, anti-inflamma-
tory and analgesia, thermogenic influence,
and beneficial effects on gastrointestinal
system (Srinivasan
et al
., 2016).
An endophytic fungal strain identified as
Alternaria alternata
has been isolated from
fruits of
C. annuum
and has been found to
produce and secrete capsaicin up to three
generations (Devari
et al
., 2014).
Ginkgo biloba L. (Ginkoaceae)
Ginkgo tree contains in bark and leaves
flavones and terpenoide lactones, among
which, bilobalide and ginkgolides (terpe-
noide lactones) have been shown to be
beneficial to human health (Usai
et al
., 2011).
Ginkgolide B has revealed potent antagonis-
tic effects on platelet activating factors in-
volved in the development of a number of
renal cardiovascular, respiratory and central
nervous system disorders (Usai
et al
., 2011)
while bilobalide was found to exert neuro-
protective effects (Kiewert
et al.,
2008).
Screening of 27 endophytic fungal
strains isolated from the bark of
G. biloba
trees revealed that only one isolate
F. ox-
ysporum
SY0056, was capable of produc-
ing Ginkgolide B (Cui
et al
., 2012). The search
for bilobalide -producing endophytic fun-
gi was far more copious; a total of 57 fungal
strains were isolated from stem, root, leaf,
and bark of the plant
G. biloba
and their ex-
tracts were evaluated for the presence of bi-
lobalide. Only the isolate
Pestalotiopsis uvi-
cola
GZUYX13 residing in leaves was proven
to be a bilobalide-producing fungus (Qian
et al
., 2016).
Silybum marianum (L.) Gaertn. (Aster-
aceae)
Silymarin is a bioactive extract of the
fruits of
Silybum marianum
and contains
seven flavolignans (silybin A, silybin B, isosi-
lybin A, isosilybin B, silychristin, isosilychris-
tin, and silydianin) with reported chemopre-
vention and hepatoprotective properties
(Feher and Lengyel, 2012).
Twenty one endophytic fungi were iso-
lated from stems, leaves, roots, and seeds of
S. marianum
and were examined for produc-
tion of
flavolignans (El-Elimat
et al
., 2014).
Two of these compounds, silybin A and si-
lybin B, have been extracted as fermenta-
tion products of two strains of
Aspergillus ii-
zukae
isolated from the leaves and stems of
S. marianum,
respectively. Subcultur of one
flavonolignan-producing strain revealed an
attenuation of the production of flavono-
lignans. However, when autoclaved leaves
of the host plant were added to the growth
medium, the production of flavonolignans
could be resumed (El-Elimat
et al
., 2014).
Vinca minor L. (Apocynaceae) and Neri-
um indicum Mill. (Apocynaceae)
Vincamine indole alkaloids (vincamine,
tabersonine and catharanthine) are widely
found in plants of the
Apocynaceae
family
and show beneficial properties for human,
such as prevention of cerebrovascular, pre-
caution of chronic ischemic stroke, and re-
duction of vascular dementia or memory
impairment (Saurabh and Kishor, 2013). Vin-
camine is a precursor compound for other
medicinal alkaloids such as 11-bromovin-
camine, ethyl-vincamine and vinpocetine,
which have shown potential clinical thera-
peutic effect (Manda
et al
., 2015). Vincamine
is accumulated in the leaves and stems of
Vinca minor
and
Nerium indicum
. Though
abundant chemical synthesis and semi-syn-
thesis research results have been reported,
the main sources of vincamine indole alka-
loids are stems and leaves of
Vinca minor
L.
Eleven fungal strains have been isolated
from the stems and roots of
Nerium indicum
and fungal culture extracts were screened
for the presence of indole alkaloids (Yin and
Sun, 2011). One fungal strain, CH1, produces
vincamine alkaloids as its host plant as de-
termined by TLC, HPLC and LC–MS analy-
sis. The yield of vincamine, ethyl-vincamine,
