© Benaki Phytopathological Institute
Endophytic fungi & secondary metabolites in medicinal plants
53
and rosmarinic acid) have been found in the
roots and leaves of
S. miltiorrhiza
, respec-
tively. Tanshinones belong to diterpenoid
quinones, and are considered as potent an-
ti-carcinogenic, antiatherosclerosis, and an-
tihypertensive, whereas salvianolic acids are
phenolic acids, which are mainly respon-
sible for beneficial effects on cardiovascu-
lar and cerebrovascular diseases (Chun-Yan
et al
., 2015). Several
Salvia
species produce
the bioactive phenolic labdane-type diter-
penes rosemarinic acid, carnosic acid and
carnosol. These compounds show distinct
anti-oxidant activity with carnosic acid car-
nosol being approved food additives (Wu
et
al
., 2012).
Salvia divinorum
produces a novel
diterpenoid, salvinorin A, which is a power-
ful hallucinogen in humans and shows a se-
lective, high efficacy agonist activity (Butel-
man and Kreek, 2015).
Eighteen endophytic fungal strains have
been isolated from the roots of
Salvia milti-
orrhizae,
the site of tanshinones accumula-
tion, and 58 fungal strains from the leaves,
the main site of salvianolic acid accumula-
tion. Liquid culture extracts of all the fungi
were screened for the presence of tanshino-
nes or salvianolic acid, respectively. One fun-
gus in each case was proven to produce tan-
shinones or salvianolic acid compared with
authentic standards. However, the yield was
quite low; about 4μg/L for tanshinones and
47μg/L for salvianolic acid (Ming
et al
., 2013;
Li
et al
., 2016).
Catharanthus roseus (L.) G.Don (Apocyn-
aceae)
Catharanthus roseus
is well known for the
production of several anticancer vinca alka-
loids such as vincristine, vindesine, vinorel-
bine, vinblastin and the recently discovered
vinflunine (Kumar
et al
., 2014). The two ma-
jor anticancer vinca alkaloids, vincristine
and vinblastine, used in chemotherapy reg-
imens, have been isolated from leaves (Ku-
mar
et al
., 2014).
The different
C. roseus
plant organs har-
bour a plethora of endophytic fungi (Khar-
war
et al
., 2008; Kumar
et al
., 2013; Palem
et
al
., 2015; Kuriakose
et al
., 2016). Screening all
the endophytes for the production of vinca
alkaloids revealed that only endophytic fun-
gi residing in the leaves of
C. roseus
were ca-
pable of producing vinblastine and vincris-
tine. These endophytic fungi were identified
as
Fusarium oxysporum,
Talaromyces radicus
and
Eutypella
spp. The drugs were purified
by TLC and HPLC and authenticated using
UV-Vis spectroscopy, ESI-MS, MS/MS and
1
H NMR. Culture filtrates of the fungi yield-
ed >55 μg/L of vinblastine or vincristine, re-
spectively (Kumar
et al
., 2013; Palem
et al
.,
2015; Kuriakose
et al
., 2016).
Coleus forskohlii (Willd.) Briq. (Lamiace-
ae)
Coleus forskohlii
or Indian
Coleus
is a trop-
ical perennial shrub of the
Lamiaceae
fam-
ily and grows in the subtropical temperate
climates of South-east Asia and India. The
plant is extensively cultivated in southern
India and the roots are used in Indian folk
medicine for treating a broad range of hu-
man health disorders (Kavitha
et al
., 2010).
The roots of the herb contain a pharmaco-
logically active compound called forskolin
that accumulates in the root cork
(Patera-
ki
et al
., 2014). The approved and potential
applications of forskolin range from allevia-
tion of glaucoma, anti-HIV or antitumor ac-
tivities, treatment of hypertension and heart
failure to lipolysis and body weight control
(Pateraki
et al
., 2017).
Screening of endophytic fungi isolat-
ed from inner tissues of root and stems of
C. forskohlii
for the production of
forskolin
revealed that one of the endophytic fun-
gi identified as
Rhizoctonia bataticola
was
able to stably synthesize forskolin and inter-
estingly, release it into the broth (Mir
et al
.,
2015).
Macleaya cordata (Willd.) R.Br. (Papaver-
aceae)
Sanguinarine (SA) is a benzophenanthri-
dine alkaloid isolated from
Macleaya cor-
data
leaves, and is known to have a wide
spectrum of biological activities, such as
antibacterial, antihelmintic, antitumor and
anti-inflammatory (Wang
et al
., 2014). SA is
