Anthraquinones have been used medicinally in China formore

Anthraquinones and its derivatives include many important drugs
(collectively called anthracenediones).
They acts as Laxatives (dantron, emodin, and aloe emodin), and some of the senna glycosides, Antimalarials ( rufigallol), Antineoplastics used in the treatment
of cancer    
 (mitoxantrone, pixantrone, and the anthracyclines) (Panigrahi et al., 2015).
(4,5-dihydroxyanthraquinone-2-carboxylic acid) is a anthraquinone which is
lipophillic in nature. It is extensively found in medicinal herbs and have been
used medicinally in China formore than 1,000 years. Rhein exhibits a linear
pharmacokinetics between 50 and 200mg (Layek et al., 2008) and has many
pharmacological effects, including hepatoprotective, nephroprotective,
antiinflammatory, antioxidant, anticancer, and antimicrobial activities. These
pharmacological effects lay the foundation for the treatment of hepatic disease
(Guo et al., 2003), osteoarthritis (Moldovan et al., 2000), various cancers,
such as nasopharyngeal carcinoma (Lin et al., 2009), hepatocellular carcinoma
(Shi et al., 2008), lung cancer (Hsia et al., 2009), tongue cancer (Chen et al.,
2010), atherosclerosis (Heo et al., 2009) and diabetes (Du et al., 2011),

Catechin is
a type of natural phenol and antioxidant. It belongs to the group flavanols, part of the
chemical family of flavonoids. Catechin containing extracts were thought to be
useful for treating heart diseases (Schroeder
and Johann, 1655; Berends, 1829) and an effect on the
permeability of capillaries was shown by Armentano et al., in 1936.  Some
ground evidences from dietary studies indicated that catechins have an effect
on endothelium
dependent vasodilation which aids in to normal blood flow
regulation in human beings (Hooper et al., 2012; Ellinger et al., 2012). Catechins also improve blood pressure (Khalesi et al., 2014).

Kaempferol is
a natural flavonol,
a type of flavonoid,
found Cassia fistula. It acts as an antioxidant
by reducing oxidative stress. Anti-bacterial activity of kaempferol and its
glycosides have demonstrated to decrease the number of Helicobacter pylori colonies in gerbils. Kaempferol has been reported to inhibit the
activity of enzymes that are responsible for viral infection such as reverse
transcriptase, viral proteases and neuraminidase.Kaempferol has been shown to
have an array of antioxidant effects in
vitro and in vivo. At low
concentrations, it acts as a superoxide scavenger, specifically against the
highly reactive OH.
radical and peroxynitrite species. At high concentrations it increases the
activity of superoxide dismutase, catalase, and heme oxygenase-1. Kaempferol can prevent
the oxidation of low-density lipid proteins indicating its protective role in
atherosclerosis (Calderon-Montaño et
al., 2011). Many studies suggest that
consuming kaempferol can reduce the risk of various cancers, and it is
currently under consideration as a possible cancer treatment drug. In vitro studies along has demonstrated the wide range
of potential anticancer properties of kaempferol. It has been shown effective
against malignant cancer cells. They interrupt cell growth, limit angiogenesis,
induce apoptosis, and reduce their available energy and ability to metastasize
by reducing the MMP-3 protein activity (Calderon-Montaño
et al., 2011). Kaempferol has been shown to interact with the estrogen
receptor pathway and alter signaling leding to slow growth. It has the ability
to lower levels of Aromatase (Wang et al., 1994). Kaempferol has also
found to induce apoptosis in breast cancer cells via extracellular
signal regulated kinase activation and up-regulation of p53 (Aiyer
et al., 2012). Evidences
has shown that kaempferol can inhibit VEGF production thereby suppressing the
ovarian cancer cell metastasis under in
vitro conditions (Chen et al.,
2012). Kaempferol has also been shown to reduce growth in promyelocytic
leukemic cells by altering the cell cycle (Jaganathan and Mandal, 2009). There is a correlation  found between increased levels of kaempferol
in the diet and a relatively reduced 
risk of type 2 diabetes in a cohort study in 2005 (Calderon-Montaño et al., 2011).
Kaempferol has also been reported to impart a protective effect on the apoptosis
induced by the ischemia reperfusion of cardiac cells. Therefore, it has a potential
pharmacological role in prevention of cardiovascular disease (Khalil and Sulaiman, 2010)

which is a potent phytocompound of C. fistula,
has also been demonstrated to be protective in terms of deleterious side
effects of many cancer treatments. Effectivity of coumarin and troxerutin
combination therapy for the protection of salivary glands and mucosa in
patients undergoing head and neck radiotherapy. It has been suggested that
coumarin/troxerutin has a favorable impact in the treatment of radiogenic
sialadentis and mucositis (Mahler et al, 1992). Coumarin and
7-hydroxycoumarin are now being used as anti-cancer agents in view of their
effectiveness in acheving objective responses in some patients with advanced
malignancies (Myers et al, 1994). The coumarin is also used as anticoagulants,
that blocks multiple steps in the coagulation cascade by competitively
inhibiting vitamin K in the biosynthesis of prothrombin. The coagulation
cascade relies on the conversion of prothrombin to thrombin in a very important
step under the condition (Goodman & Gilman’s, 2006).

Heterocyclic compounds like chromones (4H-chromen-4-ones) are
with the benzo-c-pyrone framework. Molecules containing the chromone or
benzopyranone ring have a very wide range of biological activities. They are
shown to be tyrosine and protein kinase inhibitors (Kim et al., 2004), as well
as anti-inflammatory (Ma et al., 2003), antiviral (Bennett
et al., 2004), antioxidant (Krishnamachari
et al., 2004), antihypertensive agents (Bennett
et al., 2004) and Chromone derivatives are also
active at benzodiazepine receptors (Kametani et al., 2007). In addition to this, they have been shown to be
anticancer agents (Machado and Marques, 2010),
and possessing antimutagenic properties (Galietta et al., 2001). Chromones may also have application in cystic fibrosis
treatment, as they activate the cystic fibrosis transmembrane conductance
regulator (Horton et al., 2003). Therefore,
the vast range of biological effects associated with this scaffold has resulted
in the chromone ring system being considered as a privileged structure (Protti
et al., 2008). The main objectives of chromones
syntheses are not only for the development of more diverse and complex
bioactive compounds for biological activity and structure-activity relationship
(SAR) studies but also for other applications in Medicinal Chemistry, such as
preparation of fluorescence probes, due to photochemical properties of
chromones (Kim et al., 2012).

Lupeol has a complex pharmacology, displaying antiprotozoal,
antimicrobial, antiinflammatory, antitumor and chemopreventive
properties (Gallo and. Sarachine, 2009).
Lupeol can act as an anti-inflammatory agent. A study found lupeol to decrease
paw swelling in rats by 39%, compared to 35% for the standardized control
compound indomethacin (Geetha
and Varalakshmi, 2001). It
is an effective inhibitor in laboratory models of prostate
and skin cancers
(Prasad et al., 2008; Nigum et al., 2007; Saleem et al., 2004). It also act as
an anti-inflammatory agent, acts primarily upon the interleukin
system. Lupeol decreases IL-4 production by T-helper type 2
cells ( Bani et al., 2006).  Lupeol
has also been found to have a contraceptive effect due to its inhibiting effect
on the calcium channel of sperm (CatSper) (Nadja Mannowetza et al., 2017).