Abstract:
Chemical control techniques against larval and adult mosquito populations may be
justified if they are applied to water reserves and the atmosphere. The bioactivity
of concentrates and fractions obtained from cinnamon leaves against Anopheles
Tessellatus, a significant human vector bug in tropical areas, particularly in Sri
Lanka was investigated to identify the fractions of the methanol extract that
contain the most active chemical components. Maceration with methanol was used
to extract cinnamon leaves. A contact bioassay was used to assess the extracts for
insecticidal activity. The 59 g of crude was fractionated using a silica gel column
(1000g, Merck Kieselgel 60, 230-400 mesh ASTM) with solvents hexane, ethyl
acetate, methanol, and water as a mixture of hexane: ethyl acetate and ethyl acetate:
methanol in various ratios as in gradually increasing polarity. The eluents were
separated into smaller beakers and numbered in order of increasing polarity. In
order to separate and dry the seven different fractions, TLC methods were applied.
In order to conduct the contact bioassay, 1000 ppm methanol extracts of each of
these fractions were placed in direct contact with the larval stage of Anopheles
Tessellatus for a period of three days. After three days, the contact mortality was
found to be highest in the fractions containing 0 to 45 percent ethyl acetate mixed
with hexane, also known as F-1 (low polar), and 45 to 75 percent ethyl acetate
combined with hexane, also known as F-2 (low polar). This leads one to believe
that highly active chemicals that have the potential to be utilized as pesticides are
located in fractions 01 and 02 of all seven fractions. As polarity increased, the
diverse insecticide activities seen in the various fractions provided confirmation
that the kinds of chemical compounds and their compositions in each fraction
changed. Further studies are required to determine the structures of the biologically
active components of cinnamon, as well as the practical application of isolated
extracts and Phyto components in fractions that can be used in the prevention of
vector-borne diseases.
