P. Sharma and P. Awasthi
Journal of Molecular Structure 1231 (2021) 129945
pounds have shown diverse biological activity and serve an impor-
tant function in the pharmaceutical industry [27]. Sulfur is consid-
ered to be a general-use pesticide in agriculture. Benzene sulfon-
amides with low cost and low toxicity are popularly used as insec-
ticide/Pesticide in the agrochemical field [21,63,71]. The presence
of a nucleophilic group on this compound allows further chemi-
cal modifications to obtain novel sulfonamide derivatives. A vari-
ety of aniline derivatives as a nucleophilic agent are allowed to re-
act with benzene sulfonamide carboxylic acid chlorides to obtain
a new series of analogs. Aniline and its derivatives find vast ap-
plication in drugs, pesticides, rubber azo dyes photographic chem-
icals, etc. [70,39]. Four analogs were further modified by replac-
ing Hydrogen atom at position 11’ with chlorine or nitro group in
the aryl ring B (Fig. 1c). The nitro group/chloro group with various
electronic properties and spatial characteristics were considered to
explore the relationship between structure and pesticide activity.
The results indicate that the electron-withdrawing group at posi-
tion 11’ on the aryl ring B plays a unique role in enhancing the
Corrected mortality =
Observed mortality in treatment − observed mortality in control
100 − Control mortality
×100
Number of dead larvae
Number of larvae introduced
Percentage mortality =
× 100
The LC50 and LC90 were calculated from toxicity data using pro-
2.2.2. Efficacy of Analogs (T1-T8) for anti-Juvenile hormone activity
(Pesticidal action)
When the pest crop is on full destruction to the host; the need
is felt for the immediate action of in use IGRs. The diverse con-
centration of these in use IGRs; Pyriproxyfen (T1) and Fenoxycarb
(T2) ranging from 1000 ppm to 10,0000 ppm, in acetone on a w/v
basis, has been used for testing against lepidopteran insect species
to show pesticidal effects [3,25,31,52].
The work presented here is a part of the pest management pro-
gram carried out in our laboratory. In this paper, we report synthe-
sis, characterization, in vivo testing, Docking, ADMET, and HOMO-
LUMO study of JHAs having sulfur group, L-amino acid, and aniline
derivative having lipophilic group along with hydrophobic termi-
nations at the ends of the main chain with JHBP of G. mellonella
Larvae of the fourth instar of G. mellonella were collected and
maintained for the treatment. Acetone solution (2 ml) containing
the analog was poured on the filter paper in each petri dish and
allowed to evaporate. Later, the counted number of larvae to be
treated was transferred to the Petri dishes and applying the dif-
ferent concentrations of the analogs to them. The mortality rate
was noted for each of the replication sets. Each treatment involved
three replicates with each replicate containing ten insects. The
same procedure has been applied for all the analogs (T1-T8).
Different concentrations ranging from 250 ppm to 2000 ppm
have been prepared to check the immediate action of all the syn-
thesized analogs with a lesser exposure period (2-10 hours). Syn-
thesized analogs (T3-T8) and in use IGRs (T1 &T2) did not show any
visible change in the insect behavior up to 750 ppm for ten hours
of exposure period but changes were seen at 1000 ppm from four
hours to ten hours exposure period. 2 ml volume of each has been
used for in vivo study.
Materials and Methods
2.1. General methods and material for the synthesis
Chemical reagents and solvents used were purchased from
Sigma Aldrich of 99% purity grade.
Analogs (T3-T8) have been synthesized in our laboratory using
a simple reaction scheme (Fig. 2). The progress of the reaction was
monitored by thin-layer chromatography (TLC).
The following solvent systems were employed – a. Benzene:
Methanol (8:2), b. Ether: Pet-Ether: Ethyl acetate (5:5:2).
Melting points were determined on a hot-stage apparatus and
are uncorrected. Each compound was synthesized and verified
by spectroscopic methods. FT-IR spectra were recorded on Perkin
Elmer 1600 spectrophotometer with the samples as compressed
2.2.3. Statistical analysis
For IGR action the data were subjected to analysis of variance.
The average larval mortality data were further subjected to pro-
bit analysis for calculating LC50 and LC90 values [28]. For pesticidal
action, the data were grouped according to the number of analogs
(T1 to T8), concentration (C in ppm), and exposure time (I in hours)
and subjected to analysis of variance. Further data were statisti-
cally analyzed to calculate the critical difference (CD) at P ≤0.05.
KBr pellets ranging from 4000 to 400 cm−1 1H and 13C NMR spec-
.
tra were recorded using a Brucker Avance 400 MHz spectropho-
tometer operating at room temperature in DMSO d6 as the solvent.
The electron spray ionization-mass spectroscopy (ESI-MS) analyses
were carried out in positive ion modes using a Water Q of Micro-
mass.
2.3. Principle of Molecular docking using AutoDock 4.2
AutoDock 4.2 an automated docking tool (The Scripps Research
Institute La Jolla, CA 92037-1000, U.S.A.) has been used for the
present study to predict the mode of binding of JH Analogues to a
receptor protein. The semiempirical force field evaluates binding in
two steps. In the first step, intramolecular energetics is estimated
for the transition from unbound states to the bound state whereas
the second step evaluates the intermolecular energetics of combin-
ing the ligand and protein in their bound conformation. The force
field includes six pair-wise evaluations (V) and estimates the con-
formational entropy lost upon binding (ꢀSconf):
2.2. Rearing of the insect model
An artificial diet has been developed for mass rearing of Galleria
mellonella in our laboratory (temperature 27 1°C, relative humid-
ity 65 5 % and 16:8 hr scoto-photo-phase regime) and prepared
by a well-defined method with some modifications [5].
In vivo efficacy of Analogs (T1-T8) as IGRs
A laboratory-reared colony of G. mellonella larvae was used for
IGR activity. Ten larvae of fourth instars were kept in a 500 ml
glass beaker. The diverse concentration of all analogs (T1-T8) rang-
ing from 10 ppm to 100 ppm, in acetone on w/v basis, has been
used for testing against lepidopteran insect species to show IGR
effects. The control mortalities were corrected by using Abbott’s
ꢀ
ꢀG = V
ꢀ
ꢁ
ꢀ
ꢁ
L−L
L−L
P−P
P−P
− V
+ V
− ꢀScon f
− V
bound
unbound
bound
unbound
P−L
P−L
+ V
− V
bound
unbound
(L refers to the “ligand” and P refers to the “protein” in a ligand-
3