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Almoshadak

The total terpenoid content of S. monoica (mg/g DM) determine their identities, molecular weights, and other
was estimated by reacting the extracts with chloroform, attributes.
adding concentrated sulfuric acid, incubating, and
measuring absorbance at 532 nm, with linalool used as 2.7. Mineral analysis of plant and soil samples
a standard terpenoid. 27 The root and leaf powders, alongside the soil samples
collected, underwent wet digestion procedures utilizing
2.5. Antioxidant activity of root and shoot extracts a mixture of 65% nitric acid and 30% hydrogen peroxide
The electron-donating activity of S. monoica extracted (5:2 v/v). Digestion vessels were subjected to heating
with ethanol was determined by assessing its ability in a sand bath on a hot plate, reaching temperatures
to bleach the purple color of the 1,1-diphenyl-2- between 95°C and 135°C until the solutions were
picrylhydrazyl (DPPH). A 0.1 mL extract sample was clear. Post-cooling, the clear solutions were filtered,
28
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added to 3.9 mL of a 36 mg DPPH-methanol solution. transferred into volumetric flasks, and diluted to their
After a 60-min dark incubation, the absorbance final volumes using deionized water. The concentrations
was measured at 515 nm relative to a blank. The of the selected heavy metal ions (aluminum [Al],
decrease in the DPPH free radical was quantified as a cadmium [Cd], cobalt [C], chromium [Cr], copper [Cu],
percentage (%). nickel [Ni], lead [Pb], and zinc [Zn]) within the digested
The total antioxidant capacity (TAC) of S. monoica samples were quantified utilizing inductively coupled
ethanolic extracts was quantified using the procedure by plasma-optical emission spectroscopy (Polyscan 61E,
Ahmed et al. A mixture of 3 mL phosphomolybdate Thermo Jarrell-Ash Corp., United States).
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reagent, and 300 µL of the ethanolic extract or standard
ascorbic acid was incubated at 95°C for 90 min. After 2.8. Statistical analysis
cooling, the absorbance was recorded at 765 nm, and All analyses were conducted in triplicate, and the results
the TAC was expressed in µg ascorbic acid equivalent were presented as the mean of three replicates ± the
(AAE)/g DM. standard deviation. Statistical analysis was performed
using a one-way analysis of variance to separate means,
2.6. Phytochemical active constituents of S. monoica with the least significant difference post hoc test utilized
leaf extracts using gas chromatography‑mass at a significance threshold of p≤0.05. The statistical
spectrometry software Statistical Package for Social Sciences
To determine the phytochemical composition of the version 19.0 was utilized to conduct all statistical
leaf extracts of S. monoica collected from the study assessments of the obtained data. Using the Origin
sites in Jeddah, a Clarus 580/560S mass spectrometer software (SPSS version 19.0), the Pearson correlation
(PerkinElmer, United States) was utilized. The coefficients were employed to determine the level and
chromatographic column employed for separation type of the relationship between each pair of determined
was an Elite-5MS with a length of 30 m length, an attributes.
internal diameter of 0.25 mm, and a film thickness of
0.25 µm. The temperature program for the oven was 3. Results and discussion
meticulously controlled: initially set at 35°C, ramped
up at a rate of 8°C/min to 150°C with a 3-min hold 3.1. Physical and chemical soil properties of the
time, and subsequently increased at a rate of 10°C/min study sites
to reach 280°C. Inlet and transfer lines were kept at The data in Table 2 delineates the variation in the
250°C. Helium was used as the carrier gas at 1 mL/min. physical and chemical properties among the three
To inject 1 µL aliquots from diluted samples, the investigated soil sites where S. monoica was collected.
Autosampler AS3000 (Thermo Fisher Scientific, United Statistically, all studied parameters varied significantly
States) was used in split mode with a solvent delay of (p<0.05) across the collection sites. The obtained data
3 min. In full scan mode, a 70 eV ionization voltage was revealed that site S1 exhibited the highest pH (7.47), EC
used to capture the mass spectrum from 40 to 650 m/z. (2.93 mS/cm), and TDS (4,052 mg/L) among the sites.
Flame ionization detection identified the components Conversely, the soil at site S3 demonstrated a propensity
after chromatographic separation. Their spectra toward neutrality (pH 7.06) with lower salinity levels
were rigorously examined against the recognized (EC, 0.53 mS/cm) and TDS (2,185 mg/L). Notably, OM
National Institute of Standards and Technology’s Mass was most abundant at site S3 (1.65%) and lowest at site
Spectrometry 2.0 structural database compounds to S2 (0.45%).

Volume 22 Issue 3 (2025) 50 doi: 10.36922/ajwep.8523