Page 96 - ITPS-8-2

INNOSC Theranostics and
Pharmacological Sciences Transformative natural product-drug combinations

A B

Figure 2. Attenuated total reflectance-Fourier transform infrared spectroscopy spectra of guava extract (A) and reacted guava extract (B). Image
reproduced with permission from Gideon. 26

Table 1. Fourier transform infrared spectroscopy analysis of guava extract and reacted guava extract, including attributed
functional groups. Reproduced with permission from Gideon 26
FTIR functional Wavenumber Guava extract Reacted guava Associated phytochemicals
group region range (cm⁻¹) peaks (cm⁻¹) peaks (cm⁻¹)
O-H/N-H Stretch 3,200–3,600 3,693.8; 3,280.1 3,250.2 Alcohols, phenols, amines, or carboxylic acids
C-H Stretch 2,850–3,000 2,918.5; 2,851.4 - Alkanes
Clkanes Stretch 2,100–2,260 2,109.7; 1,994.1 2,117.1; 1,994.1 Alkynes or nitriles
C=O Stretch 1,630–1,820 1,617.7 1,688.5; 1,610.2 Ketones, aldehydes, esters, or carboxylic acids
N-H Bending 1,500–1,600 - 1,513.3 Primary and secondary amines
C-H Bending 1,400–1,500 1,449.9 1,442.5 Aromatic compounds
Abbreviation: FTIR: Fourier transform infrared spectroscopy.
Saddaf et al.’s results showed that the root extracts of – such as an inorganic/organic acid, alkali, or catalyst –
Bergenia ciliata and Bergenia stracheyi (at 1200 μg/well) and modifying the reaction conditions. For antibacterial
and their synthesized AgNPs (at 150 μg/well) did not applications, multiple plant extracts can be reacted with
inhibit the growth of E. coli, Staphylococcus haemolyticus, different inexpensive antibiotics. The antibiotic must be
or Bacillus cereus. In contrast, the root extracts of Rumex confirmed to be ineffective against the target bacteria, as
dentatus and Rumex hastatus (at 1200 μg/well) were unable using an antibiotic that is fully effective against the bacteria
to inhibit these bacteria, but their synthesized AgNPs of interest could reduce the effectiveness of the final product
(at 150 μg/well) successfully inhibited bacterial growth. if structural changes are made. For example, Gideon and
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According to Saddaf et al. (p321), “the antibacterial Ladan achieved consistent synergistic effects preparing
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activity of each type of AgNPs depends on the surface a mixture of (i) 1 mg/mL amoxicillin with aqueous leaf
modification by plant extract, which makes them effective extract of Calotropis procera; (ii) 1 mg/mL ampicillin
against specific bacteria.” In response to this statement, it with aqueous leaf extract of C. procera; (iii) 100 μg/mL
can be argued that if the modification occurred on AgNPs azithromycin with aqueous leaf extract of C. procera; and
themselves, rather than on the plant extract, lower levels (iv) 100 μg/mL ampicillin with aqueous leaf extract of
of inhibition would have been observed in B. ciliata and C. procera, and reacting each with concentrated sulfuric
B. stracheyi due to the contributory effect of silver’s inherent acid at 110°C for 20 min. Greater zones of inhibition
antimicrobial activity. Instead, it is the modification of were observed, as shown in Figure 3. The clear zones of
the phytoconstituents in these aqueous root extracts that inhibitions in Figure 2 predominantly reflect the acid-
promotes antimicrobial functionality, as demonstrated by treated plant extract in combination with the antibiotics.
Gideon. 26 This method increased the synergism of the plant extract-
antibiotic combinations, enhancing their effectiveness
2.2. Strategy 2 from 33% (as reported by Eze et al., Moussaoui and
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This strategy involves initiating a reaction between a single Alaoui, and Haq et al. ) to 100% at 1 mg/mL.
plant extract and an ineffective drug, known for treating the In a follow-up study by Gideon et al., GC-MS analysis
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disease of interest. The process includes adding a reagent of combination (i) from Gideon and Ladan’s study was
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Volume 8 Issue 2 (2025) 90 doi: 10.36922/itps.4068