**3. Phytochemical components and pharmacological potential of Jimson weed**

The phenolic compounds (metabolites) present are linked to the biological functions assigned to the genus Datura. Plants create these chemicals in both their primary and secondary metabolism [5]. Plants' primary metabolites play a direct role in their growth, development, and reproduction, whereas secondary metabolites play *Pharmacological, Biopesticide, and Post-Harvest Loss Management Application of Jimsonweed… DOI: http://dx.doi.org/10.5772/intechopen.102789*

an ecological role [6]. Different classes of phenolic compounds, such as terpenoids, flavonoids [7], steroids [8, 9], lectins [10, 11], glycosides, fatty acids, saponins [12], tannins [13], phenolic compounds [14], withanolides [15], and various volatile terpenes [16, 17], have been identified in *Datura* species.

#### **3.1 Phenolic compounds**

In methanolic and hydroalcoholic extracts, the existence of distinct classes of phenolic compounds in the genus Datura has been demonstrated. Flavonoids, tannins, and glycosidic phenolic substances are found in *D. metel* and *D. stramonium* [12].

In diverse solvent fractions such as ethyl acetate, butanol, hexane, chloroform, and methanol, Hossain et al. [14] investigated the existence of phenolic compounds in *D. metel*. Gallic acid, vanilic acid, quercetin, and ferulic acid were identified as the primary phenolic components in the methanolic extracts of *D. metel* roots and leaves [18].

On the other hand, LC-ESI-MS/MS analysis of the methanolic extract of *D. innoxia* aerial organs revealed the presence of 20 distinct phenolic compounds, with (−)-epicatechin, (+)-catechin, hyperoside, and p-coumaric acid being the most abundant metabolites detected [19].

#### *3.1.1 Withanolides*

Withanolides are steroidal lactones that have been identified from various Solanaceae genera [20]. Biological actions such as anti-inflammatory, antioxidant, anticancer, insecticide, antifood, and immunosuppressive characteristics have been found for these substances [20]. Within the genus *Datura (daturalactones)*, various withanolides have been identified and described, distinguishing themselves by having an epoxy in the lactone ring [21]. Five with anolides were discovered in the aerial portions (flowers, leaves, and stems) of *D. quercifolia Kunth* that have modest cytotoxic and prooxidant effects, as well as acetylcholinesterase inhibitory activity [22].

*D. metel* leaves have yielded a number of previously unknown withanolides, two of which exhibit anti-inflammatory properties [23]. In addition, 13 others with anolides were isolated from *D. metel* flowers and showed immunosuppressive properties against splenocyte proliferation in mice, as well as activity *in vitro* against human gastric adenocarcinoma cell proliferation (SGC-7901), human hepatoma (HepG2), and human breast cancer cell proliferation (HepG2) (MCF-7) [24].

#### *3.1.2 Terpenes*

Datura produces volatile substances that protect plants from herbivore harm by having varying quantities and types of glandular and non-glandular trichomes [25]. *D. wrightii* contains 17 volatile chemicals, the majority of which are sesquiterpenes (**Figure 2**), such as limonene, linalool, (E)-3,8-dimethyl-1,4,7-nonatriene (DMNT), and (E)—ocymene, with (E)—caryophyllene being the most common [25].

#### *3.1.3 Lectins*

*D. stramonium* and other Solanaceae have been found to contain lectins, a category of carbohydrate-specific binding proteins [26]. The biological role of lectins is controversial, albeit due to their toxicity in both mammals and insects, a defensive role for plants has been hypothesized [27].

#### **Figure 2.**

*Structure of some isolated volatile compounds (terpenes) in the genus Datura in response to insect damage.*

The chitin-binding lectin *D. stramonium* agglutinin (DSA) has been isolated and purified from *D. stramonium* seeds [28]. In diabetic patients, the use of *D. stramonium* agglutinin in lectin microarrays has been used to identify kidney diseases. The amount of nacetyl-D-glucosamine (GlcNAc) coupled to (−1,4)-linked N-acetyl-Dglucosamine identified by lectin *D. stramonium* agglutinin (DSA) was significantly higher in individuals with diabetic nephropathy, according to the results of lectin microarrays [29].

#### *3.1.4 Alkaloids*

*Datura* has a diverse phytochemical makeup of tropane-type alkaloids, which are the plant's most potent chemicals [30, 31].

Tropane alkaloids, in particular, are a collection of roughly 200 alkaloids with a tropane ring (N-methyl-8-azabicyclo in their chemical structure, with L-ornithine as the major precursor) [32]. Atropine (hyoscyamine) and scopolamine (hyoscine) are the most prevalent alkaloids in the genus *Datura* [33].

The alkaloid fraction of *D. ceratocaula* revealed 36 compounds with a distinctive mass fragmentation spectrum, with atropine being the most abundant alkaloid in seed and scopolamine being the most abundant alkaloid in flowers [34]. Atropine and scopolamine were found in similar abundances in *D. ferox*, with 0.32 g of scopolamine per 100 g of dry plant material [35].

Scopolamine and atropine were the major alkaloids, with quantities changing based on the region of the plant [36]. The most abundant alkaloids in *D. quercifolia* are tropinone, tropine, pseudotropine, atropine, and scopolamine [37].

In the species *D. stramonium*, at least 67 tropane alkaloids (**Table 1**) have been found in various sections of the plant. Tropine, 3-tigloyloxy-6-propionyloxy-7-hydroxytropane, and 3,6-ditigloyloxy-7-hydroxytropane [38] have been identified as the most prevalent, alongside atropine and scopolamine. Okwu and Igara [39], on the other hand, discovered one steroidal alkaloid in *D. metel* that had antibacterial activity.

#### **3.2 The biological functions of the Datura**

#### *3.2.1 Insecticide action*

Different writers have looked at the insecticidal and repellant properties of *Datura* species. In contact and spray application experiments, leaf extracts of *D. metel* (acetone, water, and petroleum ether) have been shown to exhibit insecticidal and insect repellent activity against a variety of insect species. In organic extracts of *Pharmacological, Biopesticide, and Post-Harvest Loss Management Application of Jimsonweed… DOI: http://dx.doi.org/10.5772/intechopen.102789*


#### **Table 1.**

*Most abundant tropane alkaloids identified in the genus Datura [33, 37, 38].*

*D. metel*, EC50 values of 12,000 ppm for grasshoppers and 11,600 ppm for red ants were found [31]. In the case of *D. stramonium*, pesticide activity has been assessed in non-polar extracts in adult individuals and larvae of various insects, both by contact and by food [27].

The larvicidal efficacy of *D. stramonium* aqueous root extract was tested on two mosquito species and found to be between 50 and 100 percent larval mortality at 100 percent concentration of the extracts 24 hours after treatment [40]. Different quantities of an aqueous extract of *D. stramonium* leaves and seeds were shown to be effective against flea beetles, a common maize pest [41].

The toxic effect of acetone extracts from *Datura inoxia* was evaluated against *Tribolium castaneum*, *Trogoderma granarium*, and *Sitophilus granarius*, where the plant extracts were observed in addition to the inhibition of enzymes acetylcholinesterase, carboxylesterase, acid phosphatases, and alkaline phosphatases (ALP) in toxicity test survivors [41].

#### *3.2.2 Herbicidal*

In aqueous and methanolic extracts, *D. metel* has shown possible herbicidal efficacy against "noxious weed parthenium," with the root showing superior effects to the stems, with both extracts reducing weed germination as well as stem development in individuals of a few weeks [1]. Similarly, germination inhibition was seen in methanolic and hexane root extracts of *D. metel* when it was tested for herbicide action against Phalaris minor.

Sakadzo et al. [42] found that an aqueous extract of *D. stramonium* inhibited root development, plumule length, and dry matter amount in *Amaranthus hybridus* and Tegetes minuta, with herbicidal effects both pre- and post-emergence.

#### *3.2.3 Acaricide activity*

The methanolic extracts of *D. stramonium* leaves and seeds showed acaricidal effects, with 98 percent mortality of adult Tetranychus urticae Koch (spider mites) in the leaf extract and 25 percent mortality in the seed extract, with a direct relationship between concentration and mortality rate for the leaf extracts but not for the seed extracts [7].

In adult mite immersion trials, an ethanolic extract from *Datura stramonium* leaves caused 20% mortality against *Rhipicephalus microplus* (Asian blue tick) [43]. *In vitro* experiments showed that the methanolic extract of *D. stramonium* inhibited the oviposition of Rhipicephalus (Boophilus) microplus by 77% [44].

#### *3.2.4 Antifungal activity*

Three members of the genus, *D. discolor, D. metel, and D. stramonium*, were tested for antifungal activity. Ethanolic and methanolic extracts from D. discolor stems and leaves were combined with culture medium to prevent the growth of Aspergillus flavus, Aspergillus niger, Penicillium chrysogenum, Penicillium expansum, Fusarium moniliforme, and Fusarium poae [12].

Rhizoctonia solani was inhibited by aqueous and methanolic extracts of *D. metel* leaves. D. metel's methanolic extract was up to 35 percent more toxic than the other 15 species investigated, preventing mycelial growth and being used in agriculture (herbicide, acaricide, insecticide) and medicine (antibacterial, cytotoxic, or antioxidant) production of sclerotium [15].

Furthermore, extracts of all parts of *D. metel* in various solvents (hexane, chloroform, acetone, and methanol) showed antifungal activity against three Aspergillus species: *A. fumigatus*, *A. niger*, and *A. flavus*, with the chloroform fraction having the lowest inhibitory concentration (MIC) of 625.0 g/mL [45].

The growth inhibition of five fungal species: *A. flavus*, *A. niger*, Alternaria solani, Fusarium solani, and Helianthus sporium used to assess the antifungal efficacy of methanol extracts from the leaves, seeds, stems, and roots of *D. inoxia* [46].

The antifungal activity of *D. stramonium* extracts on *Candida albicans* was stronger in aqueous extracts (74 percent), while methanol and chloroform extracts had good inhibitory activities (69 percent and 65 percent, respectively) [47].
