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Natural Products from the Amazon Region as Potential Antimicrobials
Published in Mahendra Rai, Chistiane M. Feitosa, Eco-Friendly Biobased Products Used in Microbial Diseases, 2022
Josiane E. A. Silva, Iasmin L. D. Paranatinga, Elaine C. P. Oliveira, Silvia K. S. Escher, Ananda S. Antonio, Leandro S. Nascimento, Patricia P. Orlandi, Valdir F. Veiga-Júnior
For instance, the EO of Copaifera reticulata has as the major diterpenes, copalic and kaurenoic acids (Fig. 2.8). Both of these are known for their remarkable properties, such as in vitro antibacterial activity, antifungal activity against dermatophytes, as an antiallergic, an immunosuppressive, apoptosis-inducing activities and antitrypanosomal activity. In addition, kaurenoic acid is being suggested to be included in medicine for the treatment of breast cancer, hypertension, Alzheimer’s, atherosclerosis and lung cancer, due to its interactions with the progesterone and mineralocorticoid receptors and myeloperoxidase enzyme (Katsuyama et al. 2013; Fidyt et al. 2016; Tobouti et al. 2017; Arruda et al. 2019).
Chemical Hybridization Approaches Applied to Natural and Synthetic Compounds for the Discovery of Drugs Active Against Neglected Tropical Diseases
Published in Venkatesan Jayaprakash, Daniele Castagnolo, Yusuf Özkay, Medicinal Chemistry of Neglected and Tropical Diseases, 2019
Elena Petricci, Paolo Governa, Fabrizio Manetti
A small library of hybrid kaurenoid terpenes and 1,2,3-triazoles was prepared by using a convergent approach involving a Huisgen’s reaction to generate regioselectively the triazole ring (de Oliveira Santos et al. 2016) (Figure 27). The modification of the natural kaurenoic acid derivatives yielded a more active analogue 98 that still had poor activity (micromolar range in W2 P. falciparum) and higher toxicity in Hep G2A16 cells with respect to chloroquine, taken as the reference compound. None of the hybrids prepared showed a promising antimalarial activity, even when a chloroquine moiety was introduced as in 99 and 101. The best results in terms of potency were obtained by introducing a 3-pyridine ring on the triazole (100 and 102). In summary, the triazole moiety seemed to have a negative impact on the antimalarial profile of kaurenoic acid derivatives, as well as the introduction of other substituents in the skeleton, as demonstrated by 103. Kaurenoic acid-triazole hybrid compounds.
Phytotherapeutic Agents in Epilepsy
Published in Vikas Kumar, Addepalli Veeranjaneyulu, Herbs for Diabetes and Neurological Disease Management, 2018
The herbal preparations of the root bark of Annona senegalensis Pers. (Fam. Annonaceae) have been employed in Nigerian ethnomedicine for the treatment of epilepsy and febrile seizures. Recently, a bioassay guided fractionation of the root bark extract of A. senegalensis has been carried out using PTZ-induced seizures in mice, affording a diterpenoid, kaur-16-en-19-oic acid (kaurenoic acid) exhibiting potent anticonvulsant effects.64 The postulated mechanism is via the enhancement of central inhibitory mechanisms mediated by GABAA-receptor chloride channel complex.64 Kaurenoic acid has also been isolated from the aerial parts of Espeletia semigloburata Cuatrec. (Compositae) demonstrating potent anticonvulsant and sedative activities.65 There have been other reports on the isolation of kaurenoic acid from the leaves of A. senegalensis66,67 and root extract of Viguiera arenaria Baker (Asteraceae).68
Antibacterial activity and physicochemical properties of a sealer containing copaiba oil
Published in Biofouling, 2023
Lara Rodrigues Schneider, Andressa da Silva Barboza, Juliana Silva Ribeiro de Andrade, Daniela Coelho dos Santos, Carlos Enrique Cuevas-Suárez, Evandro Piva, Angela Diniz Campos, Rafael Guerra Lund
Copaiba oil is obtained from the Copaifera sp. tree. This oil product is a herbal medicine used based on its antibacterial, anti-inflammatory, anesthetic, healing, and antineoplastic effects (Garrido et al. 2010; Simões et al. 2016). Its composition consists of mixtures of sesquiterpenes and diterpenes. Spectrophotometry allowed identifying the most common structures in these diterpenes, which are copalic acid, hardwickiic acid, and kaurenoic acid. The diterpenes in the plants work on the bacterial cell components, increasing permeability to the bacterial cell wall, and the terpenoids work through the membrane, swell the bacterial cell and interfere with the pH gradient, resulting in cell damage. Furthermore, the oxide provided by beta-caryophyllene works directly on fungi inhibition. This may be a potential antimicrobial action mechanism of the copaiba oil (Bardají et al. 2016). Considering the good antimicrobial activity of this compound, in recent years, a series of investigations have supported the hypothesis that adding these natural compounds to dental products can be an effective alternative to release therapeutic agents, representing great potential (Simões et al. 2016; Agrawal et al. 2017; Saha et al. 2019; dos Santos et al. 2021).
Cytotoxic compounds from the leaves and stems of the endemic Thai plant Mitrephora sirikitiae
Published in Pharmaceutical Biology, 2020
Natthinee Anantachoke, Duangporn Lovacharaporn, Vichai Reutrakul, Sylvie Michel, Thomas Gaslonde, Pawinee Piyachaturawat, Kanoknetr Suksen, Samran Prabpai, Narong Nuntasaen
The isolation of the leaf extract using chromatographic techniques and recrystallization resulted in the isolation of a new lignan, mitrephoran (6), together with five known lignans 1–3, 7, and 8, one known steroidal glycoside 4, and four known alkaloids 5, 9, 10, and 11. Moreover, the separation of the stem extract also yielded compounds 1, 4, 5, and 11 (as for the leaf extract), together with three known diterpenoids 12–14, and two known alkaloids 15 and 16. Compounds 1–5 and 7–16 were identified as (–)-epieudesmin (1) (Kaku and Ri 1937; Ahmed et al. 2002), (–)-phylligenin (2) (Rahman et al. 1990), magnone A (3) (Jung et al. 1998), stigma-5-en-3-O-β-glucopyranoside (4) (Faizi et al. 2001), liriodenine (5) (Zhang et al. 2002; Chiu et al. 2012), 3′,4-O-dimethylcedrusin (7) (Pieters et al. 1993; Rayanil et al. 2016), 2-(3,4-dimethoxyphenyl)-6-(3,5-dimethoxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (8) (Wang et al. 2012), N-trans-feruloyltyramine (9) (Kim et al. 2005), dicentrinone (10) (Zhou et al. 2000), oxoputerine (11) (Lu et al. 2011), kaurenoic acid (12) (Batista et al. 2007), ent-trachyloban-19-oic acid (13) (Leong and Harrison 1997; Ngamrojnavanich et al. 2003), ciliaric acid (14) (Ngouela et al. 1998), 6-methoxymarcanine A (15) (Tsai and Lee 2010), and stepharanine (16) (Ingkaninan et al. 2006) (Figure 1) based on their IR, UV, NMR, and MS spectroscopic data and by comparison with previously reported spectroscopic and physical data.