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Total Synthesis of Some Important Natural Products from Brazilian Flora
Published in Luzia Valentina Modolo, Mary Ann Foglio, Brazilian Medicinal Plants, 2019
Leonardo da Silva Neto, Breno Germano de Freitas Oliveira, Wellington Alves de Barros, Rosemeire Brondi Alves, Adão Aparecido Sabino, Ângelo de Fátima
Tephrosin (76; Figure 12.19) was isolated by Braz-Filho et al. (1975) from the ethanolic extract of the aerial wood of D. urucu (Fabaceae; basionym: Derris urucu and Lonchocarpus urucu; timbó-urucu) and by Parmar et al. (1988) from the seeds of Tephrosia candida (Fabaceae; tefrósia or anil branco) (ANVISA, 2010; Flora do Brasil, 2020i). In 2010, Garcia et al. reported a convergent total synthesis with seven steps starting from 3,4-dimethoxyphenol with an 8% overall yield. The main step for the synthesis is the convergence step between the routes, a coupling between the key intermediates 77 and 78 under Mitsunobu conditions followed by cyclization with Grubb's second-generation catalyst to afford intermediate 79 (Garcia et al., 2010).
On Biocatalysis as Resourceful Methodology for Complex Syntheses: Selective Catalysis, Cascades and Biosynthesis
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
Andreas Sebastian Klein, Thomas Classen, Jörg Pietruszka
Alternatives for total synthesis can be found in biosynthesis and the synergy potential by combining chemistry and biology. In the following, methodological approaches like semisynthesis, altered biosynthesis, precursor-directed biosynthesis, and mutasynthesis (Fig. 21.10) are describing the aim at optimizing biosynthesis and the production of natural product derivatives.
African Traditional Medicine
Published in Charles Wambebe, African Indigenous Medical Knowledge and Human Health, 2018
It is also worthy of note that research and development of herbal medicines is often constrained by the relatively smaller quantities of biologically active ingredients they contain, which makes large-scale production and commercialization extremely difficult. For this reason, the pharmaceutical industry would prefer total synthesis from sources that would provide higher yields or from structural analogues that frequently have more pharmacological activity than the parent compound (Ekong, 1986; Nworgu et al., 2007).
Recent progress in chemistry and bioactivity of monoterpenoid indole alkaloids from the genus gelsemium: a comprehensive review
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2023
Lin Wang, Siyu Chen, Xun Gao, Xiao Liang, Weichen Lv, Dongfang Zhang, Xin Jin
Jin’s group (2014) previously reviewed the phytochemistry, pharmacology, and toxicology together with their traditional use of the genus Gelsemium, whereas Carter’s group (2019) described the synthetic strategies towards the gelsemine- and gelsedine-type MIAs between 2005 and 201614,15. However, these reviews did not provide a comprehensive review of all types of gelsemium MIAs, especially in aspects of their frontier pharmacological effects as well as chemical structures and syntheses. A large number of breakthroughs in their novel compounds, biological activities, and more elegant total syntheses have been reported over the past decade. As such, this review is intended to comprehensively summarise the representative examples covering from 2013 to 2022 with the following novel objectives: (1) a comprehensive presentation of novel gelsemium MIAs and more elegant total synthetic methodologies; (2) a focus on recent their bioactivities of gelsemium MIAs, mainly involving specific biotarget and mechanism of actions; (3) an overview of advice how gelsemium MIAs can be utilised as promising candidates in further studies. Finally, we hope that this review will provide an insight into rational study and development of gelsemium MIAs and their derivatives in further clinical practice.
Schweinfurthin induces ICD without ER stress and caspase activation
Published in OncoImmunology, 2022
Ruoheng Zhang, J.D. Neighbors, T.D. Schell, R.J. Hohl
The schweinfurthins were discovered in an African plant (Macaranga schweinfurthii) and then evaluated by Dr. John Beutler at the NCI developmental therapeutics program.16 Since then, several additional compounds have been isolated from this and other species of the genus Macaranga.18–21 Some of these compounds show interesting potent (nanomolar) activity against cancers from the brain and renal panels of the 60 cell screen, while showing 1000 fold less activity against ovarian and some lung cancers.22 The pattern of activity is novel and is not correlated to any currently approved chemotherapy agents, and only a few other diverse compounds show a correlated pattern.22 Because these compounds were difficult to isolate from nature, a total synthesis effort was undertaken by us which has resulted in the synthesis of around 100 active analogs considerably expanding the structure activity understanding of the chemo type.23–26 These compounds have been used by our group and others in studies attempting to discover their cellular target.
Antifouling activity of portimine, select semisynthetic analogues, and other microalga-derived spirocyclic imines
Published in Biofouling, 2018
Darby G. Brooke, Gunnar Cervin, Olivier Champeau, D. Tim Harwood, Henrik Pavia, Andrew I. Selwood, Johan Svenson, Louis A. Tremblay, Patrick L. Cahill
In its native form, 1 is unlikely to be suitable for commercial scale production as an AF biocide because supply from natural sources is limited and total synthesis is chemically challenging. However, truncated versions of 1 (eg a 5-membered cyclic imine pharmacophore) may be commercially synthesisable, or chemically less challenging compounds with identical mechanisms of action could be identified. Synthetic efforts are underway (Aitken 2016), as are more detailed investigations of subcellular mode of action (Cuddihy et al. 2016). A terrestrial analogy is seen in species of the fungal genus of Strobiluris, which produce antifungal compounds (strobilurins) that suppress overgrowth by non-Strobiluris fungi via inhibition of Complex III of the respiratory chain. Total syntheses of several strobilurins have been reported (e.g. Anke et al. 1984; Sutter, 1989; Uchiro et al 2001; Kroiß and Steglich, 2004, Brooke and Morris 2008), and a plethora of synthetic strobilurins are being used commercially as agricultural fungicides (Balba 2007).