Total synthesis of indole and dihydroindole alkaloids. X.1,2 The preparation of novel oxygenated catharanthine derivatives

1977 ◽  
Vol 55 (18) ◽  
pp. 3227-3234 ◽  
Author(s):  
James P. Kutney ◽  
Gordon H. Bokelman ◽  
Masahiro Ichikawa ◽  
Edwin Jahngen ◽  
Alummoottil V. Joshua ◽  
...  

Detailed investigations involving the electrophilic attack of various reagents on the 3,4-double bond of catharanthine derivatives (e.g. 3, R = O) furnished a series of novel derivatives of potential use in the syntheses of naturally occurring bisindole alkaloids. These studies include such reagents as peracid, osmium tetroxide, and positive iodine.

2020 ◽  
Vol 24 (9) ◽  
pp. 1503-1507
Author(s):  
S.O. Okopi ◽  
L.M. Affiku

Methyl eugenol is a naturally occurring substance found in the essential oils of several plant species. It is a cheap and abundant material with a rather limited interest as perfuming ingredient. This research investigated the structure-odour relationship of methyl eugenol and its derivatives, focusing on the chemical transformation of the double bond to hydroxyether derivatives in a controlled manner. Two derivatives 2-(4-ethyl- 3-methoxybenzyl)oxirane (68.8% yield) and 1-(3,4-dimethoxyphenyl)-3-ethoxypropan-2-ol (63.58% yield), were synthesized from methyl eugenol. This research found that the odour characteristic of 2-(4-ethyl-3-methoxybenzyl)oxirane[floral, fresh, slight lime and sweet]compounds, is clearly different from the odours of the 1-(3,4-dimethoxyphenyl)-3-ethoxypropan-2-ol [Glue-like, pungent, and Caramel-like]. It is evident from our observations that double bond substitution and functional alteration of the methyl eugenol modifies the perceived odour of methyl eugenol  derivative. Thus, structural modification overall led to an increase in odour potency. Keywords: Fragrance, Methly-Eugenol, Ether, Olfactory characteristic, Epoxidation.


Marine Drugs ◽  
2021 ◽  
Vol 19 (12) ◽  
pp. 661
Author(s):  
Irene Torres-García ◽  
Josefa L. López-Martínez ◽  
Manuel Muñoz-Dorado ◽  
Ignacio Rodríguez-García ◽  
Miriam Álvarez-Corral

Organic extracts of marine invertebrates, mainly sponges, from seas all over the world are well known for their high in vitro anticancer and antibiotic activities which make them promising sources of compounds with potential use as pharmaceutical leads. Most of the structures discovered so far have a peculiar structural feature in common: a 1,2-dioxane ring. This is a highly reactive heterocycle that can be considered as an endoperoxide function. Together with other structural features, this group could be responsible for the strong biological activities of the substances present in the extracts. Numerous research programs have focused on their structural elucidation and total synthesis since the seventies. As a consequence, the number of established chiral centres and the similarity between different naturally occurring substances is increasingly higher. Most of these compounds have a terpenoid nature, mainly diterpene and sesterterpene, with several peculiar structural features, such as the loss of one carbon atom. Although there are many reviews dealing with the occurrence of marine peroxides, their activities, or potential pharmaceutical uses, no one has focused on those having a terpene origin and the endoperoxide function. We present here a comprehensive review of these compounds paying special attention to their structural features and their biological activity.


2005 ◽  
Vol 77 (7) ◽  
pp. 1131-1137 ◽  
Author(s):  
Janine Cossy ◽  
Christophe Meyer ◽  
Magali Defosseux ◽  
Nicolas Blanchard

A total synthesis of the naturally occurring ionophore zincophorin has been realized. The key steps are an intramolecular oxymercuration of a cyclopropanemethanol for the elaboration of the tetrahydropyran ring and a Carroll–Claisen rearrangement to control the configuration of the double bond at C20–C21 as well as the stereogenic center at C21.


1969 ◽  
Vol 47 (6) ◽  
pp. 603-610 ◽  
Author(s):  
Erich Baer ◽  
G. Raghltpati Sarma

The first synthesis of a naturally occurring C18-ceramide aminoethylphosphonate is described. The erythro-N-palmitoyl-D-sphingosyl-1-(2-aminoethyl)phosphonate was obtained by phosphonylation of erythro-N-palmitoyl-3-0-benzoyl-D-sphingosine with (2-phthalimidoethyl)phosphonic acid chloride and triethylamine, and consecutive removal of the protective phthaloyl and benzoyl groups of the reaction product, erythro-N-palmitoyl-3-0-benzoyl-D-sphingosyl-1-(2-phthalimidoethyl)phosphonate, by hydrazinolysis and mild alkaline hydrolysis, respectively. The unnatural l isomer was prepared in an analogous manner from erythro-N-palmitoyl-3-0-benzoyl-L-sphingosine. Comparison of the synthetic and natural ceramide aminoethylphosphonates confirmed the structure tentatively assigned by Rouser, Hori, and Hayashi and their colleagues to the C18-ceramide aminoethylphosphonates of a variety of shellfish, snails, and cephalopods, and established the fact that the natural ceramide aminoethylphosphonates are derivatives of D-sphingosine.


2014 ◽  
Vol 10 ◽  
pp. 1246-1254 ◽  
Author(s):  
Zbigniew Pakulski ◽  
Norbert Gajda ◽  
Magdalena Jawiczuk ◽  
Jadwiga Frelek ◽  
Piotr Cmoch ◽  
...  

The reaction of appropriately functionalized sucrose phosphonate with sucrose aldehyde afforded a dimer composed of two sucrose units connected via their C6-positions (‘the glucose ends’). The carbonyl group in this product (enone) was stereoselectively reduced with zinc borohydride and the double bond (after protection of the allylic alcohol formed after reduction) was oxidized with osmium tetroxide to a diol. Absolute configurations of the allylic alcohol as well as the diol were determined by circular dichroism (CD) spectroscopy using the in situ dimolybdenum methodology.


2021 ◽  
Vol 22 (6) ◽  
pp. 2855
Author(s):  
Anna Janeczko ◽  
Jana Oklestkova ◽  
Danuše Tarkowská ◽  
Barbara Drygaś

Ecdysteroids (ECs) are steroid hormones originally found in the animal kingdom where they function as insect molting hormones. Interestingly, a relatively high number of these substances can also be formed in plant cells. Moreover, ECs have certain regulatory effects on plant physiology, but their role in plants still requires further study. One of the main aims of the present study was to verify a hypothesis that fenarimol, an inhibitor of the biosynthesis of ECs in the animal kingdom, also affects the content of endogenous ECs in plants using winter wheat Triticum aestivum L. as a model plant. The levels of endogenous ECs in winter wheat, including the estimation of their changes during a course of different temperature treatments, have been determined using a sensitive analytical method based on UHPLC-MS/MS. Under our experimental conditions, four substances of EC character were detected in the tissue of interest in amounts ranging from less than 1 to over 200 pg·g−1 FW: 20-hydroxyecdysone, polypodine B, turkesterone, and isovitexirone. Among them, turkesterone was observed to be the most abundant EC and accumulated mainly in the crowns and leaves of wheat. Importantly, the level of ECs was observed to be dependent on the age of the plants, as well as on growth conditions (especially temperature). Fenarimol, an inhibitor of a cytochrome P450 monooxygenase, was shown to significantly decrease the level of naturally occurring ECs in experimental plants, which may indicate its potential use in studies related to the biosynthesis and physiological function of these substances in plants.


Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1028
Author(s):  
Monnaya Chalermnon ◽  
Sarocha Cherdchom ◽  
Amornpun Sereemaspun ◽  
Rojrit Rojanathanes ◽  
Tanatorn Khotavivattana

Twelve derivatives of biguanide-derived 1,3,5-triazines, a promising class of anticancer agent, were synthesised and evaluated for their anticancer activity against two colorectal cancer cell lines—HCT116 and SW620. 2c and 3c which are the derivatives containing o-hydroxyphenyl substituents exhibited the highest activity with IC50 against both cell lines in the range of 20–27 µM, which is comparable to the IC50 of cisplatin reference. Moreover, the potential use of the calcium citrate nanoparticles (CaCit NPs) as a platform for drug delivery system was studied on a selected 1,3,5-triazine derivative 2a. Condition optimisation revealed that the source of citrate ions and reaction time significantly influence the morphology, size and %drug loading of the particles. With the optimised conditions, “CaCit-2a NPs” were successfully synthesised with the size of 148 ± 23 nm and %drug loading of up to 16.3%. Furthermore, it was found that the release of 2a from the synthesised CaCit-2a NPs is pH-responsive, and 2a could be control released under the acidic cancer environment. The knowledge from this study is perceptive for further development of the 1,3,5-triazine-based anticancer drugs and provide the platform for the incorporation of other drugs in the CaCit NPs in the future.


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