Acetylenic Acids from the Aerial Parts of Nanodea muscosa

Abstract

The aerial parts of Nanodea muscosa, collected in Chile, yielded two new acetylenic acids. Their structures were elucidated by spectroscopic analyses, including 2D NMR techniques, as (13E)-octadec-13-en-11-ynoic acid (1) and (2E)-octadec-2-en-4-ynedioic acid (2). Compound 2 constitutes the first example of a conjugated ene-yne fatty diacid isolated from a natural source. Compounds 1 and 2 did not exhibit toxicity toward a panel of DNA damage checkpoint defective yeast mutants or show affinity for the 5-HT(1A), 5-HT(2A), D(2), and H(1) receptors.

The Use of a Bifunctional Copper Catalyst in the Cross‐Coupling Reactions of Aryl and Heteroaryl Halides with Terminal Alkynes

“…was used as the additive (Table 2, Entries 27-29). [12] Because of the importance of the 1,3-enyne unit in naturally occurring and biologically active compounds, [21] many methods have been developed to create this unit. [22] Thus, as demonstrated in Scheme 1, the coupling of (E)-β-bromostyrene [23] (12) with phenylacetylene proceeded smoothly to give the corresponding 1,3-enyne product 13 in 52 % yield.…”

Biosynthesis and function of polyacetylenes and allied natural products

“…Recent reports have shown it to be more widely distributed at low levels in members of the families Santalaceae (Jodina rhombifolia) [65] and Olacaceae (Ochanostachys amentacea [66]). A preponderance of trans-alkenes is peculiar to compounds derived from 5A, including 5B-K. Leaves of Nanodea muscosa, a Patigonian herb used in folk medicine, contained the atypical acetylenic fatty acids 5L and (13E)-octadecen-11-yneoic acid (5M), with known ene-diynoic acid 5D [67]. El-Jaber and coworkers proposed that 5M forms from cis-vaccenic acid (18:1 11c ) by a Δ 11 -acetylenase followed by a cationic allylic isomerization (Fig.…”

“…B. The formation of the (E)-alkenes has been proposed by El-Jaber to pass through an allylic cationic rearrangement [67], although other dehydration or trans-desaturation routes are plausible. C. Cyclopropenyl fatty acids, originally postulated to rise from acetylenic fatty acids, are created stepwise by an sn-1-selective cyclopropane synthase followed by an uncharacterized desaturation activity (X = PC).…”

Chemical constituents of Anacolosa pervilleana and their antiviral activities

“…2. Compound 1, which was named anacolosine, constitutes the second example of a conjugated enyne fatty diacid isolated from a natural source [9]. In a similar way to (2E)-octadec-2-en-4-ynedioic acid biosynthesis [9], anacolosine could be derived from an oxydative cleavage of a double bond present in a monoacid with a greater number of carbons, or formed by oxidation of an ω-unsaturated fatty acid.…”

“…octadeca-9,11,13-triynoic acid [10] (2), (13E)-octadec-13-en-9,11-diynoic acid [11] (3), (13E)-octadec-13-en-11-ynoic acid [9] (4), lupenone [12] (5), β-amyrone [13] (6), and (S)-sambunigrin [14] (7) was elucidated through comparison with literature data. The acetylenic products are usually unstable, undergoing photolytic or pH-dependent oxidation leading to their decomposition [15].…”