Phototoxic Effects of Naturally Occurring Polyacetylenes and Α‐terthienyl on Human Erythrocytes

Wat, Chi-Kit; MacRae, W.Donald; Yamamoto, Etsuji; Towers, G.H.N.; Lam, Jørgen

doi:10.1111/j.1751-1097.1980.tb04004.x

Cited by 66 publications

(20 citation statements)

References 14 publications

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“…New alkaloids containing 6, 7, and 8 N-methyltryptamine units were recently identified in another genus of Rubiaceae (9). The study of their cytotoxic properties on HTC cells could give additional results to verify our hypothesis.…”

supporting

confidence: 53%

“…One can also suggest that the observed cytotoxic analogies between the pairs EIC and D/B could be due to an identical position of the C-C bond in each pair of compounds (Fig. 1).New alkaloids containing 6, 7, and 8 N-methyltryptamine units were recently identified in another genus of Rubiaceae (9). The study of their cytotoxic properties on HTC cells could give additional results to verify our hypothesis.…”

supporting

confidence: 51%

“…Phenylheptatriyne (PHT) and a-terthienyl (a-T) ( Fig. 1) have been investigated in connection with their phototoxicity toward bacteria and yeasts (5), erythrocytes (3,6), and invertebrates (7)(8)(9)(10). Neither compound however causes chromosome aberrations in cultured hamster cells (11).…”

Section: Introductionmentioning

confidence: 99%

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Comparison of the Antiviral Effects of Naturally Occurring Thiophenes and Polyacetylenes

et al. 1986

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453two doses of (B) are quite superimposable on those obtained with concentrations of 5 ttM and 2.5 tMIml of(D).However, (E) and (C) did not induce the same dose-effect relationship. At concentrations of 2.5 tM of (E) and 5 .tM of (C), all of the cells were killed within 24 hours, whereas at half these concentrations, neither (E) nor (C) showed any cytotoxic activity during the three days of the experiment. Finally, it seems that the biological activity of these compounds is not directly proportional to the doses, but corresponds virtually to a threshold effect; even the usual stage of inhibition of cell proliferation ist not obvious.Also, other analogies can be noted between the two groups of alkaloids. In each group, one of the compounds possessed a stronger cytotoxicity than the other one: thus, (E) and (D) seem to be twice as cytotoxic as (C) and (B), respectively. But, at lower concentrations which varied from 2.5 .tM to 0.62 tM, according to the alkaloid neither cytotoxic nor cytostatic effects to HTC cells were observed with any of the four studied alkaloids. In the case of (E), a slightly inhibitory effect on cell growth was obtained at the dose of 1.25 tM.Since the sterochemical configurations of these alkaloids had not been determined, we do not have all the data necessary to discuss unambiguously their structure-activity relations.Nevertheless, the preceeding growth or survival curves analysis suggests that the analogies and discrepancies which appeared between the four alkaloids on HTC cells could be partly due to their respective structural characteristics.Thus, the most active alkaloids are (E) and (D) which contain five condensed units, whereas (C) and (B) with only four units show a comparatively lower cytotoxic effect (Fig. 2). One can also suggest that the observed cytotoxic analogies between the pairs EIC and D/B could be due to an identical position of the C-C bond in each pair of compounds (Fig. 1).New alkaloids containing 6, 7, and 8 N-methyltryptamine units were recently identified in another genus of Rubiaceae (9). The study of their cytotoxic properties on HTC cells could give additional results to verify our hypothesis.Abstract: Five naturally occurring compounds, containing various thiophene and polyacetylene groups, were compared with respect to their phototoxic activities against two animal viruses, murine cytomegalovirus and Sindbis virus, both of which possess membranes. u-Terthienyl was extremely toxic to both viruses, but only in the presence of long wave ultraviolet radiation. The order of potency was aterthienyl > thiarubrine-A > phenylheptatriyne ACBP-thiophene > thiophene-A (hydrolysis product of thiarubrine A). The murine-CMV, which had been inactivated by any of these compounds, was still capable of penetrating cultured mouse cells efficiently and reaching the cell nucleus, the normal site of virus replication. The results are discussed in terms of possible mechanisms of action of phototoxic thiophenes and polyacetylenes.

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confidence: 53%

supporting

confidence: 51%

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Comparison of the Antiviral Effects of Naturally Occurring Thiophenes and Polyacetylenes

et al. 1986

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“…Thus, the geomet- ric advancement in the anal gill functions could be a justification for the increase in the specific SOD activity after every molt. It has been shown that a-terthienyl is lethal to a host of living systems including microorganisms [5-71 and human erythrocytes [22,23]. The plasma membrane and the membrane proteins are thought to be primary targets of the a-terthienyl toxicity.…”

Section: Resultsmentioning

confidence: 99%

Superoxide dismutase in the anal gills of the mosquito larvae ofAedes aegypti: Its inhibition by α‐terthienyl

Nivsarkar

Kumar

Laloraya

1991

Arch Insect Biochem Physiol

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The anal gills of the mosquito larvae of Aedes aegypti were shown to possess superoxide dismutase (EC 1.15.1.1) activity, which increased with the maturation of the larvae from instar 1 to instar 4. This enzyme was highly inhibited upon treatment of the larvae with alpha-terthienyl (2,2':5,2"-terthiophene) and subsequent exposure to long-wave ultraviolet light. Inhibition also occurred with treatment of the crude enzyme extract in a similar fashion. Exposure of the enzyme to the ultraviolet light alone or the treatment of the enzyme with alpha-terthienyl in darkness could not manifest this inhibition. This finding adds a new dimension to the complex mechanism(s) proposed for the photodynamic toxicity of alpha-terthienyl.

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“…Methods for the isolation of 7-phenylhepta 2,4,6-triyne (PHT) and the synthesis of a-terthienyl (a-t) have been described by Wat et al (1980). Stock solutions of PHT and a-t at 0.1% in 95% ethanol were used.…”

Section: Methodsmentioning

confidence: 99%

Cercaricidal activity of phenylheptatriyne and α-terthienyl, naturally occurring compounds in species of Asteraceae (Compositae)

Graham¹,

Graham²,

Towers³

1980

Can. J. Zool.

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The susceptibility of some digenetic trematode cercariae to the polyacetylene phenylheptatriyne (PHT), from leaves of Bidens pilosa L. (Compositae), and the thiophene α-terthienyl (α-t), from roots of Tagetes patula L. (Compositae), with and without ultraviolet (UV) activation, was examined. In darkness the lethal concentration for 100% (LC100) for both substances was 0.3 ppm. Under UV irradiation of 300–400 nm and incident intensity of 6 W/m2, the LC100 for PHT was not markedly lowered, but for α -t it was reduced by a factor of 30 (to 0.01 ppm). A cercaricidally effective aqueous infusion (1:1000) of Tagetes roots protected the snail hosts Physa occidentalis Tyron (Physidae) from bacterially complicated death but did not reduce cercarial production or predispose the emerging cercariae to subsequent UV injury.

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Phototoxic Effects of Naturally Occurring Polyacetylenes and Α‐terthienyl on Human Erythrocytes

Cited by 66 publications

References 14 publications

Comparison of the Antiviral Effects of Naturally Occurring Thiophenes and Polyacetylenes

Comparison of the Antiviral Effects of Naturally Occurring Thiophenes and Polyacetylenes

Superoxide dismutase in the anal gills of the mosquito larvae ofAedes aegypti: Its inhibition by α‐terthienyl

Cercaricidal activity of phenylheptatriyne and α-terthienyl, naturally occurring compounds in species of Asteraceae (Compositae)

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