21 June, 2019

Scorpion venom can kill dangerous, resistant bacterias in a safe way

I usually do not post much about biochemical and toxicology research on scorpion venom as I have very little expertise on these topics. As many of you probably have noticed, there is a lot of research on scorpion venom trying to identify components in the venom that can be used for medical and/or commercial purposes. Because of this, scorpion venom is now considered one of the most expensive materials on earth. This week a very interesting study was published.

Edson Norberto Carcamo-Noriegaa and co-workers have identified twopreviously unknown benzoquinones in the venom of the Mexican scorpion Diplocentrus melici Armas, Martin-Frias & Berea, 2004 (Scorpionidae). The study shows that these two compounds can kill dangerous staphylococcus and tuberculosis bacteria in a safe way. The researchers also were able to synthesize the two compounds, making this a very promising tool for a future medicine against dangerous and resistant bacterias.

If you can not access the article, you can check out this news report from Stanford University summing up the main findings.

Two 1,4-benzoquinone derivatives, found in the venom of the scorpion Diplocentrus melici following exposure to air, have been isolated, characterized, synthesized, and assessed for antimicrobial activities. Initially a white, viscous liquid, the extracted venom colors within minutes under ambient conditions. From this colored mixture, two compounds, one red, the other blue, were isolated and purified using chromatography. After a variety of NMR and mass spectrometry experiments, the red compound was determined to be 3,5- dimethoxy-2-(methylthio)cyclohexa-2,5-diene-1,4-dione, and the blue compound was determined to be 5-methoxy-2,3- bis(methylthio) cyclohexa-2,5-diene-1,4-dione. Because extremely small amounts of these compounds were isolated from the scorpion venom, we developed laboratory syntheses from commercially available precursors, allowing us to produce sufficient quantities for crystallization nd biological assays. The red benzoquinone is effective against Staphylococcus aureus [minimum inhibitory concentration (MIC) = 4 μg/mL], while the blue benzoquinone is active against Mycobacterium tuberculosis (MIC = 4 μg/mL) and even against a multidrug-resistant (MDR) strain with nearly equal effectiveness. The bactericidal effects of both benzoquinones show comparable activity to commercially available antibiotics used against these pathogens and were cytotoxic to neoplastic cell lines, suggesting
their potential as lead compounds for the development of novel antimicrobial and anticancer drugs. Importantly, the blue benzoquinone was also effective in vivo with mouse models of MDR tuberculosis infection. After treatment for 2 mo, four mice with late-stage active MDR tuberculosis had a significant decrease in pulmonary bacillary loads and tissue damage. Healthy mice served as negative controls and tolerated treatment well, without adverse side effects.

Carcamo-Noriega EN, Sathyamoorthi S, Banerjee S, Gnanamani E, Mendoza-Trujillo M, Mata-Espinosa D, et al. 1,4-Benzoquinone antimicrobial agents against Staphylococcus aureus and Mycobacterium tuberculosis derived from scorpion venom. Proceedings of the National Academy of Sciences. 2019:201812334. [Subscription required for full text]

Thanks to Matt Simon for informing me about this interesting article!

20 June, 2019

A new species of Euscorpiops from China

Eric Ythier has recently published a new species of Euscorpiops Vachon, 1980 (Euscorpiidae) from China.

Euscorpiops zhangshuyuani Ythier, 2019

An identification key for the genus in the Yunnan Province is included.

A new species of scorpion belonging to the genus Euscorpiops Vachon, 1980 (family Scorpiopidae Kraepelin, 1905) is described on the basis of two adult females collected in a montane rainforest formation located in Tong Bi Guan Xiang, Yingjiang County, Yunnan Province, China, close to the border with Myanmar. This new scorpion taxon represents the 27th known species of the genus Euscorpiops, the tenth reported from China and the eighth reported from Yunnan Province.

Ythier E. A new species of Euscorpiops Vachon, 1980, from China (Scorpiones, Scorpiopidae). Bulletin de la Société entomologique de France. 2019;124(2):189-96. [Subscription required for full text]

Thanks to Eric Ythier for sending me his article!

Family Euscorpiidae

12 June, 2019

Two new species of Hottentotta from Iran and Pakistan

Frantisek Kovarik and co-workers have published an article where the revise the species of Hottentotta Birula, 1908 (Buthidae) described by the famous Russian arachnologist Alexei A. Byalynitskii-Birulya (or A. A. Birula).

Two new species are described:

Hottentotta juliae Kovarik, Yagmur & Fet, 2019 (Iran)

Hottentotta krivokhatskyi Kovarik, Yagmur & Fet, 2019 (Pakistan)

See abstract and article for further taxonomical conclusions.

The types of Hottentotta species described by A. A. Birula and deposited in the Zoological Institute, Russian Academy of Sciences, St. Petersburg, Russia are revised. The types of H. buchariensis (Birula, 1897), H. niloticus (Birula, 1928), H. penjabensis (Birula, 1897) stat. nov. and H. schach (Birula, 1905) are fully illustrated with color photographs of morphology. Their taxonomic position is discussed. Lectotypes are designated for H. niloticus and H. schach. We confirm synonymy of Buthus (Hottentotta) minax niloticus Birula, 1928 (Sudan) with Buthus minax L. Koch, 1875, syn. n. Two new species, Hottentotta juliae sp. n. from Iran (Fars Province) and H. krivokhatskyi sp. n. from Pakistan (Balochistan Province), are described, based on specimens which were in previous publications incorrectly identified as H. schach and H. penjabensis.

Kovarik F, Yagmur EA, Fet V. Review of Hottentotta described by A. A. Birula, with descriptions of two new species and comments on Birula’s collection (Scorpiones: Buthidae). Euscorpius. 2019(282):1-30. [Open Access]

Family Buthidae