No evidence of cardiovascular toxicity in workers exposed below 5 ppm carbon disulfide

Progress in the past five years of small organic molecule dyes for tumor microenvironment imaging

The tumor microenvironment (TME) is the survival environment for tumor cell proliferation and metastasis in deep tissues.

Bioimaging of Glutathione with a Two-Photon Fluorescent Probe and Its Potential Application for Surgery Guide in Laryngeal Cancer

As the most abundant nonprotein biothiol in living cells, glutathione (GSH) prevents cellular components from oxidative damage and maintains the intracellular redox homeostasis. For further exploring whether GSH can be employed as a bioindicator to discriminate tumor lesion at a cellular level, the highly selective detection and accurate quantification of GSH under pathological conditions are critical. Herein, we design a coumarin derivative-based two-photon fluorescent probe Cou-Br for the detection of GSH in living cells, mice models, and clinical specimens. The prepared probe is capable of sensitively and selectively detecting GSH in complex biological systems. Cou-Br displays a good linear relationship in response to GSH and a low limit of detection. With the fluorescence signal positively associated with intracellular GSH levels, the probe enables real-time imaging of GSH in various cell lines. Under the condition of CS₂ stimulation, Cou-Br can rapidly respond to the fluctuation of intracellular GSH induced by oxidative damage. Furthermore, the in situ and in vivo bioimaging performances of Cou-Br are demonstrated. Typically, relying on the different cellular concentrations of GSH, the probe is successfully employed to identify the human laryngeal cancer lesion with outstanding capabilities of deep tissue imaging and tumor margin recognition. We assume that the abnormal expression level of GSH may be utilized as a potential bioindicator to discriminate tumor tissues from the surrounding disease-free tissues. To conclude, the proposed probe Cou-Br may potentially serve as a powerful chemical tool for the surgical navigation of cancer in clinic.

Biological Thiols and Carbon Disulfide: The Formation and Decay of Trithiocarbonates under Physiologically Relevant Conditions

Carbon disulfide is an environmental toxin, but there are suggestions in the literature that it may also have regulatory and/or therapeutic roles in mammalian physiology. Thiols or thiolates would be likely biological targets for an electrophile, such as CS₂, and in this context, the present study examines the dynamics of CS₂ reactions with various thiols (RSH) in physiologically relevant near-neutral aqueous media to form the respective trithiocarbonate anions (TTC^-, also known as "thioxanthate anions"). The rates of TTC^- formation are markedly pH-dependent, indicating that the reactive form of RSH is the conjugate base RS^-. The rates of the reverse reaction, that is, decay of TTC^- anions to release CS₂, is pH-independent, with rates roughly antiparallel to the basicities of the RS^- conjugate base. These observations indicate that the rate-limiting step of decay is simple CS₂ dissociation from RS^-, and according to microscopic reversibility, the transition state of TTC^- formation would be simple addition of the RS^- nucleophile to the CS₂ electrophile. At pH 7.4 and 37 °C, cysteine and glutathione react with CS₂ at a similar rate but the trithiocarbonate product undergoes a slow cyclization to give 2-thiothiazolidine-4-carboxylic acid. The potential biological relevance of these observations is briefly discussed.

Carbon disulfide. Just toxic or also bioregulatory and/or therapeutic?

The overview presented here has the goal of examining whether carbon disulfide (CS₂) may play a role as an endogenously generated bioregulator and/or has therapeutic value.