https://translate.google.ru/#view=home&op=translate&sl=en&tl=ru&text=Pyrrole%20is%20a%20five-membered%20aromatic%20heterocyclic%20compound%2C%20which%20contains%20one%20nitrogen%20atom.%20Pyrrole%20is%20a%20colorless%20volatile%20liquid%20that%20darkens%20readily%20upon%20exposure%20to%20air%20and%20is%20usually%20purified%20by%20distillation%20immediately%20before%20use.%20Due%20to%20its%20aromatic%20character%2C%20pyrrole%20is%20difficult%20to%20hydrogenate%2C%20does%20not%20easily%20react%20as%20a%20diene%20in%20Diels%E2%80%93Alder%20reactions%2C%20and%20does%20not%20undergo%20usual%20olefin%20reactions.%20Its%20reactivity%20is%20similar%20to%20that%20of%20benzene%20and%20aniline%2C%20in%20that%20it%20is%20easy%20to%20alkylate%20and%20acylate.%20Under%20acidic%20conditions%2C%20pyrroles%20polymerize%20easily%2C%20and%20thus%20many%20electrophilic%20reagents%20that%20are%20used%20in%20benzene%20chemistry%20are%20not%20applicable%20to%20pyrroles.%20Pyrrole%20and%20its%20derivatives%20(pyrroles)%20are%20widely%20used%20as%20an%20intermediate%20in%20the%20synthesis%20of%20pharmaceuticals%2C%20medicines%2C%20agrochemicals%2C%20dyes%2C%20photographic%20chemicals%2C%20perfumes%2C%20and%20other%20organic%20compounds.%20For%20example%2C%20chlorophyll%20and%20heme%20are%20the%20derivatives%20which%20are%20made%20by%20four%20pyrrole%20ring%20formation%20of%20the%20porphyrin%20ring%20system.%20Pyrrole%20is%20a%20precursor%20to%20the%20nonsteroidal%20anti-inflammatory%20drug%20tolmetin.

Tributyrin is a prodrug of natural butyrate. It is a neutral short-chain fatty acid triglyceride that is likely to overcome the pharmacokinetic drawbacks of natural butyrate as a drug. Tributyrin has potent antiproliferative, proapoptotic and differentiation-inducing effects in neoplastic cells. Compared with butyrate, tributyrin has more favorable pharmacokinetics and is well tolerated. Because it is rapidly absorbed and chemically stable in plasma, tributyrin diffuses through biological membranes and is metabolized by intracellular lipases, releasing therapeutically effective butyrate over time directly into the cell. Tributyrin may, at least in part, exert its growth-reducing and differentiation-inducing effect in Caco-2 cells by an upregulation of the vitamin D receptor; this may provide a useful therapeutic approach in chemoprevention and treatment of colorectal cancer. In phase I study of the orally administered tributyrin there was no consistent increase in hemoglobin F. Peak plasma butyrate concentrations occurred between 0.25 and 3 h after dose. Development of tributyrin as an anticancer agent was discontinued.

The monoterpene perillyl alcohol (POH) is a naturally occurring compound derived from citrus fruits, mint, and herbs. It exhibited chemotherapeutic potential against various malignant tumors in preclinical models and was being tested in clinical trials in patients with refractory advanced cancers. POH was formulated in soft gelatine capsules and orally administered to cancer patients several times a day on a continuous basis. However, such clinical trials in humans yielded disappointing results, also because of the large number of capsules that had to be swallowed caused hard-to-tolerate intestinal side effects, causing many patients to withdraw from treatment due to unrelenting nausea, fatigue, and vomiting. The clinical trials in Brazil have explored intranasal POH delivery as an alternative to circumvent the toxic limitations of oral administration. In these trials, patients with recurrent malignant gliomas were given comparatively small doses of POH via simple inhalation through the nose. Results from these studies showed, that this type of long-term, daily chemotherapy was well tolerated and effective. The precise mechanism of action is still undetermined, but it is known, that perillyl alcohol plays an important role in the process of hepatoma cell invasion and migration via decreasing the activity of Notch signaling pathway and increasing E-cadherin expression regulated by Snail. Another possible mechanism is included inhibition of Na/K-ATPase (NKA). The NKA α1 subunit is known to be superexpresses in glioblastoma cells (GBM) and POH acts in signaling cascades associated with NKA can control cell proliferation and/or cellular death.

Phenethyl isothiocyanate (PEITC) presents in cruciferous vegetables which have been shown to decrease the risk of various types of malignancies. PEITC targets multiple proteins to suppress various cancer-promoting mechanisms such as cell proliferation, progression and metastasis. PEITC induces apoptosis in human colon cancer HT-29 cells, prostate cancer cells, and osteogenic sarcoma U-2 OS cells. Unique to prostate cancer is that PEITC downregulates the transcriptional factor Sp1, a regulator of AR expression. PEITC suppresses 4-(methylnitrosamino)-1-(3-pyridyl)-1-butoneinduced pulmonary neoplasia in A/J mouse lung, exhibits cancer chemopreventive activity in rat and reduces azoxymethane-induced colonic aberrant crypt foci formation. PEITC appears to be a promising agent for cancer therapy and is already under clinical trials for leukemia and lung cancer.

Canthaxanthin is a keto-carotenoid pigment and potent lipid-soluble antioxidant widely distributed in nature. Canthaxanthin has been found in edible mushrooms green algae, bacteria, crustaceans, and bioaccumulates in fish such as carp, golden mullet, seabream and trash wrasse. Canthaxanthin is used to reduce sensitivity to sunlight (photosensitivity) experienced by people who have a rare genetic disease called erythropoietic protoporphyria (EPP). In these people, sunlight can cause skin reactions such as rash, itch, and eczema. Canthaxanthin is also used to reduce sun sensitivity caused by certain medications. Some people also try it for relieving itching caused by sun exposure. Canthaxanthin is associated with E number E161g and is approved for use as a food coloring agent in different countries, including the United States and the EU; however, it is not approved for use in Australia and New Zealand. It is generally authorized for feed applications in at least the following countries: US, Canada, EU. In the EU, canthaxanthin is allowed by law to be added to trout feed, salmon feed, and poultry feed. The European Union limit is 80 mg/kg of feedstuffs, 8 mg/kg feed for egg-laying hens and 25 mg/kg in feed for other poultry and salmonids.

Phenylacetate is the ester of a phenol and acetic acid. It is a metabolite of anticancer drug phenylbutyrate (PB), natural neurotransmitter phenylethylamine. Naturally, it is an odorant found in strawberries, passion fruit, and black tea. Phenylacetate level in urine was used as a marker for the diagnosis of some forms of unipolar major depressive disorders. Phenylacetate is used as a tool substrate to study esterase activity in the blood of patients in clinical studies of the effect of nutritional supplements on paraoxonase-1 levels.