Our previous investigations showed that homolytic reactions of C 60 with a number of perfluoroorganic and organomercury(II) compounds occurring under electron impact (EI) in the ionization chamber (IC) of a mass spectrometer could predict the reactivity of C 60 towards these compounds in solution or solid state. To expand the scope of this statement, C 60 and C 70 have been reacted with ketones RCOR 1 , where R and R 1 are alkyl, aryl, benzyl, and CF 3 , in an IC under EI to yield products of the addition of R · and R 1 · radicals to the fullerenes, paramagnetic ones being stabilized by hydrogen addition and loss. Experimental evidence in support of a mechanism involving homolytic dissociation of ketone molecules via superexcited states to afford these radicals that react with the fullerenes at the IC surface has been obtained. As anticipated, the reactions between C 60 and several ketones conducted in solution under UV irradiation have afforded Me-, Ph-, and CF 3 -derivatives of C 60 . However, some other products have been identified by mass spectrometry and their formation is reasonably explained. When decalin has been employed as a solvent, decalinyl derivatives of the fullerene have been found among the products and the (9-decalinyl)fullerenyl radical has been registered by EPR. Thus, incomplete but reasonable conformity of the results of the reactions of fullerenes with ketones in an IC under EI with those of the reactions of the same reagents in solution under UV irradiation has been demonstrated, and the former results can predict the latter ones to a reasonable extent.

In this study, several methods were used to analyze the hydrolysis of hyaluronic acid (HA)-based cosmetic fillers by the hepatopancreas homogenate of the Red king crab. The results show that the homogenate and commercially available hyaluronidases have similar hydrolysis activities on the fillers. Atomic force microscopy images reveal that the HA fillers consist mainly of spherical-like particles, which are converted into filamentous structures as a result of hydrolysis by the Red king crab hepatopancreas homogenate. Turbidimetric analysis of the hydrolysis process shows that HA aggregation with acidic albumin exhibits a bell-shaped dependence on reaction time. Analysis of the hydrolysis process by nuclear magnetic resonance shows that HA degradation lasts several days. The maximum rate of the reaction is detected in the 1st h of incubation. The data confirm that the purified homogenate of the Red king crab hepatopancreas exerts hyaluronidase activity on HA-based cosmetic fillers; therefore, it may be considered as a potential therapeutic agent for treating filler complications.

Since the early 1980s, a large number of studies on enzymes from the red king crab hepatopancreas were conducted. They have been relevant both from a fundamental point of view in terms of studying the enzymes of marine organisms and in terms of rational natural resource management aimed to obtain new valuable products from the processing of crab fishing waste. Most of these works were performed by Russian scientists due to the area and amount of waste of red king crab processing in Russia (or the Soviet Union). However, the close phylogenetic kinship and the similar ecological niches of commercial crab species and the production scale of the catch provide the bases for the successful transfer of experience in the processing of the red king crab hepatopancreas to other commercial crab species caught worldwide. This review describes the value of recycled commercial crab species, discusses processing problems, and suggests possible solutions for these issues. The main emphasis is made on hepatopancreatic enzymes as the most salubrious products of red king crab waste processing.

C(60) was reacted in the ionization chamber of a mass spectrometer under electron impact (EI) with aldehydes, RCHO (R = Ph, p-FC(6)H(4), F(5)C(6), p-MeOC(6)H(4), α-thienyl, o-HOC(6)H(4), o-BrC(6)H(4), m-BrC(6)H(4) and t-Bu), with the transfer of R• radicals and with Me•-transfer from i-PrCHO and t-BuCHO. Paramagnetic fullerene derivatives were stabilized by the addition of the next R• radical or a hydrogen atom, or hydrogen or bromine atom loss. A detailed study showed that the reaction between C(60) and PhCHO occurred via a homolytic mechanism that matches one reported earlier for the reaction with acetone. This suggests the generality of the mechanism for the reactions of fullerenes with other species in ionization chambers under EI at ca 300°C. All aldehydes, except one, had radicals at the carbonyl group which were different from those in the ketones examined earlier in the reactions. This expanded the variety of radicals which can be transferred to fullerenes during reactions in ionization chambers under EI. Due to this and the hydrogen atom at the CO group of aldehydes, some reactions occurred that were not found for the ketones: the formation of cyclic products C(60)COC(6)H(4) and C(60)OC(6)H(4) for PhCHO, o-BrC(6)H(4)CHO and o-HOC(6)H(4)CHO, respectively, and HC(60)Ph for o- and m-BrC(6)H(4)CHO. The reaction with α- formylthiophen gives the first example of transferring an aromatic heterocyclic radical to C(60) in an ionization chamber under EI. C(70) reacted with PhCHO, p-FC(6)H(4)CHO and i- PrCHO similarly to C(60). The results for the reactions of C(60) with PhCHO and with i- PrCHO were compared with those in solution under UV irradiation. Incomplete but reasonable coincidence was found; in both modes, the addition of Ph•, PhCO• and Me• radicals to C(60) occurred, whereas some other products were formed in solution, and the explanation is given as to why this occurred. This conformity supports the hypothesis based on the results of kindred reactions with ketones and organomercurials: the results of EI-initiated homolytic reactions between fullerenes and other compounds in an ionization chamber can predict the reactivity of the fullerenes toward them in solution.

Crustacean hyaluronidases are poorly understood both in terms of their enzymatic properties and in terms of their structural features. In this work, we show that the hepatopancreas homogenate of the red king crab has a hyaluronidase activity that is an order of magnitude higher than its commercial counterpart. Zymography revealed that the molecular weight of a protein with hyalorunidase activity is 40–50 kDa. Analysis of the hepatopancreas transcriptome and results of cloning and sequencing of cDNA revealed a hyaluronidase sequence with an expected molecular weight of 42.5 kDa. Further analysis showed that hyaluronat enzymatic cleavage follows the $$\beta $$ β -elimination mechanism, which is well known for bacterial hyaluronidases. The results of ion-exchange chromatography showed that the final product of hyaluronate degradation is unsaturated tetrasaccharide. Thus, we identified a new hyaluronidase of higher eukaryotes, which is not integrated into the modern classification of hyaluronidases.

Since the early 1980s, a large number of research works on enzymes from the red king crab hepatopancreas have been conducted. These studies have been relevant both from a fundamental point of view for studying the enzymes of marine organisms and in terms of the rational management of nature to obtain new and valuable products from the processing of crab fishing waste. Most of these works were performed by Russian scientists due to the area and amount of waste of red king crab processing in Russia (or the Soviet Union). However, the close phylogenetic kinship and the similar ecological niches of commercial crab species and the production scale of the catch provide the bases for the successful transfer of experience in the processing of red king crab hepatopancreas to other commercial crab species mined worldwide. This review describes the value of recycled commercial crab species, discusses processing problems, and suggests possible solutions to these problems. The main emphasis is placed on the enzymes of the hepatopancreas as the most highly salubrious product of waste processed from red king crab fishing.

This study focused on hydrolysis of cosmetic fillers hyaluronic acid (HA) and kinetics of the HA hydrolysis using the homogenate of the red king crab hepatopancreas. Turbidimetric analysis of the reaction mixture revealed a bell-shaped time dependence of aggregation formation. It was shown that the obtained homogenate has the similar activity to the commercially available hyaluronidase. The atomic force microscopy (AFM) examination found that the HA fillers were represented by spherical-like structures. These structures were destroyed under the action of the homogenate of the red king crab hepatopancreas. NMR of the reaction mixture showed that HA degradation lasts for some days, but a maximum rate of the reaction is detected in the first hours of incubation. The preparation with hyaluronidase activity obtained from the red king crab hepatopancreas could be used as potentially safe product for treating filler complications.

The kinetics of the hydrolysis of hyaluronic acid (HA) of cosmetic fillers using the homogenate of the red king crab hepatopancreas was studied for the first time. Turbidimetric analysis of the reaction mixture revealed a bell-shaped time dependence of aggregation formation. The HA fillers were examined by atomic force microscopy (AFM) and it was found that they were represented by spherical-like structures. These structures were disrupted under the action of the homogenate of the red king crab hepatopancreas. It was shown that the prepared homogenate has the activity which is similar to that observed in the commercially available hyaluronidase products. The preparation with hyaluronidase activity obtained from the red king crab hepatopancreas could be used as potentially safe product for treating filler complications.