Construction Of Extract Library From Traditional Medicinal And Edible Insect Predacious Diving Beetle And Analysis On Their Chemical Compositions

Object Constructing the extract library of Hydrophilus acuminatus with the application of different polar solvents and macroporous resin chromatographic column separation, to accumulate material basis for its pharmacological evaluation.Determining and analyzing the properties and contents of main chemical compositions in H. acuminatus and Cybister lateralimarginalis, to provide the reference for better utilization and development of resources form the title medicinal and edible insect.Method Extract library of organic and water phases from H.acuminatus was established with systematic solvent extraction and macroporous resin chromatography separation, meanwhile the complexity and distribution of components from isolated extracts were investigated with the application of HPLC. The contents of polysaccharides in raw materials of predacious diving beetle were determined by the method of phenylhydrate-sulfuric acid, while the contents of proteins in raw materials of studied medicinal insects were measured with Folin-Ciocalteu system and BCA kit.The contents of fat and elements in medicinal materials were measured by soxhlet extraction and ICP-AES, respectively. Meanwhile, the moisture contents in studied insects were determined by oven drying method, the second method of moisture determination recorded as general principle 0832 in the fourth-part of Chinese Pharmacopoeia (2015 version). The volatile oil composition and liposoluble constituents in raw materials of investigated medicinal insects were analyzed with the instrument of GC-MS.Result Two kinds of predacious diving beetles were purchased frm markets of Traditional Chinese Medicine, and they were identified as Hydrophilus acumintatus Motschulsky and Cybister lateralimarginalis (De Geer). Ninety extracts isolated from H. acuminatus were warehoused into the insect extract library. The HPLC spectrum illustrated that types of compounds reflected by retention times were consistent with the characteristics of corresponding organic solvents. The contents of polysaccharides were 0.44% (RSD=0.02%, n=3) and 0.63% (RSD=0.05%, n=3) for H. acuminatus and C. lateralimarginalis, respecively. The content of alkali-extraction proteins was 11.78% (RSD=1.28%, n=3) in H. acuminatus and 24.38% (RSD=2.63%, n=3) in C.Lateralimarginalis measured by Folin-Ciocalteu method, and alkali-extraction protein content exceed those of salt-extraction and Tris-HCl-extraction. Meanwhile, the content of alkali-extraction proteins was 6.70% (RSD=1.43%, n=3) in H. acuimincatus and 14.67% (RSD=2.31%, n=3) in C. lateralimarginalis by BCA kit method, also alkali-extraction protein content exceed those of salt-extraction and Tris-HCl-extraction proteins. The fat contents were 12.49% (RSD=0.11%,n=3) and 14.15% (RSD=0.14%, n=3) in H. acuminatus and C. lateralimarginalis, respectively.Both H. acuminatus and C. Lateralimaginalis were relatively rich at useful elements,such as K, Mg, Zn, in which H. acuminatus contained more of these elements. The contents of heavy metals, including As, Pb and Cd in two medicine materials were all did not exceed the legally allowed standards. The moisture content was 9.40%(RSD=0.09%, n=3) in H. acuminatus medicine and 9.37% (RSD=0.15%, n=3) in C.lateralimarginalis medicine. 67 compounds from the volatile oil of C.lateralimarginalis have been detected by GC-MS, and 51 of them were identified,accounting for 87.00% of all volatile oil constituents. Olefin substance was the kind of chemicals of highest content (37.83%). Meanwhile, 45 chemical identities of liposoluble part of C. lateralimarginalis have been disclosed with 37 of them identified and making up 82.17%. According to the analyses of GC-MS assays, 40 compounds from liposoluble part of H acuminatus have been revealed, while 32 of them were identified and consisting of 97.95%. Unsaturated lipid acids and lipids were the major constituents for the liposoluble parts of C. lateralimarginalis and H.acuminatus, accounting for 59.75% and 61.32%, respectively.Conclusion The results of HPLC analyses suggested the designed protocol based on systematic solvent extraction and macroporous resin chromatography separation could efficiently isolate extracts containing various characteristic major chemical constituents, and 90 extracts were obtained from H. acuminatus. H. acuminatus and C.lateralimarginalis contained abundant nutrition ingredients, including proteins, amino acids, fat, beneficial elements, and liposoluble components, etc., possessing the potential for further development and utilization as sources of functional or healthy food. Results reported herein could provide certain references for the pharmacological research and further chemical composition analysis on traditional medicinal and edible insect predacious diving beetle.