Synthesis Of Diosgenin In Dioscoreae Nipponicae Rhizoma And Screening The Activity In Vitro

Dioscoreae Nipponicae Rhizoma(DNR) is the dry rhizome of Diosocorea nipponica Makino which also known as “Chuan di long”, “Chuan long gu”,“Huo teng gen” and so on. It’s applied to treat a variety of diseases and the study of new drugs with its abundant resource and wide distribution. In the records of Pharmacopoeia, Dioscorea can be used to treat rheumatism disease, pain and numbness, or flutter injury, cough, asthma and other diseases. According to the reports of clinical and pharmacological, the total saponins of DNR also have good analgesic, anti-inflammatory, relaxing blood vessels and resist tumor activity. Its medicinal value is very high.Diosgenin(Dio), is a kind of natural steroidal compounds, white needle crystal or light power, Chemical name is △ 5- iso spiral androsteno-3β- alcohol, Relative molecular mass is 414.63, insoluble in water, soluble in the common organic solvents and acetic acid. Its structural formula is C27H42O3(Figure 1-1), spirostan structure with six rings of A, B, C, D, E, F. Diosgenin has a higher levels in Dioscorea zingiberensis C.H.Wright, D.nipponica Makino and other plants of Yam.So far, the domestic and forign scholars found that diosgenin has obvious antitumor, anti-inflammatory, antioxidant, anti hyperlipidemia, antiplatelet aggregati- on, In addition, it’s an important raw material for the synthesis of steroid hormone durg and contraceptive steroids. In this thesis, we first detected the content of amino acid in DNR and the total saponins in alcohol extract of DNR. Then, we optimized method of the total saponin hydrolyzed to diosgenin. Finally we took diosgenin as lead compound and synthesized some diosgenin derivatives with various acids. Meanwhile, a various of pharmacological activivties of the derivatives were screened. The main contents and results are follows:(1) To optimize the biphasic acid hydrolysis technology of diosgenin from total saponins by central composite design response surface method. Based on the two-phase acid hydrolysis method, we selected three main factors to optimization witch are sulfuric acid concentration, solid-liquid ratio and hydrolysis time. The optimal process conditions were as follows: sulfuric acid concentration 6%, solid-liquid ratio 1:40, and hydrolysis time 4 h.(2)Study the preparation of diosgenin derivatives. Using the principle of esterifition synthesis with EDCI and DMAP, diosgenin reacted with different organic acids including(S)-2-(Boc-amino)-3-methylbutyric acid, Docosanoic acid, Benzoic acid, Palmitic acid, N-(tert-Butoxycarbonyl)-L-aspartic acid, Boc-Glycine, Boc-beta-alanine, Linoleic acid, Coumalic acid, Lauric acid, Thioctic acid, Stearic acid, N-(tert-Butoxycarbonyl)-L-leucine Monohydrate, Sorbic acid, 2-Naphthoic acid, 2-Tetrahydrofuroic acid, 2-Furoic acid, 3-Furoic acid, N-(tert-Butoxycarbonyl)-L-phe nylalanie, Malonic acid to afford compounds was prepared. The chemical structures are defined by IR,1HNMR and 13 NMR, respectively. Wherein 3-Furoic acid ester, 2-Furoic acid ester, Palmitic acid ester, Thioctic acid ester, Lauric acid ester, Docosanoic acid ester, Malonic acid ester, 2-Furoic acid ester, 2-Naphthoic acid ester, Coumalic acid ester, Sorbic acid ester are 11 new compounds.(3)There are five derivatives pharmacological activities of 20 diosgenin derivatives were screened in vitro, by using spectrophotometry and HPLC. They are the inhibition effect of ACE inhibition, HMG-CoA reductase, inhibition of alphaglucosidase, NO2- free radial and AchE inhibition. The results showed that the majority of diosgenin ester has better bio-inhibitory activity. Including 2-tetrahydrofur furyl acid diosgenin ester, furoate diosgenin ester, furan-3-carboxylic acid diosgenin esters, sorbic acid diosgenin ester, malonic diosgenin ester, laurate diosgenin ester, leucine diosgenin ester, naphthenic acid diosgenin ester, behenic acid diosgenin ester, 2- naphthoic acid diosgenin ester, aspartic acid diosgenin ester and so on. These new synthesis inhibitors will have potential applications in medicine and food industry, but also provides a valuable reference for other related ester synthesis of diosgenin.