Enzymes in organic syntheses: A novel elimination reaction in andrographolide triacetate

Natural Product Letters

Volumn 12, Issue 1, 1998, Pages 1-4

  Mathad, Vijayavitthal T ^a   Raj, Kanwal ^a   Bhaduri, Amiya P ^a  

^a CENTRAL DRUG RESEARCH INSTITUTE   (India)

Author keywords

Andrographolide; L arginine; Protease; Trypsin

Indexed keywords

ANDROGRAPHOLIDE; ARGININE; PROTEINASE; TRYPSIN;

ARTICLE; CHEMICAL REACTION; ENZYME MECHANISM;

EID: 0031836991     PISSN: 10575634     EISSN: None     Source Type: Journal    
DOI: 10.1080/10575639808048862     Document Type: Article

References (8)

1. R. Bently, and H. Trimen, (1983), Medicinal Plants, 3, 197. J. and A. Churchill Publ, London. First Indian Edn. by International Book Distributors, Dehradun (1981).
2. A. Puri, R. Saxena, R.P. Saxena and K.C. Saxena, (1993), Immunostimulant Agents from Andrographis paniculata. J. Nat. Prod. 56, 995.
3. S. Gupta, M.A. Chowdhury, J.N.S. Yadav, V. Srivastava and J.S. Tandon, (1990), Antidiarrhoeal activity of ditirpenes of Andrographis paniculata (Kal-Megh) against Escherichia coli Enterotoxins in in-vivo models. Int. J. Crude Drug Res., 28, 273.
4. M.P. Cava, W.R. Chan, R.P. Stein and C.R. Willis (1965). Andrographolide. Further transformation and stereochemical evidence; The structure of isoandrographide. Tetrahedron, 21, 2617.
5. 3).
6. 3).
7. 280; P-1512, SIGMA) in ethanol (20 ml) was stirred at room temperature for 5 days. There after, reaction mixture was filtered and filtrate was concentrated in vaccuo to yield the thick syrup containing 3 and 4. Column chromatography of the crude product over silica gel using ethyl acetate : hexane (40:60, v/v) and ethyl acetate: hexane (60:40, v/v) as solvent mixture provided compounds 4 (66.42 mg, 76%) and 3 (16 mg, 18%) respectively. Recrystallization of 4 with methanol gave granular crystals.
8. Reaction of 2 with L-arginine: To a stirred solution of L-arginine (44.1 mg, 0.21 mmol) and triethylamine (29 μl, 0.21 mmol) in ethanol (5 mL) was added compound 2 (100 mg, 0.21 mmol) and stirred overnight at room temperature. The reaction mixture was filtered and concentrated in vaccuo to yield crude product containing 3 & 4. Water (5 ml) was added and extracted with chloroform (3 × 30 ml). Usual workup of organic layer followed by separation of compounds over silica using ethylacetate:hexane (40:60, v/v) and ethylacetate:hexane (60:40, v/v) as solvent mixtures yielded the compounds 4 (54.18 mg 62%) and 3 (31.46 mg, 36%) respectively.