Red pepper(Capsicum annum L.) which belongs to the family Solanaceae has been widely used for stomachic, analgesic, etc. for a long time and become one of nutrient vegetables indispensable for people's diet.
More than 150 years' research has been carried out about capsaicin, a pungent alkaloid; an all-around and concrete study has been made of its origin, extraction, purification, application and so on.
Capsaicin has now been used in a variety of fields including medicine, food industry, agriculture, fishery, etc. For medical services, it is applied to skin for the treatment of neuralgia, myalgia and arthralgia from various causes in the form of cream, gel and ointment, containing 0.025～0.075% of capsaicin which shows a strong and lasting analgesic, anti-inflammatory, anti-cancer and anti-bacterial effect.
Red pepper contains 0.1~1% of capsaicinoids including capsaicin and its analogues, among which capsaicin and dihydrocapsaicin are main components to account for more than 90% of all capsaicinoids. Capsaicin and dihydrocapsaicin are structurally very similar which let it found to be difficult to separate them. Therefore, during earlier study on pungent components in red pepper, the mixture of these two substances were thought to be single one and thereafter, with the advance of separating technology, they could be isolated from each other.
Also in present, the isolation and purification of high purity capsaicin for the quality evaluation of red pepper and its preparations is patented technology and the exclusive property of only some countries and companies.
Recently research for preparing capsaicin standard as a quantitative criterion for the quality evaluation of red pepper and its preparations has been carried out at the Laboratory of Natural Pharmaceuticals, Pharmaceutical Faculty, Pyongyang Medical College,
The research group has used dried and cut fruits of red pepper (Capsicum annum L.) which is cultivated in our country. The extraction was done using exclusion method with basic ethyl alcohol as solvent and capsaicinoids were obtained by treatment of the extract with porous absorption resin Diaion Hp-20.
The capsaicinoids obtained could be separated into two fractions of capsaicin and dihydrocapsaicin by reverse-phase column chromatography, and the first fraction was crystallized and recrystallized to get crystal, which was subjected to structural analysis to ensure that it is capsaicin.
By the use of carboxymethyl cellulose sodium as its base, they have also prepared analgesic capsaicin gel containing 0.025% of capsaicinoids on the basis of the capsaicin standard and confirmed that it could be used effectively for the treatment of arthralgia caused by knee arthritis.
The group will broaden the research and strengthen the scientific exchange on capsaicin-containing preparations, aiming at quality priority.
