At one time Amla was considered a rich source of Vit.C. Earlier studies which identified presence of Ascorbic acid, were done by bioassay of extracts. But if you want to see Ascorbic acid (Vit. C) in PC or TLC chromatograms you will be disappointed. It was Ghosal and co-workers who, in 1996, discovered that the Vit.C like action of Amla is due to two gallotannins, Emblicanin A and –B, which have the core sugar acid structure similar to that of ascorbic acid, and there is no free or conjugated ascorbic acid in fruits of Emblica officinalis (Sukhdev, 2006).The vitamin C action of Emblicanin lasts much more (as it is a stable tannin), than the short lived action of Ascorbic acid (Ascorbic acid is very unstable and gets converted to its derivatives).
The constituents of the fruit are tannins (upto 28%), carbohydrates (14%), proteins (0.5%) alkaloids, minerals and a good amount of pectin. Tannins are gallotannins and of these, emblicanin –A and -B are biologically active. The phenolic acids include ellagic and phyllemblic acids and emblicol. Also present are a good amount of free amino acids such as alanine, aspartic acid, glutamic acid, lysine and proline The alkaloids present are phyllantidine and phyllantine. Flavonoids such as quercetin rutin and kaempferol are the other compounds present. Curcuminoids also are reported from certain samples (Daniel. 2013).
Amla is a well-known rasayana drug rich in antioxidants and it is proved to be antiageing,protects heart and liver and from carcinogens. It is also immunomodulatory and helps to withstand all forms of stress. It helps in gastric ulcer and reduces blood triglycerides and cholesterol as well as diabetes. Amla (or rather putranjivain A- a tannin) inhibits HIV virus also.
References:
1.Ghosal, S. Tripathi,V.K and S. Chauhan (1996) Indian J. Chemistry, 35B:94
2. Sukh Dev (2006) A selection of Prime Ayurvedic Plant Drugs: Ancient Modern Concordance ,
Anamaya Publishers, New Delhi.
3. Daniel, M. (2013) Useful Herbs of Planet Earth, Scientific Publishers, Jodhpur.
Mammen Daniel