The rupee depreciated 23 paise to three month low of 51.70 rupees against dollar in the noon trade today due to sustained demand for the American currency from importers and weak equity markets. The domestic currency moved from 51.45 rupees to 51.70 rupees against the dollar during the morning deals.Forex dealers said that strong demand for the American currency from importers, some banks and oil refiners amid weakness in Indian stock markets impacted the rupee value.In New York, the dollar was lower against major rivals yesterday.Meanwhile, crude oil prices moved up in Asia early today. Brent North Sea crude for May gained 24 cents to 120 dollar 12 cents in morning trade.