Dear Rooh

Is it Dioscorea deltoidea? The tubers of different wild yams or Dioscorea species (deltoidea, composita, floribunda etc.) and Costus speciosus are famous for their steroidal sapogenin diosgenin which is widely used for making oral contraceptive pills. These species have been extensively investigated. You will find several research articles on these species on the internet.

Hello Rooh

please check the attached files.

Dear,

You can also read other papers also for phytochemical isolation and characterization

Article Phytochemical Screening and Free-Radical Scavenging Activity...

Article Chemical Composition and Biological Activities of Essential ...

Article Antifungal activity evaluation of different extracts of Berg...

I agree with Rajeswara Rao, Dioscorea species are characterized by its diosgenin contain and there are many papers dealing in this topic. In a general way you can extract them using petroleum ether or hexane for the extraction using a soxhlet and powdered material. It is preferable to continue the  extraction using dichloromethane and methanol because many times diosgenin is as a more polar glycosides.