The research work embodied in this thesis deals with the isolation of chemical constituents from the Omani plant named Caralluma flava (N.E.Br) Meve & Liede along with the spectral characterization, biological activities and computational studies. Crude crystals (CR) obtained from the squeezed sap of succulent C. flava showed significant anticancer activity against MDA-MB-231 breast cancer cells and provided nine new pregnane glycosides namely Desmiflavaside A (1), Desmiflavaside B (2), Desmiflavaside C (3), Desmiflavaside D (4), Nizwaside (5), Desflavaside A (6), Desflavaside B (7), Desflavaside C (8) and Desflavaside D (9). The structures of these isolates were elucidated through spectral analysis using UV, IR, HRSEIMS, NMR and by comparing with literature reports. Treatment of MDA-MB-231 breast cancer and SKOV-3 ovarian cancer cells with compounds 3-5 demonstrated a prominent reduction in the viability of both types of cancer cells. Furthermore, 3-5 were also tested for their effect on normal breast epithelial cells (MCF-10-2A) which displayed no significant cytotoxicity on normal cells. The molecular docking studies of 3-5 revealed that these molecules have a good potential to bind with the target protein tyrosine phosphatase. The methanolic extract (ME) of squeezed residual plant and its different fractions also showed good anticancer activity against MDA-MB-231 cells. Different fractions of ME, CR and compounds (1-5) were additionally evaluated for enzyme inhibition (urease, acetylcholinesterase and α-glucosidase) and DPPH antioxidant activities which displayed no remarkable results. The research work embodied in this dissertation has resulted four publications as mentioned in the end of the thesis.