Background: Capsicum annuum (CA) fruits are consumed in the human diet for more than six centuries. Less research evidence for critical isolation experiment over CA fruits methanolic extract (CAFME) is an important concern for the investigators. Objectives: The present investigation was intended to explore the CAFME for the presence of any new phytoisolate. Materials and Methods: The study involved the preparation of CAFME, followed by critical isolation through normal phase silica-gel based column chromatography using various combinations of petroleum ether and chloroform. The phytoisolate was characterized using ultraviolet, Fourier transformed infrared, Nuclear magnetic resonance (1H, 13C, Distortion less enhancement by polarization transfer and correlation spectroscopy), and mass spectrometry. Results: The chromatographic critical isolation and spectrometric experiment over CAFME offered a new phytoisolate characterized as 3,11,15-trimethyl-14 β-hydroxy-n-hexadeca-7-en-4,18-olide (CA-1). Conclusion: The present study concludes the isolation of a new diterpene 3,11,15-trimethyl-14 β-hydroxy-n-hexadeca-7-en-4,18-olide (CA-1) for the first time in CAFME. The present study also recommends that in future this new phytoisolate should be further standardized and explored for its therapeutic properties.