Background:
Cucurbitacins belong to a group of tetracyclic triterpenoids that display a wide
range of biological effects. In the past, numerous cucurbitacins have been isolated from natural sources
and many active compounds have been synthesized using the privileged scaffold in order to enhance its
cytotoxic effects.
Objective:
his review covers patents on the therapeutic effects of natural cucurbitacins and their synthetic
analogs published during the past decade. By far, the majority of patents published are related to
cancer and Structure-Activity Relationships (SAR) of these compounds are included to lend gravitas to
this important class of natural products.
Methods:
The date about the published patents was downloaded via online open access patent databases.
Results:
Cucurbitacins display significant cytotoxic properties, in particular cucurbitacins B and D
which possess very potent effects towards a number of cancer cells. Numerous cucurbitacins isolated
from natural sources have been derivatized through chemical modification at the C(2)-OH and C(25)-
OH groups. Most importantly, an acyl ester of the C(25)-OH and, iso-propyl, n-propyl and ethyl ether
groups of the C(2)-OH demonstrated the most increased cytotoxic activity.
Conclusion:
The significant cytotoxic effects of natural and semi-synthetic cucurbitacins make them
attractive as new drug candidates. Moreover, cucurbitacins have the capability to form conjugates with
other anticancer drugs which will synergistically enhance their anticancer effects. The authors believe
that in order to get lead compounds, there should be a greater focus on the synthesis of homodimers,
heterodimers, and halo derivatives of cucurbitacins. In the opinion of the authors the analysis of the
published patents on the cucurbitacins indicates that these compounds can be developed into a regimen
to treat a wide spectrum of cancers.
Isolation and Identification of Three New 5-Alkenyl-3,3(2H)-furanones from Two Streptomyces species using a Genomic Screening Approach