Caldoramide Explained

Caldoramide is a pentapeptide^[1] isolated from the cyanobacteria Caldora penicillata.^[2] It has cytotoxic effects on cancer cells and has been the subject of extensive oncological research. It is structurally analogous to belamide A and dolastatin 15. Its appearance is that of a powdery, white, substance.^[3]

Structure

The N-terminus for Caldoramide is N,N-dimethylvaline which is attached to a valine which is attached to an N-Me-valine connected to an N-Me-isoleucine which is attached to the C-terminus. The molecule can also be written as N,N-diMe-Val-Val-N-Me-Val-N-Me-Ile-3-O-Me-4-benzylpyrrolinone.

Extraction

Freeze-dried samples of Caldora penicillata had EtOAc−MeOH and H₂O−EtOH applied to them in order to extract Caldoramide. The extracts were partitioned with n-BuOH and H₂O and then fractions were taken based on solubility in either EtOAc or BuOH. Caldoramide was extracted from the BuOH soluble fraction.

Pharmacological activity

Caldoramide has been found to be cytotoxic against HCT116 colorectal cancer cell lines.

See also

• Laucysteinamide A

Notes and References

1. 10.1016/j.tet.2018.04.004 . Synthesis and anticancer activity of the proposed structure of caldoramide, an N-peptidyltetramate from the cyanobacterium Caldora penicillata . Tetrahedron . 2018 . Wunder A, Rothemund M, Schobert R . 74 . 38 . 5138–5142 . 103025376 .
2. Iwasaki A, Tadenuma T, Sumimoto S, Shiota I, Matsubara T, Saito-Nakano Y, Nozaki T, Sato T, Suenaga K . 6 . Hoshinoamides A and B, Acyclic Lipopeptides from the Marine Cyanobacterium Caldora penicillata . Journal of Natural Products . 81 . 11 . 2545–2552 . November 2018 . 30387355 . 10.1021/acs.jnatprod.8b00643 . 53725718 .
3. Gunasekera SP, Imperial L, Garst C, Ratnayake R, Dang LH, Paul VJ, Luesch H . Caldoramide, a Modified Pentapeptide from the Marine Cyanobacterium Caldora penicillata . Journal of Natural Products . 79 . 7 . 1867–71 . July 2016 . 27380142 . 5215049 . 10.1021/acs.jnatprod.6b00203 .