Cucurbitane

Cucurbitane is a class of tetracyclic chemical compounds with formula (CAS number 65441-59-0). It is a polycyclic hydrocarbon, specifically triterpene. It is also an isomer of lanostane (specifically 19(10→9β)-abeolanostane), from which it differs by the formal shift of a methyl group (carbon number 19) from the 10 to the 9β position in the standard steroid numbering scheme.

The name is applied to two stereoisomers, distinguished by the prefixes 5α- and 5β-, which differ by the handedness of the bonds at a particular carbon atom (number 5 in the standard steroid numbering scheme).

Natural compounds
Compounds with the basic cucurbitane skeleton are found in many plants, and some are important phytopharmaceuticals. Natural cucurbitane-related compounds include:

Named

 * Balsaminapentaol, from Momordica balsamina.
 * Balsaminol A, from Momordica balsamina.
 * Balsaminol B, from Momordica balsamina.
 * Brydioside A from Bryonia dioica
 * Bryoamaride and derivatives from Bryonia dioica
 * Charantin or foetidin, from Momordica charantia and Momordica foetida
 * Charantosides I-VIII, from Momordica charantia.
 * Cucurbalsaminol B, from Momordica balsamina.
 * Cucurbalsaminol A, from Momordica balsamina.
 * Cucurbitacins A-L, O-T
 * Datiscosides, from Datisca glomerata
 * Endecaphyllacins A and B, from roots of Hemsleya endecaphylla
 * Hemslecins A and B, from roots of H. endecaphylla
 * Lepidolide, from the mushroom Russula lepida
 * Karavilagenin E, from Momordica balsamina.
 * Khekadaengosides A, B, D and K, from Trichosanthes tricuspidata
 * Kuguacins A-S, from stems and leaves of Momordica charantia
 * Kuguaglycosides A-H, from the root of Momordica charantia
 * Mogrosides I-V, from the fruits of Siraitia grosvenorii
 * Momordicin I, II and 28, from Momordica charantia
 * Momordicines II and IV, from leaves of Momordica charantia
 * Momordicosides A-S, from Momordica charantia fruits
 * Neokuguaglucoside, from Momordica charantia fruits
 * Neomogroside, from the fruit of Siraitia grosvenorii.
 * Pentanorcucurbitacins A and B
 * Perseapicroside A, from Persea mexicana
 * Scandenoside R9, from Hemsleya panacis-scandens
 * Spinosides A and B, from Desfontainia spinosa

Unnamed

 * 3β,7β,23ξ-trihydroxycucurbita-5,24-dien-19-al, soluble in chloroform, melts at 123−125 °C, from Momordica charantia, Momordica foetida.
 * 3β,7β,25-trihydroxycucurbita-5,23-dien-19-al, soluble in chloroform, melts at 188−191 °C, from Momordica charantia, Momordica foetida
 * 3β,7β-dihydroxy-25-methoxycucurbita-5,23-dien-19-al, soluble in chloroform, from Momordica charantia, Momordica foetida
 * 5β,19-epoxy-25-methoxycucurbita-6,23-dien-3β,19-diol, soluble in chloroform, melts at 182−184 °C, from Momordica foetida
 * 5β,19-epoxycucurbita-6,23-dien-3β,19,25-triol, soluble in chloroform, from Momordica foetida
 * 5β,19-epoxy-19-methoxycucurbita-6,23-dien-3β,25-diol, soluble in chloroform, melts at 102−104 °C, from Momordica charantia, Momordica foetida
 * 5β,19-epoxy-19,25-dimethoxycucurbita-6,23-dien-3β-ol, soluble in chloroform, from Momordica charantia, Momordica foetida
 * 5β,19-epoxy-25-methoxycucurbita-6,23-dien-3β-ol, soluble in chloroform, melts at 139−141 °C, from Momordica charantia, Momordica foetida
 * 19(R)-n-butanoxy-5β,19-epoxycucurbita-6,23-diene-3β,25-diol 3-O-β-glucopyranoside,, white powder soluble in methanol, from Momordica charantia fruit (8 mg/35 kg)
 * 23-O-β-allopyranosylecucurbita-5,24-dien-7α,3β,22(R),23(S)-tetraol 3-O-β-allopyranoside,, white powder soluble in methanol, from Momordica charantia fruit (10 mg/35 kg)
 * 23(R),24(S),25-trihydroxycucurbit-5-ene 3-O-{[β-glucopyranosyl(1→6)]-O-β-glucopyranosyl}-25-O-β-glucopyranoside,, white powder soluble in methanol, from Momordica charantia fruit (10 mg/35 kg)
 * 2,16-dihydroxy-22,23,24,25,26,27-hexanorcucurbit-5-en-11,20-dione 2-O-β-D-glucopyranoside, soluble in ethanol, from Cucurbita pepo fruits (25 mg/15 kg)
 * 16-hydroxy-22,23,24,25,26,27-hexanorcucurbit-5-en-11,20-dione 3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside, white powder, soluble in ethanol, from Cucurbita pepo fruits (12 mg/15 kg)
 * 7-methoxycucurbita-5,24-diene-3β,23(R)-diol, from Momordica balsamina
 * 25,26,27-trinorcucurbit-5-ene-3,7,23-trione, white powder, soluble in methanol, from stems of Momordica charantia (6 mg/18 kg)