Cytotoxic Activity of Inositol Angelates and Tirucallane-Type Alkaloids from Amoora Dasyclada

Abstract

Three new inositol angelate compounds (1–3) and two new tirucallane-type alkaloids (4 and 5) were isolated from the Amoora dasyclada, and their structures were established mainly by means of combination of 1D and 2D nuclear magnetic resonance and HR-ESI-MS. Based on cytotoxicity testing, compounds 4 and 5 exhibited significant cytotoxic activity against human cancer cell line HepG2 with IC50 value at 8.4 and 13.2 μM. In addition, compounds 4 and 5 also showed remarkable growth inhibitory activity to Artemia salina larvae.

d-chiro-Inositol Derivatives with Multidrug Resistance Reversal Activities from the Fruits of Chisocheton siamensis

“…Meanwhile, two sets of tigloyloxy groups (δ H 6.83, 1.76, and 1.75; δ C 167.0, 139.1, 127.9, 14.6, and 12.1; δ H 6.72, 1.70, and 1.71; δ C 167.2, 138.3, 127.9, 14.5, and 12.1) were located at C-3/C-6 and C-4/C-5 by the key HMBC correlations (Figure ) of H-3 (δ H 5.43) to C-1′ (δ C 167.0) and H-4 (δ H 5.71) to C-1″ (δ C 167.2) (or H-6 to C-1⁗ and H-5 to C-1‴). Based on the above information, the planar structure of 1 was determined as that of a symmetrical inositol derivative. − , …”

“…Based on the above information, the planar structure of 1 was determined as that of a symmetrical inositol derivative. [5][6][7]14 The characteristic coupling constants ( 3 J H2/H3 ≈ 0 Hz and 3 J H3/H4 = 7.1 Hz) and ROESY cross-peaks (Figure 2) between H-3/H-2, H-3/H-5, H-6/H-1, and H-6/H-4 indicated compound 1 is a chiro-inositol derivative 6,9 with two axial protons and four equatorial protons. According to the symmetrical structure and substituted chromophores at adjacent hydroxyl groups, the absolute configuration of 1 could be determined by the ECD exciton chirality method.…”

“…Another known symmetrical chiro-inositol derivative, 5,7 Dchiro-inositol-3,6-ditiglate-4,5-di-5-hydroxytiglate (12), was also obtained and was crystallized from MeOH/H 2 O. The similarity of the ECD spectra between 1 and 12 and X-ray crystallographic analysis (Figure S8, CCDC 2128203, Flack parameter: −0.02(5), Supporting Information) enabled the structure and the absolute configuration at 12 to be resolved as 1S,2S,3S,4R,5R,6S.…”

“…In particular, phosphoinositide is involved in human cell metabolism, , which has attracted the attention of organic chemists and biochemists to construct additional biological inositol derivatives . Naturally occurring inositol derivatives are distributed mainly in plants of the Meliaceae and Compositae families, − but their structure determination requires careful attention toward resolving their absolute configuration. As part of our research program on natural products of Meliaceae species, plants in the Chisocheton genus that are rich in limonoids and inositol derivatives have been investigated. − …”

Marine Natural Products: The Important Resource of Biological Insecticide

“…Alkaloids are a class of compounds usually contain nitrogen heterogeneous structure and has significant biological activity, we have found a series of these compounds in our previous work and demonstrated their excellent insecticidal activity [39,40] . Two caulerpynyne alkaloids, caulerpin ( 1 ) and caulerpinic acid ( 2 ), were obtained from the chloroform/methanol extract of the green alga Caulerpa racemose and considered as novel mosquito insecticide for their effective performance against C. pipiens mosquito ( Figure 1, Table 1).…”