Botany, traditional usages, phytochemistry, pharmacology, and toxicology of Guilandina bonduc L.: a systematic review

Guilandina bonduc L. is popularly known as a fever nut that grows widely in evergreen forests and moist deciduous forests with a pantropical distribution. The plant is highly therapeutic in various systems of medicine, including Ayurveda, Siddha, and homeopathy. The purpose of this review is to analyze the published data on G. bonduc, including traditional uses, taxonomic position, botanical description, phytochemistry, pharmacological properties, and toxicological assessment of its various parts. Phytochemical and pharmacological studies were the main focus of this review. The previously published research on G. bonduc was tracked from scientific databases such as Online Library, Google, Taylor and Francis, PubMed, Research Gate, Scopus, Springer, Wiley, Web of Sciences. Numerous phytochemical, pharmaceutical, and pharmacological studies have been carried out on the various parts of G. bonduc. To date, more than 97 phytochemicals have been isolated from the leaves, roots, stems, stem bark, flowers, twigs, and seeds of this plant. The phytochemicals isolated from the plants are flavonoids, homoisoflavonoids, terpenoids, diterpenoids, steroids, fatty acids, alkanes, acids, phenols, ketones, esters, amides, azides, silanes, and ether groups. This plant has been extensively studied in in vitro and in vivo pharmacological experiments, where it showed analgesic, anti-inflammatory, antioxidant, antiviral, antidiabetic, abortive, anticataleptic, immunomodulatory, and antiestrogenic effects. This comprehensive review revealed that phytochemicals isolated from various parts of G. bonduc have significant therapeutic efficacy, with promising anticancer, antidiabetic, hepatoprotective, antioxidant, and antimicrobial activities. This review provides a good source of information for the development of a drug using modern scientific tools, in view of its underexplored traditional uses. Further studies on preclinical and clinical trials and toxicological studies on the bioactive molecules of G. bonduc to validate its traditional uses are warranted.

New cassane-type diterpenoids from kernels of Caesalpinia bonduc (Linn.) Roxb. and their inhibitory activities on phosphodiesterase (PDE) and nuclear factor-kappa B (NF-κB) expression

In this paper, chemical investigation on the chloroform soluble fraction of seed kernels of Caesalpinia bonduc resulted in the isolation of five new cassane diterpenoids: norcaesalpinin O (1), norcaesalpinin P (2), caesalpinin MQ (3), caesall O/P (4/5) and seven known compounds (6-12). Compounds structures were elucidated by ¹H NMR, ¹³C NMR, 2D NMR, HR-MS and ECD (electronic circular dichroism) spectral analysis. The characters for new compounds with the presence of an aromatized C ring or demethyl group at C-17 position in the structures were found. By means of bioactive screenings, the inhibitory effect on type-4 phosphodiesterase (PDE4, the target protein of asthma disease) and nuclear factor-kappa B (NF-κB) expression were valued. Compound 1 was found to exhibit moderate inhibitory activity on PDE4 and much better binding affinity than other structures by docking studies for interaction analyzing. Compounds 6, 10 and 11 displayed considerable inhibitory strength against NF-κB expression with inhibitory ratio 48.6%, 42.9% and 37.1% at 10 µM, respectively. The isolation of cassane-type diterpenoids with anti-inflammation activity from C. bonduc implied that this plant might be a good source for anti-inflammation agents finding.

Cassane Diterpenoids from the Pericarps of Caesalpinia bonduc

Ten new cassane-type diterpenoids, caesalbonducins D-F (1-3), 6-deacetoxybonducellpin B (4), 3-acetoxy-α-caesalpin (5), 2(3)-en-α-caesalpin (6), 1α-hydroxycaesalpinin J (7), 1α-hydroxy-6-decaetoxysalpinin J (8), 6α-hydroxycaesall M (9), and 6α-hydroxy-14(17)-dehydrocaesalpin F (10), along with eight known compounds (11-18), were isolated from the pericarps of Caesalpinia bonduc. Compounds 1-3 and 11 are methyl-migrated cassane-type diterpenoids with a 19(4→3)-cassane skeleton. The structures of 1-10 were elucidated on the basis of 1D and 2D NMR methods and other spectroscopic analysis. The neuroprotective effects of the isolated compounds were evaluated.

Antimalarial and Antiproliferative Cassane Diterpenes of Caesalpinia sappan

Bioassay-guided fractionation of a methanol extract of the seeds of Caesalpinia sappan led to the isolation of 12 new cassane-type diterpenes, caesalsappanins A-L (1-12). Their structures were elucidated on the basis of NMR and HRESIMS analysis, and the absolute configuration of compound 1 was determined by single-crystal X-ray crystallography. All isolated compounds were tested against a chloroquine-resistant Plasmodium falciparum strain for antiplasmodial activities and against a small panel of human cancer cell lines for antiproliferative activities. Compounds 7 and 8 displayed antimalarial activity against the chloroquine-resistant K1 strain of P. falciparum with IC50 values of 0.78 and 0.52 μM and selectivity indices of 17.6 and 16.4, respectively. Compound 10 showed antiproliferative activity against the KB cancer cell line with an IC50 value of 7.4 μM.

Cassane-type diterpenoids from Caesalpinia echinata (Leguminosae) and their NF-κB signaling inhibition activities

Fourteen cassane-type diterpenoids, echinalides H-U, were isolated from the stem of Caesalpinia echinata Lam. (Leguminosae). The structures of the echinalides were elucidated by spectroscopic investigation, including 2D NMR spectroscopic analysis. The structures of echinalide H and echinalide T were further confirmed by single-crystal X-ray diffraction. The absolute configurations of echinalides H, I, J and K were determined by CD spectroscopy. Additionally, the absolute configurations of echinalide L and M were determined by chemical conversion from echinalide H. These compounds were evaluated for inhibitory activity against nuclear factor κB (NF-κB). Echinalide M showed the most potent inhibitory activity (47±11% at 5μM) toward NF-κB-responsive gene expression.

Diterpenoids of terrestrial origin

This review covers the isolation and chemistry of diterpenoids from terrestrial as opposed to marine sources and includes, labdanes, clerodanes, pimaranes, abietanes, kauranes, gibberellins, cembranes and their cyclization products. The literature from January to December, 2014 is reviewed.