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New copaene-type and nerolidol-type sesquiterpenoids, 7-hydroxymustakone (1) and 15-hydroxynerolidol (2), and a 15-norlabdane diterpenoid, kaempcandiol (3), together with four known compounds (4-7) were isolated from the chloroform extract of Kaempferia candida roots and rhizomes. The structures of the new compounds 1-3 were elucidated based on 1D and 2D NMR and HRESIMS spectroscopic analyses. The extract of the K. candida roots and rhizomes and all isolated compounds 1-7 possessed HIV-1 viral protein R (Vpr) inhibitory activities on the TREx-HeLa-Vpr cell line at a 5 μM concentration, without detectable cytotoxicity.

Six new isopimarane diterpenoids, shanpanootols A-F (1-6), along with two known analogues, were isolated from the ethyl acetate-soluble extract of Kaempferia pulchra rhizomes collected in Myanmar. The structures of these compounds were elucidated by extensive spectroscopic techniques such as 1D and 2D NMR and HRESIMS. The absolute configuration of 1 was determined by the modified Mosher method. The new isolates (1-6) were tested for their Vpr inhibitory activities against TREx-HeLa-Vpr cells. Shanpanootols C (3) and E (5) inhibited Vpr at doses of 2.5 and 5 μM, respectively., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Two new trihydroxy derivative of Δ 8(14),15 -isopimarane diterpenoids, shanpanootols G (1) and H (2), along with three known analogues were isolated from the ethyl acetate-soluble extract of Kaempferia pulchra rhizomes collected in Shan State of Myanmar. The structures of these compounds including their absolute configurations were elucidated by the combination of one dimensional (1D) and 2D-NMR spectroscopic methods, high resolution mass spectrometric technique, and the experimental and the calculated electronic circular dichroism (ECD) data. The isopimarane diterpenoids (1-5) were tested for their Viral protein R (Vpr) inhibitory activities against TREx-HeLa-Vpr cells. Shanpanootol H (2) and (1R,2S,5S,9R,10S,13R)-1,2-dihydroxypimara-8(14),15-dien-7-one (4) exhibited anti-Vpr activities at the 5 µM treated dose.

Two new homodrimane sesquiterpenoids, globbatones A and B (1 and 2), and one 16-norlabdane diterpenoid, globbatone C (3), together with two new naturally occurring, (E)-labda-8(17),12-diene-15,16-olide (4) and γ-bicyclohomofarnesen-12-ol (5), and one known homodrimane sesquiterpenoid (6), nine known labdane diterpenoids (7-15), and one isospongian diterpenoid (16), were isolated from the chloroform extract of Globba sherwoodiana rhizomes. The structures of the new compounds 1-3 were elucidated based on 1D and 2D NMR and HRESIMS spectroscopic analyses. The chloroform extract of G. sherwoodiana rhizomes and 10 μM concentrations of some of its constituents 1, 3, 4, 8, 9, 12, and 14 showed the moderate anti-Vpr activities, without cytotoxic effects on the TREx-HeLa-Vpr cell line., Competing Interests: Declaration of Competing Interest The authors declare no competing final interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Kaempulchraols B-D (2-4), isopimara-8(9),15-diene diterpenoids isolated from Kaempferia pulchra rhizomes collected in Myanmar, were identified as potent NF-κB inhibitors. These compounds were also effective as NO inhibitory agents, with IC 50 values of 47.69, 44.97, and 38.17 μM, respectively, without showing any cytotoxicity against LPS-induced RAW264.7 cells. Investigations of the mechanisms of action of 2-4 revealed that they inhibit the NF-κB-mediated transactivation of a luciferase reporter gene, IL-6 production, and COX-2 expression, with an effective dose of 25 μM. Thus, isopimarane diterpenoids are suggested to be potent inhibitors of NF-κB pathways and could be further explored as potential anti-inflammatory lead compounds.

Inflammation is an extensively recognized link to many pathological diseases. It is a host response for protection from infections and tissue damage. Infections trigger acute inflammation; however, persistent infection will contribute to chronic inflammation and higher disease susceptibility. Deregulated inflammatory responses can cause excessive or long-lasting tissue damage, manifested as cancer, immune disorders, diabetes, etc. NF-κB is a central mediator of pro-inflammatory gene induction and functions in both innate and adaptive immune cells; therefore, the anti-inflammatory regulation of NF-κB is needed. Natural products reportedly play an important role in controlling the inflammatory response pathways. However, the anti-inflammatory activities of isopimara-8-(14),15-diene diterpenoids have not yet been fully elucidated. To elucidate the anti-inflammatory activities of the isopimara-8(14),15-diene diterpenoids, we investigated 21 isopimara-8(14),15-diene diterpenoids previously isolated from Kaempferia pulchra rhizomes. Eleven compounds exhibited NO inhibitory activity against lipopolysaccharide (LPS)-induced RAW264.7 cells, with IC 50 values ranging from 30 to 100 μM. Furthermore, the most potent kaempulchraols P and Q, with IC 50 values of 39.88 and 36.05 μM, respectively, inhibited the NF-κB-mediated transactivation of a luciferase reporter gene, IL-6 production, and COX-2 expression, with an effective dose of 25 μM. These findings provide new insights into the anti-inflammatory activities of the isopimara-8(14),15-diene diterpenoids., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

A new dinorcassane diterpenoid, seikphoochinal A (1), and four known compounds, pinostrobin (2), 4',7-dimethylkaempferol (3), and galanals A (4) and B (5), were isolated from the chloroform-soluble crude extract of wild type Boesenbergia rotunda rhizomes collected in Lower Myanmar. The chemical structures of these compounds were identified, using a combination of spectroscopic methods. The presence of the diterpenoids 1, 4, and 5 demonstrated the structural diversity of wild type B. rotunda. Among the isolates, compounds 4 and 5 exhibited significant antiproliferative activities against a small panel of human cancer cell lines, including lung (LK-2, A549), stomach (ECC4), breast (MCF7), cervix (HeLa), and prostate (DU145)., (© 2019 Wiley-VHCA AG, Zurich, Switzerland.)

Four new labdane diterpenoids, 12β-hydroxy-15-norlabda-8(17),13(14)-dien-16-oic acid (1), (E)-15-ethoxy-15-methoxylabda-8(17),12-dien-16-al (2), (E)-15α-ethoxy-14α-hydroxylabda-8(17),12-dien-16-olide (3), and 15-ethoxy-12β-hydroxylabda-8(17),13(14)-dien-16,15-olide (4) were isolated from the methanol extract of Curcuma amada rhizomes collected in Myanmar, together with 13 known analogs. Their structures were elucidated by extensive spectroscopic techniques. All of the isolates were evaluated for their antiproliferative activities against a small panel of five different human cancer cell lines (A549, human lung cancer; HeLa, human cervical cancer; MCF7, human breast cancer; PANC-1 and PSN-1, human pancreatic cancer). Among the isolates, compounds 2-4, 7, 8, 12, and 17 showed mild antiproliferative activities with IC 50 values ranging from 19.7 to 96.1μM. (E)-14-Hydroxy-15-norlabda-8(17),12-dien-16-al (11) exhibited strong antiproliferative activities selectively against HeLa, PANC-1, and PSN-1 cells, with IC 50 values of 5.88, 1.00, and 3.98μM, respectively. These potencies were comparable to those of the positive control, 5-fluorouracil., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Viral protein R (Vpr), an accessory gene of HIV-1, plays important roles in viral pathogenesis. Screening of Myanmar medicinal plants that are popular as primary treatments for HIV/AIDS and for HIV-related problems revealed the potent anti-Vpr activity of the CHCl3-soluble extract of Kaempferia pulchra rhizomes, in comparison with that of the positive control, damnacanthal. Fractionation of the active CHCl3-soluble extract led to the identification of 30 isopimarane diterpenoids, including kaempulchraols A-W (1-23). All isolates were assayed for anti-Vpr activity against TREx-HeLa-Vpr cells, in which Vpr expression is tightly regulated by tetracycline. Kaempulchraols B (2), D (4), G (7), Q (17), T (20), U (21), and W (23) exhibited potent anti-Vpr activity, at concentrations ranging from 1.56 to 6.25μM. The structure-activity relationships of the active kaempulchraols suggested that the presence of a hydroxy group at C-14 in an isopimara-8(9),15-diene skeleton and the presence of an acetoxy group at C-1 or C-7 in an isopimara-8(14),15-diene skeleton are the critical factors for the inhibitory effects against TREx-HeLa-Vpr cells., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The isolation of the oily fraction obtained from the CHCl3-soluble extract of the rhizomes of Kaempferia pulchra afforded five new isopimarane diterpenoids, kaempulchraols P-T (1-5), along with two known analogues. The structures were elucidated using spectroscopic techniques, including 2D NMR spectroscopy.

Eight new diterpenoids, kaempulchraols A-H (1-8), along with five known analogues were isolated from the CHCl3-soluble extract of rhizomes of Kaempferia pulchra of Myanmar. The structures of these compounds were elucidated using extensive spectroscopic techniques including X-ray diffraction analysis. All the isolates were tested for their antiproliferative activity against a panel of five human cancer cell lines (A549, human lung cancer; HeLa, human cervix cancer; PANC-1 and PSN-1, human pancreatic cancer; MDA-MB-231, human breast cancer) and TIG-3, normal human primary fibroblast cells. Kaempulchraol F (6) exhibited weak activity against the human pancreatic PSN-1 cell line with an IC50 value of 12.3 μM.