A total of fourteen pyrazoline derivatives were synthesized through cyclo-condensation reactions by chalcone derivatives with different types of semicarbazide. These compounds were characterized by IR, 1D-NMR (1H, 13C and Distortionless Enhancement by Polarization Transfer - DEPT-135) and 2D-NMR (COSY, HSQC and HMBC) as well as mass spectroscopy analysis (HRMS). The synthesized compounds were tested for their antituberculosis activity against Mycobacterium tuberculosis H37Ra in vitro. Based on this activity, compound 4a showed the most potent inhibitory activity, with a minimum inhibitory concentration (MIC) value of 17 μM. In addition, six other synthesized compounds, 5a and 5c–5g, exhibited moderate activity, with MIC ranges between 60 μM to 140 μM. Compound 4a showed good bactericidal activity with a minimum bactericidal concentration (MBC) value of 34 μM against Mycobacterium tuberculosis H37Ra. Molecular docking studies for compound 4a on alpha-sterol demethylase was done to understand and explore ligand–receptor interactions, and to hypothesize potential refinements for the compound.

The α 1 β 2 γ 2 subtype of GABA A receptors is the most commonly found GABA A receptor subtype in the mammalian cortex and hippocampus. It is expressed heterologously in the Xenopus laevis oocyte as a α 1 β 2 γ 2 S/L subtype for application as an in vitro model for the screening of compounds that modulate receptor activities. In fact, 4-hydroxybenzaldehyde (4-HB) has been identified as one of the major components in Dendrocalamus asper bamboo shoots in our previous study, and the current study showed that at 101.7 µM, 4-HB significantly reduced the GABA-induced chloride current of GABA A receptors expressed on Xenopus oocytes, indicating a possible GABAergic antagonistic effect at high concentrations.

Background: Bamboo shoot has been used as a treatment for epilepsy in traditional Chinese medicine for generations to treat neuronal disorders such as convulsive, dizziness and headaches. 4-hydroxybenzoic acid (4-hba) is a non-flavonoid phenol found abundantly in Dendrocalamus asper shoots (bamboo), fruits (strawberries and apples) and flowers. Kv1.4 is a rapidly inactivating Shaker-related member of the voltage-gated potassium channels with two inactivation mechanisms; the fast N-type and slow C-type. It plays vital roles in repolarisation, hyperpolarisation and signaling the restoration of resting membrane potential through the regulation of the movement of K + across the cellular membrane. Methods: Chemical compounds from Dendrocalamus asper bamboo shoots were purified and identified as major palmitic acids mixed with other minor fatty acids, palmitic acid, 4-hydroxybenzaldehyde, lauric acid, 4-hydroxybenzoic acid and cholest-4-ene-3-one. The response of synthetic 4-hydroxybenzoic acid was tested on Kv1.4 potassium channel which was injected into viable oocytes that was extracted from Xenopus laevis. The current were detected by the two-microelectrode voltage clamp, holding potential starting from −80 mV with 20 mV stepup until +80 mV. Readings of treatments with 0.1% DMSO, 4-hba concentrations and K channel blockers were taken at +60 mV. The ratio of tail/peak amplitude is the index of the activity of the Kv1.4 channels with n ≥ 6 (number of oocytes tested). The decreases of the ratios of five different concentrations (1 µM, 10 µM, 100 µM, 1 mM and 2.5 mM) were compared with 0.1% DMSO as the control. 4-hydroxybenzoic acid (4-hba) is a nonflavonoid phenolic compound from benzoic acid derivatives (BADs) along with other biocompounds such as salicylic acid, gallic acid and vanilic acid (18). It constitutes of aromatic benzene ring, hydroxyl substituent and functional derivative that influences the mechanisms, biological activities and properties (19). It is able to pass through blood vessels, blood brain barriers (BBB) and cerebrospinal fluid (CSF) due to its low molecular weight (138.12074 Da) (20). As to date, there are not many toxicity studies of this compound on human however, it has been recorded to be slightly irritating to skin and eyes and the maximum bodily intake is estimated to be 0.067 mg/kg/day (for body weight; 70 kg) (21). Other than being used in pharmaceuticals and cosmetic products, 4-hba has been reported to have antifungal, antialgal, antimutagenic, antisickling properties, extrogenic activity and used as trapping agent on hydroxyl radical generation using cerebral ischemia and reperfusion (22).Voltage-gated potassium channels play essential role in restoring the membrane potential and signaling subsequent action potential during neuronal regulation. It is the most abundant and diverse ionic channel identified in the human body with more than 40 types encoded by more than 70 genes and classified into 12 subfamilies (Kv1-Kv12) (23). Kv1 family (Shaker) is mostly distributed around b...

Knoevenagel condensation reaction (KCR) and Pechmann condensation reaction are the simplest and most widely used method to synthesize various substituted coumarins. The compounds such as 3–acetylcoumarin, 3–acetyl–7–(diethylamino)coumarin, and 7–(diethylamino)–3–(1–oxobutyl)coumarin were synthesized by KCR method which involved the condensation of salicylaldehyde or 4–(diethylamino)salicylaldehyde with ethyl acetoacetate, 4–(diethylamino)– salicylaldehyde with ethyl butyrylacetate in the presence of dimethylamine as a catalyst. Meanwhile, 7–hydroxy–4–methylcoumarin, 4–methyl–2H–benzo[h]chromen–2–one, 7–hydroxy–4,8–dimethyl– coumarin, 7–hydroxy–4–propylcoumarin, 4–propyl–2H–benzo[h]chromen–2–one, 7–hydroxy–8–methyl–4–propylcoumarin and 7,8–dihydroxy–4–propylcoumarin were synthesized through Pechmann condensation reaction by condensation of resorcinol, 1–napthol or 2–methylresorcinol with ethyl acetoacetate, and resorcinol, 1–napthol, 2–methylresorcinol or pyrogallol with ethyl butyrylacetate, respectively in the presence of sulphuric acid as a catalyst. All compounds were characterized by spectroscopic techniques using infrared (IR), proton and carbon nuclear magnetic resonance (1H and 13C NMR).

Bamboo shoots of Dendrocalamus asper is essential for human health because of the high content of dietary fiber, low sugar, negligible amount of fat, and rich vitamin and mineral content. The bamboo shoots' chemical constituents were evaluated against the P. falciparum strain 3D7 as a potential antimalarial drug. One new metabolite, (11Z,13E,17E,19Z)-dimethyl-15,16-dibutoxytriconta-11,13,17,19-tetraenedioate (1) along with four known compounds; β-sitosterol (2), methyl-4hydroxybenzoate (3), 1-methoxy-4-(methoxymethyl)benzene (4) and 4-hydroxybenzaldehyde (5) were isolated from the crude extract of Dendrocalamus asper using chromatographic methods: MPLC, UPLC/MS, analytical and preparative HPLC. Among these, compounds 1, 3, and 4 showed promising antimalarial activity with IC50 between 0.8-2.2 μg/mL. The molecular docking between the most potent compound 3 and dihydrofolate reductase-thymidylate synthase (DHFR-TS) was done to understand and explore the ligand-receptor interactions and hypothesize the compound's refinements.