Pseudolaric Acid B | CAS 93127-75-4 | 98% HPLC | White to Off-White Crystalline Powder | Natural Diterpene Acid / Microtubule Inhibitor & Anti-Angiog

1. Product Overview

Pseudolaric Acid B (CAS 93127-75-4), systematically named (5aS,6S,8aS,9R,10S)-6-hydroxy-2,9-dimethyl-8-oxo-5a,6,7,8,8a,9,10,10a-octahydro-5H-5a,9-propanobenzo[7,8]cycloocta[1,2-b]furan-10a-yl (2E,4E)-2-methyl-5-oxohepta-2,4-dienoate (common semisystematic: pseudolaric acid B, a labdane-type diterpene acid with a tropolone moiety), is a bioactive constituent isolated from the root bark of Pseudolarix kaempferi (Pinaceae). With the molecular formula C₂₃H₂₈O₇ and a molecular weight of 432.47 g/mol, it appears as a white to off-white crystalline powder. Pseudolaric Acid B disrupts microtubule polymerization by binding to tubulin (IC₅₀ ~2.1 µM in cell-free tubulin assembly assays), arrests cells at G2/M phase, inhibits VEGF-induced endothelial cell migration and tube formation (anti-angiogenic), and exhibits notable antifungal activity against Trichophyton rubrum and Candida spp. It also induces apoptosis via mitochondrial pathways (caspase-3/9 activation, Bax/Bak upregulation, ΔΨm loss) in various cancer cell lines. This product is supplied exclusively for laboratory research use and is not intended for clinical, diagnostic, veterinary, food, or cosmetic applications.

2. Key Features and Advantages

• Microtubule destabilizing agent: Inhibits tubulin polymerization (IC₅₀ ~2.1 µM), causes G2/M arrest and mitotic catastrophe—comparable in phenotype to colchicine/vinblastine but structurally distinct (tropolone-containing diterpene).

• Anti-angiogenic: Suppresses VEGF- and bFGF-induced HUVEC migration, invasion, and capillary-like tube formation at 0.5–5 µM without significant cytotoxicity to quiescent endothelium.

• Pro-apoptotic in cancer cells: Induces caspase-dependent apoptosis (via intrinsic/mitochondrial pathway) in HepG2, A549, MCF-7, and multidrug-resistant sublines; partially reverses P-gp-mediated MDR.

• Antifungal activity: Active against dermatophytes (Trichophyton spp., MIC 2–8 µg/mL) and some yeasts; historically used in traditional Chinese medicine (Tu Jing Pi) for tinea infections.

• High purity: Typically ≥98% by HPLC (suppliers offer 98–99%+), suitable for MTT/XTT viability, Annexin V/PI flow, tubulin polymerization assay (spectrophotometric), CAM assay (chick chorioallantoic membrane), and Western blot (cyclin B1, phospho-tubulin, cleaved caspase).

• Soluble in DMSO (≥5 mg/mL with mild warming), also soluble in ethanol, methanol, ethyl acetate; poorly soluble in water; light- and acid/base-sensitive (tropolone ring).

3. Main Applications

• Tubulin/microtubule research: Evaluating inhibition of tubulin assembly, cold-stable polymer disassembly, and spindle checkpoint activation (phospho-histone H3 Ser10) in mitotic cells.

• Antiangiogenesis studies: In vitro (HUVEC tube formation, migration/wound healing, Matrigel invasion) and in vivo (zebrafish/intersegmental vessel regression, mouse Matrigel plug) models of neovascularization.

• Antitumor mechanism: Assessing G2/M arrest, apoptosis induction, ROS generation, and autophagy (LC3-II) in solid tumor and MDR cell lines; comparison with taxanes/vinca alkaloids.

• Antifungal & natural product research: MIC determination against dermatophytes and yeasts; HPLC quantification in P. kaempferi extracts; SAR studies on tropolone-modified analogs.

• Traditional medicine & phytochemistry: Investigating bioactive constituents of Pseudolarix bark (Tu Jing Pi / Chin. herbal cortex) and structure–activity relationships of pseudolaric acid analogs (A, B, C, D).

4. Technical Specifications

5. Storage and Handling

• Store the powdered compound sealed with desiccant, strictly protected from light (amber vial or foil-wrapped); recommended storage at -20°C (long term 2 years) or 4°C (≤6 months). For DMSO or ethanolic stock solutions, prepare fresh when possible; if storing, aliquot and keep at -20°C or -80°C wrapped in foil (3–6 months stable); avoid repeated freeze–thaw cycles. Typical working stocks are 5 mM or 10 mM in anhydrous DMSO, prepared with gentle warming (≤40°C) if needed.

• Before opening, allow the sealed vial to warm to room temperature to prevent moisture condensation. Keep container tightly closed and wrapped in aluminum foil when not in use.

• Handle in a well-ventilated area or fume hood. Use personal protective equipment including safety glasses, nitrile gloves, and a lab coat. Avoid inhalation of dust and contact with skin or eyes. Tropolone-containing natural products can be skin-sensitizing in rare cases.

• Intended exclusively for laboratory research by qualified personnel; not for human or veterinary use, food additive, or therapeutic preparation (despite traditional topical use—this material is research-grade only).

6. Safety Overview

• Pseudolaric Acid B is a bioactive plant diterpene with cytotoxicity (IC₅₀ 0.5–5 µM in many cancer lines) and antifungal activity. Treat as potentially hazardous: may cause irritation to eyes, skin, and respiratory system; possible skin sensitizer.

• In case of eye contact, rinse immediately with plenty of running water for at least 15 minutes and seek medical advice. In case of skin contact, wash thoroughly with soap and water.

• If inhaled, move the person to fresh air and keep at rest in a position comfortable for breathing. If ingested, rinse mouth and seek medical attention—do not induce vomiting unless directed by medical personnel.

• Use appropriate engineering controls (fume hood) and personal protective equipment (safety goggles, nitrile gloves, lab coat). Avoid generating dust; work under reduced light due to photosensitivity.

• Dispose of in accordance with local regulations for hazardous chemical and natural product waste. Do not discharge into drains, waterways, or soil.

• For detailed safety information, refer to the applicable Safety Data Sheet (SDS) prior to handling.